Patent Application
20230314946
The present disclosure relates to a film formed with a metal precursor and an organic precursor, as well as methods for forming and employing such films. The film can be employed as a photopatternable film or a radiation-sensitive film. In particular embodiments, the film includes alternating metal-containing layers and organic layers. In other embodiments, the film includes a matrix of deposited metal and organic constituents.
The background description provided herein is for the purpose of generally presenting the context of the present technology. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present technology.
Patterning of thin films in semiconductor processing is often an important step in the fabrication of semiconductors. Patterning involves lithography. In photolithography, such as 193 nm photolithography, patterns are printed by emitting photons from a photon source onto a mask and printing the pattern onto a photosensitive photoresist, thereby causing a chemical reaction in the photoresist that, after development, removes certain portions of the photoresist to form the pattern.
Advanced technology nodes (as defined by the International Technology Roadmap for Semiconductors) include nodes 22 nm, 16 nm, and beyond. In the 16 nm node, for example, the width of a typical via or line in a Damascene structure is typically no greater than about 30 nm. Scaling of features on advanced semiconductor integrated circuits (ICs) and other devices is driving lithography to improve resolution.
Extreme ultraviolet (EUV) lithography can extend lithography technology by moving to smaller imaging source wavelengths than would be achievable with other photolithography methods. EUV light sources at approximately 10-20 nm, or 11-14 nm wavelength, for example 13.5 nm wavelength, can be used for leading-edge lithography tools, also referred to as scanners. EUV radiation is strongly absorbed in a wide range of solid and fluid materials including quartz and water vapor, and so operates in a vacuum.
The present disclosure relates to use of a metal precursor and an organic precursor to form a metal-organic hybrid film. For instance, the metal precursor can be an organometallic compound that can be deposited to provide a metal-containing layer, and the organic precursor can be employed to deposit an organic layer. Such layers can be submonolayers or atomic monolayers. In some instances, multiple cycles can be employed within each layer, thereby providing nanolayers. Alternatively, the metal and organic precursors can be co-deposited to provide a matrix or an alloy having constituents derived from both metal and organic precursors. Furthermore, the film can be a nanolaminate having a first metal-containing layer and a second metal-containing layer, in which these layers are different (e.g., different metals and/or different organic constituents). Such metal-organic films can be deposited in any useful manner, such as chemical vapor deposition (CVD), as well as atomic layer deposition (ALD), molecular layer deposition (MLD), and plasma-enhanced forms thereof.
In use, the films can be employed as a radiation-sensitive film. In non-limiting embodiments, the radiation can include extreme ultraviolet (EUV), deep ultraviolet (DUV), or ultraviolet (UV) radiation. Such radiation can be provided as a pattern to the film, e.g., by use of masks, to provide a photopatterned film that can itself be employed as a mask.
In some embodiments, the films and processes herein employ MLD and can be used as photosensitive resists for EUV photolithography. In particular embodiments, the metal-organic or inorganic-organic hybrid films contain high EUV absorbing metal atoms that are suitable as EUV absorbers, as well as organic linker molecules that undergo transformations in the presence of EUV absorption and re-emission processes from the metal atoms.
For instance, the metal-organic film can include a metal-containing layer or an organometallic layer having high EUV absorbing elements, which can serve as an efficient source of primary and secondary electrons useful for inducing reactions in the interdispersed organic layer. In particular instances, the organic layer need not be particularly EUV sensitive in the absence of the metal-containing layer.
Accordingly, in a first aspect, the present disclosure features a method (e.g., of forming a film) including: depositing a metal-containing layer on a surface of a substrate by providing a metal precursor to the surface, wherein the substrate is disposed within a chamber; and depositing an organic layer on a surface of the metal-containing layer by providing an organic precursor to the surface. In some embodiments, the organic layer includes a photosensitive organic moiety, thereby forming a patterning radiation-sensitive film.
The metal-containing layers and organic layers can be deposited in any order. Thus, in another aspect, the method includes: depositing an organic layer on a surface of a substrate by providing an organic precursor to the surface, wherein the substrate is disposed within a chamber; and depositing a metal-containing layer on a surface of the organic layer by providing a metal precursor to the surface.
In some embodiments, the method further includes (e.g., prior to depositing the organic layer): activating a top surface of the metal-containing layer, thereby providing an activated surface for depositing the organic layer In other embodiments, the method further includes (e.g., prior to depositing the metal-containing layer): activating a top surface of the organic layer, thereby providing an activated surface for depositing the metal-containing layer.
In some embodiment, said depositing includes providing a plurality of organic precursors, in which a first organic precursor reacts with the metal precursor and a second organic precursor reacts with the first precursor. Non-limiting first and second precursors include homofunctional and heterofunctional compounds, including compounds having diamino moieties, dialcohol moieties, trialcohol moieties, dithiol moieties, aminoalcohol moieties, diisocyanate moieties, dithioisocyanate moieties, diacyl chloride moieties, dialdehyde moieties, diacid moieties, anhydride moieties, dianhydride moieties, and diene moieties, as described herein.
Purging operations can be performed after deposition. Thus, in some embodiments, the method further includes (e.g., after depositing the organic layer or before depositing the metal-containing layer): purging the organic precursor from the chamber. In yet other embodiments, the method further includes (e.g., after depositing the metal-containing layer or before depositing the organic layer): purging the metal precursor from the chamber.
In some embodiments, the method further includes (e.g., purging the chamber of the organic precursor): repeating said depositing of the metal-containing layer, said purging of the metal precursor, said depositing of the organic layer, and said purging of the organic precursor for a plurality of cycles. In embodiments, the plurality of cycles includes 2 or more cycles or about 2 to about 1000 cycles, including of from about 5 to about 50 cycles. In particular embodiments, the method further provides a patterning radiation-sensitive film including a plurality of alternating metal-containing layers and organic layers. In yet other embodiments, each layer has a thickness of about 1 nm; the film has a thickness of from about 5 nm to 50 nm; and deposition includes from about 5 to about 50 cycles.
In some embodiments, the method further includes (e.g., after purging the metal precursor and/or the organic precursor): activating a top surface of the metal-containing layer and/or the organic layer, thereby providing an activated surface for depositing a further layer.
In other embodiments, the method further includes: annealing the patterning radiation-sensitive film to provide an annealed film. In particular embodiments, the annealed film includes a homogenized alloy or matrix of metal and organic substituents provided by the precursors employed during deposition.
In a second aspect, the present disclosure features a method including: depositing a metal precursor in the presence of an organic precursor on a surface of a substrate. In some embodiments, the method provides a patterning radiation-sensitive film. In other embodiments, the film includes a matrix of metal and organic constituents, wherein the organic precursor includes a photosensitive organic moiety. In further embodiments, the method optionally includes: annealing the matrix to provide an annealed film.
In a third aspect, the present disclosure features a method of employing a resist (e.g., a positive tone resist). In some embodiments, the method includes: depositing a metal-containing layer on a surface of a substrate by providing a metal precursor to the surface; purging the metal precursor (e.g., from the chamber having the substrate); depositing an organic layer on a surface of the metal-containing layer by providing an organic precursor to the surface, thereby forming a patterning radiation-sensitive film as a resist film; patterning the resist film by a patterning radiation exposure, thereby providing an exposed film having radiation exposed areas and radiation unexposed areas; and developing the exposed film. In other embodiments, the substrate is disposed within a chamber, and the metal precursor is volatile. In yet other embodiments, the organic precursor is volatile.
In some embodiments, the organic layer includes a photosensitive organic moiety. In other embodiments, the metal-containing layer includes a high EUV absorptive element (e.g., an atom having a high EUV absorption cross-section).
In other embodiments, the method further includes (e.g., after said depositing): soaking the resist film in the presence of a soak precursor including a metal or an atom having a high EUV absorption cross-section. In some embodiments, the soak precursor and the metal precursor can be same or different.
In particular embodiments, said developing includes removing the radiation exposed areas to provide a pattern within the resist film. In some embodiments, said patterning includes patterning the resist film by an EUV exposure, and said depositing includes removing the EUV exposed areas to provide a pattern within a positive resist film.
In some embodiments, the method includes: patterning a patterning radiation-sensitive film (e.g., any described herein) by a patterning radiation exposure, thereby providing an exposed film having radiation exposed areas and radiation unexposed areas; and developing the exposed film. In some embodiments, said developing thereby removes the radiation exposed areas to provide a pattern within the patterning radiation-sensitive film. In yet other embodiments, the patterning radiation includes EUV radiation having a wavelength in the range of about 10 nm to about 20 nm in a vacuum ambient.
In some embodiments, said patterning includes a release of carbon dioxide and/or carbon monoxide from the exposed film. In particular embodiments, carbon dioxide and/or carbon monoxide are released from one or more organic layers. In other embodiments, said patterning further includes depolymerization (e.g., of the film or a portion thereof, such as one or more organic layers) upon exposure to a patterning radiation.
In a fourth aspect, the present disclosure features an apparatus for forming a patterned resist film, the apparatus including: a deposition module; a patterning module; a development module; and a controller including one or more memory devices, one or more processors, and system control software coded with instructions including machine-readable instructions.
In some embodiments, the deposition module includes a chamber for depositing a patterning radiation-sensitive film (e.g., an EUV-sensitive film). In other embodiments, the patterning module includes a photolithography tool with a source of sub-300 nm wavelength radiation (e.g., in which the source can be a source of sub-30 nm wavelength radiation). In yet other embodiments, the development module includes a chamber for developing the resist film.
In particular embodiments, the controller instructions include machine-readable instructions for (e.g., in the deposition module) causing deposition of a metal-containing layer and an organic layer on a top surface of a semiconductor substrate to form the patterning radiation-sensitive film as a resist film. In other embodiments, the controller instructions include machine-readable instructions for (e.g., in the patterning module) causing patterning of the resist film with sub-300 nm resolution (e.g., or with sub-30 nm resolution) directly by patterning radiation exposure, thereby forming an exposed film having radiation exposed areas and radiation unexposed areas. In yet other embodiments, the exposed film has EUV exposed areas and EUV unexposed areas. In particular embodiments, the controller instructions include machine-readable instructions for (e.g., in the development module) causing development of the exposed film to remove the radiation exposed areas or the radiation unexposed areas to provide a pattern within the resist film. In other particular embodiments, the machine-readable instructions include instructions for causing removal of the EUV exposed areas or the EUV unexposed areas.
In some embodiments, the machine-readable instructions for causing deposition of the metal-containing layer further include: instructions for causing deposition of a metal having a high patterning radiation-absorption cross-section. In particular embodiments, the metal has a high EUV absorption cross-section.
In some embodiments, the apparatus can further include: a cleaning module (e.g., including a chamber for cleaning the substrate or the resist film). In particular embodiments, the controller instructions include machine-readable instructions for (e.g., in the cleaning module) causing cleaning of a backside surface or a bevel of the semiconductor substrate after said deposition and/or causing removal of an edge bead of the resist film after said deposition.
In some embodiments, the apparatus can further include: a bake module. In particular embodiments, the controller instructions include machine-readable instructions for (e.g., in the bake module) causing baking of the resist film after said deposition and/or causing baking of the exposed film after said patterning.
In a fifth aspect, the present disclosure encompasses a stack including: a semiconductor substrate having a top surface; and a patterning radiation-sensitive film disposed on the top surface of the semiconductor substrate, wherein the film includes a plurality of alternating layers of a metal-containing layer and an organic layer. In some embodiments, the metal-containing layer includes a metal having a high patterning radiation-absorption cross-section. In particular embodiments, the metal-containing layer and/or the organic layer includes a UV-sensitive moiety, a DUV-sensitive moiety, or an EUV-sensitive moiety. In further embodiments, the stack further includes an underlayer (e.g., an organic underlayer) disposed between the substrate and the patterning radiation-sensitive film.
In any embodiment herein, the patterning radiation-sensitive film includes a nanolaminate. In other embodiments, the patterning radiation-sensitive film includes an annealed or alloyed form of the plurality of alternating layers of the metal-containing layer and the organic layer. In yet other embodiments, the patterning radiation-sensitive film includes a matrix of metal and organic substituents.
In any embodiment herein, the patterning radiation-sensitive film includes an EUV-sensitive film, a DUV-sensitive film, a UV-sensitive film, a photoresist film, or a photopatternable film.
In any embodiment herein, the patterning radiation-sensitive film includes a vertical gradient characterized by a change in radiation absorbance (e.g., a change in EUV, DUV, or UV absorbance). In particular embodiments, the vertical gradient includes an increase in radiation absorbance, in which a bottom portion of the film in proximity to the substrate has a higher radiation absorbance than a top portion of the film.
In any embodiment herein, the patterning radiation-sensitive film includes an organometallic material or an organometal oxide material.
In any embodiment herein, the metal-containing layer includes a metal or an atom having a high patterning radiation-absorption cross-section. In particular embodiments, the metal or the atom includes a high EUV absorption cross-section. In other embodiments, the metal-containing layer includes tin (Sn), bismuth (Bi), tellurium (Te), cesium (Cs), antimony (Sb), indium (In), molybdenum (Mo), hafnium (Hf), iodine (I), zirconium (Zr), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), silver (Ag), platinum (Pt), or lead (Pb), as well as combinations thereof. In some embodiments, the metal-containing layer is a photosensitive layer.
In any embodiment herein, the organic layer includes a polymer, such as a poly(ester) or other described herein.
In any embodiment herein, the organic layer includes a photosensitive organic moiety. In particular embodiments, the photosensitive organic moiety is electron-sensitive. In other embodiments, the photosensitive organic moiety is polymerizable or depolymerizable upon exposure to a patterning radiation. In yet other embodiments, the photosensitive organic moiety is an UV-sensitive moiety, a DUV-sensitive moiety, or an EUV-sensitive moiety.
Non-limiting examples of photosensitive moieties (e.g., for the metal precursor, the metal-containing layer, the organic precursor, and/or the organic layer) includes a metal or a metalloid or an atom having a high EUV absorption cross-section (e.g., Sn, Bi, Te, Cs, Sb, In, Mo, Hf, I, Zr, Fe, Co, Ni, Cu, Zn, Ag, Pt, or Pb, or a combination thereof), as well as an organic moiety or substituent (e.g., a polymerizable moiety, a depolymerizable moiety, an alkynyl moiety, an alkenyl moiety, a cycloalkenyl moiety, a hydroxyl moiety, a hydroxyalkyl moiety, a hydroxyaryl moiety, an acrylate moiety, a vinyl ester moiety, a carboxylic acid moiety, a diacid moiety, a triacid moiety, a dialcohol moiety, a trialcohol moiety, a carbonyl moiety, or a cyclic anhydride moiety, as well as others described herein).
In any embodiment herein, each of the metal-containing layer and the organic layer, independently, has a thickness of from about 0.1 Å to about 1000 Å. Non-limiting thicknesses include from about 0.2 Å to 100 Å, 0.2 Å to 250 Å, 0.2 Å to 500 Å, 0.2 Å to 750 Å, 0.2 Å to 1000 Å, 0.3 Å to 100 Å, 0.3 Å to 250 Å, 03 Å to 500 Å, 0.3 Å to 750 Å, 0.3 Å to 1000 Å, 0.5 Å to 100 Å, 0.5 Å to 250 Å, 0.5 Å to 500 Å, 0.5 Å to 750 Å, 0.5 Å to 1000 Å, 1 Å to 100 Å, 1 Å to 250 Å, 1 Å to 500 Å, 1 Å to 750 Å, 5 Å to 100 Å, 5 Å to 250 Å, 5 Å to 500 Å, 5 Å to 750 Å, 5 Å to 1000 Å, 10 Å to 100 Å, 10 Å to 250 Å, 10 Å to 500 Å, 10 Å to 750 Å, 10 Å to 1000 Å, 30 Å to 100 Å, 30 Å to 250 Å, 30 Å to 500 Å, 30 Å to 750 Å, 30 Å to 1000 Å, 50 Å to 100 Å, 50 Å to 250 Å, 50 Å to 500 Å, 50 Å to 750 Å, 50 Å to 1000 Å, 80 Å to 250 Å, 80 Å to 500 Å, 80 Å to 750 Å, 80 Å to 1000 Å, 100 Å to 250 Å, 100 Å to 500 Å, 100 Å to 750 Å, 100 Å to 1000 Å, 200 Å to 500 Å, 200 Å to 750 Å, 200 Å to 1000 Å, 500 Å to 750 Å, and 500 Å to 1000 Å.
In any embodiment herein, each of the metal-containing layer(s) and the organic layer(s), independently, has a thickness of from about 1 Å to about 200 Å. Non-limiting thicknesses include from about 1 Å to 5 Å, 1 Å to 10 Å, 1 Å to 15 Å, 1 Å to 20 Å, 1 Å to 25 Å, 1 Å to 30 Å, 1 Å to 35 Å, 1 Å to 40 Å, 1 Å to 45 Å, 1 Å to 50 Å, 1 Å to 60 Å, 1 Å to 70 Å, 1 Å to 80 Å, 1 Å to 90 Å, 1 Å to 100 Å, 1 Å to 120 Å, 1 Å to 150 Å, 1 Å to 180 Å, 3 Å to 5 Å, 3 Å to 10 Å, 3 Å to 15 Å, 3 Å to 20 Å, 3 Å to 25 Å, 3 Å to 30 Å, 3 Å to 35 Å, 3 Å to 40 Å, 3 Å to 45 Å, 3 Å to 50 Å, 3 Å to 60 Å, 3 Å to 70 Å, 3 Å to 80 Å, 3 Å to 90 Å, 3 Å to 100 Å, 3 Å to 120 Å, 3 Å to 150 Å, 3 Å to 180 Å, 3 Å to 200 Å, 5 Å to 10 Å, 5 Å to 15 Å, 5 Å to 20 Å, 5 Å to 25 Å, 5 Å to 30 Å, 5 Å to 35 Å, 5 Å to 40 Å, 5 Å to 45 Å, 5 Å to 50 Å, 5 Å to 60 Å, 5 Å to 70 Å, 5 Å to 80 Å, 5 Å to 90 Å, 5 Å to 100 Å, 5 Å to 120 Å, 5 Å to 150 Å, 5 Å to 180 Å, 5 Å to 200 Å, 10 Å to 15 Å, 10 Å to 20 Å, 10 Å to 25 Å, 10 Å to 30 Å, 10 Å to 35 Å, 10 Å to 40 Å, 10 Å to 45 Å, 10 Å to 50 Å, 10 Å to 60 Å, 10 Å to 70 Å, 10 Å to 80 Å, 10 Å to 90 Å, 10 Å to 100 Å, 10 Å to 120 Å, 10 Å to 150 Å, 10 Å to 180 Å, 10 Å to 200 Å, 20 Å to 30 Å, 20 Å to 40 Å, 20 Å to 50 Å, 20 Å to 60 Å, 20 Å to 70 Å, 20 Å to 80 Å, 20 Å to 90 Å, 20 Å to 100 Å, 20 Å to 120 Å, 20 Å to 150 Å, 20 Å to 180 Å, 20 Å to 200 Å, 30 Å to 60 Å, 30 Å to 70 Å, 30 Å to 80 Å, 30 Å to 90 Å, 30 Å to 100 Å, 30 Å to 120 Å, 30 Å to 150 Å, 30 Å to 180 Å, 30 Å to 200 Å, 50 Å to 60 Å, 50 Å to 70 Å, 50 Å to 80 Å, 50 Å to 90 Å, 50 Å to 100 Å, 50 Å to 120 Å, 50 Å to 150 Å, 50 Å to 180 Å, or 50 Å to 200 Å.
In any embodiment herein, the metal precursor includes a metal or an atom having a high patterning radiation-absorption cross-section. In particular embodiments, the metal or the atom includes a high EUV absorption cross-section (e.g., equal to or greater than 1×107 cm2/mol, such as for Sn or Te). In some embodiments, the metal or the atom includes an EUV absorption cross-section that is equal to less than about 1×107 cm2/mol (e.g., such as for Ag, Pb, Mo, Hf, Zr, Fe, Co, Cu, Zn, or Pt). In other embodiments, the metal precursor includes Sn, Bi, Te, Cs, Sb, In, Mo, Hf, I, Zr, Fe, Co, Ni, Cu, Zn, Ag, Pt, or Pb, as well as combinations thereof. In yet other embodiments, the metal precursor is a high photoabsorbing precursor (e.g., having a high Beer’s absorption coefficient α, including an α of more than about 6 µm-1).
In any embodiment herein, the metal precursor and/or the soak precursor includes a structure having formula (I), (II), (IIa), (III), (IV), (V), (VI), (VII), or (VIII), as described herein.
In any embodiment herein, the metal precursor includes a structure having formula (I):
wherein: M is a metal or a metalloid or an atom having a high EUV absorption cross-section (e.g., any herein); each R is, independently, H, halo, optionally substituted alkyl, optionally substituted cycloalkyl, optionally substituted cycloalkenyl, optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted alkoxy, optionally substituted alkanoyloxy, optionally substituted aryl, optionally substituted amino, optionally substituted bis(trialkylsilyl)amino, optionally substituted trialkylsilyl, oxo, an anionic ligand, a neutral ligand, or a multidentate ligand; a ≥ 1 (e.g., a is 1, 2, or 3); and b ≥ 1 (e.g., b is 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12).
In any embodiment herein, the metal precursor includes a structure having formula (II):
wherein: M is a metal or a metalloid or an atom having a high EUV absorption cross-section (e.g., any herein); each R is, independently, halo, optionally substituted alkyl, optionally substituted aryl, optionally substituted amino, optionally substituted alkoxy, or L; each L is, independently, a ligand, an anionic ligand, a neutral ligand, a multidentate ligand, ion, or other moiety that is reactive with the organic precursor or a counter-reactant, in which R and L with M, taken together, can optionally form a heterocyclyl group or in which R and L, taken together, can optionally form a heterocyclyl group; a ≥ 1 (e.g., a is 1, 2, or 3); b ≥ 1 (e.g., b is 1, 2, 3, 4, 5, or 6); and c ≥ 1 (eg., c is 1, 2, 3, 4, 5, 6). In particular embodiments, each R is L, and/or M is tin (Sn), such as Sn(IV) or Sn(II). In some embodiments, each L is, independently, H, halo, optionally substituted alkyl, optionally substituted aryl, optionally substituted amino, optionally substituted bis(trialkylsilyl)amino, optionally substituted trialkylsilyl, or optionally substituted alkoxy (e.g., any L described herein).
In any embodiment herein, a single metal precursor is employed with one or more organic precursors. In other embodiments, two, three, four, or more different metal precursors are employed within one or more organic precursors.
In any embodiment herein, the organic precursor includes one or more polymerizable moieties, depolymerizable moieties, alkynyl moieties, alkenyl moieties, cycloalkenyl moieties, hydroxyalkyl moieties, hydroxyaryl moieties, acrylate moieties, vinyl ester moieties, carboxylic acid moieties, diacid moieties, triacid moieties, dialcohol moieties, trialcohol moieties, cyclic anhydride moieties, or any described herein. In other embodiments, the organic precursor includes optionally substituted alkyl, optionally substituted alkenyl, or optionally substituted aryl, in which each of these can have one or more substitutions selected from hydroxyl, carboxyl, amino, or oxo.
In any embodiment herein, a single metal precursor is employed with a single organic precursor. In other embodiments, a single metal precursor is employed with two, three, four, or more different organic precursors. In yet other embodiments, two or more different metal precursors are employed with two or more different organic precursors.
In any embodiment herein, depositing includes providing or depositing the metal precursor and/or the organic precursor in vapor form. In other embodiments, depositing includes providing a counter-reactant in vapor form. In particular embodiments, depositing includes CVD, ALD, or MLD.
In any embodiment herein, depositing of the metal-containing layer further includes providing a counter-reactant. Non-limiting counter-reactants include an oxygen-containing counter-reactant, including O2, O3, water, a peroxide, hydrogen peroxide, oxygen plasma, water plasma, an alcohol, a dihydroxy alcohol, a polyhydroxy alcohol, a fluorinated dihydroxy alcohol, a fluorinated polyhydroxy alcohol, a fluorinated glycol, formic acid, and other sources of hydroxyl moieties, as well as combinations thereof.
In any embodiment herein, the method further includes: soaking the patterning radiation-sensitive film in the presence of a soak precursor. In particular embodiments, the soak precursor includes a metal or an atom having a high EUV absorption cross-section, wherein the soak precursor and the metal precursor can be same or different. Additional details follow.
By “acyloxy” or “alkanoyloxy,” as used interchangeably herein, is meant an acyl or alkanoyl group, as defined herein, attached to the parent molecular group through an oxy group. In particular embodiments, the alkanoyloxy is —O—C(O)—Ak, in which Ak is an alkyl group, as defined herein. In some embodiments, an unsubstituted alkanoyloxy is a C2-7 alkanoyloxy group. Exemplary alkanoyloxy groups include acetoxy.
By “alkenyl” is meant an optionally substituted C2-24 alkyl group having one or more double bonds. The alkenyl group can be cyclic (e.g., C3-24 cycloalkenyl) or acyclic. The alkenyl group can also be substituted or unsubstituted. For example, the alkenyl group can be substituted with one or more substitution groups, as described herein for alkyl.
By “alkenylene” is meant a multivalent (e.g., bivalent) form of an alkenyl group, which is an optionally substituted C2-24 alkyl group having one or more double bonds. The alkenylene group can be cyclic (e.g., C3-24 cycloalkenyl) or acyclic. The alkenylene group can be substituted or unsubstituted. For example, the alkenylene group can be substituted with one or more substitution groups, as described herein for alkyl. Exemplary, non-limiting alkenylene groups include —CH═CH— or —CH═CHCH2—.
By “alkoxy” is meant —OR, where R is an optionally substituted alkyl group, as described herein. Exemplary alkoxy groups include methoxy, ethoxy, butoxy, trihaloalkoxy, such as trifluoromethoxy, etc. The alkoxy group can be substituted or unsubstituted. For example, the alkoxy group can be substituted with one or more substitution groups, as described herein for alkyl. Exemplary unsubstituted alkoxy groups include C1-3, C1-6, C1-12, C1-16, C1-18, C1-20, or C1-24 alkoxy groups.
By “alkyl” and the prefix “alk” is meant a branched or unbranched saturated hydrocarbon group of 1 to 24 carbon atoms, such as methyl (Me), ethyl (Et), n-propyl (n-Pr), isopropyl (i-Pr), cyclopropyl, n-butyl (n-Bu), isobutyl (i-Bu), s-butyl (s-Bu), t-butyl (t-Bu), cyclobutyl, n-pentyl, isopentyl, s-pentyl, neopentyl, hexyl, heptyl, octyl, nonyl, decyl, dodecyl, tetradecyl, hexadecyl, eicosyl, tetracosyl, and the like. The alkyl group can be cyclic (e.g., C3-24 cycloalkyl) or acyclic. The alkyl group can be branched or unbranched. The alkyl group can also be substituted or unsubstituted. For example, the alkyl group can include haloalkyl, in which the alkyl group is substituted by one or more halo groups, as described herein. In another example, the alkyl group can be substituted with one, two, three or, in the case of alkyl groups of two carbons or more, four substituents independently selected from the group consisting of: (1) C1-6 alkoxy (e.g., —O—Ak, wherein Ak is optionally substituted C1-6 alkyl); (2) amino (e.g., -NRN1RN2, where each of RN1 and RN2 is, independently, H or optionally substituted alkyl, or RN1 and RN2, taken together with the nitrogen atom to which each are attached, form a heterocyclyl group); (3) aryl; (4) arylalkoxy (e.g., —O—Lk—Ar, wherein Lk is a bivalent form of optionally substituted alkyl and Ar is optionally substituted aryl); (5) aryloyl (e.g., —C(O)—Ar, wherein Ar is optionally substituted aryl); (6) cyano (e.g., —CN); (7) carboxyaldehyde (e.g., —C(O)H); (8) carboxyl (e.g., —CO2H); (9) C3-8 cycloalkyl (e.g., a monovalent saturated or unsaturated non-aromatic cyclic C3-8 hydrocarbon group); (10) halo (e.g., F, Cl, Br, or I); (11) heterocyclyl (e.g., a 5-, 6- or 7-membered ring, unless otherwise specified, containing one, two, three, or four non-carbon heteroatoms, such as nitrogen, oxygen, phosphorous, sulfur, or halo); (12) heterocyclyloxy (e.g., —O—Het, wherein Het is heterocyclyl, as described herein); (13) heterocyclyloyl (e.g., —C(O)—Het, wherein Het is heterocyclyl, as described herein); (14) hydroxyl (e.g., —OH); (15) N-protected amino; (16) nitro (e.g., —NO2); (17) oxo (e.g., ═O); (18) —CO2RA, where RA is selected from the group consisting of (a) C1-6 alkyl, (b) C4-18 aryl, and (c) (C4-18 aryl) C1-6 alkyl (e.g., —Lk—Ar, wherein Lk is a bivalent form of optionally substituted alkyl group and Ar is optionally substituted aryl); (19) -C(O)NRBRC, where each of RB and RC is, independently, selected from the group consisting of (a) hydrogen, (b) C1-6 alkyl, (c) C4-18 aryl, and (d) (C4-18 aryl) C1-6 alkyl (e.g., —Lk—Ar, wherein Lk is a bivalent form of optionally substituted alkyl group and Ar is optionally substituted aryl); and (20) —NRGRH, where each of RG and RH is, independently, selected from the group consisting of (a) hydrogen, (b) an N-protecting group, (c) C1-6 alkyl, (d) C2-6 alkenyl (e.g., optionally substituted alkyl having one or more double bonds), (e) C2-6 alkynyl (e.g., optionally substituted alkyl having one or more triple bonds), (f) C4-18 aryl, (g) (C4-18 aryl) C1-6 alkyl (e.g., Lk-Ar, wherein Lk is a bivalent form of optionally substituted alkyl group and Ar is optionally substituted aryl), (h) C3-8 cycloalkyl, and (i) (C3-8 cycloalkyl) C1-6 alkyl (e.g., —Lk—Cy, wherein Lk is a bivalent form of optionally substituted alkyl group and Cy is optionally substituted cycloalkyl, as described herein), wherein in one embodiment no two groups are bound to the nitrogen atom through a carbonyl group. The alkyl group can be a primary, secondary, or tertiary alkyl group substituted with one or more substituents (e.g., one or more halo or alkoxy). In some embodiments, the unsubstituted alkyl group is a C1-3, C1-6, C1-12, C1-16, C1-18, C1-20, or C1-24 alkyl group.
By “alkylene” is meant a multivalent (e.g., bivalent) form of an alkyl group, as described herein. Exemplary alkylene groups include methylene, ethylene, propylene, butylene, etc. In some embodiments, the alkylene group is a C1-3, C1-6, C1-12, C1-16, C1-18, C1-20, C1-24, C2-3, C2-6, C2-12, C2-16, C2-18, C2-20, or C2-24 alkylene group. The alkylene group can be branched or unbranched. The alkylene group can also be substituted or unsubstituted. For example, the alkylene group can be substituted with one or more substitution groups, as described herein for alkyl.
By “alkynyl” is meant an optionally substituted C2-24 alkyl group having one or more triple bonds. The alkynyl group can be cyclic or acyclic and is exemplified by ethynyl, 1-propynyl, and the like. The alkynyl group can also be substituted or unsubstituted. For example, the alkynyl group can be substituted with one or more substitution groups, as described herein for alkyl.
By “alkynylene” is meant a multivalent (e.g., bivalent) form of an alkynyl group, which is an optionally substituted C2-24 alkyl group having one or more triple bonds. The alkynylene group can be cyclic or acyclic. The alkynylene group can be substituted or unsubstituted. For example, the alkynylene group can be substituted with one or more substitution groups, as described herein for alkyl. Exemplary, non-limiting alkynylene groups include —C═C— or —C≡CCH2—.
By “amino” is meant —NRN1RN2, where each of RN1 and RN2 is, independently, H, optionally substituted alkyl, or optionally substituted aryl, or RN1 and RN2, taken together with the nitrogen atom to which each are attached, form a heterocyclyl group, as defined herein.
By “aryl” is meant a group that contains any carbon-based aromatic group including, but not limited to, phenyl, benzyl, anthracenyl, anthryl, benzocyclobutenyl, benzocyclooctenyl, biphenylyl, chrysenyl, dihydroindenyl, fluoranthenyl, indacenyl, indenyl, naphthyl, phenanthryl, phenoxybenzyl, picenyl, pyrenyl, terphenyl, and the like, including fused benzo-C4-8 cycloalkyl radicals (e.g., as defined herein) such as, for instance, indanyl, tetrahydronaphthyl, fluorenyl, and the like. The term aryl also includes heteroaryl, which is defined as a group that contains an aromatic group that has at least one heteroatom incorporated within the ring of the aromatic group. Examples of heteroatoms include, but are not limited to, nitrogen, oxygen, sulfur, and phosphorus. Likewise, the term non-heteroaryl, which is also included in the term aryl, defines a group that contains an aromatic group that does not contain a heteroatom. The aryl group can be substituted or unsubstituted. The aryl group can be substituted with one, two, three, four, or five substituents, such as any described herein for alkyl.
By “arylene” is meant a multivalent (e.g., bivalent) form of an aryl group, as described herein. Exemplary arylene groups include phenylene, naphthylene, biphenylene, triphenylene, diphenyl ether, acenaphthenylene, anthrylene, or phenanthrylene. In some embodiments, the arylene group is a C4-18, C4-14, C4-12, C4-10, C6-18, C6-14, C6-12, or C6-10 arylene group. The arylene group can be branched or unbranched. The arylene group can also be substituted or unsubstituted. For example, the arylene group can be substituted with one or more substitution groups, as described herein for alkyl or aryl.
By “(aryl)(alkyl)ene” is meant a bivalent form including an arylene group, as described herein, attached to an alkylene or a heteroalkylene group, as described herein. In some embodiments, the (aryl)(alkyl)ene group is —L—Ar— or —L—Ar—L— or —Ar—L—, in which Ar is an arylene group and each L is, independently, an optionally substituted alkylene group or an optionally substituted heteroalkylene group.
By “carbonyl” is meant a —C(O)— group, which can also be represented as >C═O, or a —CO group.
By “carboxyl” is meant a —CO2H group.
By “carboxyalkyl” is meant an alkyl group, as defined herein, substituted by one or more carboxyl groups, as defined herein.
By “carboxyaryl” is meant an aryl group, as defined herein, substituted by one or more carboxyl groups, as defined herein.
By “cyclic anhydride” is meant a 3-, 4-, 5-, 6- or 7-membered ring (e.g., a 5-, 6- or 7-membered ring), unless otherwise specified, having a —C(O)—O—C(O)— group within the ring. The term “cyclic anhydride” also includes bicyclic, tricyclic and tetracyclic groups in which any of the above rings is fused to one, two, or three rings independently selected from the group consisting of an aryl ring, a cyclohexane ring, a cyclohexene ring, a cyclopentane ring, a cyclopentene ring, and another monocyclic heterocyclic ring. Exemplary cyclic anhydride groups include a radical formed from succinic anhydride, glutaric anhydride, maleic anhydride, phthalic anhydride, isochroman-1,3-dione, oxepanedione, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, pyromellitic dianhydride, naphthalic anhydride, 1,2-cyclohexanedicarboxylic anhydride, etc., by removing one or more hydrogen. Other exemplary cyclic anhydride groups include dioxotetrahydrofuranyl, dioxodihydroisobenzofuranyl, etc. The cyclic anhydride group can also be substituted or unsubstituted. For example, the cyclic anhydride group can be substituted with one or more groups including those described herein for heterocyclyl.
By “cycloalkenyl” is meant a monovalent unsaturated non-aromatic or aromatic cyclic hydrocarbon group of from three to eight carbons, unless otherwise specified, having one or more double bonds. The cycloalkenyl group can also be substituted or unsubstituted. For example, the cycloalkenyl group can be substituted with one or more groups including those described herein for alkyl.
By “cycloalkyl” is meant a monovalent saturated or unsaturated non-aromatic or aromatic cyclic hydrocarbon group of from three to eight carbons, unless otherwise specified, and is exemplified by cyclopropyl, cyclobutyl, cyclopentyl, cyclopentadienyl, cyclohexyl, cycloheptyl, bicyclo[2.2.1.]heptyl, and the like. The cycloalkyl group can also be substituted or unsubstituted. For example, the cycloalkyl group can be substituted with one or more groups including those described herein for alkyl.
By “halo” is meant F, Cl, Br, or I.
By “haloalkyl” is meant an alkyl group, as defined herein, substituted with one or more halo.
By “heteroalkyl” is meant an alkyl group, as defined herein, containing one, two, three, or four non-carbon heteroatoms (e.g., independently selected from the group consisting of nitrogen, oxygen, phosphorous, sulfur, selenium, or halo).
By “heteroalkylene” is meant a bivalent form of an alkylene group, as defined herein, containing one, two, three, or four non-carbon heteroatoms (e.g., independently selected from the group consisting of nitrogen, oxygen, phosphorous, sulfur, selenium, or halo). The heteroalkylene group can be substituted or unsubstituted. For example, the heteroalkylene group can be substituted with one or more substitution groups, as described herein for alkyl.
By “heterocyclyl” is meant a 3-, 4-, 5-, 6- or 7-membered ring (e.g., a 5-, 6- or 7-membered ring), unless otherwise specified, containing one, two, three, or four non-carbon heteroatoms (e.g., independently selected from the group consisting of nitrogen, oxygen, phosphorous, sulfur, selenium, or halo). The 3-membered ring has zero to one double bonds, the 4- and 5-membered ring has zero to two double bonds, and the 6- and 7-membered rings have zero to three double bonds. The term “heterocyclyl” also includes bicyclic, tricyclic and tetracyclic groups in which any of the above heterocyclic rings is fused to one, two, or three rings independently selected from the group consisting of an aryl ring, a cyclohexane ring, a cyclohexene ring, a cyclopentane ring, a cyclopentene ring, and another monocyclic heterocyclic ring, such as indolyl, quinolyl, isoquinolyl, tetrahydroquinolyl, benzofuryl, benzothienyl and the like. Heterocyclics include acridinyl, adenyl, alloxazinyl, azaadamantanyl, azabenzimidazolyl, azabicyclononyl, azacycloheptyl, azacyclooctyl, azacyclononyl, azahypoxanthinyl, azaindazolyl, azaindolyl, azecinyl, azepanyl, azepinyl, azetidinyl, azetyl, aziridinyl, azirinyl, azocanyl, azocinyl, azonanyl, benzimidazolyl, benzisothiazolyl, benzisoxazolyl, benzodiazepinyl, benzodiazocinyl, benzodihydrofuryl, benzodioxepinyl, benzodioxinyl, benzodioxanyl, benzodioxocinyl, benzodioxolyl, benzodithiepinyl, benzodithiinyl, benzodioxocinyl, benzofuranyl, benzophenazinyl, benzopyranonyl, benzopyranyl, benzopyrenyl, benzopyronyl, benzoquinolinyl, benzoquinolizinyl, benzothiadiazepinyl, benzothiadiazolyl, benzothiazepinyl, benzothiazocinyl, benzothiazolyl, benzothienyl, benzothiophenyl, benzothiazinonyl, benzothiazinyl, benzothiopyranyl, benzothiopyronyl, benzotriazepinyl, benzotriazinonyl, benzotriazinyl, benzotriazolyl, benzoxathiinyl, benzotrioxepinyl, benzoxadiazepinyl, benzoxathiazepinyl, benzoxathiepinyl, benzoxathiocinyl, benzoxazepinyl, benzoxazinyl, benzoxazocinyl, benzoxazolinonyl, benzoxazolinyl, benzoxazolyl, benzylsultamyl benzylsultimyl, bipyrazinyl, bipyridinyl, carbazolyl (e.g., 4H-carbazolyl), carbolinyl (e.g., β-carbolinyl), chromanonyl, chromanyl, chromenyl, cinnolinyl, coumarinyl, cytdinyl, cytosinyl, decahydroisoquinolinyl, decahydroquinolinyl, diazabicyclooctyl, diazetyl, diaziridinethionyl, diaziridinonyl, diaziridinyl, diazirinyl, dibenzisoquinolinyl, dibenzoacridinyl, dibenzocarbazolyl, dibenzofuranyl, dibenzophenazinyl, dibenzopyranonyl, dibenzopyronyl (xanthonyl), dibenzoquinoxalinyl, dibenzothiazepinyl, dibenzothiepinyl, dibenzothiophenyl, dibenzoxepinyl, dihydroazepinyl, dihydroazetyl, dihydrofuranyl, dihydrofuryl, dihydroisoquinolinyl, dihydropyranyl, dihydropyridinyl, dihydroypyridyl, dihydroquinolinyl, dihydrothienyl, dihydroindolyl, dioxanyl, dioxazinyl, dioxindolyl, dioxiranyl, dioxenyl, dioxinyl, dioxobenzofuranyl, dioxolyl, dioxotetrahydrofuranyl, dioxothiomorpholinyl, dithianyl, dithiazolyl, dithienyl, dithiinyl, furanyl, furazanyl, furoyl, furyl, guaninyl, homopiperazinyl, homopiperidinyl, hypoxanthinyl, hydantoinyl, imidazolidinyl, imidazolinyl, imidazolyl, indazolyl (e.g., 1H-indazolyl), indolenyl, indolinyl, indolizinyl, indolyl (e.g., 1H-indolyl or 3H-indolyl), isatinyl, isatyl, isobenzofuranyl, isochromanyl, isochromenyl, isoindazoyl, isoindolinyl, isoindolyl, isopyrazolonyl, isopyrazolyl, isoxazolidiniyl, isoxazolyl, isoquinolinyl, isoquinolinyl, isothiazolidinyl, isothiazolyl, morpholinyl, naphthindazolyl, naphthindolyl, naphthiridinyl, naphthopyranyl, naphthothiazolyl, naphthothioxolyl, naphthotriazolyl, naphthoxindolyl, naphthyridinyl, octahydroisoquinolinyl, oxabicycloheptyl, oxauracil, oxadiazolyl, oxazinyl, oxaziridinyl, oxazolidinyl, oxazolidonyl, oxazolinyl, oxazolonyl, oxazolyl, oxepanyl, oxetanonyl, oxetanyl, oxetyl, oxtenayl, oxindolyl, oxiranyl, oxobenzoisothiazolyl, oxochromenyl, oxoisoquinolinyl, oxoquinolinyl, oxothiolanyl, phenanthridinyl, phenanthrolinyl, phenazinyl, phenothiazinyl, phenothienyl (benzothiofuranyl), phenoxathiinyl, phenoxazinyl, phthalazinyl, phthalazonyl, phthalidyl, phthalimidinyl, piperazinyl, piperidinyl, piperidonyl (e.g., 4-piperidonyl), pteridinyl, purinyl, pyranyl, pyrazinyl, pyrazolidinyl, pyrazolinyl, pyrazolopyrimidinyl, pyrazolyl, pyridazinyl, pyridinyl, pyridopyrazinyl, pyridopyrimidinyl, pyridyl, pyrimidinyl, pyrimidyl, pyronyl, pyrrolidinyl, pyrrolidonyl (e.g., 2-pyrrolidonyl), pyrrolinyl, pyrrolizidinyl, pyrrolyl (e.g., 2H-pyrrolyl), pyrylium, quinazolinyl, quinolinyl, quinolizinyl (e.g., 4H-quinolizinyl), quinoxalinyl, quinuclidinyl, selenazinyl, selenazolyl, selenophenyl, succinimidyl, sulfolanyl, tetrahydrofuranyl, tetrahydrofuryl, tetrahydroisoquinolinyl, tetrahydroisoquinolyl, tetrahydropyridinyl, tetrahydropyridyl (piperidyl), tetrahydropyranyl, tetrahydropyronyl, tetrahydroquinolinyl, tetrahydroquinolyl, tetrahydrothienyl, tetrahydrothiophenyl, tetrazinyl, tetrazolyl, thiadiazinyl (e.g., 6H-1,2,5-thiadiazinyl or 2H,6H-1,5,2-dithiazinyl), thiadiazolyl, thianthrenyl, thianyl, thianaphthenyl, thiazepinyl, thiazinyl, thiazolidinedionyl, thiazolidinyl, thiazolyl, thienyl, thiepanyl, thiepinyl, thietanyl, thietyl, thiiranyl, thiocanyl, thiochromanonyl, thiochromanyl, thiochromenyl, thiodiazinyl, thiodiazolyl, thioindoxyl, thiomorpholinyl, thiophenyl, thiopyranyl, thiopyronyl, thiotriazolyl, thiourazolyl, thioxanyl, thioxolyl, thymidinyl, thyminyl, triazinyl, triazolyl, trithianyl, urazinyl, urazolyl, uretidinyl, uretinyl, uricyl, uridinyl, xanthenyl, xanthinyl, xanthionyl, and the like, as well as modified forms thereof (e.g., including one or more oxo and/or amino) and salts thereof. The heterocyclyl group can be substituted or unsubstituted. For example, the heterocyclyl group can be substituted with one or more substitution groups, as described herein for alkyl.
By “hydrocarbyl” is meant a univalent group formed by removing a hydrogen atom from a hydrocarbon. Non-limiting unsubstituted hydrocarbyl groups include alkyl, alkenyl, alkynyl, and aryl, as defined herein, in which these groups include only carbon and hydrogen atoms. The hydrocarbyl group can be substituted or unsubstituted. For example, the hydrocarbyl group can be substituted with one or more substitution groups, as described herein for alkyl. In other embodiments, any alkyl or aryl group herein can be replaced with a hydrocarbyl group, as defined herein.
By “hydroxyl” is meant —OH.
By “hydroxyalkyl” is meant an alkyl group, as defined herein, substituted by one to three hydroxyl groups, with the proviso that no more than one hydroxyl group may be attached to a single carbon atom of the alkyl group and is exemplified by hydroxymethyl, dihydroxypropyl, and the like.
By “hydroxyaryl” is meant an aryl group, as defined herein, substituted by one to three hydroxyl groups, with the proviso that no more than one hydroxyl group may be attached to a single carbon atom of the aryl group and is exemplified by hydroxyphenyl, dihydroxyphenyl, and the like.
By “isocyanato” is meant -NCO.
By “oxido” is meant an —O- group.
By “oxo” is meant an =O group.
By “phosphine” is meant a trivalent or tetravalent phosphorous having hydrocarbyl moieties. In some embodiments, phosphine is a -PRP3 group, where each RP is, independently, H, optionally substituted alkyl, or optionally substituted aryl. The phosphine group can be substituted or unsubstituted. For example, the phosphine group can be substituted with one or more substitution groups, as described herein for alkyl.
By “selenol” is meant an —SeH group.
By “tellurol” is meant an —TeH group.
By “thioisocyanato” is meant -NCS.
By “thiol” is meant an —SH group.
As used herein, the terms “top,” “bottom,” “upper,” “lower,” “above,” and “below” are used to provide a relative relationship between structures. The use of these terms does not indicate or require that a particular structure must be located at a particular location in the apparatus.
Other features and advantages of the invention will be apparent from the following description and the claims.
This disclosure relates generally to the field of semiconductor processing. In particular, the disclosure is directed to the use of one or more metal precursors in combination with one or more organic precursors. Such precursors can be provided to the substrate sequentially (e.g., first the metal precursor and then the organic precursor, or vice versa) or simultaneously (e.g., both the metal and organic precursors at the same time). In this way, the deposited films can exhibit controlled layers having metal and organic substituents. In particular embodiments, the organic layer includes a polymer, and the metal-containing layer includes an atom having a high EUV absorption cross-section.
Reference is made herein in detail to specific embodiments of the disclosure. Examples of the specific embodiments are illustrated in the accompanying drawings. While the disclosure will be described in conjunction with these specific embodiments, it will be understood that it is not intended to limit the disclosure to such specific embodiments. On the contrary, it is intended to cover alternatives, modifications, and equivalents as may be included within the spirit and scope of the disclosure. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present disclosure. The present disclosure may be practiced without some or all of these specific details. In other instances, well known process operations have not been described in detail so as to not unnecessarily obscure the present disclosure.
EUV lithography makes use of EUV resists that are patterned to form masks for use in etching underlying layers. EUV resists may be polymer-based chemically amplified resists (CARs) produced by liquid-based spin-on techniques. An alternative to CARs is directly photopatternable metal oxide-containing films, such as those available from Inpria Corp. (Corvallis, OR), and described, for example, in U.S. Pat. Pub. Nos. US 2017/0102612, US 2016/0216606, and US 2016/0116839, incorporated by reference herein at least for their disclosure of photopatternable metal oxide-containing films. Such films may be produced by spin-on techniques or dry vapor-deposited. The metal oxide-containing film can be patterned directly (i.e., without the use of a separate photoresist) by EUV exposure in a vacuum ambient providing sub-30 nm patterning resolution, for example as described in U.S. Pat. No. 9,996,004, issued Jun. 12, 2018 and titled EUV PHOTOPATTERNING OF VAPOR-DEPOSITED METAL OXIDE-CONTAINING HARDMASKS, and/or in International Appl. No. PCT/US19/31618, published as International Pub. No. WO2019/217749, filed May 9, 2019, and titled METHODS FOR MAKING EUV PATTERNABLE HARD MASKS, the disclosures of which at least relating to the composition, deposition, and patterning of directly photopatternable metal oxide films to form EUV resist masks is incorporated by reference herein. Generally, the patterning involves exposure of the EUV resist with EUV radiation to form a photo pattern in the resist, followed by development to remove a portion of the resist according to the photo pattern to form the mask.
Directly photopatternable EUV or DUV resists may be composed of or contain metals and/or metal oxides mixed within organic components. The metals/metal oxides are highly promising in that they can enhance the EUV or DUV photon adsorption, generate secondary electrons, and/or show increased etch selectivity to an underlying film stack and device layers. Up to date, these resists have been developed using a wet (solvent) approach, which requires the wafer to move to the track, where it is exposed to developing solvent, dried, and then baked. This wet development step does not only limit productivity but can also lead to line collapse due to surface tension effects during the evaporation of solvent between fine features.
Generally, resists can be employed as a positive tone resist or a negative tone resist by controlling the chemistry of the resist and/or the solubility or reactivity of the developer. It would be beneficial to have a EUV or DUV resist that can serve as either a negative tone resist or a positive tone resist.
The present disclosure generally includes any useful method that employs a metal precursor with an organic precursor, as described herein. Such methods can include any useful lithography processes, deposition processes, radiation exposure processes, development processes, and post-application processes, as described herein. In some embodiments, the choice of the organic precursor can provide either a positive tone resist or a negative tone resist. Accordingly, the method herein also includes those that employ a positive tone resist or a negative tone resist.
While the following may describe techniques as relating to EUV processes, such techniques may also be applicable to other next generation lithographic techniques. Various radiation sources may be employed, including EUV (generally about 13.5 nm), DUV (deep-UV, generally in the 248 nm or 193 nm range with excimer laser sources), X-ray (including EUV at the lower energy range of the X-ray range), and e-beam (including a wide energy range).
Exemplary methods can include sequential or simultaneous delivery of metal precursors and organic precursors to a substrate. For instance,
The metal precursor can be optionally deposited in the presence of one or more counter-reactants. Counter-reactants preferably have the ability to replace the reactive moieties, ligands, or ions (e.g., L in formulas herein) so as to link at least two metal atoms via chemical bonding. Exemplary counter-reactants include oxygen-containing counter-reactants, such as O2, O3, water, peroxides (e.g., hydrogen peroxide), oxygen plasma, water plasma, alcohols, di- or polyhydroxy alcohols, fluorinated di- or polyhydroxy alcohols, fluorinated glycols, formic acid, and other sources of hydroxyl moieties, as well as combinations thereof. In various embodiments, a counter-reactant reacts with the metal precursor by forming oxygen bridges between neighboring metal atoms. Other potential counter-reactants include hydrogen sulfide and hydrogen disulfide, which can crosslink metal atoms via sulfur bridges and bis(trimethylsilyl)tellurium, which can crosslink metal atoms via tellurium bridges. In addition, hydrogen iodide may be utilized to incorporate iodine into the film.
Further operations can include depositing 103 an organic precursor 12 to provide an organic layer 112b on a top surface of the metal-containing layer 112a. In this way, a pair of a metal-containing layer and an organic layer can be deposited. The precursors can be deposited in the opposite order (i.e., first the organic precursor and then the metal precursor, with an optional purge period therebetween), thereby providing an organic layer in proximity to the substrate and then a metal-containing layer disposed on the top surface of the organic layer. Such layers can be a nanolayer (e.g., having a thickness in the nm range, including such ranges disclosed herein) or an atomic monolayer (e.g., having a thickness in the angstrom range, including such ranges disclosed herein).
The vapor deposition processes described here, e.g., ALD or MLD, generally include sequential exposures of a substrate to metal precursors and organic precursors, which are separated in time by inert gas purge periods. The metal-containing precursor provide metal atoms, which act as EUV absorbers in the resist film. The organic precursor provides reaction pathways to create resist contrast through absorption and re-emission processes from the absorber atoms.
Such EUV-absorbing and EUV-sensitive materials can be deposited in any useful manner, as described herein. Exemplary deposition techniques include atomic layer deposition (ALD) (e.g., thermal ALD and plasma-enhanced ALD (PE-ALD)), spin-coat deposition, physical vapor deposition (PVD) including PVD co-sputtering, chemical vapor deposition (CVD), plasma enhanced CVD (PE-CVD), low pressure CVD (LP-CVD), sputter deposition, electron-beam (e-beam) deposition including e-beam co-evaporation, etc., or a combination thereof. Other deposition processes and conditions are described herein.
A non-limiting MLD process includes providing a metal precursor to a substrate within a chamber, thereby depositing a metal-containing layer on a top surface of the substrate; purging the chamber; providing an organic precursor to the chamber, thereby depositing an organic layer on a top surface of the metal-containing layer; and again purging the chamber. By repeating such deposition and purge operations in cycles, a film is formed having alternating metal-containing layers and organic layers.
Various process conditions for deposition can be varied and optimized. For instance, deposition can be performed at a temperature between about 20° C. to about 400° C., such as about 50° C. to about 300° C., about 100° C. to about 200° C., or about 150° C. In some embodiments, the metal precursor(s) and the organic precursor(s) have thermal decomposition points that are higher than the process temperature, so as to yield self-limiting surface reactions. Non-limiting pressure conditions include in the range of about 0.1 Torr to about 50 Torr, such as about 1 Torr to about 15 Torr. In some embodiments, the metal precursor(s) and the organic precursor(s) have vapor pressures that are greater than 0.5 Torr at 100° C. or less.
The process step time for each operation can include the following ranges: a metal precursor dose of from about 0.1 to 10 seconds; an organic precursor dose of from about 0.1 to about 60 seconds; and a purge period of from about 0.1 to about 60 seconds.
Deposition can be repeated for any number of cycles by alternately delivering the metal precursor and organic precursor to the substrate, thereby forming a film. A single cycle can include a first deposition operation of a metal precursor with a subsequent purge operation and a second deposition operation of an organic precursor with a subsequent purge operation. The first and second deposition operations can be performed in any order. Furthermore, such cycles can be repeated for any useful number of cycles, e.g., 1 to 1000 cycles to deposit the desired film thickness. As seen in
When the desired film thickness is deposited, post-deposition treatment steps may be performed. In one instance, such post-deposition treatment involves exposing the film to a long dose (or soak) with a soak precursor. The soak can be used to increase the EUV absorbance of the film. In one embodiment, the soak precursor is a metal-containing precursor, and use of this soak precursor increases the concentration of metal atoms in the film. The soak precursor can be the same or different from the metal precursor used in the deposition process. The soak may be performed under similar conditions as the deposition process, but generally the dose time may be relatively longer, such as in the range of 30 seconds to 30 minutes.
In other embodiments, the soak precursor can include xenon, which causes adsorption and uptake of xenon (Xe) into the film’s pores and increases EUV absorbance. The exposure may be performed at or around room temperature, under about 1 Torr to about 760 Torr of xenon, for a duration of about 10 seconds to about 30 minutes.
Alternatively or additionally, post-deposition treatment can include annealing. As seen in
Deposition can also include co-flow of the metal and organic precursors. For example,
The methods herein can include deposition directly onto a substrate or onto a layer disposed on a surface of the substrate. For instance,
At times, the deposition surface can be activated to promote adhesion or stability of the layer to be deposited. Surface activation of a surface (e.g., on the substrate or a layer) can include wet or dry surface modification, such as oxidation, plasma treatment, etc.
Surface activation can be performed between layers within the hybrid film. As seen in
The hybrid film can have any useful structure. In one embodiment, the film has a thickness of from about 0.5 nm to about 100 nm (e.g., about 5 nm to 100 nm, as well as other thickness described herein). The film can include a plurality of layers having alternating organic/inorganic layers (e.g., organic/metal-containing layers) or alternating inorganic/organic layers (e.g., metal-containing/organic layers). The film can include an optional underlayer or an optional surface activation step prior to deposition of the metal precursor or the organic precursor.
The film can have a vertical gradient that is characterized by a vertical change in EUV absorbance. In some instances, an increase in EUV absorbance along a depth (e.g., going from a top surface of the film towards the substrate) can correspond with an increase in metal content, iodine content, or xenon content along that same depth through the film layer. Non-limiting gradients include a linear gradient, an exponential gradient, a sigmoidal gradient, and the like. In particular embodiments, gradient density films of EUV-responsive moieties can yield more homogeneous film properties of EUV exposed areas at all depths in the film, which might improve development processes, improve EUV sensitivity, and/or improve patterning quality (e.g., having improved line-width-roughness (LWR) and/or line-edge-roughness (LER)).
The radiation-sensitive film can include metal constituents and organic substituents, each of which may include UV-, DUV-, or EUV-sensitive moieties. Non-limiting examples of these include, e.g., a metal or a metalloid or an atom with a high EUV absorption cross-section, such as equal to or greater than 1×107 cm2/mol. In other embodiments, the atom can include an EUV absorption cross-section that is equal to less than about 1×107 cm2/mol. In yet other embodiments, the constituent includes or is M (e.g., in which M can be Sn, Bi, Te, Cs, Sb, In, Mo, Hf, I, Zr, Fe, Co, Ni, Cu, Zn, Ag, Pt, Pb, Xe, or a combination thereof). In some embodiments, the constituent includes an organic precursor or a reaction product thereof. Non-limiting examples of such constituents include, e.g., an organic moiety, such as any described herein (e.g., one or more polymerizable moieties, depolymerizable moieties, alkynyl moieties, alkenyl moieties, cycloalkenyl moieties, hydroxyalkyl moieties, hydroxyaryl moieties, acrylate moieties, vinyl ester moieties, carboxylic acid moieties, diacid moieties, triacid moieties, dialcohol moieties, trialcohol moieties, cyclic anhydride moieties, or combinations thereof).
The patterning radiation-sensitive film can have any useful structure composed of metal and organic components. Examples of useful structure may include a plurality of metal and organic layers, arranged in any useful sequence. In one non-limiting embodiment, the film has a plurality of alternating metal-containing layers and organic layers (e.g., an A-B-A sequence, a B-A-B sequence, an A-B-B-A sequence, etc., in which A is a metal-containing layer and B is an organic layer). In some embodiments, each of the alternating layers is a nanolayer (e.g., having a thickness of about 0.5 nm to 10 nm). Such alternating layers can be formed in any useful manner, e.g., ALD or MLD. In particular embodiments, the film is porous, thereby exhibiting improved dry development selectivity.
The film can be a nanolaminate having a first metal-containing layer and a second metal-containing layer, in which these layers are different. Each of these layer can be deposited by ALD, CVD, or MLD. In one instance, the metals in these layers are different, in which the first metal-containing layer includes metal M1, the second metal-containing layer includes M2, and M1 is different from M2.
In another instance of a nanolaminate, the organic constituents in these layers are different. The first layer can be formed by depositing a first metal precursor and a first organic precursor, and the second layer can be formed by depositing a first metal precursor with a second organic precursor, in which the first and second organic precursors are different. Alternatively, the second layer can include different metal and organic constituents, as compared to the first layer, by using different metal precursors and organic precursors.
In other embodiments, each of the alternating layers is an atomic monolayer (e.g., having a thickness of about 1 Å to about 10 Å).
The film can be homogenous. Thus, in one embodiment, the film is a homogenized matrix formed by annealing a nanolaminate having alternating metal-containing layers and organic layers. In yet another embodiment, the film is a homogenized matrix formed by co-deposition of the metal precursor(s) and the organic precursor(s). In particular embodiments, the homogenized matrix can be an alloy film. Non-limiting precursors and films are described in U.S. Provisional Pat. Appl. No. 62/705,854, filed Oct. 2, 2019, and titled SUBSTRATE SURFACE MODIFICATION WITH HIGH EUV ABSORBERS FOR HIGH PERFORMANCE EUV PHOTORESISTS, the disclosures of which at least relating to the composition, deposition, and patterning are incorporated by reference herein.
Co-deposition can occur in any useful methodology that uses co-flow of both the metal and organic precursors (e.g., CVD). As can be seen, the stack can include a matrix 222 including metal and organic substituents disposed on a substrate 221 (
The resulting hybrid film can be used as a photoresist. In particular non-limiting embodiments, the organic layer can include moieties that undergo polymerization after radiation exposure (e.g., exposure to UV, DUV, and/or EUV radiation). In further embodiments, the metal-containing layer can include metal centers that promote radiation absorption. After deposition, the film can be patterned by radiation exposure, which can promote polymerization of the resist. In this way, a negative tone resist can be formed. Non-limiting polymerizable moieties and organic precursors for providing such moieties are described herein.
Alternatively, the organic layer can include depolymerizable moieties, which undergo depolymerization after radiation exposure. In this way, a positive tone resist can be formed. Non-limiting depolymerizable moieties and organic precursors for providing such moieties are described herein. If radiation is provided through a patterned mask to the organic layer, polymerization or depolymerization of the organic layer can be done so in order to pattern the film.
In particular embodiments, a positive tone process can include chemistry and conditions in which the reaction, deposition, conversion, and decomposition of the film (e.g., an MLD film or a nanolaminate resist stack) will provide byproducts that are soluble in the wet (liquid) developer. Alternatively, the positive tone process can include a dry development process that provides gaseous volatile etch byproducts.
The method can further include steps to treat the deposited EUV-sensitive film. Such steps, while not required for creating the film, can be useful for using the film as a PR. Accordingly, the method 300 further includes patterning the film by an EUV exposure 302 to provide an exposed film having EUV exposed areas 312b and EUV unexposed areas 312c. Patterning can include use of a mask 314 having EUV transparent regions and EUV opaque regions, in which EUV beams 315 are transmitted through the EUV transparent region and into the film 312. EUV exposure can include, e.g., an exposure having a wavelength in the range of about 10 nm to about 20 nm in a vacuum ambient (e.g., about 13.5 nm in a vacuum ambient).
Once a pattern is provided, the method 300 can include developing 303 the film, thereby either (i) removing the EUV exposed areas to provide a pattern within a positive tone resist film or (ii) removing the EUV unexposed areas to provide a pattern within a negative tone resist. Path (i) in
Any useful metal and organic precursors can be used to provide a negative tone resist or a positive tone resist. As seen in
In another example,
Positive tone resists can include the use of photosensitive and depolymerizable moieties, which are designed into the polymer film. Exposure of the photosensitive film to light, such as EUV light, triggers depolymerization of the film. As seen in
As seen in
In particular embodiments, deposition includes a gas phase combination of spontaneously reactive precursors (e.g., a high EUV absorbing metal precursor with an organic precursor in an MLD scheme) to deposit kinetically favored, high molecular weight positive tone resist films. EUV exposure results in irreversible fragmentation and/or accelerated removal as volatile etch byproducts. Furthermore, unexposed areas may be converted to hard oxide etch masks during pattern transfer, e.g., though carbon based underlayers.
Optional steps may be conducted to further modulate, modify, or treat the EUV-sensitive film(s), substrate, photoresist layer(s), and/or underlayer(s) in any method herein.
The method can include optional operation 358 for cleaning the backside surface or bevel of the substrate or removing an edge bead of the deposited film in the prior step. Such cleaning or removing operations can be useful for removing particles that may be present after depositing a film layer. The removing step can include processing the wafer with a wet metal oxide (MeOx) edge bead removal (EBR) step.
Optional operation 360 includes performing a post application bake (PAB) of the deposited film, thereby removing residual moisture; or pretreating the deposited film in any useful manner. The optional PAB can occur after film deposition and prior to EUV exposure; and the PAB can involve some combination of thermal treatment, chemical exposure, and/or moisture to increase the EUV sensitivity of the film, thereby reducing the EUV dose to develop a pattern in the film. In particular embodiments, the PAB step is conducted at a temperature greater than about 100° C. or at a temperature of from about 100° C. to about 200° C. or from about 100° C. to about 250° C. In some instances, a PAB is not performed within the method. In other instances, the PAB step is conducted at a temperature less than about 180° C., less than about 200° C., or less than about 250° C.
In operation 362, the film is exposed to EUV radiation to develop a pattern. Generally, the EUV exposure causes a change in the chemical composition of the film, creating a contrast in etch selectivity that can be used to remove a portion of the film. Such a contrast can provide a positive tone resist or a negative tone resist, as described herein.
Operation 364 is an optional post exposure bake (PEB) of the exposed film, e.g., to further increase contrast in etch selectivity of the exposed film, remove residual moisture, and/or promote chemical condensation. Non-limiting examples of temperature for PEB include, for example from about 90° C. to 600° C., 100° C. to 400° C., 125° C. to 300° C., 170° C. to 250° C. or more, 190° C. to 240° C., as well as others described herein. In other instances, the PEB step is conducted at a temperature less than about 180° C., less than about 200° C., or less than about 250° C. The exposed film can be post-treated in any useful manner. In one instance, the exposed film can be thermally treated (e.g., optionally in the presence of various chemical species) to promote reactivity within the EUV exposed portions of the resist upon exposure to a stripping agent (e.g., a halide-based etchant, such as HCl, HBr, H2, Cl2, Br2, BCl3, or combinations thereof, as well as any halide-based development process described herein; an aqueous alkali development solution; or an organic development solution) or a positive tone developer.
In another instance, the exposed film can be thermally treated to further cross-link ligands within the EUV exposed portions of the resist, thereby providing EUV unexposed portions that can be selectively removed upon exposure to a stripping agent (e.g., a negative tone developer).
Then, in operation 366, the PR pattern is developed. In various embodiments of development, the exposed regions are removed (positive tone) or the unexposed regions are removed (negative tone). In various embodiments, these steps may be dry processes or wet processes.
After exposure, development can include dry or wet techniques. For instance, developing steps can include use of halide chemistry in a gas phase or use of aqueous or organic solvents in a liquid phase. Developing steps can include any useful experimental conditions, such as a low pressure condition (e.g., of from about 1 mTorr to about 100 mTorr), a plasma exposure (e.g., in the presence of vacuum), and/or a thermal condition (e.g., of from about -10° C. to about 100° C.) that may be combined with any useful chemistry (e.g., halide chemistry or aqueous chemistry). Development can include, e.g., a halide-based etchant, such as HCl, HBr, H2, Cl2, Br2, BCl3, or combinations thereof, as well as any halide-based development process described herein; an aqueous alkali development solution; or an organic development solution. Additional development process conditions are described herein.
In yet another instance, the method can include (e.g., after development) hardening the patterned film, thereby providing a resist mask (e.g., a metal oxide or a hardmask) disposed on a top surface of the substrate. Hardening steps can include any useful process to further crosslink or react the EUV unexposed or exposed areas, such as steps of exposing to plasma (e.g., O2, Ar, He, or CO2 plasma), exposing to ultraviolet radiation, annealing (e.g., at a temperature of about 180° C. to about 240° C.), thermal baking, or combinations thereof that can be useful for a post development baking (PDB) step. In other instances, the PDB step is conducted at a temperature less than about 180° C., less than about 200° C., or less than about 250° C. Additional post-application processes are described herein and may be conducted as an optional step for any method described herein.
Any useful type of chemistry can be employed during the depositing, patterning, and/or developing steps. Such steps may be based on dry processes employing chemistry in a gaseous phase or wet processes employing chemistry in a wet phase. Various embodiments include combining all dry operations of film formation by vapor deposition, (EUV) lithographic photopatterning, dry stripping, and dry development. Various other embodiments include dry processing operations described herein advantageously combined with wet processing operations, for example, spin-on EUV photoresists (wet process), such as available from Inpria Corp., may be combined with dry development or other wet or dry processes as described herein. In various embodiments, the wafer clean may be a wet process as described herein, while other processes are dry processes. In yet other embodiments, a wet development process may be used.
Without limiting the mechanism, function, or utility of the present technology, dry processes may provide various benefits relative to wet processes. For example, dry vapor deposition techniques described herein can be used to deposit thinner and more defect free films than can be applied using spin-coating techniques, in which the exact thickness of the deposited film can be modulated and controlled simply by increasing or decreasing the length of the deposition step or sequence. In other embodiments, dry and wet operations can be combined to provide a dry/wet process. For any of the process herein (e.g., for lithographic processes, deposition processes, EUV exposure processes, development processes, pretreatment processes, post-application processes, etc.), various specific operation can include wet, dry, or wet and dry embodiments. For instance, a wet deposition can be combined with a dry development; or wet deposition can be combined with wet development; or dry deposition can be combined with wet development; or dry deposition can be combined with dry development. Any of these, in turn, can be combined with wet or dry pre- and post-application processes, as described herein.
Accordingly, in some embodiments, a dry process may provide more tunability and give further critical dimension (CD) control and scum removal. Dry development can improve performance (e.g., prevent line collapse due to surface tension in wet development) and/or enhance throughput (e.g., by avoiding wet development track). Other advantages may include eliminating the use of organic solvent developers, reducing sensitivity to adhesion issues, avoiding the need to apply and remove wet resist formulations (e.g., avoiding scumming and pattern distortion), improving line edge roughness, patterning directly over device topography, offering the ability to tune hardmask chemistry to the specific substrate and semiconductor device design, and avoiding other solubility-based limitations. Additional details, materials, processes, steps, and apparatuses are described herein.
The present disclosure relates to use of metal precursor(s) and organic precursor(s) that can be deposited to form a patterning radiation-sensitive film (e.g., an EUV-sensitive film). This film, in turn, can serve as an EUV resist, as further described herein. In particular embodiments, the film can include one or more ligands (e.g., EUV labile ligands) that can be removed, cleaved, or cross-linked by radiation (e.g., EUV or DUV radiation), in which such ligands can be present within the metal-containing layer (e.g., as a ligand for a metal precursor) or within the organic layer (e.g., as an organic substituent).
The metal precursor can include any precursor (e.g., described herein) that provides a patternable film that is sensitive to radiation (or a patterning radiation-sensitive film or a photopatternable film). Such radiation can include EUV radiation, DUV radiation, or UV radiation that is provided by irradiating through a patterned mask, thereby being a patterning radiation. The film itself can be altered by being exposed to such radiation, such that the film is radiation-sensitive or photosensitive. In particular embodiments, the metal precursor is an organometallic compound, which includes at least one metal center. In other embodiments, the film obtained from the metal precursor is characterized by a Beer’s absorption coefficient α of more than about 6 µm-1 (e.g., more than about 7 µm-1, 8 µm-1, 9 µm-1, or 10 µm-1) at the wavelength of the patterning radiation being exposed to the film.
The organic precursor, itself, can also enhance UV/DUV/EUV sensitivity of the film (e.g., by increasing UV/DUV/EUV absorptivity) or enhance contrast selectivity during development. Furthermore, an organic moiety within the organic layer can be reactive in the presence of patterning radiation, such as by undergoing removal or elimination from the metal center or by reacting or polymerizing with other moieties within the film.
The metal precursor can have any useful number and type of ligand(s). In some embodiments, at least one ligand can react with the organic precursor. In other embodiments, the ligand can be characterized by its ability to react in the presence of a counter-reactant or in the presence of patterning radiation. For instance, the metal precursor can include a ligand that reacts with a counter-reactant, which can introduce linkages between metal centers (e.g., an —O— linkage). Such a ligand (e.g., dialkylamino groups or alkoxy groups) could, in some instances, also react with an organic precursor. In another instance, the metal precursor can include a ligand that eliminates in the presence of patterning radiation. Such an EUV labile ligand can include branched or linear alkyl groups having a beta-hydrogen, as well as any described herein for R in formula (I) or (II).
The metal precursor can be any useful metal-containing precursor, such as an organometallic agent, a metal halide, or a capping agent (e.g., as described herein). In a non-limiting instance, the metal precursor includes a structure having formula (I):
wherein:
In another non-limiting instance, the metal precursor includes a structure having formula (II):
wherein:
In some embodiments, each ligand within the metal precursor can be one that is reactive with an organic precursor or a counter-reactant. In one instance, the metal precursor includes a structure having formula (II), in which each R is, independently, L. In another instance, the metal precursor includes a structure having formula (IIa):
wherein:
For any formula herein, M can be a metal or a metalloid or an atom with a high patterning radiation absorption cross-section (e.g., an EUV absorption cross-section that is equal to or greater than 1x107 cm2/mol). In other embodiments, the atom can include an EUV absorption cross-section that is equal to less than about 1×107 cm2/mol. In yet other embodiments, M is tin (Sn), bismuth (Bi), tellurium (Te), cesium (Cs), antimony (Sb), indium (In), molybdenum (Mo), hafnium (Hf), iodine (I), zirconium (Zr), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), silver (Ag), platinum (Pt), and lead (Pb). In further embodiments, M is Sn, a is 1, and c is 4 in formula (I), (II), or (IIa). In other embodiments, M is Sn, a is 1, and c is 2 in formula (I), (II), or (IIa). In particular embodiments, M is Sn(II) (e.g., in formula (I), (II), or (IIa)), thereby providing a metal precursor that is a Sn(II)-based compound. In other embodiments, M is Sn(IV) (e.g., in formula (I), (II), or (IIa)), thereby providing a metal precursor that is a Sn(IV)-based compound. In particular embodiments, the precursor includes iodine (e.g., as in periodate).
For any formula herein, each R is, independently, H, halo, optionally substituted alkyl, optionally substituted cycloalkyl, optionally substituted cycloalkenyl, optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted alkoxy (e.g., —OR1, in which R1 can be optionally substituted alkyl), optionally substituted alkanoyloxy, optionally substituted aryl, optionally substituted amino, optionally substituted bis(trialkylsilyl)amino, optionally substituted trialkylsilyl, oxo, an anionic ligand (e.g., oxido, chlorido, hydrido, acetate, iminodiacetate, etc.), a neutral ligand, or a multidentate ligand.
In some embodiments, the optionally substituted amino is —NR1R2, in which each R1 and R2 is, independently, H or alkyl; or in which R1 and R2, taken together with the nitrogen atom to which each are attached, form a heterocyclyl group, as defined herein. In other embodiments, the optionally substituted bis(trialkylsilyl)amino is —N(SiR1R 2R3)2, in which each R1, R2, and R3 is, independently, optionally substituted alkyl. In yet other embodiments, the optionally substituted trialkylsilyl is —SiR1R2R3, in which each R1, R2, and R3 is, independently, optionally substituted alkyl.
In other embodiments, the formula includes a first R (or first L) that is —NR1R2 and a second R (or second L) that is —NR1R2, in which each R1 and R2 is, independently, H or optionally substituted alkyl; or in which R1 from a first R (or first L) and R1 from a second R (or second L), taken together with the nitrogen atom and the metal atom to which each are attached, form a heterocyclyl group, as defined herein. In yet other embodiments, the formula includes a first R that is —OR1 and a second R that is —OR1, in which each R1 is, independently, H or optionally substituted alkyl; or in which R1 from a first R and R1 from a second R, taken together with the oxygen atom and the metal atom to which each are attached, form a heterocyclyl group, as defined herein.
In some embodiments, at least one of R or L (e.g., in formula (I), (II), or (IIa)) is optionally substituted alkyl. Non-limiting alkyl groups include, e.g., CnH2n+1, where n is 1, 2, 3, or greater, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, or t-butyl. In various embodiments, R or L has at least one beta-hydrogen or beta-fluorine.
In some embodiments, each R or L or at least one R or L (e.g., in formula (I), (II), or (IIa)) is halo. In particular, the metal precursor can be a metal halide. Non-limiting metal halides include SnBr4, SnCl4, SnI4, and SbCl3.
In some embodiments, each R or L or at least one R or L (e.g., in formula (I), (II), or (IIa)) can include a nitrogen atom. In particular embodiments, one or more R or L can be optionally substituted amino, an optionally substituted monoalkylamino (e.g., —NR1H, in which R1 is optionally substituted alkyl), an optionally substituted dialkylamino (e.g., —NR1R2, in which each R1 and R2 is, independently, optionally substituted alkyl), or optionally substituted bis(trialkylsilyl)amino. Non-limiting R and L substituents can include, e.g., —NMe2, -NHMe, —NEt2, -NHEt, —NMeEt, -N(t-Bu)-[CHCH3]2-N(t—Bu)— (tbba), —N(SiMe3)2, and —N(SiEt3)2.
In some embodiments, each R or L or at least one R or L (e.g., in formula (I), (II), or (IIa)) can include a silicon atom. In particular embodiments, one or more R or L can be optionally substituted trialkylsilyl or optionally substituted bis(trialkylsilyl)amino. Non-limiting R or L substituents can include, e.g., —SiMe3, —SiEt3, —N(SiMe3)2, and —N(SiEt3)2.
In some embodiments, each R or L or at least one R or L (e.g., in formula (I), (II), or (IIa)) can include an oxygen atom. In particular embodiments, one or more R or L can be optionally substituted alkoxy or optionally substituted alkanoyloxy. Non-limiting R or L substituents include, e.g., methoxy, ethoxy, isopropoxy (i-PrO), t-butoxy (t-BuO), acetate (—OC(O)—CH3), and —O═C(CH3)—CH═C(CH3)—O— (acac).
Any formulas herein can include one or more neutral ligands. Non-limiting neutral ligands include an optionally substituted amine (e.g., NR3 or R2N—Ak—NR2, in which each R can be, independently, H, optionally substituted alkyl, optionally substituted hydrocarbyl, or optionally substituted aryl, and Ak is optionally substituted alkylene), an optionally substituted phosphine (e.g., PR3 or R2P—Ak—PR2, in which each R can be, independently, H, optionally substituted alkyl, optionally substituted hydrocarbyl, or optionally substituted aryl, and Ak is optionally substituted alkylene), an optionally substituted ether (e.g., OR2, in which each R can be, independently, H, optionally substituted alkyl, optionally substituted hydrocarbyl, or optionally substituted aryl), an optionally substituted alkyl, an optionally substituted alkene, an optionally substituted alkyne, an optionally substituted benzene, oxo, or carbon monoxide.
Any formulas herein can include one or more multidentate (e.g., bidentate) ligands. Non-limiting multidentate ligand include a diketonate (e.g., acetylacetonate (acac) or —OC(R1)—Ak—(R1)CO— or —OC(R1)—C(R2)—(R1)CO—), a bidentate chelating dinitrogen (e.g., —N(R1)—Ak—N(R1)— or —N(R3)—CR4—CR2═N(R1)—), an aromatic (e.g., —Ar—), an amidinate (e.g., —N(R1)—C(R2)—N(R1)—), an aminoalkoxide (e.g., —N(R1)—Ak—O— or —N(R1)2—Ak—O—), a diazadienyl (e.g., —N(R1)—C(R2)—C(R2)—N(R1)—), a cyclopentadienyl, a pyrazolate, an optionally substituted heterocyclyl, an optionally substituted alkylene, or an optionally substituted heteroalkylene. In particular embodiments, each R1 is, independently, H, optionally substituted alkyl, optionally substituted haloalkyl, or optionally substituted aryl; each R2 is, independently, H or optionally substituted alkyl; R3 and R4, taken together, forms an optionally substituted heterocyclyl; Ak is optionally substituted alkylene; and Ar is optionally substituted arylene.
In particular embodiments, the metal precursor includes tin. In some embodiments, the tin precursor includes SnR or SnR2 or SnR4 or R3SnSnR3, wherein each R is, independently, H, halo, optionally substituted C1-12 alkyl, optionally substituted C1-12 alkoxy, optionally substituted amino (e.g., —NR1R2), optionally substituted C2-12 alkenyl, optionally substituted C2-12 alkynyl, optionally substituted C3-8 cycloalkyl, optionally substituted aryl, cyclopentadienyl, optionally substituted bis(trialkylsilyl)amino (e.g., —N(SiR1R2R3)2), optionally substituted alkanoyloxy (e.g., acetate), a diketonate (e.g., —OC(R1)—Ak—(R2)CO—), or a bidentate chelating dinitrogen (e.g., —N(R1)—Ak—N(R1)—). In particular embodiments, each R1, R2, and R3 is, independently, H or C1-12 alkyl (e.g., methyl, ethyl, isopropyl, t-butyl, or neopentyl); and Ak is optionally substituted C1-6 alkylene. In particular embodiments, each R is, independently, halo, optionally substituted C1-12 alkoxy, optionally substituted amino, optionally substituted aryl, cyclopentadienyl, or a diketonate. Non-limiting tin precursors include SnF2, SnH4, SnBr4, SnCl4, SnI4, tetramethyl tin (SnMe4), tetraethyl tin (SnEt4), trimethyl tin chloride (SnMe3Cl), dimethyl tin dichloride (SnMe2Cl2), methyl tin trichloride (SnMeCl3), tetraallyltin, tetravinyl tin, hexaphenyl ditin (IV) (Ph3Sn—SnPh3, in which Ph is phenyl), dibutyldiphenyltin (SnBu2Ph2), trimethyl(phenyl) tin (SnMe3Ph), trimethyl (phenylethynyl) tin, tricyclohexyl tin hydride, tributyl tin hydride (SnBu3H), dibutyltin diacetate (SnBu2(CH3COO)2), tin(II) acetylacetonate (Sn(acac)2), SnBu3(OEt), SnBu2(OMe)2, SnBu3(OMe), Sn(t-BuO)4, Sn(n-Bu)(t-BuO)3, tetrakis(dimethylamino)tin (Sn(NMe2)4), tetrakis(ethylmethylamino)tin (Sn(NMeEt)4), tetrakis(diethylamino)tin(IV) (Sn(NEt2)4), (dimethylamino)trimethyl tin(IV) (Sn(Me)3(NMe2), Sn(i-Pr)(NMe2)3, Sn(n-Bu)(NMe2)3, Sn(s-Bu)(NMe2)3, Sn(i-Bu)(NMe2)3, Sn(t-Bu)(NMe2)3, Sn(t-Bu)2(NMe2)2, Sn(t-Bu)(NEt2)3, Sn(tbba), Sn(II) (1,3-bis(1,1-dimethylethyl)-4,5-dimethyl-(4R,5R)-1,3,2-diazastannolidin-2-ylidene), or bis[bis(trimethylsilyl)amino] tin (Sn[N(SiMe3)2]2).
In other embodiments, the metal precursor includes bismuth, such as in BiR3, wherein each R is, independently, halo, optionally substituted C1-12 alkyl, mono-C1-12 alkylamino (e.g., —NR1H), di-C1-12 alkylamino (e.g., —NR1R2), optionally substituted aryl, optionally substituted bis(trialkylsilyl)amino (e.g., —N(SiR1R2R3)2), or a diketonate (e.g., —OC(R4)—Ak—(R5)CO—). In particular embodiments, each R1, R2, and R3 is, independently, C1-12 alkyl (e.g., methyl, ethyl, isopropyl, t-butyl, or neopentyl); and each R4 and R5 is, independently, H or optionally substituted C1-12 alkyl (e.g., methyl, ethyl, isopropyl, t-butyl, or neopentyl). Non-limiting bismuth precursors include BiCl3, BiMe3, BiPh3, Bi(NMe2)3, Bi[N(SiMe3)2]3, and Bi(thd)3, in which thd is 2,2,6,6-tetramethyl-3,5-heptanedionate.
In other embodiments, the metal precursor includes tellurium, such as TeR2 or TeR4, wherein each R is, independently, halo, optionally substituted C1-12 alkyl (e.g., methyl, ethyl, isopropyl, t-butyl, and neopentyl), optionally substituted C1-12 alkoxy, optionally substituted aryl, hydroxyl, oxo, or optionally substituted trialkylsilyl. Non-limiting tellurium precursors include dimethyl tellurium (TeMe2), diethyl tellurium (TeEt2), di(n-butyl) tellurium (Te(n-Bu)2), di(isopropyl) tellurium (Te(i-Pr)2), di(t-butyl) tellurium (Te(t-Bu)2), t-butyl tellurium hydride (Te(t-Bu)(H)), Te(OEt)4, bis(trimethylsilyl)tellurium (Te(SiMe3)2), and bis(triethylsilyl) tellurium (Te(SiEt3)2).
The metal precursor can also include cesium. Non-limiting cesium precursors include Cs(OR), wherein R is optionally substituted C1-12 alkyl or optionally substituted aryl. Other cesium precursors include Cs(Ot—Bu) and Cs(Oi—Pr).
The metal precursor can include antimony, such as in SbR3, wherein each R is, independently, halo, optionally substituted C1-12 alkyl (e.g., methyl, ethyl, isopropyl, t-butyl, and neopentyl), optionally substituted C1-12 alkoxy, or optionally substituted amino (e.g., —NR1R2, in which each R1 and R2 is, independently, H or optionally substituted C1-12 alkyl). Non-limiting antimony precursors include SbCl3, Sb(OEt)3, Sb(On—Bu)3, and Sb(NMe2)3.
Other metal precursors include indium precursors, such as in InR3, wherein each R is, independently, halo, optionally substituted C1-12 alkyl (e.g., methyl, ethyl, isopropyl, t-butyl, and neopentyl), or a diketonate (e.g., —OC(R4)—Ak—(R5)CO—, in which each R4 and R5 is, independently, H or C1-12 alkyl). Non-limiting indium precursors include InCp, in which Cp is cyclopentadienyl, InCl3, InMe3, In(acac)3, In(CF3COCHCOCH3)3, and In(thd)3.
Yet other metal precursors include molybdenum precursors, such as MoR4, MoR5, or MoR6, wherein each R is, independently, optionally substituted C1-12 alkyl (e.g., methyl, ethyl, isopropyl, t-butyl, and neopentyl), optionally substituted allyl (e.g., allyl, such as C3H5, or oxide of allyl, such as C3H5O), optionally substituted alkylimido (e.g., ═N—R1), acetonitrile, optionally substituted amino (e.g., —NR1R2), halo (e.g., chloro or bromo), carbonyl, a diketonate (e.g., —OC(R3)—Ak—(R3)CO—), or a bidentate chelating dinitrogen (e.g., —N(R3)—Ak—N(R3)— or —N(R4)—CR5—CR2═N(R3)—). In particular embodiments, each R1 and each R2 is, independently, H or optionally substituted alkyl; each R3 is, independently, H, optionally substituted alkyl, optionally substituted haloalkyl, or optionally substituted aryl; and R4 and R5, taken together, forms an optionally substituted heterocyclyl. Non-limiting molybdenum precursors include Mo(CO)6, bis(t-butylimido)bis(dimethylamino) molybdenum(VI) or Mo(NMe2)2(═Nt—Bu)2, molybdenum(VI) dioxide bis(2,2,6,6-tetramethyl-3,5-heptanedionate) or Mo(=O)2(thd)2, or molybdenum allyl complexes, such as Mo(η3-allyl)X(CO)2(CH3CN)2, in which allyl can be C3H5 or C5H5O and X can be Cl, Br, or alkyl (e.g., methyl, ethyl, isopropyl, t-butyl, or neopentyl).
Metal precursors can also include hafnium precursors, such as HfR3 or HfR4, wherein each R is, independently, optionally substituted C1-12 alkyl, optionally substituted C1-12 alkoxy, mono-C1-12 alkylamino (e.g., —NR1H, in which R1 is optionally substituted C1-12 alkyl), di-C1-12 alkylamino (e.g., —NR1R2, in which each R1 and R2 is, independently, optionally substituted C1-12 alkyl), optionally substituted aryl (e.g., phenyl, benzene, or cyclopentadienyl, as well as substituted forms thereof), optionally substituted allyl (e.g., allyl or allyl oxide), or diketonate (e.g., —OC(R4)—Ak—(R5)CO—, each R4 and R5 is, independently, H or optionally substituted C1-12 alkyl). Non-limiting hafnium precursors include Hf(i-Pr)(NMe2)3; Hf(η—C6H5R1)(η-C3H5)2 in which R1 is H or alkyl; HfR1(NR2R3)3 in which each of R1, R2, and R3 is, independently, optionally substituted C1-12 alkyl (e.g., methyl, ethyl, isopropyl, t-butyl, or neopentyl); HfCp2Me2; Hf(Ot—Bu)4, Hf(OEt)4; Hf(,NEt2)4; Hf(NMe2)4; Hf(NMeEt)4, and Hf(thd)4.
Yet other metal precursors and non-limiting substituents are described herein. For instance, metal precursors can be any having a structure of formulas (I), (II), and (IIa), as described above; or formulas (III), (IV), (V), (VI), (VII), or (VIII), as described below. Any of the substituents M, R, X, or L, as described herein, can be employed in any of formulas (I), (II), (IIa), (III), (IV), (V), (VI), (VII), or (VIII).
Various atoms present in the metal precursor, organic precursor, and/or counter-reactant can be provided within a gradient film. In some embodiments of the techniques discussed herein, a non-limiting strategy that can further improve the EUV sensitivity in a PR film is to create a film in which the film composition is vertically graded, resulting in depth-dependent EUV sensitivity. In a homogenous PR with a high absorption coefficient, the decreasing light intensity throughout the film depth necessitates a higher EUV dose to ensure the bottom is sufficiently exposed. By increasing the density of atoms with high EUV absorptivity at the bottom of the film relative to the top of the film (i.e., by creating a gradient with increasing EUV absorption), it becomes possible to more efficiently use available EUV photons while more uniformly distributing absorption (and the effects of secondary electrons) towards the bottom of more highly absorbing films. In one non-limiting instance, the gradient film includes Te, I, or other atoms towards the bottom of the film (e.g., closer to the substrate).
The strategy of engineering a vertical composition gradient in a PR film is particularly applicable to dry deposition methods, such as MLD, CVD, and ALD, and can be realized by tuning the flow ratios between different reactants during deposition. The type of composition gradients that can be engineered include: the ratios between different high-absorbing metals, the percentage of metal atoms that have EUV-cleavable organic groups, the percentages of organic precursors and/or counter-reactants that contain high-absorbing elements, and combinations of the above.
The composition gradient in the EUV PR film can also bring additional benefits. For instance, high density of high EUV-absorbing elements in the bottom part of the film can effectively generate more secondary electrons that can better expose upper portions of the film. In addition, such compositional gradients can also be directly correlated with a higher fraction of EUV-absorbing species that are not bonded to bulky, terminal substituents. For example, in the case of Sn-based resists, the incorporation of tin precursors with four leaving groups is possible, thereby promoting the formation of Sn—O— substrate bonding at the interface for improved adhesion.
Such gradient films can be formed by using any metal precursors (e.g., tin or non-tin precursors), organic precursors, counter-reactants, and/or modified precursors described herein. Yet other films, methods, precursors, and other compounds are described in U.S. Provisional Pat. Appl. No. 62/909,430, filed Oct. 2, 2019, and International Appl No. PCT/US20/53856, filed Oct. 1, 2020, published as International Pub. No. WO 2021/067632, in which each is titled SUBSTRATE SURFACE MODIFICATION WITH HIGH EUV ABSORBERS FOR HIGH PERFORMANCE EUV PHOTORESISTS; and International Appl. No. PCT/US20/70172, filed Jun. 24, 2020, published as International Pub. No. WO 2020/264557, and titled PHOTORESIST WITH MULTIPLE PATTERNING RADIATION-ABSORBING ELEMENTS AND/OR VERTICAL COMPOSITION GRADIENT, the disclosures of which at least relating to the composition, deposition, and patterning of directly photopatternable metal oxide films to form EUV resist masks are incorporated by reference herein.
Furthermore, two or more different precursors can be employed within each layer (e.g., a film). For instance, two or more of any metal-containing precursors herein can be employed to form an alloy. In one non-limiting instance, tin telluride can be formed by employing tin precursor including an —NR2 ligand with RTeH, RTeD, or TeR2 precursors, in which R is an alkyl, particularly t-butyl or i-propyl. In another instance, a metal telluride can be formed by using a first metal precursor including an alkoxy or a halo ligand (e.g., SbCl3) with a tellurium-containing precursor including a trialkylsilyl ligand (e.g., bis(trimethylsilyl)tellurium).
Yet other exemplary EUV-sensitive materials, as well as processing methods and apparatuses, are described in U.S. Pat. No. 9,996,004 and Int. Pat. Pub. No. WO 2019/217749, each of which is incorporated herein by reference in its entirety.
As described herein, the films, layers, and methods herein can be employed with any useful precursor. In some instances, the metal precursor includes a metal halide having the following formula (III):
in which M is a metal, X is halo, and n is 2 to 4, depending on the selection of M. Exemplary metals for M include Sn, Te, Bi, or Sb. Exemplary metal halides include SnBr4, SnCl4, SnI4, and SbCl3.
Another non-limiting metal-containing precursor includes a structure having formula (IV):
in which M is a metal; each R is independently H, an optionally substituted alkyl, amino (e.g., —NR2, in which each R is independently alkyl), optionally substituted bis(trialkylsilyl)amino (e.g., —N(SiR3)2, in which each R is independently alkyl), or an optionally substituted trialkylsilyl (e.g., —SiR3, in which each R is independently alkyl); and n is 2 to 4, depending on the selection of M. Exemplary metals for M include Sn, Te, Bi, or Sb. The alkyl group may be CnH2n+1, where n is 1, 2, 3, or greater. Exemplary organometallic agents include SnMe4, SnEt4, TeRn, RTeR, t-butyl tellurium hydride (Te(t-Bu)(H)), dimethyl tellurium (TeMe2), di(t-butyl) tellurium (Te(t-Bu)2), di(isopropyl)tellurium (Te(i-Pr)2), bis(trimethylsilyl)tellurium (Te(SiMe3)2), bis(triethylsilyl) tellurium (Te(SiEt3)2), tris(bis(trimethylsilyl)amido) bismuth (Bi[N(SiMe3)2]3), Sb(NMe2)3, and the like.
Another non-limiting metal-containing precursor can include a capping agent having the following formula (V):
in which M is a metal; each L is independently an optionally substituted alkyl, amino (e.g., —NR1R2, in which each of R1 and R2 can be H or alkyl, such as any described herein), alkoxy (e.g., —OR, in which R is alkyl, such as any described herein), halo, or other organic substituent; and n is 2 to 4, depending on the selection of M. Exemplary metals for M include Sn, Te, Bi, or Sb. Exemplary ligands include dialkylamino (e.g., dimethylamino, methylethylamino, and diethylamino), alkoxy (e.g., t-butoxy and isopropoxy), halo (e.g., F, Cl, Br, and I), or other organic substituents (e.g., acetylacetone or N2,N3-di-tertbutyl-butane-2,3-diamino). Non-limiting capping agents include SnCl4; SnI4; Sn(NR2)4, wherein each of R is independently methyl or ethyl; or Sn(t-BuO)4. In some embodiments, multiple types of ligands are present.
A metal-containing precursor can include a hydrocarbyl-substituted capping agent having the following formula (VI):
wherein M is a metal, R is a C2-10 alkyl or substituted alkyl having a beta-hydrogen, and X is a suitable leaving group upon reaction with a hydroxyl group of the exposed hydroxyl groups. In various embodiments, n = 1 to 3, and m = 4 - n, 3 - n, or 2 - n, so long as m > 0 (or m ≥ 1). For example, R may be t-butyl, t-pentyl, t-hexyl, cyclohexyl, isopropyl, isobutyl, sec-butyl, n-butyl, n-pentyl, n-hexyl, or derivatives thereof having a heteroatom substituent in the beta position. Suitable heteroatoms include halogen (F, Cl, Br, or I), or oxygen (—OH or —OR). X may be dialkylamino (e.g., dimethylamino, methylethylamino, or diethylamino), alkoxy (e.g., t-butoxy, isopropoxy), halo (e.g., F, Cl, Br, or I), or another organic ligand. Examples of hydrocarbyl-substituted capping agents include t-butyltris(dimethylamino)tin (Sn(t-Bu)(NMe2)3), n-butyltris(dimethylamino)tin (Sn(n-Bu)(NMe2)3), t-butyltris (diethylamino)tin (Sn(t-Bu)(NEt2)3), di(t-butyl)di(dimethylamino)tin (Sn(t-Bu)2(NMe2)2), sec-butyltris(dimethylamino)tin (Sn(s-Bu)(NMe2)3), n-pentyltris(dimethylamino)tin (Sn(n-pentyl)(NMe2)3), i-butyltris(dimethylamino) tin (Sn(i-Bu)(NMe2)3), i-propyltris (dimethylamino)tin (Sn(i-Pr)(NMe2)3), t-butyltris(t-butoxy)tin (Sn(t-Bu)(t-BuO)3), n-butyl(tris(t-butoxy)tin (Sn(n-Bu)(t-BuO)3), or isopropyltris(t-butoxy)tin (Sn(i-Pr)(t-BuO)3).
In various embodiments, a metal-containing precursor includes at least one alkyl group on each metal atom that can survive the vapor-phase reaction, while other ligands or ions coordinated to the metal atom can be replaced by the counter-reactants. Accordingly, another non-limiting metal-containing precursor includes an organometallic agent having the formula (VII):
in which M is a metal; R is an optionally substituted alkyl; L is a ligand, ion, or other moiety which is reactive with the counter-reactant; a ≥ 1; b ≥ 1; and c ≥ 1. In particular embodiments, a = 1, and b + c = 4. In some embodiments, M is Sn, Te, Bi, or Sb. In particular embodiments, each L is independently amino (e.g., —NR1R2, in which each of R1 and R2 can be H or alkyl, such as any described herein), alkoxy (e.g., -OR, in which R is alkyl, such as any described herein), or halo (e.g., F, Cl, Br, or I). Exemplary agents include SnMe3Cl, SnMe2Cl2, SnMeCl3, SnMe(NMe2)3, SnMe2(NMe2)2, SnMe3(NMe2), and the like.
In other embodiments, the non-limiting metal-containing precursor includes an organometallic agent having the formula (VIII):
in which M is a metal; L is a ligand, ion, or other moiety which is reactive with the counter-reactant; a ≥ 1; and c ≥ 1. In particular embodiments, c = n - 1, and n is 2, 3, or 4. In some embodiments, M is Sn, Te, Bi, or Sb. Counter-reactants preferably have the ability to replace the reactive moieties ligands or ions (e.g., L in formulas herein) so as to link at least two metal atoms via chemical bonding.
In any embodiment herein, R can be an optionally substituted alkyl (e.g., C1-10 alkyl). In one embodiment, alkyl is substituted with one or more halo (e.g., halo-substituted C1-10 alkyl, including one, two, three, four, or more halo, such as F, Cl, Br, or I). Exemplary R substituents include CnH2n+1, preferably wherein n ≥ 3; and CnFxH(2n+1-x), wherein 2n+1 ≤ x ≤ 1. In various embodiments, R has at least one beta-hydrogen or beta-fluorine. For example, R may be selected from the group consisting of i-propyl, n-propyl, t-butyl, i-butyl, n-butyl, sec-butyl, n-pentyl, i-pentyl, t-pentyl, sec-pentyl, and mixtures thereof.
In any embodiment herein, L may be any moiety readily displaced by a counter-reactant to generate an M-OH moiety, such as a moiety selected from the group consisting of an amino (e.g., —NR1R2, in which each of R1 and R2 can be H or alkyl, such as any described herein), alkoxy (e.g., —OR, in which R is alkyl, such as any described herein), carboxylates, halo (e.g., F, Cl, Br, or I), and mixtures thereof.
Exemplary organometallic agents include SnMeCl3, (N2,N3-di-t-butyl-butane-2,3-diamido) tin(II) (Sn(tbba)), bis(bis(trimethylsilyl)amido) tin(II), tetrakis(dimethylamino) tin(IV) (Sn(NMe2)4), t-butyl tris(dimethylamino) tin (Sn(t-butyl)(NMe2)3), i-butyl tris(dimethylamino) tin (Sn(i-Bu)(NMe2)3), n-butyl tris(dimethylamino) tin (Sn(n-Bu)(NMe2)3), sec-butyl tris(dimethylamino) tin (Sn(s-Bu)(NMe2)3), i-propyl(tris) dimethylamino tin (Sn(i-Pr)(NMe2)3), n-propyl tris(diethylamino) tin (Sn(n-Pr)(NEt2)3), and analogous alkyl(tris)(t-butoxy) tin compounds, such as t-butyl tris(t-butoxy) tin (Sn(t-Bu)(t-BuO)3). In some embodiments, the organometallic agents are partially fluorinated.
Suitable organic precursors can be chosen to enable self-limiting and/or complementary reactions with the metal precursor. In particular embodiments, the reaction can be self-limiting, in that once all available sites with the adsorbed metal precursor layer have reacted, the organic precursor does not continue to react with itself. In other embodiments, the reaction can be complementary, such that the organic precursor regenerates a surface that is reactive towards a subsequent exposure to the metal precursor.
The organic precursor can include one or more polymerizable moieties, depolymerizable moieties, alkyl moieties (e.g., optionally substituted alkyl), alkynyl moieties (e.g., optionally substituted alkynyl), alkenyl moieties (e.g., optionally substituted alkenyl), cycloalkenyl moieties, hydroxyalkyl moieties, hydroxyaryl moieties, acrylate moieties, vinyl ester moieties, carboxylic acid moieties (e.g., methacrylic acids), diacid moieties (e.g., HO2C—Lk—CO2H), triacid moieties (e.g., HO2C—Lk—CO2H, in which Lk is substituted with one or more carboxyl), diacyl chloride moieties (e.g., ClC(O)—Lk—C(O)Cl), dialdehyde moieties (e.g., HC(O)—Lk—C(O)H), diamino moieties (e.g., H2N—Lk—NH2), dialcohol moieties (e.g., HO—Lk—OH), trialcohol moieties (e.g., HO—Lk—OH, in which Lk is substituted with one or more hydroxyl), dithiol moieties (e.g., HS—Lk—SH), aminoalcohol moieties (e.g., HO—Lk—NH2), diisocyanate moieties (e.g., OCN-Lk-NCO), dithioisocyanate moieties (e.g., SCN-Lk-NCS), anhydride moieties, cyclic anhydride moieties, dianhydride moieties, or diene moieties (e.g., CH2═CH—Ak—CH═CH2). Examples of Lk include optionally substituted alkylene, optionally substituted alkenylene, optionally substituted alkynylene, optionally substituted heteroalkylene, optionally substituted arylene, or optionally substituted (aryl)(alkyl)ene.
Such organic precursors can include homofunctional compounds or heterofunctional compounds. For instance, the organic precursor can be X1-Lk-X2, in which each of X1 and X2 is, independently, carboxyl, hydroxyl, thiol, isocyanato, thioisocyanato, halo, —C(O)—halo, or optionally substituted amino; and Lk is optionally substituted alkylene, optionally substituted alkenylene, optionally substituted alkynylene, optionally substituted heteroalkylene, optionally substituted arylene, or optionally substituted (aryl)(alkyl)ene. A homofunctional compound is one in which X1 and X2 are the same, and a heterofunctional compound is one in which X1 and X2 are different.
In other embodiments, the organic precursor is a compound having one or more substitutions selected from hydroxyl, carboxyl, amino, or oxo. Such groups can be present to promote polymerization between precursor molecules Exemplary compounds can include phenolic compounds, acrylates (e.g., methacrylates), acids (e.g., methacrylic acids), olefins (e.g., dienes, cyclodienes, etc.), diacids (e.g., HO2C—Ak—CO2H, in which Ak is optionally alkylene, optionally heteroalkylene, or optionally arylene), dialcohols (e.g., HO—Ak—OH, in which Ak is optionally alkylene, optionally heteroalkylene, or optionally arylene), diamines (e.g., H2N—Ak—NH2, in which Ak is optionally alkylene, optionally heteroalkylene, or optionally arylene), diisocyanates (e.g., OCN-Ak-NCO, in which Ak is optionally alkylene, optionally heteroalkylene, or optionally arylene), dialdehydes (e.g., phthalaldehyde or HC(O)—Ak—C(O)H, in which Ak is optionally alkylene, optionally heteroalkylene, or optionally arylene), and vinyl esters.
For instance, the organic precursor includes one or more hydroxyl groups. In particular embodiments, the organic precursor can include a hydroxyl moiety, a hydroxyalkyl moiety, or a hydroxyaryl moiety. Yet other non-limiting organic precursors can include HO—Ak—OH, in which Ak is an optionally substituted alkylene, optionally substituted alkenylene, optionally substituted alkynylene, or optionally substituted arylene. In particular embodiments, Ak can be substituted with one or more hydroxyl, oxo, and/or carboxyl substituents. Further organic precursors include diols, triols, polyols, ynols, benzenediols, benzenetriols, and benzenetetrols, including ethylene glycol, glycerol, propylene glycol, ethynol, diacetylene glycol (2,4-hexadiyne-1,6-diol), hydroquinone (1,4-dihydroxybenzene), catechol (1,2-dihydroxybenzene), resorcinol (1,3-dihydroxybenzene), and benzene-1,3,5-triol.
In another instance, the organic precursor includes one or more carboxyl groups. In particular embodiments, the organic precursor can include a carboxyl moiety, a carboxyalkyl moiety, or a carboxyaryl moiety. Yet other non-limiting organic precursors can include HOC(O)-Ak-C(O)OH, in which Ak is an optionally substituted alkylene or optionally substituted arylene. In particular embodiments, Ak can be substituted with one or more hydroxyl, oxo, and/or carboxyl substituents. Further organic precursors include diacids, triacids, and enoic acids, including oxalic acid, malonic acid, succinic acid, citric acid, acetylenedicarboxylic acid, tartronic acid, phthalic acid, terephthalic acid, isophthalic acid, and trimesic acid.
Other functional groups can be provided for the organic precursor, such as amino, thiol, selenol, and tellurol. Yet other non-limiting organic precursors can include N(RN1)(RN2)—Ak—N(RN3)(RN4), HS—Ak—SH, HSe—Ak—SeH, or HTe—Ak—TeH, in which Ak is an optionally substituted alkylene or optionally substituted arylene and each of RN1, RN2, RN3, and RN4 is, independently, H or optionally substituted alkyl. In particular embodiments, Ak can be substituted with one or more hydroxyl, oxo, carboxyl, amino, thiol, selenol, and/or tellurol substituents.
Use of the organic precursor(s) can result in deposition of any useful polymer (e.g., within an organic layer or within a matrix), in which the polymer can include polymerizable moieties or depolymerizable moieties. For instance, the organic precursor can provide a film having one or more polymerizable moieties, in which exposure to radiation polymerizes these moieties. Non-limiting polymerizable moieties include those than can be cross-linked after exposure to UV, DUV, and/or EUV radiation, such as alkyne moieties and alkene moieties.
Alternatively, the organic precursor can provide a film having one or more depolymerizable moieties, in which exposure to radiation depolymerizes these moieties. Non-limiting depolymerizable moieties include those than can be unzipped or photolyzed after exposure to UV, DUV, and/or EUV radiation, such as ester moieties, acrylate moieties, or carbonate moieties.
Constituents within the organic layer can be formed by using one, two, or more organic precursors. In one instance, a single organic precursor is employed, in which reactions occur between precursors of the same type within the organic layer and the organic precursor can also react with the metal precursor. In another instance, two organic precursors are employed, in which a first organic precursor reacts with the metal precursor and the second organic precursor reacts with the first organic precursor that is bound to the metal precursor.
The first organic precursor (P1) and the second organic precursor (P2) can provided in one, two, three, or more steps. The first step can include providing P1 to the metal precursor (MP) to form MP-P1. Then, P2 can be provided to react with P1, thus forming MP-P1-P2. Optionally, further steps can be conducted, such as by providing P1 in a third step to produce MP-P1-P2-P1 or by providing P2 to produce MP-P1-P2-P2. Further organic precursors can be used to build up the organic layer, in which such precursors can be provided at the same time or sequentially in cycles.
Organic precursor can include polymers or can react together to provide polymers. Non-limiting polymers (e.g., polymerizable or unzippable polymers) include a poly(ester), such as polyethylene terephthalate, polyhydroxybutyrate, polyhydroxyvalerate, poly(vinyl ester), poly(vinyl acetate), or copolymers thereof; a poly(hydroxyalkanoate); a poly(lactic acid); a poly(caprolactone); a poly(imide); a poly(urea), a poly(amide); a poly(ether), such as poly(phthalaldehyde) or poly(benzyl ether); a poly(carbamate), such as poly(benzyl carbamate); a polysaccharide or a derivative thereof, such as amylose, cellulose, or carboxymethyl cellulose; a poly(alkylene succinate), such as poly(propylene succinate) or poly(butylene succinate); a poly(aspartate) or a poly(aspartic acid); or an aliphatic-aromatic resin, such as a copolymer having at least one aliphatic section and at least one aromatic section.
In one embodiment, a poly(ester) is deposited employing a diacid (e.g., an optionally substituted alkyl or an optionally substituted aryl substituted with two carboxyl groups, such as terephthalic acid) as a first organic precursor with a dialcohol (e.g., an optionally substituted alkyl or an optionally substituted aryl substituted with two hydroxyl groups, such as ethylene glycol) as a second organic precursor. In particular embodiments, the poly(ester) is a polyethylene terephthalate. In particular embodiments, the first organic precursor is a diacyl chloride. In some embodiments, the dialcohol is HO—Lk—OH, and the diacyl chloride is ClC(O)—Lk—C(O)Cl, in which each of RN1, RN2, RN3, and RN4 is, independently, H or optionally substituted alkyl, and Lk is optionally substituted alkylene, optionally substituted alkenylene, optionally substituted alkynylene, optionally substituted heteroalkylene, optionally substituted arylene, or optionally substituted (aryl)(alkyl)ene.
In another embodiment, a poly(ester) (e.g., a poly(vinyl ester)) is deposited employing a vinyl ester moiety. Non-limiting vinyl esters include, for instance, vinyl acetate (VAc), vinyl propionate (VPr), vinyl butyrate (VBu), vinyl pivalate (VPiv), vinyl octanoate (VOc), vinyl neodecanoate (VNDec), vinyl stearate (VSt), vinyl benzoate (VBz), vinyl chloroacetate (VClAc), vinyl trifluoroacetate (VTFAc), isopropenyl acetate (iPAc), and 1-(trifluoromethyl)vinyl acetate (CF3VAc).
In one embodiment, a poly(imide) is deposited employing a diamine as a first organic precursor with a dianhydride as a second organic precursor. In some embodiments, the diamine is N(RN1)(RN2)—Lk—N(RN3)(RN4), in which each of RN1, RN2, RN3, and RN4 is, independently, H or optionally substituted alkyl, and Lk is optionally substituted alkylene, optionally substituted alkenylene, optionally substituted alkynylene, optionally substituted heteroalkylene, optionally substituted arylene, or optionally substituted (aryl)(alkyl)ene.
In another embodiment, a poly(urea) is deposited employing a diamine as a first organic precursor with a diisocyanate as a second organic precursor. In some embodiments, the diamine is N(RN1)(RN2)—Lk—N(RN3)(RN4), and the diisocyanate is OCN-Lk-NCO, in which each of RN1, RN2, RN3, and RN4 is, independently, H or optionally substituted alkyl, and Lk is optionally substituted alkylene, optionally substituted alkenylene, optionally substituted alkynylene, optionally substituted heteroalkylene, optionally substituted arylene, or optionally substituted (aryl)(alkyl)ene. In further embodiments, a third organic precursor is a diamine, which is reacted with the diisocyanate that is the second organic precursor.
In one embodiment, a poly(amide) is deposited employing a diamine as a first organic precursor with a diacyl chloride as a second organic precursor. In some embodiments, the diamine is N(RN1)(RN2)—Lk—N(RN3)(RN4), and the diacyl chloride is ClC(O)—Lk—C(O)Cl, in which each of RN1, RN2, RN3, and RN4 is, independently, H or optionally substituted alkyl, and Lk is optionally substituted alkylene, optionally substituted alkenylene, optionally substituted alkynylene, optionally substituted heteroalkylene, optionally substituted arylene, or optionally substituted (aryl)(alkyl)ene.
In one embodiment, a poly(alkylene terephthalate) is deposited employing a dialcohol as a first organic precursor with a diacyl chloride as a second organic precursor. In some embodiments, the dialcohol is HO—Lk—OH, and the diacyl chloride is ClC(O)—ArC(O)Cl, in which each of RN1, RN2, RN3, and RN4 is, independently, H or optionally substituted alkyl, Ar is optionally substituted arylene, and Lk is optionally substituted alkylene, optionally substituted alkenylene, optionally substituted alkynylene, optionally substituted heteroalkylene, optionally substituted arylene, or optionally substituted (aryl)(alkyl)ene.
Copolymer can be formed. In one embodiment, a poly(imide)-poly(amide) is deposited employing a dianhydride as a first organic precursor, a diamine as a second organic precursor, and a diacyl chloride as a third organic precursor, in which non-limiting dianhydrides, diamines, and diacyl chlorides are described herein.
EUV lithography makes use of EUV resists, which may be polymer-based chemically amplified resists produced by liquid-based spin-on techniques or metal oxide-based resists produced by dry vapor-deposited techniques. Such EUV resists can include any EUV-sensitive film or material described herein. Lithographic methods can include patterning the resist, e.g., by exposure of the EUV resist with EUV radiation to form a photo pattern, followed by developing the pattern by removing a portion of the resist according to the photo pattern to form a mask.
It should also be understood that while the present disclosure relates to lithographic patterning techniques and materials exemplified by EUV lithography, it is also applicable to other next generation lithographic techniques. In addition to EUV, which includes the standard 13.5 nm EUV wavelength currently in use and development, the radiation sources most relevant to such lithography are DUV (deep-UV), which generally refers to use of 248 nm or 193 nm excimer laser sources, X-ray, which formally includes EUV at the lower energy range of the X-ray range, as well as e-beam, which can cover a wide energy range. Such methods include those where a substrate (e.g., optionally having exposed hydroxyl groups) is contacted with a metal-containing precursor (e.g., any described herein) to form a metal oxide (e.g., a layer including a network of metal oxide bonds, which may include other non-metal and non-oxygen groups) film as the imaging/PR layer on the surface of the substrate. The specific methods may depend on the particular materials and applications used in the semiconductor substrate and ultimate semiconducting device. Thus, the methods described in this application are merely exemplary of the methods and materials that may be used in present technology.
Directly photopatternable EUV resists may be composed of or contain metals and/or metal oxides mixed within organic components. The metals/metal oxides are highly promising in that they can enhance the EUV photon adsorption and generate secondary electrons and/or show increased etch selectivity to an underlying film stack and device layers. To date, these resists have been developed using a wet (solvent) approach, which requires the wafer to move to the track, where it is exposed to developing solvent, dried and baked. Wet development does not only limit productivity but can also lead to line collapse due to surface tension effects during the evaporation of solvent between fine features.
Dry development techniques have been proposed to overcome these issues by eliminating substrate delamination and interface failures. Dry development has its own challenges, including etch selectivity between unexposed and EUV exposed resist material which can lead to a higher dose to size requirement for effective resist exposure when compared to wet development. Suboptimal selectivity can also cause PR corner rounding due to longer exposures under etching gas, which may increase line CD variation in the following transfer etch step. Additional processes employed during lithography are described in detail below.
As discussed above, the present disclosure provides methods for making imaging layers on semiconductor substrates, which may be patterned using EUV or other next generation lithographic techniques. Methods include those where polymerized organometallic materials are produced in a vapor and deposited on a substrate. In some embodiments, dry deposition can employ any useful metal-containing precursor (e.g., metal halides, capping agents, or organometallic agents described herein). Deposition processes can include applying a EUV-sensitive material as a resist film. Exemplary EUV-sensitive materials are described herein.
The present technology includes methods by which EUV-sensitive films are deposited on a substrate, such films being operable as resists for subsequent EUV lithography and processing.
Such EUV-sensitive films comprise materials which, upon exposure to EUV, undergo changes, such as the loss of bulky pendant ligands bonded to metal atoms in low density M-OH rich materials, allowing their crosslinking to denser M-O-M bonded metal oxide materials. In other embodiments, EUV exposure results in further cross-linking between ligands bonded to metal atoms, thereby providing denser M-L-M bonded organometallic materials, in which L is a ligand. In yet other embodiments, EUV exposure results in loss of ligands to provide M-OH materials that can be removed by positive tone developers.
Through EUV patterning, areas of the film are created that have altered physical or chemical properties relative to unexposed areas. These properties may be exploited in subsequent processing, such as to dissolve either unexposed or exposed areas or to selectively deposit materials on either the exposed or unexposed areas. In some embodiments, the unexposed film has a hydrophobic surface, and the exposed film has a hydrophilic surface (it being recognized that the hydrophilic properties of exposed and unexposed areas are relative to one another) under the conditions at which such subsequent processing is performed. For example, the removal of material may be performed by leveraging differences in chemical composition, density, and cross-linking of the film. Removal may be by wet processing or dry processing, as further described herein.
The thickness of the EUV-patternable film formed on the surface of the substrate may vary according to the surface characteristics, materials used, and processing conditions. In various embodiments, the film thickness may range from about 0.5 nm to about 100 nm. Preferably, the film has a sufficient thickness to absorb most of the EUV light under the conditions of EUV patterning. For example, the overall absorption of the resist film may be 30% or less (e.g., 10% or less, or 5% or less), so that the resist material at the bottom of the resist film is sufficiently exposed. In some embodiments, the film thickness is from 10 nm to 20 nm. Without limiting the mechanism, function, or utility of the present disclosure, it is believed that, unlike wet, spin-coating processes, dry processes have fewer restrictions on the surface adhesion properties of the substrate, and therefore can be applied to a wide variety of substrates. Moreover, as discussed above, the deposited films may closely conform to surface features, providing advantages in forming masks over substrates, such as substrates having underlying features, without “filling in” or otherwise planarizing such features.
The film (e.g., imaging layer) may be composed of a metal oxide layer deposited in any useful manner. Such a metal oxide layer can be deposited or applied by using any EUV-sensitive material described herein, such as a metal-containing precursor (e.g., a metal halide, a capping agent, or an organometallic agent) in combination with an organic precursor. In exemplary processes, a polymerized organometallic material is formed in vapor phase or in situ on the surface of the substrate in order to provide the metal oxide layer. The metal oxide layer may be employed as a film, an adhesion layer, or a capping layer.
Optionally, the metal oxide layer can include a hydroxyl-terminated metal oxide layer, which can be deposited by employing a capping agent (e.g., any described herein) with an oxygen-containing counter-reactant. Such a hydroxyl-terminated metal oxide layer can be employed, e.g., as an adhesion layer between two other layers, such as between the substrate and the film and/or between the photoresist layer and the underlayer.
Exemplary deposition techniques (e.g., for a film) include any described herein, such as ALD (e.g., thermal ALD and plasma-enhanced ALD), spin-coat deposition, PVD including PVD co-sputtering, CVD (e.g., PE-CVD or LP-CVD), sputter deposition, e-beam deposition including e-beam co-evaporation, etc., or a combination thereof, such as ALD with a CVD component, such as a discontinuous, ALD-like process in which metal-containing precursors, organic precursors, and counter-reactants are separated in either time or space.
Further description of precursors and methods for their deposition as EUV photoresist films applicable to this disclosure may be found in International Appl. No. PCT/US19/31618, published as International Pub. No. WO 2019/217749, filed May 9, 2019, and titled METHODS FOR MAKING EUV PATTERNABLE HARD MASKS. The thin films may include optional materials in addition to a metal precursor, an organic precursor, and a counter-reactant to modify the chemical or physical properties of the film, such as to modify the sensitivity of the film to EUV or enhancing etch resistance. Such optional materials may be introduced, such as by doping during vapor phase formation prior to deposition on the substrate, after deposition of the film, or both. In some embodiments, a gentle remote H2 plasma may be introduced so as to replace some Sn-L bonds with Sn-H, for example, which can increase reactivity of the resist under EUV.
In general, methods can include mixing a vapor stream of a metal precursor (e.g., a metal-containing precursor, such as an organometallic agent) with a vapor stream of an organic precursor and an optional vapor stream of a counter-reactant so as to form a polymerized organometallic material, and depositing the organometallic material onto the surface of the semiconductor substrate In some embodiments, mixing the metal-containing precursor with the organic precursor and optional counter-reactant can form a polymerized organometallic material. As will be understood by one of ordinary skill, the mixing and depositing aspects of the process may be concurrent, in a substantially continuous process.
In an exemplary continuous CVD process, two or more gas streams, in separate inlet paths, of sources of metal precursor, organic precursor, and optional counter-reactant are introduced to the deposition chamber of a CVD apparatus, where they mix and react in the gas phase, to form agglomerated polymeric materials (e.g., via metal-oxygen-metal bond formation) or a film on the substrate. Gas streams may be introduced, for example, using separate injection inlets or a dual-plenum showerhead. The apparatus is configured so that the streams of metal precursor, organic precursor, and optional counter-reactant are mixed in the chamber, allowing the metal precursor, organic precursor, and optional counter-reactant to react to form a polymerized organometallic material or a film (e.g., a metal oxide coating or agglomerated polymeric materials, such as via metal-oxygen-metal bond formation).
For depositing metal oxide, the CVD process is generally conducted at reduced pressures, such as from 0.1 Torr to 10 Torr. In some embodiments, the process is conducted at pressures from 1 Torr to 2 Torr. The temperature of the substrate is preferably below the temperature of the reactant streams. For example, the substrate temperature may be from 0° C. to 250° C., or from ambient temperature (e.g., 23° C.) to 150° C.
For depositing agglomerated polymeric materials, the CVD process is generallyconducted at reduced pressures, such as from 10 mTorr to 10 Torr. In some embodiments, the process is conducted at from 0.5 to 2 Torr. The temperature of the substrate is preferably at or below the temperature of the reactant streams. For example, the substrate temperature may be from 0° C. to 250° C., or from ambient temperature (e.g., 23° C.) to 150° C. In various processes, deposition of the polymerized organometallic material on the substrate occurs at rates inversely proportional to surface temperature. Without limiting the mechanism, function or utility of present technology, it is believed that the product from such vapor-phase reaction becomes heavier in molecular weight as metal atoms are crosslinked by organic precursors and/or counter-reactants, and is then condensed or otherwise deposited onto the substrate. In various embodiments, the steric hindrance of the bulky alkyl groups (e.g., provided by the organic precursor) further prevents the formation of densely packed network and produces low density films having increased porosity.
A potential advantage of using dry deposition methods is ease of tuning the composition of the film as it grows. In a CVD process, this may be accomplished by changing the relative flows of the metal precursor and the organic precursor during deposition. Deposition may occur between 30° C. and 200° C. and at pressures between 0.01 Torr to 100 Torr, but more generally between about 0.1 Torr and 10 Torr.
A film (e.g., a metal oxide coating or agglomerated polymeric materials, such as via metal-oxygen-metal bond formation) may also be deposited by an ALD process. For example, the metal precursor, organic precursor, and optional counter-reactant are introduced at separate times, representing an ALD cycle. The metal precursors and organic precursors react on the surface, forming up to a monolayer of material at a time for each cycle. This may allow for excellent control over the uniformity of film thickness across the surface. The ALD process is generally conducted at reduced pressures, such as from 0.1 Torr to 10 Torr.In some embodiments, the process is conducted from 1 Torr to 2 Torr. The substrate temperature may be from 0° C. to 250° C., or from ambient temperature (e.g., 23° C.) to 150° C. The process may be a thermal process or, preferably, a plasma-assisted deposition.
Any of the deposition methods herein can be modified to allow for use of two or more different metal precursors. In one embodiment, the precursors can include the same metal but different ligands. In another embodiment, the precursors can include different metal groups. In one non-limiting instance, alternating flows of various volatile metal-containing precursors can provide a mixed metal-containing layer, such as use of a metal alkoxide precursor having a first metal (e.g., Sn) with a silyl-based precursor having a different second metal (e.g., Te).
Also, any of the deposition methods herein can be modified to allow for use of two or more different organic precursors. In one embodiment, the organic precursors can provide different bound ligands to the metal centers. In one non-limiting instance, alternating flows of various organic precursors can provide a layer with varying carbon content, such as in a gradient film.
Furthermore, any of the deposition methods herein can be modified to provide one or more layers within a film. In one instance, different metal precursors and/or organic precursors can be employed in each layer. In another instance, the same precursor may be employed for each layer, but the top-most layer can possess a different chemical composition (e.g., a different density of metal-ligand bonds, a different metal to carbon ratio, or a different bound ligand, as provided by modulating or changing the organic precursor).
Processes herein can be used to achieve a surface modification. In some iterations, a vapor of the metal precursor may be passed over the wafer. The wafer may be heated to provide thermal energy for the reaction to proceed. In some iterations, the heating can be between about 50° C. to about 250° C. In some cases, pulses of the organic precursor may be used, separated by pump and/or purging steps. For instance, an organic precursor may be pulsed between the precursor pulses resulting in ALD or ALD-like growth. In other cases, both the precursor and the organic precursor may be flowed at the same time. Examples of elements useful for surface modification include I, F, Sn, Bi, Sb, Te, and oxides or alloys of these compounds.
The processes herein can be used to deposit a thin metal oxide or metal by ALD or CVD. Examples include SnOx, BiOx, and Te. Following deposition, the film may be capped with an alkyl substituted precursor of the form MaRbLc, as described elsewhere herein. A counter-reactant may be used to better remove the ligands, and multiple cycles may be repeated to ensure complete saturation of the substrate surface. The surface can then ready for the EUV-sensitive film to be deposited. One possible method is to produce a thin film of SnOx. Possible chemistries include growth of SnO2 by cycling tetrakis(dimethylamino)tin and a counter-reactant such as water or O2 plasma. After the growth, a capping agent could be used. For example, isopropyltris(dimethylamino)tin vapor may be flown over the surface.
Deposition processes can be employed on any useful surface. As referred to herein, the “surface” is a surface onto which a film of the present technology is to be deposited or that is to be exposed to EUV during processing. Such a surface can be present on a substrate (e.g., upon which a film is to be deposited), on a film (e.g., upon which a capping layer can be deposited), or on an underlayer.
Any useful substrate can be employed, including any material construct suitable for lithographic processing, particularly for the production of integrated circuits and other semiconducting devices. In some embodiments, substrates are silicon wafers. Substrates may be silicon wafers upon which features have been created (“underlying topographical features”), having an irregular surface topography.
Such underlying topographical features may include regions in which material has been removed (e.g., by etching) or regions in which materials have been added (e.g., by deposition) during processing prior to conducting a method of this technology. Such prior processing may include methods of this technology or other processing methods in an iterative process by which two or more layers of features are formed on the substrate. Without limiting the mechanism, function, or utility of the present technology, it is believed that, in some embodiments, methods of the present technology offer advantages relative to methods among those in which photolithographic films are deposited on the surface of substrates using spin casting methods. Such advantages may derive from the conformance of the films of the present technology to underlying features without “filling in” or otherwise planarizing such features, and the ability to deposit films on a wide variety of material surfaces.
In some embodiments, an incoming wafer can be prepared with a substrate surface of a desired material, with the uppermost material being the layer into which the resist pattern is transferred. While the material selection may vary depending on integration, it is generally desired to select a material that can be etched with high selectivity to (i.e., much faster than) the EUV resist or imaging layer. Suitable substrate materials can include various carbon-based films (e.g., ashable hard mask (AHM)), silicon-based films (e.g., silicon, silicon oxide, silicon nitride, silicon oxynitride, or silicon oxycarbonitride, as well as doped forms thereof, including SiOx, SiOxNy, SiOxCyNz, a-Si:H, poly-Si, or SiN), or any other (generally sacrificial) film applied to facilitate the patterning process.
In some embodiments, the substrate is a hard mask, which is used in lithographic etching of an underlying semiconductor material. The hard mask may comprise any of a variety of materials, including amorphous carbon (a-C), SnOx, SiO2, SiOxNy, SiOxC, Si3N4, TiO2, TiN, W, W-doped C, WOx, HfO2, ZrO2, and Al2O3. For example, the substrate may preferably comprise SnOx, such as SnO2. In various embodiments, the layer may be from 1 nm to 100 nm thick, or from 2 nm to 10 nm thick.
In some non-limiting embodiments, a substrate comprises an underlayer. An underlayer may be deposited on a hard mask or other layer and is generally underneath an imaging layer (or film), as described herein. An underlayer may be used to improve the sensitivity of a PR, increase EUV absorptivity, and/or increase the patterning performance of the PR. In cases where there are device features present on the substrate to be patterned which create significant topography, another important function of the underlayer can be to overcoat and planarize the existing topography so that the subsequent patterning step may be performed on a flat surface with all areas of the pattern in focus. For such applications, the underlayer (or at least one of multiple underlayers) may be applied using spin-coating techniques. When the PR material being employed possesses a significant inorganic component, for example it exhibits a predominately metal oxide framework, the underlayer may advantageously be a carbon-based film, applied either by spin-coating or by dry vacuum-based deposition processes. The layer may include various ashable hard mask (AHM) films with carbon- and hydrogen-based compositions and may be doped with additional elements, such as tungsten, boron, nitrogen, or fluorine.
In some embodiments, a surface activation operation may be used to activate the surface (e.g., of the substrate and/or a film) for future operations. For example, for a SiOx surface, a water or oxygen/hydrogen plasma may be used to create hydroxyl groups on the surface. For a carbon- or hydrocarbon-based surface, various treatment (e.g., a water, hydrogen/oxygen, CO2 plasma, or ozone treatment) may be used to create carboxylic acids/or hydroxyl groups. Such approaches can prove critical for improving the adhesion of resist features to the substrate, which might otherwise delaminate or lift off during handling or within the solvent during development.
Adhesion may also be enhanced by inducing roughness in the surface to increase the surface area available for interaction, as well as directly improve mechanical adhesion. For example, first a sputtering process using Ar or other non-reactive ion bombardment can be used to produce rough surfaces. Then, the surface can be terminated with a desired surface functionality as described above (e.g., hydroxyl and/or carboxylic acid groups). On carbon, a combination approach can be employed, in which a chemically reactive oxygen-containing plasma such as CO2, O2, or H2O (or mixtures of H2 and O2) can be used to etch away a thin layer of film with local non-uniformity and simultaneously terminate with —OH, —OOH, or —COOH groups. This may be done with or without bias. In conjunction with the surface modification strategies mentioned above, this approach could serve the dual purpose of surface roughening and chemical activation of the substrate surface, either for direct adhesion to an inorganic metal-oxide based resist or as an intermediate surface modification for further functionalization.
In various embodiments, the surface (e.g., of the substrate and/or the film) comprises exposed hydroxyl groups on its surface. In general, the surface may be any surface that comprises, or has been treated to produce, an exposed hydroxyl surface. Such hydroxyl groups may be formed on the surface by surface treatment of a substrate using oxygen plasma, water plasma, or ozone. In other embodiments, the surface of the film can be treated to provide exposed hydroxyl groups, upon which a capping layer can be applied. In various embodiments, the hydroxyl-terminated metal oxide layer has a thickness of from 0.1 nm to 20 nm, or from 0.2 nm to 10 nm, or from 0.5 nm to 5 nm.
EUV exposure of the film can provide EUV exposed areas having activated reactive centers including a metal atom (M), which are produced by EUV-mediated cleavage events. Such reactive centers can include dangling metal bonds, M-H groups, cleaved M-ligand groups, dimerized M-M bonds, or M-O-M bridges. In other embodiments, EUV exposure provides cross-linked organic moieties by photopolymerizing ligands within the film; or EUV exposures releases gaseous by-products resulting from photolysis of bonds within a ligand.
A vacuum-integrated metal hardmask process and related vacuum-integrated hardware that combines film formation (deposition/condensation) and optical lithography with the result of greatly improved EUV lithography (EUVL) performance - e.g. reduced line edge roughness - is disclosed herein. With wet methods that operate in air, the wafer may need to be transported into and out of a vacuum chamber, which can potentially introduce particles, contamination, undesirable air or moisture exposure for some resist formula. Thus, in some embodiments, such unwanted effects can be avoided by integrating the deposition tool and the lithography tool.
For any exposure process herein, EUV may be employed. EUV exposure can have a wavelength in the range of about 10 nm to about 20 nm in a vacuum ambient, such as a wavelength of from 10 nm to 15 nm, e.g., 13.5 nm. In particular, patterning can provide EUV exposed areas and EUV unexposed areas to form a pattern.
The present technology can include patterning using EUV, as well as DUV or e-beam. In such patterning, the radiation is focused on one or more regions of the imaging layer. The exposure is typically performed such that imaging layer film comprises one or more regions that are not exposed to the radiation. The resulting imaging layer may comprise a plurality of exposed and unexposed regions, creating a pattern consistent with the creation of transistor or other features of a semiconductor device, formed by addition or removal of material from the substrate in subsequent processing of the substrate. EUV, DUV, and e-beam radiation methods and equipment among useful herein include known methods and equipment.
In various embodiments described herein, a deposition (e.g., condensation) process (e.g., ALD or MOCVD carried out in a PECVD tool, such as the Lam Vector®) can be used to form a thin film of a metal-containing film, such a photosensitive metal salt or metal-containing organic compound (organometallic compound), with a strong absorption in the EUV (e.g., at wavelengths on the order of 10 nm to 20 nm), for example at the wavelength of the EUVL light source (e.g., 13.5 nm = 91.8 eV). This film photo-decomposes upon EUV exposure and forms a metal mask that is the pattern transfer layer during subsequent etching (e.g., in a conductor etch tool, such as the Lam 2300® Kiyo®).
Following deposition, the EUV-patternable thin film is patterned by exposure to a beam of EUV light, typically under relatively high vacuum. For EUV exposure, the metal-containing film can then be deposited in a chamber integrated with a lithography platform (e.g., a wafer stepper such as the TWINSCAN NXE: 3300B® platform supplied by ASML of Veldhoven, NL) and transferred under vacuum so as not to react before exposure. Integration with the lithography tool is facilitated by the fact that EUVL also requires a greatly reduced pressure given the strong optical absorption of the incident photons by ambient gases such as H2O, O2, etc. In other embodiments, the photosensitive metal film deposition and EUV exposure may be conducted in the same chamber.
EUV exposed or unexposed areas can be removed by any useful development process. In one embodiment, the EUV exposed area can have activated reactive centers, such as dangling metal bonds, M-H groups, or dimerized M-M bonds. In particular embodiments, M-H groups can be selectively removed by employing one or more dry development processes (e.g., halide chemistry). In other embodiments, M-M bonds can be selectively removed by employing a wet development process, e.g., use of hot ethanol and water to provide soluble M(OH)n groups. In yet other embodiments, EUV exposed areas are removed by use of wet development (e.g., by using a positive tone developer). In some embodiments, EUV unexposed areas are removed by use of dry development.
Dry development processes can include use of halides, such as HCl— or HBr-based processes. While this disclosure is not limited to any particular theory or mechanism of operation, the approach is understood to leverage the chemical reactivity of the dry-deposited EUV photoresist films with the clean chemistry (e.g., HCl, HBr, and BCl3) to form volatile products using vapors or plasma. The dry-deposited EUV photoresist films can be removed with etch rates of up to 1 nm/s. The quick removal of dry-deposited EUV photoresist films by these chemistries is applicable to chamber cleaning, backside clean, bevel clean, and PR developing. Although the films can be removed using vapors at various temperatures (e.g., HCl or HBr at a temperature greater than -10° C., or BCl3 at a temperature greater than 80° C., for example), a plasma can also be used to further accelerate or enhance the reactivity.
Plasma processes include transformer coupled plasma (TCP), inductively coupled plasma (ICP) or capacitively coupled plasma (CCP), employing known equipment and techniques. For example, a process may be conducted at a pressure of > 0.5 mTorr (e.g., such as from 1 mTorr to 100 mTorr), at a power level of < 1000 W (e.g., < 500 W). Temperatures may be from 30° C. to 300° C. (e.g., 30° C. to 120° C.), at flow rate of 100 to 1000 standard cubic centimeters per minute (sccm), e.g., about 500 sccm, for from 1 to 3000 seconds (e.g., 10 seconds to 600 seconds).
Where the halide reactant flows are of hydrogen gas and halide gas, a remote plasma/UV radiation is used to generate radicals from the H2 and Cl2 and/or Br2, and the hydrogen and halide radicals are flowed to the reaction chamber to contact the patterned EUV photoresist on the substrate layer of the wafer. Suitable plasma power may range from 100 W to 500 W, with no bias. It should be understood that while these conditions are suitable for some processing reactors, e.g., a Kiyo etch tool available from Lam Research Corporation, Fremont, CA, a wider range of process conditions may be used according to the capabilities of the processing reactor.
In thermal development processes, the substrate is exposed to dry development chemistry (e.g., a Lewis Acid) in a vacuum chamber (e.g., oven). Suitable chambers can include a vacuum line, a dry development hydrogen halide chemistry gas (e.g., HBr, HCl) line, and heaters for temperature control. In some embodiments, the chamber interior can be coated with corrosion resistant films, such as organic polymers or inorganic coatings. One such coating is polytetrafluoroethylene ((PTFE), e.g., Teflon™). Such materials can be used in thermal processes of this disclosure without risk of removal by plasma exposure.
The process conditions for the dry development may be reactant flow of 100 sccm to 500 sccm (e.g., 500 sccm HBr or HCl), temperature of -10° C. to 120° C. (e.g., -10° C.), pressure of 1 mTorr to 500 mTorr (e.g., 300 mTorr) with no plasma and for a time of about 10 sec to 1 min, dependent on the photoresist film and their composition and properties.
In various embodiments, methods of the present disclosure combine all dry steps of film deposition, formation by vapor deposition, (EUV) lithographic photopatterning, and dry development. In such processes, a substrate may directly go to a dry development/etch chamber following photopatterning in an EUV scanner. Such processes may avoid material and productivity costs associated with a wet development. A dry process can also provide more tunability and give further CD control and/or scum removal.
In various embodiments, the EUV photoresist, containing some amount of metal, metal oxide and organic components, can be dry developed by a thermal, plasma (e.g., including possibly photoactivated plasma, such as lamp-heated or UV lamp heated), or a mixture of thermal and plasma methods while flowing a dry development gas including a compound of formula RxZy, where R = B, Al, Si, C, S, SO with x > 0 and Z = Cl, H, Br, F, CH4 and y > 0. The dry development can result in a positive tone, in which the RxZy species selectively removes the exposed material, leaving behind the unexposed counterpart as a mask. In some embodiments, the exposed portions of organotin oxide-based photoresist films are removed by dry development in accordance with this disclosure. Positive tone dry development may be achieved by the selective dry development (removal) of EUV exposed regions exposed to flows comprising hydrogen halides or hydrogen and halides, including HCl and/or HBr without striking a plasma, or flows of H2 and Cl2 and/or Br2 with a remote plasma or UV radiation generated from plasma to generate radicals.
Wet development methods can also be employed. In particular embodiments, such wet developments methods are used to remove EUV exposed regions to provide a positive tone photoresist or a negative tone resist. Exemplary, non-limiting wet development can include use of an alkaline developer (e.g., an aqueous alkaline developer), such as those including ammonium, e.g., ammonium hydroxide (NH4OH); ammonium-based ionic liquids, e.g., tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide (TEAH), tetrapropylammonium hydroxide (TPAH), tetrabutylammonium hydroxide (TBAH), or other quaternary alkylammonium hydroxides; an organoamine, such as mono-, di-, and tri-organoamines (e.g., dimethylamine, diethylamine, ethylenediamine, triethylenetetramine); or an alkanolamine, such as monoethanolamine, diethanolamine, triethanolamine, or diethyleneglycolamine. In other embodiments, the alkaline developer can include nitrogen-containing bases, e.g., compounds having the formula RN1NH2, RN1RN2NH, RN1RN2RN3N, or RN1RN2RN3RN4N+XN1-, where each of RN1, RN2, RN3, and RN4 is, independently, an organo substituent (e.g., optionally substituted alkyl or any described herein), or two or more organo substituents that can be joined together, and XN1- may comprise OH-, F-, Cl-, Br-, I-, or other art-known quaternary ammonium cationic species. These bases may also comprise heterocyclyl nitrogen compounds, some of which are described herein.
Other development methodologies can include use of an acidic developer (e.g., an aqueous acidic developer or an acid developer in an organic solvent) that includes a halide (e.g., HCl or HBr), an organic acid (e.g., formic acid, acetic acid, or citric acid), or an organofluorine compound (e.g., trifluoroacetic acid); or use of an organic developer, such as a ketone (e.g., 2-heptanone, cyclohexanone, or acetone), an ester (e.g., γ-butyrolactone or ethyl 3-ethoxypropionate (EEP)), an alcohol (e.g., isopropyl alcohol (IPA)), or an ether, such as a glycol ether (e.g., propylene glycol methyl ether (PGME) or propylene glycol methyl ether acetate (PGMEA)), as well as combinations thereof.
In particular embodiments, the positive tone developer is an aqueous alkaline developer (e.g., including NH4OH, TMAH, TEAH, TPAH, or TBAN). In other embodiments, the negative tone developer is an aqueous acidic developer, an acidic developer in an organic solvent, or an organic developer (e.g., HCl, HBr, formic acid, trifluoroacetic acid, 2-heptanone, IPA, PGME, PGMEA, or combinations thereof).
The methods herein can include any useful post-application processes, as described below.
For the backside and bevel clean process, the vapor and/or the plasma can be limited to a specific region of the wafer to ensure that only the backside and the bevel are removed, without any film degradation on the frontside of the wafer. The dry-deposited EUV photoresist films being removed are generally composed of Sn, O and C, but the same clean approaches can be extended to films of other metal oxide resists and materials. In addition, this approach can also be used for film strip and PR rework.
Suitable process conditions for a dry bevel edge and backside clean may be a reactant flow of 100 sccm to 500 sccm (e.g., 500 sccm HCl, HBr, or H2 and Cl2 or Br2, BCl3 or H2), temperature of -10° C. to 120° C. (e.g., 20° C.), pressure of 20 mTorr to 500 mTorr (e.g., 300 mTorr), plasma power of 0 to 500 W at high frequency (e.g., 13.56 MHz), and for a time of about 10 sec to 20 sec, dependent on the photoresist film and composition and properties. It should be understood that while these conditions are suitable for some processing reactors, e.g., a Kiyo etch tool available from Lam Research Corporation, Fremont, CA, a wider range of process conditions may be used according to the capabilities of the processing reactor.
Photolithography processes typically involve one or more bake steps, to facilitate the chemical reactions required to produce chemical contrast between exposed and unexposed areas of the photoresist. For high volume manufacturing (HVM), such bake steps are typically performed on tracks where the wafers are baked on a hot-plate at a pre-set temperature under ambient air or in some cases N2 flow. More careful control of the bake ambient as well as introduction of additional reactive gas component in the ambient during these bake steps can help further reduce the dose requirement and/or improve pattern fidelity.
According to various aspects of this disclosure, one or more post treatments to metal and/or metal oxide-based photoresists after deposition (e.g., post-application bake (PAB)) and/or exposure (e.g., post-exposure bake (PEB)) and/or development (e.g., post-development bake (PDB)) are capable of increasing material property differences between exposed and unexposed photoresist and therefore decreasing dose to size (DtS), improving PR profile, and improving line edge and width roughness (LER/LWR) after subsequent dry development. Such processing can involve a thermal process with the control of temperature, gas ambient, and moisture, resulting in improved dry development performance in processing to follow. In some instances, a remote plasma might be used.
In the case of post-application processing (e.g., PAB), a thermal process with control of temperature, gas ambient (e.g., air, H2O, CO2, CO, O2, O3, CH4, CH3OH, N2, H2, NH3, N2O, NO, Ar, He, or their mixtures) or under vacuum, and moisture can be used after deposition and before exposure to change the composition of unexposed metal and/or metal oxide photoresist. The change can increase the EUV sensitivity of the material and thus lower dose to size and edge roughness can be achieved after exposure and dry development.
In the case of post-exposure processing (e.g., PEB), a thermal process with the control of temperature, gas atmosphere (e.g., air, H2O, CO2, CO, O2, O3, CH4, CH3OH, N2, H2, NH3, N2O, NO, Ar, He, or their mixtures) or under vacuum, and moisture can be used to change the composition of both unexposed and exposed photoresist. The change can increase the composition/material properties difference between the unexposed and exposed photoresist and the etch rate difference of dry development etch gas between the unexposed and exposed photoresist. A higher etch selectivity can thereby be achieved Due to the improved selectivity, a squarer PR profile can be obtained with improved surface roughness, and/or less photoresist residual/scum. In particular embodiments, PEB can be performed in air and in the optional presence of moisture and CO2.
In the case of post-development processing (e.g., post development bake or PDB), a thermal process with the control of temperature, gas atmosphere (e.g., air, H2O, CO2, CO, O2, O3, CH4, CH3OH, N2, H2, NH3, N2O, NO, Ar, He, or their mixtures) or under vacuum (e.g., with UV), and moisture can be used to change the composition of the unexposed photoresist. In particular embodiments, the condition also includes use of plasma (e.g., including O2, O3, Ar, He, or their mixtures). The change can increase the hardness of material, which can be beneficial if the film will be used as a resist mask when etching the underlying substrate.
In these cases, in alternative implementations, the thermal process could be replaced by a remote plasma process to increase reactive species to lower the energy barrier for the reaction and increase productivity. Remote plasma can generate more reactive radicals and therefore lower the reaction temperature/time for the treatment, leading to increased productivity.
Accordingly, one or multiple processes may be applied to modify the photoresist itself to increase dry development selectivity. This thermal or radical modification can increase the contrast between unexposed and exposed material and thus increase the selectivity of the subsequent dry development step. The resulting difference between the material properties of unexposed and exposed material can be tuned by adjusting process conditions including temperature, gas flow, moisture, pressure, and/or RF power. The large process latitude enabled by dry development, which is not limited by material solubility in a wet developer solvent, allows more aggressive conditions to be applied further enhancing the material contrast that can be achieved. The resulting high material contrast feeds back a wider process window for dry development and thus enables increased productivity, lower cost, and better defectivity performance.
A substantial limitation of wet-developed resist films is limited temperature bakes. Since wet development relies on material solubility, heating to or beyond 220° C., for example, can greatly increase the degree of cross-linking in both exposed and unexposed regions of a metal-containing PR film such that both become insoluble in the wet development solvents, so that the film can no longer by reliably wet developed. For instance, for wet spin-on or wet-developed metal-containing PR films, baking such as PAB or PEB may be performed, for example at temperatures below 180° C. or below 200° C. or below 250° C. For resist films, in which the etch rate difference (i.e., selectivity) between the exposed and unexposed regions of the PR is relied upon for removal of just the exposed or unexposed portion of the resist, the treatment temperature in a PAB, PEB, or PDB can be varied across a much broader window to tune and optimize the treatment process, for example from about 90° C. to 250° C., such as 90° C. to 190° C., 90° C. to 600° C., 100° C. to 400° C., 125° C. to 300° C., and about 170° C. to 250° C. or more, such as 190° C. to 240° C. (e.g., for PAB, PEB, and/or PDB). Decreasing etch rate and greater etch selectivity has been found to occur with higher treatment temperatures in the noted ranges.
In particular embodiments, the PAB, PEB, and/or PDB treatments may be conducted with gas ambient flow in the range of 100 sccm to 10000 sccm, moisture content in the amount of a few percent up to 100% (e.g., 20%-50%), at a pressure between atmospheric and vacuum, and for a duration of about 1 to 15 minutes, for example about 2 minutes.
These findings can be used to tune the treatment conditions to tailor or optimize processing for particular materials and circumstances. For example, the selectivity achieved for a given EUV dose with a 220° C. to 250° C. PEB thermal treatment in air at about 20% humidity for about 2 minutes can be made similar to that for about a 30% higher EUV dose with no such thermal treatment. So, depending on the selectivity requirements/constraints of the semiconductor processing operation, a thermal treatment such as described herein can be used to lower the EUV dose needed. Or, if higher selectivity is required and higher dose can be tolerated, much higher selectivity, up to 100 times exposed vs. unexposed, can be obtained than would be possible in a wet development context.
Yet other steps can include in situ metrology, in which physical and structural characteristics (e.g., critical dimension, film thickness, etc.) can be assessed during the photolithography process. Modules to implement in situ metrology include, e.g., scatterometry, ellipsometry, downstream mass spectroscopy, and/or plasma enhanced downstream optical emission spectroscopy modules.
The present disclosure also includes any apparatus configured to perform any methods described herein. In one embodiment, the apparatus for depositing a film includes a deposition module comprising a chamber for depositing an EUV-sensitive material as a film by providing a metal precursor in the presence of an organic precursor; a patterning module comprising an EUV photolithography tool with a source of sub-30 nm wavelength radiation; and a development module comprising a chamber for developing the film.
The apparatus can further include a controller having instructions for such modules. In one embodiment, the controller includes one or more memory devices, one or more processors, and system control software coded with instructions for conducting deposition of the film. Such includes can include for, in the deposition module, depositing a modified precursor as a film on a top surface of a substrate or a photoresist layer; in the patterning module, patterning the film with sub-30 nm resolution directly by EUV exposure, thereby forming a pattern within the film; and in the development module, developing the film. In particular embodiments, the development module provides for removal of the EUV exposed or EUV unexposed areas, thereby providing a pattern within the film.
A process station may be configured as a module in a cluster tool.
In some embodiments, certain of the processing functions can be performed consecutively in the same module, for example dry development and etch. And embodiments of this disclosure are directed to methods and apparatus for receiving a wafer, including a photopatterned EUV resist thin film layer disposed on a layer or layer stack to be etched, to a dry development/etch chamber following photopatterning in an EUV scanner; dry developing photopatterned EUV resist thin film layer; and then etching the underlying layer using the patterned EUV resist as a mask, as described herein.
Returning to
Showerhead 406 distributes process gases toward substrate 412. In the embodiment shown in
In some embodiments, pedestal 408 may be raised or lowered to expose substrate 412 to a volume between the substrate 412 and the showerhead 406. It will be appreciated that, in some embodiments, pedestal height may be adjusted programmatically by a suitable computer controller 450.
In some embodiments, pedestal 408 may be temperature controlled via heater 410. In some embodiments, the pedestal 408 may be heated to a temperature of greater than 0° C. and up to 300° C. or more, for example 50° C. to 120° C., such as about 65° C. to 80° C., during non-plasma thermal exposure of a photopatterned resist to dry development chemistry, such as HBr, HCl, or BCl3, as described in disclosed embodiments.
Further, in some embodiments, pressure control for process station 400 may be provided by a butterfly valve 418. As shown in the embodiment of
In some embodiments, a position of showerhead 406 may be adjusted relative to pedestal 408 to vary a volume between the substrate 412 and the showerhead 406. Further, it will be appreciated that a vertical position of pedestal 408 and/or showerhead 406 may be varied by any suitable mechanism within the scope of the present disclosure. In some embodiments, pedestal 408 may include a rotational axis for rotating an orientation of substrate 412. It will be appreciated that, in some embodiments, one or more of these example adjustments may be performed programmatically by one or more suitable computer controllers 450.
Where plasma may be used, for example in gentle plasma-based dry development embodiments and /or etch operations conducted in the same chamber, showerhead 406 and pedestal 408 electrically communicate with a radio frequency (RF) power supply 414 and matching network 416 for powering a plasma 407. In some embodiments, the plasma energy may be controlled by controlling one or more of a process station pressure, a gas concentration, an RF source power, an RF source frequency, and a plasma power pulse timing. For example, RF power supply 414 and matching network 416 may be operated at any suitable power to form a plasma having a desired composition of radical species. Examples of suitable powers are up to about 500 W.
In some embodiments, instructions for a controller 450 may be provided via input/output control (IOC) sequencing instructions. In one example, the instructions for setting conditions for a process phase may be included in a corresponding recipe phase of a process recipe. In some cases, process recipe phases may be sequentially arranged, so that all instructions for a process phase are executed concurrently with that process phase. In some embodiments, instructions for setting one or more reactor parameters may be included in a recipe phase. For example, a recipe phase may include instructions for setting a flow rate of a dry development chemistry reactant gas, such as HBr or HCl, and time delay instructions for the recipe phase. In some embodiments, the controller 450 may include any of the features described below with respect to system controller 550 of
As described above, one or more process stations may be included in a multi station processing tool.
The depicted processing chamber 514 includes four process stations, numbered from 1 to 4 in the embodiment shown in
In some embodiments, system controller 550 controls all of the activities of process tool 500. System controller 550 executes system control software 558 stored in mass storage device 554, loaded into memory device 556, and executed on processor 552. Alternatively, the control logic may be hard coded in the controller 550. Applications Specific Integrated Circuits, Programmable Logic Devices (e.g., field-programmable gate arrays, or FPGAs) and the like may be used for these purposes. In the following discussion, wherever “software” or “code” is used, functionally comparable hard coded logic may be used in its place. System control software 558 may include instructions for controlling the timing, mixture of gases, gas flow rates, chamber and/or station pressure, chamber and/or station temperature, wafer temperature, target power levels, RF power levels, substrate pedestal, chuck and/or susceptor position, and other parameters of a particular process performed by process tool 500. System control software 558 may be configured in any suitable way. For example, various process tool component subroutines or control objects may be written to control operation of the process tool components used to carry out various process tool processes. System control software 558 may be coded in any suitable computer readable programming language.
In some embodiments, system control software 558 may include input/output control (lOC) sequencing instructions for controlling the various parameters described above. Other computer software and/or programs stored on mass storage device 554 and/or memory device 556 associated with system controller 550 may be employed in some embodiments. Examples of programs or sections of programs for this purpose include a substrate positioning program, a process gas control program, a pressure control program, a heater control program, and a plasma control program.
A substrate positioning program may include program code for process tool components that are used to load the substrate onto pedestal 518 and to control the spacing between the substrate and other parts of process tool 500.
A process gas control program may include code for controlling various gas compositions (e.g., HBr or HCl gas as described herein) and flow rates and optionally for flowing gas into one or more process stations prior to deposition in order to stabilize the pressure in the process station. A pressure control program may include code for controlling the pressure in the process station by regulating, for example, a throttle valve in the exhaust system of the process station, a gas flow into the process station, etc.
A heater control program may include code for controlling the current to a heating unit that is used to heat the substrate. Alternatively, the heater control program may control delivery of a heat transfer gas (such as helium) to the substrate.
A plasma control program may include code for setting RF power levels applied to the process electrodes in one or more process stations in accordance with the embodiments herein.
A pressure control program may include code for maintaining the pressure in the reaction chamber in accordance with the embodiments herein.
In some embodiments, there may be a user interface associated with system controller 550. The user interface may include a display screen, graphical software displays of the apparatus and/or process conditions, and user input devices such as pointing devices, keyboards, touch screens, microphones, etc.
In some embodiments, parameters adjusted by system controller 550 may relate to process conditions. Non-limiting examples include process gas composition and flow rates, temperature, pressure, plasma conditions (such as RF bias power levels), etc. These parameters may be provided to the user in the form of a recipe, which may be entered utilizing the user interface.
Signals for monitoring the process may be provided by analog and/or digital input connections of system controller 550 from various process tool sensors. The signals for controlling the process may be output on the analog and digital output connections of process tool 500. Non-limiting examples of process tool sensors that may be monitored include mass flow controllers, pressure sensors (such as manometers), thermocouples, etc. Appropriately programmed feedback and control algorithms may be used with data from these sensors to maintain process conditions.
System controller 550 may provide program instructions for implementing the above-described deposition processes. The program instructions may control a variety of process parameters, such as DC power level, RF bias power level, pressure, temperature, etc. The instructions may control the parameters to operate dry development and/or etch processes according to various embodiments described herein.
The system controller 550 will typically include one or more memory devices and one or more processors configured to execute the instructions so that the apparatus will perform a method in accordance with disclosed embodiments. Machine-readable media containing instructions for controlling process operations in accordance with disclosed embodiments may be coupled to the system controller 550.
In some implementations, the system controller 550 is part of a system, which may be part of the above-described examples. Such systems can include semiconductor processing equipment, including a processing tool or tools, chamber or chambers, a platform or platforms for processing, and/or specific processing components (a wafer pedestal, a gas flow system, etc.). These systems may be integrated with electronics for controlling their operation before, during, and after processing of a semiconductor wafer or substrate. The electronics may be referred to as the “controller,” which may control various components or subparts of the system or systems. The system controller 550, depending on the processing conditions and/or the type of system, may be programmed to control any of the processes disclosed herein, including the delivery of processing gases, temperature settings (e.g., heating and/or cooling), pressure settings, vacuum settings, power settings, radio frequency (RF) generator settings, RF matching circuit settings, frequency settings, flow rate settings, fluid delivery settings, positional and operation settings, wafer transfers into and out of a tool and other transfer tools and/or load locks connected to or interfaced with a specific system.
Broadly speaking, the system controller 550 may be defined as electronics having various integrated circuits, logic, memory, and/or software that receive instructions, issue instructions, control operation, enable cleaning operations, enable endpoint measurements, and the like. The integrated circuits may include chips in the form of firmware that store program instructions, digital signal processors (DSPs), chips defined as application specific integrated circuits (ASICs), and/or one or more microprocessors, or microcontrollers that execute program instructions (e.g., software). Program instructions may be instructions communicated to the system controller 550 in the form of various individual settings (or program files), defining operational parameters for carrying out a particular process on or for a semiconductor wafer or to a system. The operational parameters may, in some embodiments, be part of a recipe defined by process engineers to accomplish one or more processing steps during the fabrication of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and/or dies of a wafer.
The system controller 550, in some implementations, may be a part of or coupled to a computer that is integrated with, coupled to the system, otherwise networked to the system, or a combination thereof. For example, the system controller 550 may be in the “cloud” or all or a part of a fab host computer system, which can allow for remote access of the wafer processing. The computer may enable remote access to the system to monitor current progress of fabrication operations, examine a history of past fabrication operations, examine trends or performance metrics from a plurality of fabrication operations, to change parameters of current processing, to set processing steps to follow a current processing, or to start a new process. In some examples, a remote computer (e.g. a server) can provide process recipes to a system over a network, which may include a local network or the Internet. The remote computer may include a user interface that enables entry or programming of parameters and/or settings, which are then communicated to the system from the remote computer. In some examples, the system controller 550 receives instructions in the form of data, which specify parameters for each of the processing steps to be performed during one or more operations. It should be understood that the parameters may be specific to the type of process to be performed and the type of tool that the system controller 550 is configured to interface with or control. Thus, as described above, the system controller 550 may be distributed, such as by including one or more discrete controllers that are networked together and working towards a common purpose, such as the processes and controls described herein. An example of a distributed controller for such purposes would be one or more integrated circuits on a chamber in communication with one or more integrated circuits located remotely (such as at the platform level or as part of a remote computer) that combine to control a process on the chamber.
Without limitation, example systems may include a plasma etch chamber or module, a deposition chamber or module, a spin-rinse chamber or module, a metal plating chamber or module, a clean chamber or module, a bevel edge etch chamber or module, a physical vapor deposition (PVD) chamber or module, a chemical vapor deposition (CVD) chamber or module, an ALD chamber or module, an atomic layer etch (ALE) chamber or module, an ion implantation chamber or module, a track chamber or module, an EUV lithography chamber (scanner) or module, a dry development chamber or module, and any other semiconductor processing systems that may be associated or used in the fabrication and/or manufacturing of semiconductor wafers.
As noted above, depending on the process step or steps to be performed by the tool, the system controller 550 might communicate with one or more of other tool circuits or modules, other tool components, cluster tools, other tool interfaces, adjacent tools, neighboring tools, tools located throughout a factory, a main computer, another controller, or tools used in material transport that bring containers of wafers to and from tool locations and/or load ports in a semiconductor manufacturing factory.
Inductively coupled plasma (ICP) reactors which, in certain embodiments, may be suitable for etch operations suitable for implementation of some embodiments, are now described. Although ICP reactors are described herein, in some embodiments, it should be understood that capacitively coupled plasma reactors may also be used.
In addition, As described above, one or more process stations may be included in a multi-station processing tool.
The depicted processing chamber 814 comprises four process stations, numbered from 1 to 4 in the embodiment shown in
In some embodiments, the system controller controls the activities of process tool 800. The system controller can execute system control software 858 stored in mass storage device 854, loaded into memory device 856, and executed on processor 852. Alternatively, the control logic may be hard coded in the system controller. Applications Specific Integrated Circuits, Programmable Logic Devices (e.g., field-programmable gate arrays, or FPGAs) and the like may be used for these purposes. In the following discussion, wherever “software” or “code” is used, functionally comparable hard coded logic may be used in its place. The system control software may include instructions for controlling the timing, mixture of gases, amount of gas flow, chamber and/or station pressure, chamber and/or station temperature, substrate temperature, target power levels, RF power levels, substrate pedestal, chuck and/or susceptor position, and other parameters of a particular process performed by process tool 800. System control software 858 may be configured in any suitable way. For example, various process tool component subroutines or control objects may be written to control operation of the process tool components used to carry out various process tool processes. System control software 858 may be coded in any suitable computer readable programming language. Any of the components (e.g., for the system controller or other components) described herein for process tool 800 and process tool 500 may be employed interchangeably.
The inductively coupled plasma apparatus 600 includes an overall process chamber structurally defined by chamber walls 601 and a window 611. The chamber walls 601 may be fabricated from stainless steel or aluminum. The window 611 may be fabricated from quartz or other dielectric material. An optional internal plasma grid 650 divides the overall process chamber into an upper sub-chamber 602 and a lower sub-chamber 603. In most embodiments, plasma grid 650 may be removed, thereby utilizing a chamber space made of sub-chambers 602 and 603. A chuck 617 is positioned within the lower sub-chamber 603 near the bottom inner surface. The chuck 617 is configured to receive and hold a semiconductor wafer 619 upon which the etching and deposition processes are performed. The chuck 617 can be an electrostatic chuck for supporting the wafer 619 when present. In some embodiments, an edge ring (not shown) surrounds the chuck 617 and has an upper surface that is approximately planar with a top surface of the wafer 619, when present over the chuck 617. The chuck 617 also includes electrostatic electrodes for chucking and dechucking the wafer 619. A filter and DC clamp power supply (not shown) may be provided for this purpose.
Other control systems for lifting the wafer 619 off the chuck 617 can also be provided. The chuck 617 can be electrically charged using an RF power supply 623. The RF power supply 623 is connected to matching circuitry 621 through a connection 627. The matching circuitry 621 is connected to the chuck 617 through a connection 625. In this manner, the RF power supply 623 is connected to the chuck 617. In various embodiments, a bias power of the electrostatic chuck may be set at about 50 V or may be set at a different bias power depending on the process performed in accordance with disclosed embodiments. For example, the bias power may be between about 20 V and about 100 V, or between about 30 V and about 150 V.
Elements for plasma generation include a coil 633 positioned above window 611. In some embodiments, a coil is not used in disclosed embodiments. The coil 633 is fabricated from an electrically conductive material and includes at least one complete turn. The example of a coil 633 shown in
Process gases may be flowed into the process chamber through one or more main gas flow inlets 660 positioned in the upper sub-chamber 602 and/or through one or more side gas flow inlets 670. Likewise, though not explicitly shown, similar gas flow inlets may be used to supply process gases to a capacitively coupled plasma processing chamber. A vacuum pump, e.g., a one or two stage mechanical dry pump and/or turbomolecular pump 640, may be used to draw process gases out of the process chamber and to maintain a pressure within the process chamber. For example, the vacuum pump may be used to evacuate the lower sub-chamber 603 during a purge operation of ALD. A valve-controlled conduit may be used to fluidically connect the vacuum pump to the process chamber so as to selectively control application of the vacuum environment provided by the vacuum pump. This may be done employing a closed loop-controlled flow restriction device, such as a throttle valve (not shown) or a pendulum valve (not shown), during operational plasma processing. Likewise, a vacuum pump and valve controlled fluidic connection to the capacitively coupled plasma processing chamber may also be employed.
During operation of the apparatus 600, one or more process gases may be supplied through the gas flow inlets 660 and/or 670. In certain embodiments, process gas may be supplied only through the main gas flow inlet 660, or only through the side gas flow inlet 670. In some cases, the gas flow inlets shown in the figure may be replaced by more complex gas flow inlets, one or more showerheads, for example. The Faraday shield 649 and/or optional grid 650 may include internal channels and holes that allow delivery of process gases to the process chamber. Either or both of Faraday shield 649 and optional grid 650 may serve as a showerhead for delivery of process gases. In some embodiments, a liquid vaporization and delivery system may be situated upstream of the process chamber, such that once a liquid reactant or precursor is vaporized, the vaporized reactant or precursor is introduced into the process chamber via a gas flow inlet 660 and/or 670.
Radio frequency power is supplied from the RF power supply 641 to the coil 633 to cause an RF current to flow through the coil 633. The RF current flowing through the coil 633 generates an electromagnetic field about the coil 633. The electromagnetic field generates an inductive current within the upper sub-chamber 602. The physical and chemical interactions of various generated ions and radicals with the wafer 619 etch features of and selectively deposit layers on the wafer 619.
If the plasma grid 650 is used such that there is both an upper sub-chamber 602 and a lower sub-chamber 603, the inductive current acts on the gas present in the upper sub-chamber 602 to generate an electron-ion plasma in the upper sub-chamber 602. The optional internal plasma grid 650 limits the amount of hot electrons in the lower sub-chamber 603. In some embodiments, the apparatus 600 is designed and operated such that the plasma present in the lower sub-chamber 603 is an ion-ion plasma.
Both the upper electron-ion plasma and the lower ion-ion plasma may contain positive and negative ions, though the ion-ion plasma will have a greater ratio of negative ions to positive ions. Volatile etching and/or deposition byproducts may be removed from the lower sub-chamber 603 through port 622. The chuck 617 disclosed herein may operate at elevated temperatures ranging between about 10° C. and about 250° C. The temperature will depend on the process operation and specific recipe.
Apparatus 600 may be coupled to facilities (not shown) when installed in a clean room or a fabrication facility. Facilities include plumbing that provide processing gases, vacuum, temperature control, and environmental particle control. These facilities are coupled to apparatus 600, when installed in the target fabrication facility. Additionally, apparatus 600 may be coupled to a transfer chamber that allows robotics to transfer semiconductor wafers into and out of apparatus 600 using typical automation.
In some embodiments, a system controller 630 (which may include one or more physical or logical controllers) controls some or all of the operations of a process chamber. The system controller 630 may include one or more memory devices and one or more processors. In some embodiments, the apparatus 600 includes a switching system for controlling flow rates and durations when disclosed embodiments are performed. In some embodiments, the apparatus 600 may have a switching time of up to about 600 ms, or up to about 750 ms. Switching time may depend on the flow chemistry, recipe chosen, reactor architecture, and other factors.
In some implementations, the system controller 630 is part of a system, which may be part of the above-described examples. Such systems can include semiconductor processing equipment, including a processing tool or tools, chamber or chambers, a platform or platforms for processing, and/or specific processing components (a wafer pedestal, a gas flow system, etc.). These systems may be integrated with electronics for controlling their operation before, during, and after processing of a semiconductor wafer or substrate. The electronics may be integrated into the system controller 630, which may control various components or subparts of the system or systems. The system controller, depending on the processing parameters and/or the type of system, may be programmed to control any of the processes disclosed herein, including the delivery of processing gases, temperature settings (e.g., heating and/or cooling), pressure settings, vacuum settings, power settings, radio frequency (RF) generator settings, RF matching circuit settings, frequency settings, flow rate settings, fluid delivery settings, positional and operation settings, wafer transfers into and out of a tool and other transfer tools and/or load locks connected to or interfaced with a specific system.
Broadly speaking, the system controller 630 may be defined as electronics having various integrated circuits, logic, memory, and/or software that receive instructions, issue instructions, control operation, enable cleaning operations, enable endpoint measurements, and the like. The integrated circuits may include chips in the form of firmware that store program instructions, digital signal processors (DSPs), chips defined as application specific integrated circuits (ASICs), and/or one or more microprocessors, or microcontrollers that execute program instructions (e.g., software). Program instructions may be instructions communicated to the controller in the form of various individual settings (or program files), defining operational parameters for carrying out a particular process on or for a semiconductor wafer or to a system. The operational parameters may, in some embodiments, be part of a recipe defined by process engineers to accomplish one or more processing steps during the fabrication or removal of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and/or dies of a wafer.
The system controller 630, in some implementations, may be a part of or coupled to a computer that is integrated with, coupled to the system, otherwise networked to the system, or a combination thereof. For example, the controller may be in the “cloud” or all or a part of a fab host computer system, which can allow for remote access of the wafer processing. The computer may enable remote access to the system to monitor current progress of fabrication operations, examine a history of past fabrication operations, examine trends or performance metrics from a plurality of fabrication operations, to change parameters of current processing, to set processing steps to follow a current processing, or to start a new process. In some examples, a remote computer (e.g. a server) can provide process recipes to a system over a network, which may include a local network or the Internet. The remote computer may include a user interface that enables entry or programming of parameters and/or settings, which are then communicated to the system from the remote computer. In some examples, the system controller 630 receives instructions in the form of data, which specify parameters for each of the processing steps to be performed during one or more operations. It should be understood that the parameters may be specific to the type of process to be performed and the type of tool that the controller is configured to interface with or control. Thus, as described above, the system controller 630 may be distributed, such as by including one or more discrete controllers that are networked together and working towards a common purpose, such as the processes and controls described herein. An example of a distributed controller for such purposes would be one or more integrated circuits on a chamber in communication with one or more integrated circuits located remotely (such as at the platform level or as part of a remote computer) that combine to control a process on the chamber.
Without limitation, example systems may include a plasma etch chamber or module, a deposition chamber or module, a spin-rinse chamber or module, a metal plating chamber or module, a clean chamber or module, a bevel edge etch chamber or module, a physical vapor deposition (PVD) chamber or module, a chemical vapor deposition (CVD) chamber or module, an ALD chamber or module, an ALE chamber or module, an ion implantation chamber or module, a track chamber or module, an EUV lithography chamber (scanner) or module, a dry development chamber or module, and any other semiconductor processing systems that may be associated or used in the fabrication and/or manufacturing of semiconductor wafers.
As noted above, depending on the process step or steps to be performed by the tool, the controller might communicate with one or more of other tool circuits or modules, other tool components, cluster tools, other tool interfaces, adjacent tools, neighboring tools, tools located throughout a factory, a main computer, another controller, or tools used in material transport that bring containers of wafers to and from tool locations and/or load ports in a semiconductor manufacturing factory.
EUVL patterning may be conducted using any suitable tool, often referred to as a scanner, for example the TWINSCAN NXE: 3300B® platform supplied by ASML of Veldhoven, NL. The EUVL patterning tool may be a standalone device from which the substrate is moved into and out of for deposition and etching as described herein. Or, as described below, the EUVL patterning tool may be a module on a larger multi-component tool.
A vacuum transport module (VTM) 738 interfaces with four processing modules 720a-720d, which may be individually optimized to perform various fabrication processes. By way of example, processing modules 720a-720d may be implemented to perform deposition, evaporation, ELD, dry development, etch, strip, and/or other semiconductor processes. For example, module 720a may be an ALD reactor that may be operated to perform in a non-plasma, thermal atomic layer depositions as described herein, such as a Vector tool, available from Lam Research Corporation, Fremont, CA. And module 720b may be a PECVD tool, such as the Lam Vector®. It should be understood that the figure is not necessarily drawn to scale.
Airlocks 742 and 746, also known as a loadlocks or transfer modules, interface with the VTM 738 and a patterning module 740. For example, as noted above, a suitable patterning module may be the TWINSCAN NXE: 3300B® platform supplied by ASML of Veldhoven, NL. This tool architecture allows for work pieces, such as semiconductor substrates or wafers, to be transferred under vacuum so as not to react before exposure. Integration of the deposition modules with the lithography tool is facilitated by the fact that EUVL also requires a greatly reduced pressure given the strong optical absorption of the incident photons by ambient gases such as H2O, O2, etc.
As noted above, this integrated architecture is just one possible embodiment of a tool for implementation of the described processes. The processes may also be implemented with a stand-alone EUVL scanner and a deposition reactor, such as a Lam Vector tool, either stand alone or integrated in a cluster architecture with other tools, such as etch, strip etc. (e.g., Lam Kiyo or Gamma tools), as modules, for example as described with reference to
Airlock 742 may be an “outgoing” loadlock, referring to the transfer of a substrate out from the VTM 738 serving a deposition module 720a to the patterning module 740, and airlock 746 may be an “ingoing” loadlock, referring to the transfer of a substrate from the patterning module 740 back in to the VTM 738. The ingoing loadlock 746 may also provide an interface to the exterior of the tool for access and egress of substrates. Each process module has a facet that interfaces the module to VTM 738. For example, deposition process module 720a has facet 736. Inside each facet, sensors, for example, sensors 1-18 as shown, are used to detect the passing of wafer 726 when moved between respective stations. Patterning module 740 and airlocks 742 and 746 may be similarly equipped with additional facets and sensors, not shown.
Main VTM robot 722 transfers wafer 726 between modules, including airlocks 742 and 746. In one embodiment, robot 722 has one arm, and in another embodiment, robot 722 has two arms, where each arm has an end effector 724 to pick wafers such as wafer 726 for transport. Front-end robot 744, in is used to transfer wafers 726 from outgoing airlock 742 into the patterning module 740, from the patterning module 740 into ingoing airlock 746. Front-end robot 744 may also transport wafers 726 between the ingoing loadlock and the exterior of the tool for access and egress of substrates. Because ingoing airlock module 746 has the ability to match the environment between atmospheric and vacuum, the wafer 726 is able to move between the two pressure environments without being damaged.
It should be noted that a EUVL tool typically operates at a higher vacuum than a deposition tool. If this is the case, it is desirable to increase the vacuum environment of the substrate during the transfer between the deposition to the EUVL tool to allow the substrate to degas prior to entry into the patterning tool. Outgoing airlock 742 may provide this function by holding the transferred wafers at a lower pressure, no higher than the pressure in the patterning module 740, for a period of time and exhausting any off-gassing, so that the optics of the patterning tool 740 are not contaminated by off-gassing from the substrate. A suitable pressure for the outgoing, off-gassing airlock is no more than 1E-8 Torr.
In some embodiments, a system controller 750 (which may include one or more physical or logical controllers) controls some or all of the operations of the cluster tool and/or its separate modules. It should be noted that the controller can be local to the cluster architecture, or can be located external to the cluster architecture in the manufacturing floor, or in a remote location and connected to the cluster architecture via a network. The system controller 750 may include one or more memory devices and one or more processors. The processor may include a central processing unit (CPU) or computer, analog and/or digital input/output connections, stepper motor controller boards, and other like components. Instructions for implementing appropriate control operations are executed on the processor. These instructions may be stored on the memory devices associated with the controller or they may be provided over a network. In certain embodiments, the system controller executes system control software.
The system control software may include instructions for controlling the timing of application and/or magnitude of any aspect of tool or module operation. System control software may be configured in any suitable way. For example, various process tool component subroutines or control objects may be written to control operations of the process tool components necessary to carry out various process tool processes. System control software may be coded in any suitable compute readable programming language. In some embodiments, system control software includes input/output control (IOC) sequencing instructions for controlling the various parameters described above. For example, each phase of a semiconductor fabrication process may include one or more instructions for execution by the system controller. The instructions for setting process conditions for condensation, deposition, evaporation, patterning and/or etching phase may be included in a corresponding recipe phase, for example.
In various embodiments, an apparatus for forming a negative pattern mask is provided. The apparatus may include a processing chamber for patterning, deposition and etch, and a controller including instructions for forming a negative pattern mask. The instructions may include code for, in the processing chamber, patterning a feature in a chemically amplified (CAR) resist on a semiconductor substrate by EUV exposure to expose a surface of the substrate, dry developing the photopatterned resist, and etching the underlying layer or layer stack using the patterned resist as a mask.
It should be noted that the computer controlling the wafer movement can be local to the cluster architecture or can be located external to the cluster architecture in the manufacturing floor, or in a remote location and connected to the cluster architecture via a network.
Although the foregoing embodiments have been described in some detail for purposes of clarity of understanding, it will be apparent that certain changes and modifications may be practiced within the scope of the appended claims. Embodiments disclosed herein may be practiced without some or all of these specific details. In other instances, well-known process operations have not been described in detail to not unnecessarily obscure the disclosed embodiments. Further, while the disclosed embodiments will be described in conjunction with specific embodiments, it will be understood that the specific embodiments are not intended to limit the disclosed embodiments. It should be noted that there are many alternative ways of implementing the processes, systems, and apparatus of the present embodiments. Accordingly, the present embodiments are to be considered as illustrative and not restrictive, and the embodiments are not to be limited to the details given herein.
A PCT Request Form is filed concurrently with this specification as part of the present application. Each application that the present application claims benefit of or priority to as identified in the concurrently filed PCT Request Form is incorporated by reference herein in their entireties and for all purposes. This application claims the benefit of U.S. Provisional Patent Application No. 62/705,857, filed Jul. 17, 2021, which is incorporated herein by reference in its entirety.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2021/042108 | 7/16/2021 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 62705857 | Jul 2020 | US |
