Patent Application
20250180993
The present invention relates to a resist underlayer film-forming composition, a resist underlayer film, a semiconductor processing substrate, a method for producing a semiconductor element, and a method for forming a pattern.
In the related art, fine processing by lithography using a photoresist composition has been performed in the production of semiconductor devices. The fine processing is a processing method of forming a thin film of a photoresist composition on a silicon wafer, irradiating the thin film with active energy rays such as ultraviolet rays through a mask pattern having a semiconductor device pattern drawn thereon, developing the irradiated thin film, and etching the silicon wafer using the resultant resist pattern serving as a protective film.
However, in recent years, as a result of an increase in the degree of integration of semiconductor devices, active energy rays having a shorter wavelength have tended to be used, i.e. shifting from KrF excimer laser (248 nm) to ArF excimer laser (193 nm). The use of such active energy rays having a shorter wavelength has caused a serious problem in terms of irregular reflection and standing wave of active energy rays from a substrate. Thus, there has been widely studied a method of providing a bottom anti-reflective coating (BARC), i.e. a resist underlayer film between a photoresist and a substrate.
For example, the present applicant has proposed an anti-reflective coating-forming composition which has a high reflected-light preventing effect, does not cause intermixing with a resist layer, can provide an excellent resist pattern and a wide focus depth margin, and can produce an anti-reflective coating for lithography having a higher dry etching rate than a resist (see Patent Literature 1).
Patent Literature 1: WO 2003/017002 A
The resist underlayer film-forming composition is generally an organic solvent-based composition prepared by dissolution of a polymer in an organic solvent.
Replacement of organic solvent-based paints with aqueous paints has been actively studied from the viewpoints of the influence of volatile organic solvents on the environment, the health of operators who handle paints, and the like.
The resist underlayer film-forming composition is used in a clean room. Accordingly, volatile organic solvents are hardly released into the environment, and operators are not exposed to the organic solvents.
However, an aqueous composition is preferred from the viewpoint of treatment of waste liquid and the viewpoint that the organic solvent-based composition is combustible and care is required for handling and transportation.
It is an object of the present invention to provide a resist underlayer film-forming composition using water as a solvent, a resist underlayer film, a semiconductor processing substrate, a method for producing a semiconductor element, and a method for forming a pattern.
As a result of intensive studies to solve the above problem, the present inventors have found that the above problem can be solved, thereby completing the present invention having the following gist.
That is, the present invention includes the followings.
[1] A resist underlayer film-forming composition containing:
[2] A resist underlayer film-forming composition containing:
[3] The resist underlayer film-forming composition according to [1], wherein the first component is a compound containing at least one selected from a structure represented by the following Formula (1) and a structure represented by the following Formula (2):
[4] The resist underlayer film-forming composition according to [2] or [3], wherein Q1 is represented by the following Formula (2-1):
[5] The resist underlayer film-forming composition according to any one of [1] to [3], wherein the first component includes at least one of a structure represented by the following Formula (E-1) or a structure represented by the following Formula (E-2):
[6] The resist underlayer film-forming composition according to [2], further containing a second component, wherein the second component is a water-soluble polymer.
[7] The resist underlayer film-forming composition according to [1] or [6], wherein the water-soluble polymer is at least one selected from polyvinyl alcohol, polystyrenesulfonic acid, and water-soluble cellulose.
[8] The resist underlayer film-forming composition according to [6] or [7], wherein a mass ratio (first component:second component) between the first component and the second component is 99:1 to 50:50.
[9] The resist underlayer film-forming composition according to any one of [1] to [8], further containing a crosslinking agent.
[10] The resist underlayer film-forming composition according to any one of [1] to [9], further containing a curing catalyst.
[11]A resist underlayer film which is a cured product of the resist underlayer film-forming composition according to any one of [1] to [10].
[12]A semiconductor processing substrate including:
[13]A method for producing a semiconductor element, the method including the steps of:
[14]A method for forming a pattern including the steps of:
According to the present invention, it is possible to provide a resist underlayer film-forming composition using water as a solvent, a resist underlayer film, a semiconductor processing substrate, a method for producing a semiconductor element, and a method for forming a pattern. The amount of the organic solvent used in this field in the related art can be reduced, and this can contribute to reduction in environmental load.
An embodiment of the resist underlayer film-forming composition of the present invention contains a first component and water.
An embodiment of the resist underlayer film-forming composition of the present invention contains a first component, a second component, and water.
The first component is an organic compound.
The first component is, for example, a component that may be used in combination with the second component, in the resist underlayer film-forming composition. The first component is an organic compound that is dissolved in the solvent in order to be used as the resist underlayer film-forming composition.
The molecular weight of the first component is not particularly limited, and the first component may be a low molecular weight compound or a high molecular weight compound.
The first component is preferably a compound containing at least one selected from a structure represented by the following Formula (1) and a structure represented by the following Formula (2).
When the first component is the compound containing at least one selected from the structure represented by the following Formula (1) and the structure represented by the following Formula (2), excellent solvent resistance and excellent antireflection performance are imparted to the resist underlayer film prepared from the resist underlayer film-forming composition:
Examples of the alkyl group having 1 to 10 carbon atoms and optionally interrupted by an oxygen atom or a sulfur atom in R1 to R5 in Formulae (1-1) to (1-3) include an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkoxyalkyl group having 2 to 10 carbon atoms, an alkoxyalkoxyalkyl group having 3 to 10 carbon atoms, an alkylthio group having 1 to 10 carbon atoms, and an alkylthioalkyl group having 2 to 10 carbon atoms.
The alkyl group having 1 to 10 carbon atoms and optionally interrupted by an oxygen atom or a sulfur atom may contain two or more oxygen atoms or sulfur atoms.
X1 in Formula (1) is preferably represented by Formula (1-3) or Formula (1-4) from the viewpoint of suitably achieving the effects of the present invention.
Examples of Formula (1) include structures exemplified below.
In the above structures, each asterisk * represents a bonding hand.
Q1 represents a divalent organic group having at least one selected from an aromatic hydrocarbon ring and an aliphatic hydrocarbon ring.
The aromatic hydrocarbon ring may be a monocyclic ring or a polycyclic ring. The aromatic hydrocarbon ring is not particularly limited, and examples thereof include a benzene ring, a naphthalene ring, and an anthracene ring.
The aliphatic hydrocarbon ring may be a monocyclic ring or a polycyclic ring. The aliphatic hydrocarbon ring is not particularly limited, and examples thereof include a cyclohexane ring.
Q1 is preferably represented by the following Formula (2-1):
In the present specification, examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
In the present specification, the alkyl group is not limited to be linear, and may be branched or cyclic. Examples of the linear or branched alkyl group include methyl group, ethyl group, isopropyl group, tert-butyl group, and n-hexyl group. Examples of the cyclic alkyl group (cycloalkyl group) include cyclobutyl group, cyclopentyl group, and cyclohexyl group.
In the present specification, examples of the alkoxy group include methoxy group, ethoxy group, n-pentyloxy group, and isopropoxy group.
In the present specification, examples of the alkylthio group include methylthio group, ethylthio group, n-pentylthio group, and isopropylthio group.
In the present specification, examples of the alkenyl group include ethenyl group, 1-propenyl group, 2-propenyl group, 1-methyl-1-ethenyl group, 1-butenyl group, 2-butenyl group, 3-butenyl group, 2-methyl-1-propenyl group, and 2-methyl-2-propenyl group.
In the present specification, the alkynyl group is, for example, a group in which a double bond of each of the alkenyl groups listed in the examples of the “alkenyl group” is replaced with a triple bond.
In the present specification, examples of the alkenyloxy group include vinyloxy group, 1-propenyloxy group, 2-n-propenyloxy group (allyloxy group), 1-n-butenyloxy group, and prenyloxy group.
In the present specification, examples of the alkynyloxy group include 2-propynyloxy group, 1-methyl-2-propynyloxy group, 2-methyl-2-propynyloxy group, 2-butynyloxy group, and 3-butynyloxy group.
In the present specification, examples of the acyl group include acetyl group and propionyl group.
In the present specification, examples of the aryloxy group include phenoxy group and naphthyloxy.
In the present specification, examples of the arylcarbonyl group include phenylcarbonyl group.
In the present specification, examples of the aralkyl group include benzyl group and phenethyl group.
In the present specification, examples of the alkylene group include methylene group, ethylene group, 1,3-propylene group, 2,2-propylene group, 1-methylethylene group, 1,4-butylene group, 1-ethylethylene group, 1-methylpropylene group, 2-methylpropylene group, 1,5-pentylene group, 1-methylbutylene group, 2-methylbutylene group, 1,1-dimethylpropylene group, 1,2-dimethylpropylene group, 1-ethylpropylene group, 2-ethylpropylene group, 1,6-hexylene group, 1,4-cyclohexylene group, 1,8-octylene group, 2-ethyloctylene group, 1,9-nonylene group, and 1,10-decylene group.
Examples of the structure represented by Formula (2-1) include structures exemplified below.
In the above structures, each asterick * represents a bonding hand.
Further, the first component is preferably a compound containing at least one selected from a structure represented by the following Formula (11) and a structure represented by the following Formula (12).
Furthermore, the first component is preferably a compound containing at least one selected from a structure represented by Formula (1), a structure represented by Formula (2), a structure represented by Formula (11), and a structure represented by Formula (12):
The first component preferably includes at least one of a structure represented by the following Formula (E-1) or a structure represented by the following Formula (E-2). When the first component includes these structures, the solubility of the first component in water can be enhanced.
Where in Formulae (E-1) and (E-2), each asterisk * represents a bonding hand.
The number of the structures represented by Formula (E-1) and the number of the structures represented by Formula (E-2) are preferably plural in the first component, and more preferably 2 to 3 in the compound as the first component.
The molecular weight of the first component is not particularly limited.
From the viewpoint of the solubility in water, the weight-average molecular weight of the first component is preferably small.
The weight-average molecular weight of the first component is, for example, 300 to 100,000, preferably 300 to 50,000, more preferably 300 to 10,000, and particularly preferably 300 to 5,000.
A method for producing an example of the first component will be described.
An example of the first component is prepared, for example, by the following reactions (I) to (III).
(I) Reaction between at least one of a compound represented by the following Formula (11A) or a compound represented by the following Formula (12A) and a compound represented by the following Formula (EA):
Examples of the compound represented by Formula (11 A) include the following compounds.
Examples of the compound represented by Formula (12A) include the following compounds.
(II) Reaction between at least one of a compound represented by the following Formula (11B) or a compound represented by the following Formula (12A) and a compound represented by the following Formula (EB):
[Chem. 41]
Examples of the compound represented by Formula (11B) include the following compounds.
Examples of the compound represented by Formula (12B) include the following compounds.
(III) Reaction between at least one of a compound represented by Formula (11A) above or a compound represented by Formula (12A) above and a compound represented by the following Formula (EC):
The divalent organic group may be, for example, a divalent organic group having 1 to 20 carbon atoms or a divalent organic group having 1 to 10 carbon atoms.
The divalent organic group may have a hetero atom. Examples of the heteroatom include an oxygen atom and a sulfur atom.
Examples of the divalent organic group include a hydrocarbon group having 1 to 10 carbon atoms. The hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.
Examples of the divalent organic group include a hydrocarbon group having 1 to 10 carbon atoms substituted with a hydroxy group or a mercapto group. Examples of the hydrocarbon group include an aliphatic hydrocarbon group.
Examples of the divalent organic group include a hydrocarbon group having 2 to 10 carbon atoms interrupted by an oxygen atom or a sulfur atom. Examples of the hydrocarbon group include an aliphatic hydrocarbon group.
Examples of the compound represented by Formula (EC) include the following compounds.
The reactions (I) to (III) may be performed, for example, in the presence of a catalyst. The catalyst is, for example, a quaternary phosphonium salt such as tetrabutylphosphonium bromide or ethyltriphenylphosphonium bromide, or a quaternary ammonium salt such as benzyltriethylammonium chloride. The amount of the catalyst used can be appropriately selected from a range of 0.1 to 10 mass % relative to the total mass of the polymer raw material used in the reaction. The temperature and time for the polymerization reaction can be selected from, for example, the optimal conditions (temperature: 80 to 160° C. and time: 2 to 50 hours).
The second component is used for improving the application property of the resist underlayer film-forming composition.
The second component is a water-soluble polymer.
The second component is a compound different from the first component.
The water-soluble polymer is a polymer compound that dissolves in an amount of 1 g or more in 100 g of water at 25° C., preferably a polymer compound that dissolves in an amount of 5 g or more in 100 g of water at 25° C., and more preferably a polymer compound that dissolves in an amount of 10 g or more in 100 g of water at 25° C.
The water-soluble polymer is not particularly limited, and examples thereof include polyvinyl alcohol, water-soluble cellulose, polyethylene glycol (PEG), polyethylene oxide (PEO), polyvinyl pyrrolidone, polyacrylic acid, polystyrenesulfonic acid, and polyvinyl acetamide.
The polyvinyl alcohol is a polymer prepared by hydrolyzing polyvinyl acetate to change an acetyl group in the polyvinyl acetate molecule to a hydroxyl group. A value obtained by expressing the proportion of the hydroxyl group in mol % is referred to as a saponification degree. Known polyvinyl alcohols have various properties depending on their saponification degrees. For example, polyvinyl acetate (saponification degree: 0 mol %) is generally water-insoluble, and polyvinyl alcohol having a saponification degree of 100 mol % is known as water-soluble. In the case of polyvinyl alcohol having a saponification degree of 60 mol % or less among polyvinyl alcohols, the solubility in water is deteriorated. In the case of polyvinyl alcohol having a saponification degree of 30 mol % or less, the polyvinyl alcohol is not substantially dissolved. Conversely, when the saponification degree is too high, the solubility is low, and polyvinyl alcohol having a saponification degree of 85 to 90 mol % has the highest solubility. In the present invention, polyvinyl alcohol having a saponification degree of 70 mol % or more is preferably used. In general, the higher the saponification degree, the better the developer resistance. Thus, polyvinyl alcohol having a saponification degree of 75 mol % or more is preferably used. However, conversely, when the saponification degree is too high, the storage stability of the composition (generation of insoluble foreign matters) tends to be deteriorated. Thus, the saponification degree of polyvinyl alcohol is preferably 99 mol % or less, and more preferably 98 mol % or less.
The polymerization degree of polyvinyl alcohol is ordinarily represented by a viscosity of a 4 mass % aqueous solution (at 20° C.), and the viscosity is generally about 1 to 80 cps (mPa·s). Among the polyvinyl alcohols, the polyvinyl alcohol used in the present invention preferably has a viscosity of 1 cps or more, and more preferably has a viscosity of 2 cps or more. The upper limit of the viscosity is preferably 70 cps, and the upper limit of the viscosity is more preferably 65 cps, 50 cps, 40 cps, 30 cps, 20 cps, 10 cps, 8 cps, or 5 cps. The viscosity range is, for example, 1 to 20 cps, 2 to 10 cps, or 3 to 8 cps.
The polyvinyl alcohol may be modified by substituting some of its hydroxyl groups with an alkyl ether group, an alkyloxymethyl group, an acetyl acetate group, or the like.
The water-soluble cellulose is not particularly limited, and examples thereof include alkylcelluloses such as methylcellulose and ethylcellulose; hydroxyalkylcelluloses such as hydroxyethylcellulose and hydroxypropylcellulose; and hydroxyalkylalkylcelluloses such as hydroxyethylmethylcellulose and hydroxypropylmethylcellulose.
Among these water-soluble celluloses, hydroxypropylcellulose is more preferred.
As the hydroxypropylcellulose, various products having different viscosities are commercially available from various companies, and any of them can be used in the present invention. The viscosity of a 2 mass % aqueous solution of hydroxypropylcellulose (at 20° C.) is not particularly limited, and can be appropriately selected depending on the purpose. The viscosity is preferably 2.0 mPa·s (centipoise, cps) or more and 4,000 mPa·s (centipoise, cps) or less.
Further, the viscosity of hydroxypropylcellulose is considered to depend on the weight-average molecular weight, the degree of substitution, and the molecular weight of hydroxypropylcellulose.
The weight-average molecular weight of hydroxypropylcellulose is not particularly limited, and can be appropriately selected depending on the purpose. The weight-average molecular weight is preferably 15,000 or more and 400,000 or less. The weight-average molecular weight can be measured using, for example, gel permeation chromatography (GPC).
A commercially available product of hydroxypropylcellulose is not particularly limited, and can be appropriately selected depending on the purpose. Examples of the commercially available product include the following commercially available products.
Among these commercially available products, HPC-SSL having a molecular weight of 15,000 or more and 30,000 or less and a viscosity of 2.0 mPa-s or more and 2.9 mPa-s or less is preferred.
In the commercially available products described above, the molecular weight is measured using gel permeation chromatography (GPC), and the viscosity is measured using a 2 mass % aqueous solution (at 20° C.).
The polystyrenesulfonic acid is not particularly limited as long as it exhibits water solubility. The sulfonation rate of the polystyrenesulfonic acid may be 100%, or may be less than 100%. The sulfonation rate is, for example, 80% or more and 100% or less. Here, the “sulfonation rate” refers to a molar ratio (%) of a “styrene unit having a sulfonate group” to the total of the “styrene unit having a sulfonate group” and the “styrene unit” in the molecule of the polystyrenesulfonic acid.
That is, the polystyrenesulfonic acid may be a homopolymer formed only of a repeating unit represented by the following Formula (SS), or may be a copolymer having a repeating unit represented by the following Formula (SS) and a repeating unit represented by the following Formula (St):
Examples of styrenesulfonic acid including polystyrenesulfonic acid include 4-styrenesulfonic acid.
The content of the second component (water-soluble polymer) in the resist underlayer film-forming composition is not particularly limited.
Addition of a small amount of the second component to the resist underlayer film-forming composition enables the application property of the resist underlayer film-forming composition to be improved.
Accordingly, a mass ratio (first component:second component) between the first component and the second component in the resist underlayer film-forming composition is preferably 99:1 to 50:50, more preferably 99:1 to 75:25, and particularly preferably 99:1 to 90:10.
The resist underlayer film-forming composition preferably contains a crosslinking agent.
The crosslinking agent contained as an optional component in the resist underlayer film-forming composition has, for example, a functional group which reacts in itself.
Examples of the crosslinking agent include hexamethoxymethylmelamine, tetramethoxymethyl benzoguanamine, 1,3,4,6-tetrakis(methoxymethyl)glycoluril(tetramethoxymethyl glycoluril) (POWDERLINK [registered trademark]1174), 1,3,4,6-tetrakis(butoxymethyl)glycoluril, 1,3,4,6-tetrakis(hydroxymethyl)glycoluril, 1,3-bis(hydroxymethyl)urea, 1,1,3,3-tetrakis(butoxymethyl)urea, and 1,1,3,3-tetrakis(methoxymethyl)urea.
In addition, the crosslinking agent may be a nitrogen-containing compound having 2 to 6 substituents that bond to a nitrogen atom in one molecule as described in WO 2017/187969 A, the substituents being represented by the following Formula (1d):
The nitrogen-containing compound having 2 to 6 substituents represented by Formula (1d) above in one molecule may be a glycoluril derivative represented by the following Formula (1E):
Examples of the glycoluril derivative represented by Formula (1E) above include compounds represented by the following Formulae (1E-1) to (1E-6):
The nitrogen-containing compound having 2 to 6 substituents represented by Formula (1d) above in one molecule is prepared by reacting a nitrogen-containing compound having 2 to 6 substituents represented by the following Formula (2d) that bond to a nitrogen atom in one molecule with at least one compound represented by the following Formula (3d):
The glycoluril derivative represented by Formula (1E) above is prepared by reacting a glycoluril derivative represented by the following Formula (2E) with at least one compound represented by Formula (3d) above.
The nitrogen-containing compound having 2 to 6 substituents represented by Formula (2d) above in one molecule is, for example, a glycoluril derivative represented by the following Formula (2E):
Examples of the glycoluril derivative represented by Formula (2E) above include compounds represented by the following Formulae (2E-1) to (2E-4). Further, examples of the compound represented by Formula (3d) above include compounds represented by the following Formulae (3d-1) and (3d-2):
In respect of the content related to the nitrogen-containing compound having 2 to 6 substituents represented by Formula (1d) that bond to a nitrogen atom in one molecule, the entire disclosure of WO 2017/187969 A is incorporated in the present application by reference.
The crosslinking agent may be a crosslinkable compound described in WO 2014/208542 A and represented by the following Formula (G-1) or (G-2):
The crosslinkable compound represented by Formula (G-1) or (G-2) above may be prepared by a reaction of a compound represented by the following Formula (G-3) or (G-4) with a hydroxyl group-containing ether compound or an alcohol having 2 to 10 carbon atoms:
The compounds represented by Formula (G-1) and Formula (G-2) above can be exemplified below.
The compounds represented by Formula (G-3) and Formula (G-4) can be exemplified below.
The entire disclosure of WO 2014/208542 A is incorporated in the present application by reference.
When the crosslinking agent is used, the content ratio of the crosslinking agent in the resist underlayer film-forming composition is, for example, 1 mass % to 50 mass %, preferably 5 mass % to 40 mass %, relative to the total of the first component and the second component.
When the crosslinking agent is used, the content ratio of the crosslinking agent in the resist underlayer film-forming composition is, for example, 1 mass % to 50 mass %, preferably 5 mass % to 40 mass %, relative to the total of the first component.
As the curing catalyst contained as an optional component in the resist underlayer film-forming composition, both a thermal acid generator and a photoacid generator can be used. Preferably, the thermal acid generator is used.
Examples of the thermal acid generator include sulfonic acid compounds and carboxylic acid compounds such as p-toluenesulfonic acid, trifluoromethanesulfonic acid, pyridinium-p-toluenesulfonate (pyridinium-p-toluenesulfonic acid), pyridinium phenolsulfonic acid, pyridinium-p-hydroxybenzenesulfonic acid (p-phenolsulfonic acid pyridinium salt), pyridinium-trifluoromethanesulfonic acid, salicylic acid, camphorsulfonic acid, 5-sulfosalicylic acid, 4-chlorobenzenesulfonic acid, 4-hydroxybenzenesulfonic acid, benzenedisulfonic acid, 1-naphthalenesulfonic acid, citric acid, benzoic acid, and hydroxybenzoic acid.
Examples of the photoacid generator include an onium salt compound, a sulfonimide compound, and a disulfonyldiazomethane compound.
Specific examples of the onium salt compound include, but are not limited to, iodonium salt compounds, such as diphenyliodonium hexafluorophosphate, diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoro normal butanesulfonate, diphenyliodonium perfluoro normal octanesulfonate, diphenyliodonium camphorsulfonate, bis(4-tert-butylphenyl)iodonium camphorsulfonate, and bis(4-tert-butylphenyl)iodonium trifluoromethanesulfonate; and sulfonium salt compounds, such as triphenylsulfonium hexafluoroantimonate, triphenylsulfonium nonafluoro normal butanesulfonate, triphenylsulfonium camphorsulfonate, and triphenylsulfonium trifluoromethanesulfonate.
Examples of the sulfonimide compound include N-(trifluoromethanesulfonyloxy)succinimide, N-(nonafluoro normal butane sulfonyloxy)succinimide, N-(camphorsulfonyloxy)succinimide, and N-(trifluoromethanesulfonyloxy)naphthalimide.
Examples of the disulfonyldiazomethane compound include bis(trifluoromethylsulfonyl)diazomethane, bis(cyclohexylsulfonyl)diazomethane, bis(phenylsulfonyl)diazomethane, bis(p-toluenesulfonyl)diazomethane, bis(2,4-dimethylbenzenesulfonyl)diazomethane, and methylsulfonyl-p-toluenesulfonyldiazomethane.
The curing catalysts can be used singly or in combination two or more kinds thereof.
When a curing catalyst is used, the content ratio of the curing catalyst is, for example, 0.1 mass % to 50 mass %, preferably 1 mass % to 30 mass % relative to the crosslinking agent.
The resist underlayer film-forming composition contains a solvent.
The solvent contains water.
The solvent may contain an organic solvent in addition to water.
The solvent preferably contains water in an amount of 50 mass % or more, more preferably in an amount of 70 mass % or more, still more preferably in an amount of 80 mass % or more, and particularly preferably in an amount of 90 mass % or more, relative to the solvent.
As the organic solvent, an organic solvent generally used for a chemical for a semiconductor lithography process is preferred. Specific examples of the organic solvent include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, methyl cellosolve acetate, ethyl cellosolve acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monomethyl ether acetate, propylene glycol propyl ether acetate, toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, cycloheptanone, 4-methyl-2-pentanol, methyl 2-hydroxyisobutyrate, ethyl 2-hydroxyisobutyrate, ethyl ethoxyacetate, 2-hydroxyethyl acetate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl 3-ethoxypropionate, methyl pyruvate, ethyl pyruvate, ethyl acetate, butyl acetate, ethyl lactate, butyl lactate, 2-heptanone, methoxycyclopentane, anisole, γ-butyrolactone, N-methylpyrrolidone, N,N-dimethylformamide, and N,N-dimethylacetamide. The solvents may be used singly or in combination of two or more kinds thereof.
Among these solvents, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, ethyl lactate, butyl lactate, and cyclohexanone are preferred. Particularly, propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate are preferred.
In the resist underlayer film-forming composition, a surfactant can be further added in order not to generate pinholes, striation, and the like and to further improve the application property against surface irregularity.
Examples of the surfactant include nonionic surfactants such as polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, and polyoxyethylene oleyl ether; polyoxyethylene alkyl allyl ethers such as polyoxyethylene octylphenol ether and polyoxyethylene nonylphenol ether; polyoxyethylene-polyoxypropylene block copolymers; sorbitan fatty acid esters such as sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, sorbitan trioleate, and sorbitan tristearate; polyoxyethylene sorbitan fatty acid esters such as polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate,
polyoxyethylene sorbitan trioleate, and polyoxyethylene sorbitan tristearate; fluorine-based surfactants such as EFTOP EF301, EF303, and EF352 (trade name, manufactured by Tohkem Products Corporation), MEGAFAC F171, F173, and R-30 (trade name, manufactured by DIC Corporation), Fluorad FC430 and FC431 (trade name, manufactured by Sumitomo 3M Limited), and AsahiGuard AG710 and SURFLON 5-382, SC101, SC102, SC103, SC104, SC105, and SC106 (trade name, manufactured by Asahi Glass Co., Ltd.), and Organosiloxane Polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.).
The amount of each of these surfactants added is not particularly limited, and is ordinarily 2.0 mass % or less, and preferably 1.0 mass % or less relative to the total solid content of the resist underlayer film-forming composition.
These surfactants may be added singly, or in combination of two or more kinds thereof.
The amount of the film-forming components contained in the resist underlayer film-forming composition, i.e. the components excluding the solvent is, for example, 0.01 mass % to 10 mass % relative to the entire resist underlayer film-forming composition.
The resist underlayer film-forming composition of the present invention is produced, for example, using a method of mixing the first component, the solvent, and the like by a known method. The resist underlayer film-forming composition to be used is necessary to be in a uniform solution state. The composition after production is preferably filtered with a filter or the like, in order to remove metal impurities, foreign matters, and the like present in the composition.
One of the measures for evaluating whether the resist underlayer film-forming composition is in a uniform solution state is to observe the passing property of the composition through a specific microfilter. Preferably, the resist underlayer film-forming composition according to the present invention passes through a microfilter having a pore size of 0.1 μm, 0.05 μm, 0.03 μm, 0.02 μm, or 0.01 μm and exhibits a uniform solution state.
Examples of the material of the microfilter include fluorine-based resins such as PTFE (polytetrafluoroethylene) and PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer), PE (polyethylene), UPE (ultra-high molecular weight polyethylene), PP (polypropylene), PSF (polysulfone), PES (polyether sulfone), and nylon. Among these materials, PTFE (polytetrafluoroethylene) is preferred. Since the resist underlayer film-forming composition contains water as a solvent, the filter used for filtration of the resist underlayer film-forming composition is preferably a filter subjected to a hydrophilization treatment.
The resist underlayer film of the present invention is a cured product of the silicon-containing resist underlayer film-forming composition described above.
The resist underlayer film can be produced, for example, by applying the resist underlayer film-forming composition described above onto a semiconductor substrate and baking the composition.
Examples of the semiconductor substrate to which the resist underlayer film-forming composition is applied include a silicon wafer, a germanium wafer, and a semiconductor wafer formed of a compound such as gallium arsenide, indium phosphide, gallium nitride, indium nitride, or aluminum nitride.
When a semiconductor substrate having an inorganic film formed on a surface thereof is used, the inorganic film is formed by, for example, an atomic layer deposition (ALD) method, a chemical vapor deposition (CVD) method, a reactive sputtering method, an ion plating method, a vacuum deposition method, or a spin coating method (spin-on glass: SOG). Examples of the inorganic film include a polysilicon film, a silicon oxide film, a silicon nitride film, a boro-phospho silicate glass (BPSG) film, a titanium nitride film, a titanium nitride oxide film, a tungsten film, a gallium nitride film, and a gallium arsenide film. The inorganic film may be a single layer or a multilayer of two or more layers. In the case of multilayers or more, the respective layers may be identical types of inorganic films or different types of inorganic films.
The thickness of the inorganic film is not particularly limited.
The resist underlayer film-forming composition of the present invention is applied onto the semiconductor substrate by an appropriate application method such as a spinner or a coater. Thereafter, the resultant semiconductor substrate is baked using a heating means such as a hot plate to form a resist underlayer film. The conditions for baking are appropriately selected from a baking temperature of 100° C. to 400° C. and a baking time of 0.3 minutes to 60 minutes. Preferably, the baking temperature is 120° C. to 350° C. and the baking time is 0.5 minutes to 30 minutes. More preferably, the baking temperature is 150° C. to 300° C. and the baking time is 0.8 minutes to 10 minutes.
The film thickness of the resist underlayer film is, for example, 0.001 μm (1 nm) to 10 μm, 0.002 μm (2 nm) to 1 μm, 0.005 μm (5 nm) to 0.5 μm (500 nm), 0.001 μm (1 nm) to 0.05 μm (50 nm), 0.002 μm (2 nm) to 0.05 μm (50 nm), 0.003 μm (3 nm) to 0.05 μm (50 nm), 0.004 μm (4 nm) to 0.05 μm (50 nm), 0.005 μm (5 nm) to 0.05 μm (50 nm), 0.003 μm (3 nm) to 0.03 μm (30 nm), 0.003 μm (3 nm) to 0.02 μm (20 nm), 0.005 μm (5 nm) to 0.02 μm (20 nm), 0.005 μm (5 nm) to 0.02 μm (20 nm), 0.003 μm (3 nm) to 0.01 μm (10 nm), 0.005 μm (5 nm) to 0.1 μm (10 nm), 0.003 μm (3 nm) to 0.006 μm (6 nm), or 0.005 μm (5 nm).
The method for measuring the film thickness of the resist underlayer film in the present specification is as follows.
The semiconductor processing substrate of the present invention includes a semiconductor substrate and the resist underlayer film of the present invention.
Examples of the semiconductor substrate include the semiconductor substrates described above.
The resist underlayer film is disposed on the semiconductor substrate, for example.
The method for producing a semiconductor element of the present invention includes at least the following steps:
The method for forming a pattern of the present invention includes at least the following steps:
Ordinarily, a resist film is formed on the resist underlayer film.
The film thickness of the resist film is preferably 200 nm or less, more preferably 150 nm or less, still more preferably 100 nm or less, and particularly preferably 80 nm or less. The film thickness of the resist film is preferably 10 nm or more, more preferably 20 nm or more, and particularly preferably 30 nm or more.
The resist film formed on the resist underlayer film by a known method (e.g. applying and baking) is not particularly limited as long as it responds to light or an electron beam (EB) used for irradiation. Both a negative photoresist and a positive photoresist can be used.
The light or electron beam is not particularly limited, and examples thereof include i-ray (365 nm), KrF excimer laser (248 nm), ArF excimer laser (193 nm), extreme ultraviolet (EUV; 13.5 nm), and electron beam (EB).
In the present specification, a resist responding to EB is also referred to as a photoresist.
Examples of the photoresist include a positive photoresist formed of a novolac resin and 1,2-naphthoquinone diazide sulfonic acid ester; a chemically amplified photoresist formed of a binder having a group that is decomposed by an acid to increase an alkali dissolution rate and a photoacid generator; a chemically amplified photoresist formed of a low molecular weight compound that is decomposed by an acid to increase an alkali dissolution rate of the photoresist, an alkali-soluble binder, and a photoacid generator; a chemically amplified photoresist formed of a binder having a group that is decomposed by an acid to increase an alkali dissolution rate, a low molecular weight compound having a group that is decomposed by an acid to increase an alkali dissolution rate of the photoresist, and photoacid generator; and a resist containing metal elements. Examples of the photoresist include V146G (trade name, manufactured by JSR Corporation), APEX-E (trade name, manufactured by Shipley Company L.L.C), PAR710 (trade name, manufactured by Sumitomo Chemical Co., Ltd.), and AR2772 and SEPR430 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.) Further, examples of the photoresist include a fluorine-containing atomic polymer-based photoresist as described in Proc. SPIE, Vol. 3999, 330-334 (2000), Proc. SPIE, Vol. 3999, 357-364 (2000), or Proc. SPIE, Vol. 3999, 365-374 (2000).
In addition, the resist compositions described in WO 2019/188595 A, WO 2019/187881 A, WO 2019/187803 A, WO 2019/167737 A, WO2019/167725 A, WO 2019/187445 A, WO 2019/167419 A, WO 2019/123842 A, WO 2019/054282 A, WO 2019/058945 A, WO 2019/058890 A, WO 2019/039290 A, WO 2019/044259 A, WO 2019/044231 A, WO 2019/026549 A, WO 2018/193954 A, WO 2019/172054 A, WO 2019/021975 A, WO 2018/230334 A, WO 2018/194123 A, JP 2018-180525 A, WO 2018/190088 A, JP 2018-070596 A, JP 2018-028090A, JP 2016-153409 A, JP 2016-130240 A, JP 2016-108325 A, JP 2016-047920 A, JP 2016-035570 A, JP 2016-035567 A, JP 2016-035565 A,
JP 2019-101417 A, JP 2019-117373 A, JP 2019-052294 A, JP 2019-008280 A, JP 2019-008279 A, JP 2019-003176 A, JP 2019-003175 A, JP 2018-197853 A, JP 2019-191298 A, JP 2019-061217 A, JP 2018-045152 A, JP 2018-022039 A, JP 2016-090441 A, JP 2015-10878 A, JP 2012-168279 A, JP 2012-022261 A, JP 2012-022258 A, JP 2011-043749 A, JP 2010-181857 A, JP 2010-128369 A, WO 2018/031896 A, JP 2019-113855 A, WO 2017/156388 A, WO 2017/066319 A, JP 2018-41099 A, WO 2016/065120 A, WO 2015/026482 A, JP 2016-29498 A, JP 2011-253185 A and the like, the so-called resist compositions such as a radiation-sensitive resin composition and a high-resolution patterning composition based on an organometallic solution, and a metal-containing resist composition may be used, but are not limited thereto.
Examples of the resist composition include the following compositions:
An active ray-sensitive or radiation-sensitive resin composition containing: a resin A having a repeating unit having an acid-decomposable group in which a polar group is protected by a protecting group that is removed by an action of an acid; and a compound represented by the following Formula (21):
A metal-containing film-forming composition for extreme ultraviolet ray or electron beam lithography, containing: a solvent and a compound having a metal-oxygen covalent bond, in which the metal elements constituting the compound belong to the third to seventh periods of Groups 3 to 15 of the periodic table.
A radiation-sensitive resin composition containing: an acid generator and a polymer having a first structural unit represented by the following Formula (31) and a second structural unit having an acid-dissociable group represented by the following Formula (32):
A resist composition containing: an acid generator and a resin (A1) having a structural unit having a cyclic carbonic acid ester structure, a structural unit represented by the following Formula, and a structural unit having an acid-unstable group:
Examples of the resist film include the following:
A resist film containing a base resin containing a repeating unit represented by the following Formula (a1) and/or a repeating unit represented by the following Formula (a2), and a repeating unit that generates an acid bonded to a polymer main chain upon exposure:
Examples of the resist material include the following:
A resist material including a polymer having a repeating unit represented by the following Formula (b1) or Formula (b2):
A resist material including a base resin including a polymer having a repeating unit represented by the following Formula (a):
A resist composition which generates an acid by exposure and whose solubility in a developer is changed by an action of an acid, the resist composition containing:
The structural unit (f1) includes a structural unit represented by the following Formula (f1-1) or a structural unit represented by the following Formula (f1-2):
Examples of the coating, the coating solution, and the coating composition include the following:
A coating including a metal oxo-hydroxo network having organic ligand through a metal carbon bond and/or a metal carboxylate bond.
An inorganic oxo/hydroxo-based composition.
A coating solution containing: an organic solvent; a first organometallic composition represented by Formula RzSnO(2-(z/2)-(x/2))(OH)x (where 0<z≤2 and 0<(z+x)≤4), Formula R′nSnX4-n(where n=1 or 2), or a mixture thereof, where R and R′ are independently a hydrocarbyl group having 1 to 31 carbon atoms, and X is a ligand having a hydrolyzable bond to Sn or a combination thereof; and a hydrolyzable metal compound represented by MX′v (where M is a metal selected from Groups 2 to 16 of the periodic table of the elements, v=number of 2 to 6, and X′ is a ligand having a hydrolyzable M-X bond or a combination thereof).
A coating solution containing: an organic solvent; and a first organometallic compound represented by Formula RSnO(3/2-x/2) (OH)x (where 0<x<3), in which about 0.0025 M to about 1.5 M tin is contained in the solution, R is an alkyl group or cycloalkyl group having 3 to 31 carbon atoms, and the alkyl group or cycloalkyl group is bonded to tin via a secondary or tertiary carbon atom.
An inorganic pattern forming precursor aqueous solution containing a mixture of water, a metal suboxide cation, a polyatomic inorganic anion, and a radiation-sensitive ligand containing a peroxide group.
Irradiation with light or an electron beam is performed, for example, through a mask (reticle) for forming a predetermined pattern.
The light exposure amount and the irradiation energy of the electron beam are not particularly limited.
Post exposure bake (PEB) may be performed after the irradiation with light or electron beam and before development.
The baking temperature is not particularly limited, and is preferably 60° C. to 150° C., more preferably 70° C. to 120° C., and particularly preferably 75° C. to 110° C.
The baking time is not particularly limited, and is preferably 1 second to 10 minutes, more preferably 10 seconds to 5 minutes, and particularly preferably 30 seconds to 3 minutes.
For the development, for example, an alkaline developer is used.
The development temperature is, for example, 5° C. to 50° C.
The developing time is, for example, 10 seconds to 300 seconds.
Examples of the alkaline developer that can be used include aqueous solutions of alkalis, e.g. inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and ammonia water; primary amines such as ethylamine and n-propylamine; secondary amines such as diethylamine and di-n-butyl amine; tertiary amines such as triethylamine and methyldiethylamine; alcoholamines such as dimethylethanolamine and triethanolamine; quaternary ammonium salts such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, and choline; and cyclic amines such as pyrrole and piperidine. Further, it is also possible to add an appropriate amount of alcohols such as isopropyl alcohol or surfactants such as a nonionic surfactant to the aqueous solution of the alkalis. Among these, a preferred developer is an aqueous solution of quaternary ammonium salt, more preferably an aqueous solution of tetramethylammonium hydroxide and an aqueous solution of choline. Furthermore, a surfactant or the like may be added to these developers. Instead of the method using the alkaline developer, a method in which development is conducted using an organic solvent, such as butyl acetate, can be used to develop the portion of the photoresist where the alkali dissolution rate is not improved.
Next, the resist underlayer film is etched using the formed resist pattern as a mask. The etching may be dry etching or wet etching, but is preferably dry etching.
When the inorganic film is formed on the surface of the used semiconductor substrate, the surface of the inorganic film is allowed to be exposed, whereas when the inorganic film is not formed on the surface of the used semiconductor substrate, the surface of the semiconductor substrate is allowed to be exposed. Thereafter, a semiconductor device can be produced through a step of processing the semiconductor substrate by a known method (dry etching method or the like).
Next, the contents of the present invention will be specifically described with reference to Synthesis Examples and Examples, but the present invention is not limited thereto.
The weight-average molecular weights of the polymers shown in Synthesis Examples 1 to 10 below are results measured by gel permeation chromatography (hereinafter, abbreviated as GPC). For the measurement, a GPC apparatus manufactured by Tosoh Corporation was used, and measurement conditions and the like are as follows:
A reaction flask was charged with a mixture prepared by addition of 24.52 g of propylene glycol monomethyl ether to 16.00 g of MeDGIC (28.8 mass % propylene glycol monomethyl ether solution, manufactured by Shikoku Chemicals Corporation), 3.88 g of 1-thioglycerol (manufactured by FUJIFILM Wako Pure Chemical Corporation), and 0.45 g of tetrabutylphosphonium bromide (manufactured by Hokko Chemical Industry Co., Ltd.), and heated and stirred at 105° C. for 18 hours in a nitrogen atmosphere. The resultant reaction product was found to correspond to the following Formula (X-1), and to have a weight-average molecular weight Mw of 330 as measured by GPC in terms of polystyrene. Thereafter, the reaction product solution was added dropwise to a hexane solution, and the resultant precipitate was separated by filtration and dried at 40° C. under vacuum. The resultant compound was dissolved in ultrapure water so as to be 10 mass %.
A reaction flask was charged with a mixture prepared by addition of 42.68 g of propylene glycol monomethyl ether to 5.00 g of TEPIC (manufactured by Nissan Chemical Corporation), 5.45 g of 1-thioglycerol (manufactured by FUJIFILM Wako Pure Chemical Corporation), and 0.21 g of tetrabutylphosphonium bromide (manufactured by Hokko Chemical Industry Co., Ltd.), and heated and stirred at 105° C. for 23 hours in a nitrogen atmosphere. The resultant reaction product was found to correspond to the following Formula (X-2), and to have a weight-average molecular weight Mw of 470 as measured by GPC in terms of polystyrene. Thereafter, the reaction product solution was added dropwise to a hexane solution, and the resultant precipitate was separated by filtration and dried at 40° C. under vacuum. The resultant compound was dissolved in ultrapure water so as to be 10 mass %.
A reaction flask was charged with a mixture prepared by addition of 20.32 g of propylene glycol monomethyl ether to 2.50 g of EX-201 (manufactured by Nagase ChemteX Corporation), 2.31 g of 1-thioglycerol (manufactured by FUJIFILM Wako Pure Chemical Corporation), and 0.26 g of tetrabutylphosphonium bromide (manufactured by Hokko Chemical Industry Co., Ltd.), and heated and stirred at 105° C. for 18 hours in a nitrogen atmosphere. The resultant reaction product was found to correspond to the following Formula (X-3), and to have a weight-average molecular weight Mw of 500 as measured by GPC in terms of polystyrene. Thereafter, the reaction product solution was added dropwise to a hexane solution, and the resultant precipitate was separated by filtration and dried at 40° C. under vacuum. The resultant compound was dissolved in ultrapure water so as to be 10 mass %.
A reaction flask was charged with a mixture prepared by addition of 37.10 g of propylene glycol monomethyl ether to 5.00 g of HP-4032D (manufactured by DIC Corporation), 3.96 g of 1-thioglycerol (manufactured by FUJIFILM Wako Pure Chemical Corporation), and 0.31 g of tetrabutylphosphonium bromide (manufactured by Hokko Chemical Industry Co., Ltd.), and heated and stirred at 105° C. for 18 hours in a nitrogen atmosphere. The resultant reaction product was found to correspond to the following Formula (X-4), and to have a weight-average molecular weight Mw of 700 as measured by GPC in terms of polystyrene. Thereafter, the reaction product solution was added dropwise to a hexane solution, and the resultant precipitate was separated by filtration and dried at 40° C. under vacuum. The resultant compound was dissolved in ultrapure water so as to be 10 mass %.
A reaction flask was charged with a mixture prepared by addition of 20.36 g of propylene glycol monomethyl ether to 2.30 g of TEPIC (manufactured by Nissan Chemical Corporation), 2.74 g of succinic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), and 0.04 g of tetrabutylphosphonium bromide (manufactured by Hokko Chemical Industry Co., Ltd.), and heated and stirred at 90° C. for 21 hours in a nitrogen atmosphere. The resultant reaction product was found to correspond to the following Formula (X-5), and to have a weight-average molecular weight Mw of 800 as measured by GPC in terms of polystyrene. Thereafter, the reaction product solution was added dropwise to a hexane solution, and the resultant precipitate was separated by filtration and dried at 40° C. under vacuum. The resultant compound was dissolved in ultrapure water so as to be 10 mass %.
A reaction flask was charged with a mixture prepared by addition of 17.47 g of propylene glycol monomethyl ether to 2.20 g of MAICA (manufactured by Shikoku Chemicals Corporation), 2.00 g of glycidol (manufactured by FUJIFILM Wako Pure Chemical Corporation), and 0.16 g of tetrabutylphosphonium bromide (manufactured by Hokko Chemical Industry Co., Ltd.), and heated and stirred at 105° C. for 22 hours in a nitrogen atmosphere. The resultant reaction product was found to correspond to the following Formula (X-6), and to have a weight-average molecular weight Mw of 400 as measured by GPC in terms of polystyrene. Thereafter, the reaction product solution was added dropwise to a hexane solution, and the resultant precipitate was separated by filtration and dried at 40° C. under vacuum. The resultant compound was dissolved in ultrapure water so as to be 10 mass %.
A reaction flask was charged with a mixture prepared by addition of 21.73 g of propylene glycol monomethyl ether to 3.37 g of monomethyl dicarboxy methyl isocyanuric acid, 2.00 g of glycidol (manufactured by FUJIFILM Wako Pure Chemical Corporation), and 0.55 g of tetrabutylphosphonium bromide (manufactured by Hokko Chemical Industry Co., Ltd.), and heated and stirred at 105° C. for 22 hours in a nitrogen atmosphere. The resultant reaction product was found to correspond to the following Formula (X-7), and to have a weight-average molecular weight Mw of 460 as measured by GPC in terms of polystyrene. Thereafter, the reaction product solution was added dropwise to a hexane solution, and the resultant precipitate was separated by filtration and dried at 40° C. under vacuum. The resultant compound was dissolved in ultrapure water so as to be 10 mass %.
A reaction flask was charged with a mixture prepared by addition of 21.56 g of propylene glycol monomethyl ether to 2.90 g of tricarboxymethyl isocyanurate, 2.40 g of glycidol (manufactured by FUJIFILM Wako Pure Chemical Corporation), and 0.08 g of tetrabutylphosphonium bromide (manufactured by Hokko Chemical Industry Co., Ltd.), and heated and stirred at 105° C. for 21 hours in a nitrogen atmosphere. The resultant reaction product was found to correspond to the following Formula (X-8), and to have a weight-average molecular weight Mw of 550 as measured by GPC in terms of polystyrene. Thereafter, the reaction product solution was added dropwise to a hexane solution, and the resultant precipitate was separated by filtration and dried at 40° C. under vacuum. The resultant compound was dissolved in ultrapure water so as to be 10 mass %.
A reaction flask was charged with a mixture prepared by addition of 17.54 g of propylene glycol monomethyl ether to 2.16 g of isophthalic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 2.00 g of glycidol (manufactured by FUJIFILM Wako Pure Chemical Corporation), and 0.22 g of tetrabutylphosphonium bromide (manufactured by Hokko Chemical Industry Co., Ltd.), and heated and stirred at 105° C. for 22 hours in a nitrogen atmosphere. The resultant reaction product was found to correspond to the following Formula (X-9), and to have a weight-average molecular weight Mw of 450 as measured by GPC in terms of polystyrene. Thereafter, the reaction product solution was added dropwise to a hexane solution, and the resultant precipitate was separated by filtration and dried at 40° C. under vacuum. The resultant compound was dissolved in ultrapure water so as to be 10 mass %.
A reaction flask was charged with a mixture prepared by addition of 25.7 g of ultrapure water to 3.00 g of TEPIC (manufactured by Nissan Chemical Corporation), 3.29 g of 1-thioglycerol (manufactured by FUJIFILM Wako Pure Chemical Corporation), and 0.13 g of tetrabutylphosphonium bromide (manufactured by Hokko Chemical Industry Co., Ltd.), and heated and stirred at 100° C. for 14 hours in a nitrogen atmosphere. The resultant reaction product was found to correspond to the following Formula (X-2), and to have a weight-average molecular weight Mw of 530 as measured by GPC in terms of polystyrene.
To 7.33 g of the aqueous solution (solid content: 10 mass %) of the reaction product prepared in Synthesis Example 1, 0.18 g of tetramethoxymethyl glycoluril, 0.02 g of pyridinium p-toluenesulfonic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.03 g of hydroxypropylcellulose (HPC-SSL, Nippon Soda Co., Ltd.), and 92.41 g of ultrapure water were added to prepare a solution. The solution was filtered using a hydrophilic PTFE syringe filter having a pore size of 0.02 μm to prepare a resist underlayer film-forming composition.
To 7.33 g of the aqueous solution (solid content: 10 mass %) of the reaction product prepared in Synthesis Example 2, 0.18 g of tetramethoxymethyl glycoluril, 0.02 g of pyridinium p-toluenesulfonic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.03 g of hydroxypropylcellulose (HPC-SSL, Nippon Soda Co., Ltd.), and 92.41 g of ultrapure water were added to prepare a solution. The solution was filtered using a hydrophilic PTFE syringe filter having a pore size of 0.02 μm to prepare a resist underlayer film-forming composition.
To 7.33 g of the aqueous solution (solid content: 10 mass %) of the reaction product prepared in Synthesis Example 3, 0.18 g of tetramethoxymethyl glycoluril, 0.02 g of pyridinium p-toluenesulfonic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.03 g of hydroxypropylcellulose (HPC-SSL, Nippon Soda Co., Ltd.), and 92.41 g of ultrapure water were added to prepare a solution. The solution was filtered using a hydrophilic PTFE syringe filter having a pore size of 0.02 μm to prepare a resist underlayer film-forming composition.
To 7.33 g of the aqueous solution (solid content: 10 mass %) of the reaction product prepared in Synthesis Example 4, 0.18 g of tetramethoxymethyl glycoluril, 0.02 g of pyridinium p-toluenesulfonic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.03 g of hydroxypropylcellulose (HPC-SSL, Nippon Soda Co., Ltd.), and 92.41 g of ultrapure water were added to prepare a solution. The solution was filtered using a hydrophilic PTFE syringe filter having a pore size of 0.02 μm to prepare a resist underlayer film-forming composition.
To 7.33 g of the aqueous solution (solid content: 10 mass %) of the reaction product prepared in Synthesis Example 5, 0.18 g of tetramethoxymethyl glycoluril, 0.02 g of pyridinium p-toluenesulfonic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.03 g of hydroxypropylcellulose (HPC-SSL, Nippon Soda Co., Ltd.), and 92.41 g of ultrapure water were added to prepare a solution. The solution was filtered using a hydrophilic PTFE syringe filter having a pore size of 0.02 μm to prepare a resist underlayer film-forming composition.
To 7.33 g of the aqueous solution (solid content: 10 mass %) of the reaction product prepared in Synthesis Example 6, 0.18 g of tetramethoxymethyl glycoluril, 0.02 g of pyridinium p-toluenesulfonic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.03 g of hydroxypropylcellulose (HPC-SSL, Nippon Soda Co., Ltd.), and 92.41 g of ultrapure water were added to prepare a solution. The solution was filtered using a hydrophilic PTFE syringe filter having a pore size of 0.02 μm to prepare a resist underlayer film-forming composition.
To 7.33 g of the aqueous solution (solid content: 10 mass %) of the reaction product prepared in Synthesis Example 7, 0.18 g of tetramethoxymethyl glycoluril, 0.02 g of pyridinium p-toluenesulfonic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.03 g of hydroxypropylcellulose (HPC-SSL, Nippon Soda Co., Ltd.), and 92.41 g of ultrapure water were added to prepare a solution. The solution was filtered using a hydrophilic PTFE syringe filter having a pore size of 0.02 μm to prepare a resist underlayer film-forming composition.
To 7.33 g of the aqueous solution (solid content: 10 mass %) of the reaction product prepared in Synthesis Example 8, 0.18 g of tetramethoxymethyl glycoluril, 0.02 g of pyridinium p-toluenesulfonic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.03 g of hydroxypropylcellulose (HPC-SSL, Nippon Soda Co., Ltd.), and 92.41 g of ultrapure water were added to prepare a solution. The solution was filtered using a hydrophilic PTFE syringe filter having a pore size of 0.02 μm to prepare a resist underlayer film-forming composition.
To 7.33 g of the aqueous solution (solid content: 10 mass %) of the reaction product prepared in Synthesis Example 9, 0.18 g of tetramethoxymethyl glycoluril, 0.02 g of pyridinium p-toluenesulfonic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.03 g of hydroxypropylcellulose (HPC-SSL, Nippon Soda Co., Ltd.), and 92.41 g of ultrapure water were added to prepare a solution. The solution was filtered using a hydrophilic PTFE syringe filter having a pore size of 0.02 μm to prepare a resist underlayer film-forming composition.
To 7.33 g of the aqueous solution of the reaction product prepared in Synthesis Example 2 (solid content: 10 mass %), 0.18 g of tetramethoxymethyl glycoluril, 0.02 g of pyridinium p-toluenesulfonic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.03 g of polyvinyl alcohol (PXP-05, JAPAN VAM & POVAL CO., LTD.), and 92.41 g of ultrapure water were added to prepare a solution. The solution was filtered using a hydrophilic PTFE syringe filter having a pore size of 0.02 μm to prepare a resist underlayer film-forming composition.
To 9.19 g of the aqueous solution (solid content: 10 mass %) of the reaction product prepared in Synthesis Example 2, 0.03 g of pyridinium trifluoromethanesulfonic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.05 g of hydroxypropylcellulose (HPC-SSL, Nippon Soda Co., Ltd.), and 90.72 g of ultrapure water were added to prepare a solution. The solution was filtered using a hydrophilic PTFE syringe filter having a pore size of 0.02 μm to prepare a resist underlayer film-forming composition.
To 13.59 g of the aqueous solution (solid content: 10 mass %) of the reaction product prepared in Synthesis Example 2, 0.04 g of polystyrenesulfonic acid (manufactured by Sigma-Aldrich Co. LLC.) and 86.36 g of ultrapure water were added to prepare a solution. The solution was filtered using a hydrophilic PTFE syringe filter having a pore size of 0.02 μm to prepare a resist underlayer film-forming composition.
Each of the resist underlayer film-forming compositions prepared in Examples 1 to 12 was applied (spin-coated) onto a silicon wafer with a spin coater. The composition-applied silicon wafer after was heated on a hot plate at 205° C. for 1 minute to form an applied film (underlayer film) having a film thickness of 25 nm. Next, in order to confirm the solvent resistance of the underlayer film, the silicon wafer after formation of the underlayer film was immersed in a mixed solvent prepared by mixing propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate at a mass ratio of 7:3 for 1 minute, spin-dried, and then baked at 100° C. for 30 seconds. The film thickness of the protective film before and after immersion in the mixed solvent was measured with an optical interference film thickness meter (product name: NanoSpec 6100, manufactured by Nanometrics Inc.).
The solvent resistance was evaluated by calculating the film thickness reduction rate (%) of the underlayer film removed by immersion in the solvent according to the following calculation formula:
The results are shown in Table 1. When the film thickness reduction rate is about 1% or less, it can be said that the film has sufficient solvent resistance.
From the above results, the films formed from the resist underlayer film-forming compositions of Examples 1 to 12 had a very small change in film thickness even after being immersed in the solvent. Accordingly, the films formed from the resist underlayer film-forming compositions of Examples 1 to 12 have sufficient solvent resistance to function as an underlayer film.
In Examples 1, 3, 6, 9, and 11, the film thickness reduction rate is negative, but there is no particular problem.
Each of the resist underlayer film-forming compositions prepared in Examples 2, 10, 11, and 12 was applied onto a silicon wafer with a spin coater. The composition-applied silicon wafer was heated on a hot plate at 205° C. for 1 minute to form a resist underlayer film (film thickness: 30 nm). Then, for these resist underlayer films, an n value (refractive index) and a k value (attenuation coefficient or extinction coefficient) at a wavelength of 193 nm were measured using a spectroscopic ellipsometer (product name: VUV-VASE VU-302, manufactured by J. A. Woollam). The measurement results of the optical parameters are shown in Table 2.
An example in which a resist underlayer film is formed and a resist pattern is formed thereon will be described below. The resist underlayer film-forming composition prepared in Example 2 was applied onto a substrate in which a 50-nm-thick SiON film (nitrogen-containing silicon oxide film) had been formed on a silicon wafer with a spin coater. Then, the resultant substrate was baked on a hot plate (at 205° C. for 1 min) to form a resist underlayer film having a film thickness of 20 nm to 30 nm. A commercially available photoresist solution (trade name: AR2772, manufactured by JSR Corporation) was applied onto the resist underlayer film with a spin coater, and baked on a hot plate (e.g. at 110° C. for 90 seconds) to form a photoresist film having a film thickness of 100 nm.
Next, the photoresist film was exposed to light using a scanner [NSRS307E, manufactured by Nikon Corporation; wavelength: 193 nm, NA: 0.85, o: 0.85/0.93 (Dipole)] through a photomask set such that a line width of the photoresist and the width between lines of the photoresist both become 0.065 μm, i.e. 0.065 μm L/S (dense line), and nine of such lines were to be formed, after development. Thereafter, the photoresist film was subjected to post exposure bake (PEB) on a hot plate at 110° C. for 90 seconds, and cooled. Then, the photoresist film was developed in a 60-second single paddle-type process in accordance with industrial standards using a 0.26 N tetramethylammonium hydroxide aqueous solution as a developer. A resist pattern was formed through the above process.
A cross section of the resultant photoresist pattern in a direction perpendicular to the substrate, i.e. the silicon wafer was observed with a scanning electron microscope (SEM). As the observation result, the cross section of the photoresist pattern was favorable straight skirt-shaped, i.e. approximately rectangular.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2022-094144 | Jun 2022 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2023/021446 | 6/9/2023 | WO |
