Embodiments of the invention are in the field of semiconductor devices and processing and, in particular, non-planar semiconductor devices and methods of fabricating non-planar semiconductor devices.
For the past several decades, the scaling of features in integrated circuits has been a driving force behind an ever-growing semiconductor industry. Scaling to smaller and smaller features enables increased densities of functional units on the limited real estate of semiconductor chips. For example, shrinking transistor size allows for the incorporation of an increased number of memory or logic devices on a chip, lending to the fabrication of products with increased capacity. The drive for ever-more capacity, however, is not without issue. The necessity to optimize the performance of each device becomes increasingly significant.
In the manufacture of integrated circuit devices, multi-gate transistors, such as tri-gate transistors, have become more prevalent as device dimensions continue to scale down. In conventional processes, tri-gate transistors are generally fabricated on either bulk silicon substrates or silicon-on-insulator substrates. In some instances, bulk silicon substrates are preferred due to their lower cost and compatibility with the existing high-yielding bulk silicon substrate infrastructure.
Scaling multi-gate transistors has not been without consequence, however. As the dimensions of these fundamental building blocks of microelectronic circuitry are reduced and as the sheer number of fundamental building blocks fabricated in a given region is increased, the constraints on the semiconductor processes used to fabricate these building blocks have become overwhelming.
Aligned pitch-quartered patterning approaches for lithography edge placement error advanced rectification are described. In the following description, numerous specific details are set forth, such as specific integration and material regimes, in order to provide a thorough understanding of embodiments of the present invention. It will be apparent to one skilled in the art that embodiments of the present invention may be practiced without these specific details. In other instances, well-known features, such as integrated circuit design layouts, are not described in detail in order to not unnecessarily obscure embodiments of the present invention. Furthermore, it is to be understood that the various embodiments shown in the Figures are illustrative representations and are not necessarily drawn to scale.
One or more embodiments described herein is directed to processes and structures based on and resulting from aligned pitch-quartered patterning approaches for edge placement error (EPE) rectification. One or more embodiments may be described as a differentiated or “colored” alternating hardmask approach for semiconductor fin patterning. Embodiments may include one or more of directed self-assembly (DSA), semiconductor material patterning, pitch division such as pitch quartering, differentiated hardmask selectivity, self-alignment for fin patterning. One or more embodiments is particularly suited for non-planar semiconductor device fabrication.
In accordance with an embodiment of the present invention, doubling of allowed edge placement error and doubling of the cut size for cutting of small features at tight pitch is implemented for very fine fin patterning. In one embodiment, all features (e.g., fin lines) are transferred into a semiconductor substrate with a single population of critical dimension (CD) variation. This approach is in contrast to state of the art approaches that rely on spacer-based pitch quartering which typically has three discreet populations of line widths (e.g., backbone, complement and spacer dimensions).
To provide context, it may be desirable to use bulk silicon for fins or trigate based semiconductor devices. In an embodiment, directed self-assembly (DSA) is implemented to accomplish pitch division and “coloring” of every other feature in a desired pattern. In one such embodiment, the patterning approach is particularly applicable to patterning silicon fins in a tri-gate transition patterning flow. In an embodiment advantages of implementing approaches described herein may include one or more of: (1) enabling a single population of feature widths, (2) doubling the edge placement error requirements for feature cutting, (3) doubling dimensions of the hole or opening required to cut a single feature (e.g., relaxing the restrictions on the size of the opening), or (4) reducing the cost of the patterning process. Structural artifacts resulting from the process include, in an embodiment, a single population of critical dimensions and at the transitions from one pitch to another and/or from one grid to another at the guard rings surrounding the die of the chips. Embodiments may enable cutting of tight pitch lines without scaling the edge-placement error requirements.
In an exemplary processing scheme,
In an embodiment, the first patterned hardmask 104 includes features having a pitch 106. In one such embodiment, the first patterned hardmask 104 represents half of the possibly number of fins ultimately formed in the substrate 102. That is, the pitch 106 is effectively relaxed to double the pitch of the final pattern of fins formed. In one embodiment, the first hardmask 104 is patterned directly using a lithographic process. However, in other embodiments, pitch division is applied, e.g., pitch halving, and is used to provide patterned hardmask 104 with pitch 106. It is to be appreciated that, in an embodiment, the first guide pattern can be formed using conventional patterning (litho/etch), only litho, spacer-based double patterning or other pitch division methods. In one embodiment, the guide pattern is separated from the DSA pattern through the use of two or more hardmasks such that the CDs are formed from a single population (e.g., one etch)).
In an embodiment, the second hardmask layer 108 has an etch characteristic different from an etch characteristic of the first patterned hardmask 104.
In one embodiment, one or both of the second hardmask layer 108 or the first patterned hardmask 104 is a layer of a nitride of silicon (e.g., silicon nitride) or a layer of an oxide of silicon, or both, or a combination thereof. Other suitable materials may include carbon-based materials, such as silicon carbide. In another embodiment, a hardmask material includes a metal species. For example, a hardmask or other overlying material may include a layer of a nitride of titanium (e.g., titanium nitride) or another metal. Potentially lesser amounts of other materials, such as oxygen, may be included in one or more of these layers. The hardmask layers maybe formed by CVD, PVD, or by other deposition methods.
In an embodiment, the selective brush material layer 110 includes a molecular species including polystyrene with a head group selected from the group consisting of —SH, —PO3H2, —CO2H, —NRH, —NRR′, and —Si(OR)3. In another embodiment, selective brush material layer 110 includes a molecular species including polymethacrylate with a head group selected from the group consisting of —SH, —PO3H2, —CO2H, —NRH, —NRR′, and —Si(OR)3. In an embodiment, the selective brush material layer 110 is attracted to one constituent of a DSA block co-polymer (e.g., polystrene or polymethylmethacrylate).
In an embodiment, the block copolymer molecule 114/116(A/B) is a polymeric molecule formed of a chain of covalently bonded monomers. In a di-block copolymer, there are two different types of monomers, and these different types of monomers are primarily included within two different blocks or contiguous sequences of monomers. The illustrated block copolymer molecule includes a block of polymer 114 and a block of polymer 116(A/B). In an embodiment, the block of polymer 114 includes predominantly a chain of covalently linked monomer A (e.g., A-A-A-A-A . . . ), whereas the block of polymer 116(AB) includes predominantly a chain of covalently linked monomer B (e.g., B-B-B-B-B . . . ). The monomers A and B may represent any of the different types of monomers used in block copolymers known in the arts. By way of example, the monomer A may represent monomers to form polystyrene, and the monomer B may represent monomers to form poly(methyl methacrylate) (PMMA), or vice versa, although the scope of the invention is not so limited. In other embodiments, there may be more than two blocks. Moreover, in other embodiments, each of the blocks may include different types of monomers (e.g., each block may itself be a copolymer). In one embodiment, the block of polymer 114 and the block of polymer 116(AB) are covalently bonded together. The block of polymer 114 and the block of polymer 116(A/B) may be of approximately equal length, or one block may be significantly longer than the other.
Typically, the blocks of block copolymers (e.g., the block of polymer 114 and the block of polymer 116(A/B)) may each have different chemical properties. As one example, one of the blocks may be relatively more hydrophobic (e.g., water repelling) and the other may be relatively more hydrophilic (water attracting). At least conceptually, one of the blocks may be relatively more similar to oil and the other block may be relatively more similar to water. Such differences in chemical properties between the different blocks of polymers, whether a hydrophilic-hydrophobic difference or otherwise, may cause the block copolymer molecules to self-assemble. For example, the self-assembly may be based on microphase separation of the polymer blocks. Conceptually, this may be similar to the phase separation of oil and water which are generally immiscible. Similarly, differences in hydrophilicity between the polymer blocks (e.g., one block is relatively hydrophobic and the other block is relatively hydrophilic), may cause a roughly analogous microphase separation where the different polymer blocks try to “separate” from each other due to chemical dislike for the other.
However, in an embodiment, since the polymer blocks are covalently bonded to one another, they cannot completely separate on a macroscopic scale. Rather, polymer blocks of a given type may tend to segregate or conglomerate with polymer blocks of the same type of other molecules in extremely small (e.g., nano-sized) regions or phases. The particular size and shape of the regions or microphases generally depends at least in part upon the relative lengths of the polymer blocks. In an embodiment, by way of example, in two block copolymers, if the blocks are approximately the same length, a grid like pattern of alternating polymer 114 lines and polymer 116(AB) lines is generated.
In an embodiment, the polymer 114/polymer 116(A/B) grating is first applied as an unassembled block copolymer layer portion that includes a block copolymer material applied, e.g., by brush or other coating process. The unassembled aspect refers to scenarios where, at the time of deposition, the block copolymer has not yet substantially phase separated and/or self-assembled to form nanostructures. In this unassembled form, the block polymer molecules are relatively highly randomized, with the different polymer blocks relatively highly randomly oriented and located. The unassembled block copolymer layer portion may be applied in a variety of different ways. By way of example, the block copolymer may be dissolved in a solvent and then spin coated over the surface. Alternatively, the unassembled block copolymer may be spray coated, dip coated, immersion coated, or otherwise coated or applied over the surface. Other ways of applying block copolymers, as well as other ways known in the arts for applying similar organic coatings, may potentially be used. Then, the unassembled layer may form an assembled block copolymer layer portion, e.g., by microphase separation and/or self-assembly of the unassembled block copolymer layer portion. The microphase separation and/or self-assembly occurs through rearrangement and/or repositioning of the block copolymer molecules, and in particular to rearrangement and/or repositioning of the different polymer blocks of the block copolymer molecules.
In one such embodiment, an annealing treatment may be applied to the unassembled block copolymer in order to initiate, accelerate, increase the quality of, or otherwise promote microphase separation and/or self-assembly. In some embodiments, the annealing treatment may include a treatment that is operable to increase a temperature of the block copolymer. One example of such a treatment is baking the layer, heating the layer in an oven or under a thermal lamp, applying infrared radiation to the layer, or otherwise applying heat to or increasing the temperature of the layer. The desired temperature increase will generally be sufficient to significantly accelerate the rate of microphase separation and/or self-assembly of the block polymer without damaging the block copolymer or any other important materials or structures of the integrated circuit substrate. Commonly, the heating may range between about 50° C. to about 300° C., or between about 75° C. to about 250° C., but not exceeding thermal degradation limits of the block copolymer or integrated circuit substrate. The heating or annealing may help to provide energy to the block copolymer molecules to make them more mobile/flexible in order to increase the rate of the microphase separation and/or improve the quality of the microphase separation. Such microphase separation or rearrangement/repositioning of the block copolymer molecules may lead to self-assembly to form extremely small (e.g., nano-scale) structures. The self-assembly may occur under the influence of surface energy, molecular affinities, and other surface-related and chemical-related forces.
In any case, in some embodiments, self-assembly of block copolymers, whether based on hydrophobic-hydrophilic differences or otherwise, may be used to form extremely small periodic structures (e.g., precisely spaced nano-scale structures or lines). In some embodiments, they may be used to form nano-scale lines or other nano-scale structures that can ultimately be used to form semiconductor fin lines.
In an embodiment, patterned mask 130 is composed of a photoresist layer, as is known in the art, and may be patterned by conventional lithography and development processes. In a particular embodiment, the portions of the photoresist layer exposed to the light source are removed upon developing the photoresist layer. Thus, patterned photoresist layer is composed of a positive photoresist material. In a specific embodiment, the photoresist layer is composed of a positive photoresist material such as, but not limited to, a 248 nm resist, a 193 nm resist, a 157 nm resist, an extreme ultra violet (EUV) resist, an e-beam resist, an imprint layer, or a phenolic resin matrix with a diazonaphthoquinone sensitizer. In another particular embodiment, the portions of the photoresist layer exposed to the light source are retained upon developing the photoresist layer. Thus, the photoresist layer is composed of a negative photoresist material. In a specific embodiment, the photoresist layer is composed of a negative photoresist material such as, but not limited to, consisting of poly-cis-isoprene or poly-vinyl-cinnamate. In an embodiment, lithographic operations are performed using 193 nm immersion litho (193i), EUV and/or EBDW lithography, or the like. A positive tone or a negative tone resist may be used. In one embodiment, the patterned mask 130 is a trilayer mask composed of a topographic masking portion, an anti-reflective coating (ARC) layer, and a photoresist layer. In a particular such embodiment, the topographic masking portion is a carbon hardmask (CHM) layer and the anti-reflective coating layer is a silicon-containing ARC layer. In one such embodiment, a spin-on glass material with added chromophores is used to aid in suppressing reflectivity. Chemically they are (siloxanes) silicon-carbon containing polymers. When annealed they form a mixture of silicon dioxide and carbon polymers.
However, in accordance with another embodiment,
In an exemplary embodiment, referring again to
In an exemplary embodiment, referring again to
It is to be appreciated that the structures resulting from the above exemplary processing schemes, e.g., structures from
Referring to
As is also depicted in
As is also depicted in
Referring to
In an embodiment, the semiconductor structure or device 300 is a non-planar device such as, but not limited to, a fin-FET or a tri-gate device. In such an embodiment, a corresponding semiconducting channel region is composed of or is formed in a three-dimensional body. In one such embodiment, the gate electrode stacks of gate lines 308 surround at least a top surface and a pair of sidewalls of the three-dimensional body.
Substrate 302 may be composed of a semiconductor material that can withstand a manufacturing process and in which charge can migrate. In an embodiment, substrate 302 is a bulk substrate composed of a crystalline silicon, silicon/germanium or germanium layer doped with a charge carrier, such as but not limited to phosphorus, arsenic, boron or a combination thereof, to form active region 304. In one embodiment, the concentration of silicon atoms in bulk substrate 302 is greater than 97%. In another embodiment, bulk substrate 302 is composed of an epitaxial layer grown atop a distinct crystalline substrate, e.g. a silicon epitaxial layer grown atop a boron-doped bulk silicon mono-crystalline substrate. Bulk substrate 302 may alternatively be composed of a group III-V material. In an embodiment, bulk substrate 302 is composed of a III-V material such as, but not limited to, gallium nitride, gallium phosphide, gallium arsenide, indium phosphide, indium antimonide, indium gallium arsenide, aluminum gallium arsenide, indium gallium phosphide, or a combination thereof. In one embodiment, bulk substrate 302 is composed of a III-V material and the charge-carrier dopant impurity atoms are ones such as, but not limited to, carbon, silicon, germanium, oxygen, sulfur, selenium or tellurium.
Isolation region 306 may be composed of a material suitable to ultimately electrically isolate, or contribute to the isolation of, portions of a permanent gate structure from an underlying bulk substrate or isolate active regions formed within an underlying bulk substrate, such as isolating fin active regions. For example, in one embodiment, the isolation region 306 is composed of a dielectric material such as, but not limited to, silicon dioxide, silicon oxy-nitride, silicon nitride, or carbon-doped silicon nitride.
Gate line 308 may be composed of a gate electrode stack which includes a gate dielectric layer 352 and a gate electrode layer 350. In an embodiment, the gate electrode of the gate electrode stack is composed of a metal gate and the gate dielectric layer is composed of a high-K material. For example, in one embodiment, the gate dielectric layer is composed of a material such as, but not limited to, hafnium oxide, hafnium oxy-nitride, hafnium silicate, lanthanum oxide, zirconium oxide, zirconium silicate, tantalum oxide, barium strontium titanate, barium titanate, strontium titanate, yttrium oxide, aluminum oxide, lead scandium tantalum oxide, lead zinc niobate, or a combination thereof. Furthermore, a portion of gate dielectric layer may include a layer of native oxide formed from the top few layers of the substrate 302. In an embodiment, the gate dielectric layer is composed of a top high-k portion and a lower portion composed of an oxide of a semiconductor material. In one embodiment, the gate dielectric layer is composed of a top portion of hafnium oxide and a bottom portion of silicon dioxide or silicon oxy-nitride. In some implementations, a portion of the gate dielectric is a “U”-shaped structure that includes a bottom portion substantially parallel to the surface of the substrate and two sidewall portions that are substantially perpendicular to the top surface of the substrate.
In one embodiment, the gate electrode is composed of a metal layer such as, but not limited to, metal nitrides, metal carbides, metal silicides, metal aluminides, hafnium, zirconium, titanium, tantalum, aluminum, ruthenium, palladium, platinum, cobalt, nickel or conductive metal oxides. In a specific embodiment, the gate electrode is composed of a non-workfunction-setting fill material formed above a metal workfunction-setting layer. The gate electrode layer may consist of a P-type workfunction metal or an N-type workfunction metal, depending on whether the transistor is to be a PMOS or an NMOS transistor. In some implementations, the gate electrode layer may consist of a stack of two or more metal layers, where one or more metal layers are workfunction metal layers and at least one metal layer is a conductive fill layer. For a PMOS transistor, metals that may be used for the gate electrode include, but are not limited to, ruthenium, palladium, platinum, cobalt, nickel, and conductive metal oxides, e.g., ruthenium oxide. A P-type metal layer will enable the formation of a PMOS gate electrode with a workfunction that is between about 4.9 eV and about 5.2 eV. For an NMOS transistor, metals that may be used for the gate electrode include, but are not limited to, hafnium, zirconium, titanium, tantalum, aluminum, alloys of these metals, and carbides of these metals such as hafnium carbide, zirconium carbide, titanium carbide, tantalum carbide, and aluminum carbide. An N-type metal layer will enable the formation of an NMOS gate electrode with a workfunction that is between about 3.9 eV and about 4.2 eV. In some implementations, the gate electrode may consist of a “U”-shaped structure that includes a bottom portion substantially parallel to the surface of the substrate and two sidewall portions that are substantially perpendicular to the top surface of the substrate. In another implementation, at least one of the metal layers that form the gate electrode may simply be a planar layer that is substantially parallel to the top surface of the substrate and does not include sidewall portions substantially perpendicular to the top surface of the substrate. In further implementations of the invention, the gate electrode may consist of a combination of U-shaped structures and planar, non-U-shaped structures. For example, the gate electrode may consist of one or more U-shaped metal layers formed atop one or more planar, non-U-shaped layers.
Spacers associated with the gate electrode stacks may be composed of a material suitable to ultimately electrically isolate, or contribute to the isolation of, a permanent gate structure from adjacent conductive contacts, such as self-aligned contacts. For example, in one embodiment, the spacers are composed of a dielectric material such as, but not limited to, silicon dioxide, silicon oxy-nitride, silicon nitride, or carbon-doped silicon nitride.
Gate contact 314 and overlying gate contact via 316 may be composed of a conductive material. In an embodiment, one or more of the contacts or vias are composed of a metal species. The metal species may be a pure metal, such as tungsten, nickel, or cobalt, or may be an alloy such as a metal-metal alloy or a metal-semiconductor alloy (e.g., such as a silicide material).
In an embodiment (although not shown), providing structure 300 involves formation of a contact pattern which is essentially perfectly aligned to an existing gate pattern while eliminating the use of a lithographic operation with exceedingly tight registration budget. In one such embodiment, this approach enables the use of intrinsically highly selective wet etching (e.g., versus conventionally implemented dry or plasma etching) to generate contact openings. In an embodiment, a contact pattern is formed by utilizing an existing gate pattern in combination with a contact plug lithography operation. In one such embodiment, the approach enables elimination of the need for an otherwise critical lithography operation to generate a contact pattern, as used in conventional approaches. In an embodiment, a trench contact grid is not separately patterned, but is rather formed between poly (gate) lines. For example, in one such embodiment, a trench contact grid is formed subsequent to gate grating patterning but prior to gate grating cuts.
Furthermore, the gate stack structure 308 may be fabricated by a replacement gate process. In such a scheme, dummy gate material such as polysilicon or silicon nitride pillar material, may be removed and replaced with permanent gate electrode material. In one such embodiment, a permanent gate dielectric layer is also formed in this process, as opposed to being carried through from earlier processing. In an embodiment, dummy gates are removed by a dry etch or wet etch process. In one embodiment, dummy gates are composed of polycrystalline silicon or amorphous silicon and are removed with a dry etch process including use of SF6. In another embodiment, dummy gates are composed of polycrystalline silicon or amorphous silicon and are removed with a wet etch process including use of aqueous NH4OH or tetramethylammonium hydroxide. In one embodiment, dummy gates are composed of silicon nitride and are removed with a wet etch including aqueous phosphoric acid.
In an embodiment, one or more approaches described herein contemplate essentially a dummy and replacement gate process in combination with a dummy and replacement contact process to arrive at structure 300. In one such embodiment, the replacement contact process is performed after the replacement gate process to allow high temperature anneal of at least a portion of the permanent gate stack. For example, in a specific such embodiment, an anneal of at least a portion of the permanent gate structures, e.g., after a gate dielectric layer is formed, is performed at a temperature greater than approximately 600 degrees Celsius. The anneal is performed prior to formation of the permanent contacts.
Referring again to
It is to be appreciated that not all aspects of the processes described above need be practiced to fall within the spirit and scope of embodiments of the present invention. For example, in one embodiment, dummy gates need not ever be formed prior to fabricating gate contacts over active portions of the gate stacks. The gate stacks described above may actually be permanent gate stacks as initially formed. Also, the processes described herein may be used to fabricate one or a plurality of semiconductor devices. The semiconductor devices may be transistors or like devices. For example, in an embodiment, the semiconductor devices are a metal-oxide semiconductor (MOS) transistors for logic or memory, or are bipolar transistors. Also, in an embodiment, the semiconductor devices have a three-dimensional architecture, such as a trigate device, an independently accessed double gate device, or a FIN-FET. One or more embodiments may be particularly useful for fabricating semiconductor devices at a 10 nanometer (10 nm) or smaller technology node.
Depending on its applications, computing device 400 may include other components that may or may not be physically and electrically coupled to the board 402. These other components include, but are not limited to, volatile memory (e.g., DRAM), non-volatile memory (e.g., ROM), flash memory, a graphics processor, a digital signal processor, a crypto processor, a chipset, an antenna, a display, a touchscreen display, a touchscreen controller, a battery, an audio codec, a video codec, a power amplifier, a global positioning system (GPS) device, a compass, an accelerometer, a gyroscope, a speaker, a camera, and a mass storage device (such as hard disk drive, compact disk (CD), digital versatile disk (DVD), and so forth).
The communication chip 406 enables wireless communications for the transfer of data to and from the computing device 400. The term “wireless” and its derivatives may be used to describe circuits, devices, systems, methods, techniques, communications channels, etc., that may communicate data through the use of modulated electromagnetic radiation through a non-solid medium. The term does not imply that the associated devices do not contain any wires, although in some embodiments they might not. The communication chip 406 may implement any of a number of wireless standards or protocols, including but not limited to Wi-Fi (IEEE 802.11 family), WiMAX (IEEE 802.16 family), IEEE 802.20, long term evolution (LTE), Ev-DO, HSPA+, HSDPA+, HSUPA+, EDGE, GSM, GPRS, CDMA, TDMA, DECT, Bluetooth, derivatives thereof, as well as any other wireless protocols that are designated as 3G, 4G, 5G, and beyond. The computing device 400 may include a plurality of communication chips 406. For instance, a first communication chip 406 may be dedicated to shorter range wireless communications such as Wi-Fi and Bluetooth and a second communication chip 406 may be dedicated to longer range wireless communications such as GPS, EDGE, GPRS, CDMA, WiMAX, LTE, Ev-DO, and others.
The processor 404 of the computing device 400 includes an integrated circuit die packaged within the processor 404. In some implementations of embodiments of the invention, the integrated circuit die of the processor includes one or more devices, such as MOS-FET transistors built in accordance with implementations of the invention. The term “processor” may refer to any device or portion of a device that processes electronic data from registers and/or memory to transform that electronic data into other electronic data that may be stored in registers and/or memory.
The communication chip 406 also includes an integrated circuit die packaged within the communication chip 406. In accordance with another implementation of the invention, the integrated circuit die of the communication chip includes one or more devices, such as MOS-FET transistors built in accordance with implementations of the invention.
In further implementations, another component housed within the computing device 400 may contain an integrated circuit die that includes one or more devices, such as MOS-FET transistors built in accordance with implementations of embodiments of the invention.
In various embodiments, the computing device 400 may be a laptop, a netbook, a notebook, an ultrabook, a smartphone, a tablet, a personal digital assistant (PDA), an ultramobile PC, a mobile phone, a desktop computer, a server, a printer, a scanner, a monitor, a set-top box, an entertainment control unit, a digital camera, a portable music player, or a digital video recorder. In further implementations, the computing device 400 may be any other electronic device that processes data.
The interposer 500 may be formed of an epoxy resin, a fiberglass-reinforced epoxy resin, a ceramic material, or a polymer material such as polyimide. In further implementations, the interposer may be formed of alternate rigid or flexible materials that may include the same materials described above for use in a semiconductor substrate, such as silicon, germanium, and other group III-V and group IV materials.
The interposer may include metal interconnects 508 and vias 510, including but not limited to through-silicon vias (TSVs) 512. The interposer 500 may further include embedded devices 514, including both passive and active devices. Such devices include, but are not limited to, capacitors, decoupling capacitors, resistors, inductors, fuses, diodes, transformers, sensors, and electrostatic discharge (ESD) devices. More complex devices such as radio-frequency (RF) devices, power amplifiers, power management devices, antennas, arrays, sensors, and MEMS devices may also be formed on the interposer 500. In accordance with embodiments of the invention, apparatuses or processes disclosed herein may be used in the fabrication of interposer 500.
Thus, embodiments of the present invention include aligned pitch-quartered patterning approaches for lithography edge placement error advanced rectification.
In an embodiment, a semiconductor structure includes a plurality of semiconductor fins protruding from a substantially planar surface of a semiconductor substrate. The plurality of semiconductor fins has a grating pattern interrupted by a first location having a first fin portion having a first height and interrupted by a second location having a second fin portion having a second height different from the first height. A trench isolation layer is disposed between the plurality of semiconductor fins and adjacent to lower portions of the plurality of semiconductor fins, but not adjacent to upper portions of the plurality of semiconductor fins. The trench isolation layer is disposed over the first and second fin portions. One or more gate electrode stacks is disposed on top surfaces and sidewalls of the upper portions of the plurality of semiconductor fins and on portions of the trench isolation layer. Source and drain regions are disposed on either side of the one or more gate electrode stacks.
In one embodiment, the grating pattern has a constant pitch.
In one embodiment, the source and drain regions are disposed adjacent to the upper portions of the plurality of semiconductor fins and are composed a semiconductor material different than the semiconductor material of the semiconductor fins.
In one embodiment, the source and drain regions are disposed within the upper portions of the plurality of semiconductor fins.
In one embodiment, the one or more gate electrode stacks include a high-k gate dielectric layer and a metal gate electrode.
In an embodiment, a semiconductor structure includes a plurality of semiconductor fins protruding from a substantially planar surface of a semiconductor substrate. The plurality of semiconductor fins has a grating pattern interrupted by a first location having a first recess below the substantially planar surface of the semiconductor substrate. A trench isolation layer is disposed between the plurality of semiconductor fins and adjacent to lower portions of the plurality of semiconductor fins, but not adjacent to upper portions of the plurality of semiconductor fins. The trench isolation layer is disposed in and over the first recess. One or more gate electrode stacks is disposed on top surfaces and sidewalls of the upper portions of the plurality of semiconductor fins and on portions of the trench isolation layer. Source and drain regions are disposed on either side of the one or more gate electrode stacks.
In one embodiment, the grating pattern is further interrupted by a second location having a second recess below the substantially planar surface of the semiconductor substrate, and the trench isolation layer is disposed in and over the second recess.
In one embodiment, the grating pattern is further interrupted by a second location having a fin portion above the substantially planar surface of the semiconductor substrate, and the trench isolation layer is disposed over the fin portions.
In one embodiment, the grating pattern has a constant pitch.
In one embodiment, the source and drain regions are disposed adjacent to the upper portions of the plurality of semiconductor fins and are composed of a semiconductor material different than the semiconductor material of the semiconductor fins.
In one embodiment, the source and drain regions are disposed within the upper portions of the plurality of semiconductor fins.
In one embodiment, the one or more gate electrode stacks includes a high-k gate dielectric layer and a metal gate electrode.
In an embodiment, a method of fabricating a semiconductor structure includes forming a first patterned hardmask on a semiconductor substrate, the first patterned hardmask having features spaced apart by a pitch. A second hardmask layer is formed on the semiconductor substrate, between the features of the first patterned hardmask. A segregated di-block co-polymer is formed on the first patterned hardmask and on the second hardmask layer, the segregated di-block co-polymer including alternating first and second polymer blocks having a pitch between first blocks approximately equal to half the pitch of the features of the first patterned hardmask. The second polymer blocks is removed from the segregated di-block co-polymer. Subsequent to removing the second polymer blocks, a second patterned hardmask is formed from the second hardmask layer and a plurality of semiconductor fins is formed in the semiconductor substrate using the first polymer blocks as a mask, the semiconductor fins having a pitch approximately equal to half the pitch of the features of the first patterned hardmask, wherein alternating fins of the plurality of semiconductor fins have corresponding alternating portions of the first patterned hardmask and the second patterned hardmask, respectively. A first fin of the plurality of semiconductor fins is removed, the first fin having a portion of the first patterned hardmask thereon. Subsequent to removing the first fin, a second fin of the plurality of semiconductor fins is removed, the second fin having a portion of the second patterned hardmask thereon.
In one embodiment, forming the second hardmask layer includes forming a blanket hardmask material over the semiconductor substrate and over the first patterned hardmask, and planarizing the blanket hardmask material.
In one embodiment, the method further includes, prior to forming the segregated di-block co-polymer, forming a first molecular brush layer selectively on the first patterned hardmask.
In one embodiment, the method further includes, prior to forming the segregated di-block co-polymer, forming a second molecular brush layer selectively on the second hardmask layer.
In one embodiment, forming the segregated di-block co-polymer includes forming a randomized di-block co-polymer on the first patterned hardmask and on the second hardmask layer, and then annealing the randomized di-block co-polymer.
In one embodiment, the method further includes, subsequent to forming the second patterned hardmask and forming the plurality of semiconductor fins and prior to removing the first and second fins, forming an inter-layer dielectric (ILD) layer over the plurality of semiconductor fins.
In one embodiment, the method further includes, subsequent to removing the first and second fins, recessing the ILD layer below a top surface of the plurality of semiconductor fins, exposing protruding portions of each of the plurality of semiconductor fins above sub-fin regions of each of the plurality of semiconductor fins.
In one embodiment, the method further includes forming one or more gate electrode stacks on the exposing protruding portions of each of the plurality of semiconductor fins.
In one embodiment, removing the first fin of the plurality of semiconductor fins includes etching the portion of the first patterned hardmask selective to exposed portions of the second patterned hardmask.
In one embodiment, removing the first fin of the plurality of semiconductor fins includes etching the portion of the second patterned hardmask selective to exposed portions of the first patterned hardmask.
This patent application is a division of U.S. patent application Ser. No. 16/068,095, filed Jul. 3, 2018, which is a U.S. National Phase application under 35 U.S.C. § 371 of International Application No. PCT/US2016/024556, filed Mar. 28, 2016, entitled “ALIGNED PITCH-QUARTERED PATTERNING FOR LITHOGRAPHY EDGE PLACEMENT ERROR ADVANCED RECTIFICATION,” which designates the United States of America, the entire disclosure of which are hereby incorporated by reference in their entirety and for all purposes.
Number | Date | Country | |
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Parent | 16068095 | Jul 2018 | US |
Child | 18205456 | US |