US20140273511A1 - Methods for fabricating integrated circuits including formation of chemical guide patterns for directed self-assembly lithography - Google Patents
Methods for fabricating integrated circuits including formation of chemical guide patterns for directed self-assembly lithography Download PDFInfo
- Publication number
- US20140273511A1 US20140273511A1 US13/841,694 US201313841694A US2014273511A1 US 20140273511 A1 US20140273511 A1 US 20140273511A1 US 201313841694 A US201313841694 A US 201313841694A US 2014273511 A1 US2014273511 A1 US 2014273511A1
- Authority
- US
- United States
- Prior art keywords
- layer
- pinning
- neutral
- polymeric
- bifunctional
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/027—Making masks on semiconductor bodies for further photolithographic processing not provided for in group H01L21/18 or H01L21/34
- H01L21/033—Making masks on semiconductor bodies for further photolithographic processing not provided for in group H01L21/18 or H01L21/34 comprising inorganic layers
- H01L21/0334—Making masks on semiconductor bodies for further photolithographic processing not provided for in group H01L21/18 or H01L21/34 comprising inorganic layers characterised by their size, orientation, disposition, behaviour, shape, in horizontal or vertical plane
- H01L21/0337—Making masks on semiconductor bodies for further photolithographic processing not provided for in group H01L21/18 or H01L21/34 comprising inorganic layers characterised by their size, orientation, disposition, behaviour, shape, in horizontal or vertical plane characterised by the process involved to create the mask, e.g. lift-off masks, sidewalls, or to modify the mask, e.g. pre-treatment, post-treatment
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B81—MICROSTRUCTURAL TECHNOLOGY
- B81C—PROCESSES OR APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OR TREATMENT OF MICROSTRUCTURAL DEVICES OR SYSTEMS
- B81C1/00—Manufacture or treatment of devices or systems in or on a substrate
- B81C1/00015—Manufacture or treatment of devices or systems in or on a substrate for manufacturing microsystems
- B81C1/00023—Manufacture or treatment of devices or systems in or on a substrate for manufacturing microsystems without movable or flexible elements
- B81C1/00031—Regular or irregular arrays of nanoscale structures, e.g. etch mask layer
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
- G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
- G03F7/0002—Lithographic processes using patterning methods other than those involving the exposure to radiation, e.g. by stamping
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/027—Making masks on semiconductor bodies for further photolithographic processing not provided for in group H01L21/18 or H01L21/34
- H01L21/0271—Making masks on semiconductor bodies for further photolithographic processing not provided for in group H01L21/18 or H01L21/34 comprising organic layers
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/027—Making masks on semiconductor bodies for further photolithographic processing not provided for in group H01L21/18 or H01L21/34
- H01L21/0271—Making masks on semiconductor bodies for further photolithographic processing not provided for in group H01L21/18 or H01L21/34 comprising organic layers
- H01L21/0273—Making masks on semiconductor bodies for further photolithographic processing not provided for in group H01L21/18 or H01L21/34 comprising organic layers characterised by the treatment of photoresist layers
- H01L21/0274—Photolithographic processes
- H01L21/0276—Photolithographic processes using an anti-reflective coating
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B81—MICROSTRUCTURAL TECHNOLOGY
- B81C—PROCESSES OR APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OR TREATMENT OF MICROSTRUCTURAL DEVICES OR SYSTEMS
- B81C2201/00—Manufacture or treatment of microstructural devices or systems
- B81C2201/01—Manufacture or treatment of microstructural devices or systems in or on a substrate
- B81C2201/0101—Shaping material; Structuring the bulk substrate or layers on the substrate; Film patterning
- B81C2201/0147—Film patterning
- B81C2201/0149—Forming nanoscale microstructures using auto-arranging or self-assembling material
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B82—NANOTECHNOLOGY
- B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- B82Y40/00—Manufacture or treatment of nanostructures
Definitions
- the technical field relates generally to methods for fabricating integrated circuits, and more particularly relates to methods for fabricating integrated circuits including formation of chemical guide patterns for directed self-assembly lithography.
- Optical lithography has been the driving force for device scaling.
- Conventional optical lithography is limited to about 80 nm pitch for single exposure patterning whilst double and other multi-patterning processes can realize smaller pitch, these approaches are expensive and more complex.
- Directed self-assembly a technique which aligns self-assembling polymeric materials on a lithographically defined guide pattern, is a potential option for extending current optical lithography beyond its pitch and resolution limits.
- the self-assembling materials for example, are block copolymers (BCPs) which consist of “A” homopolymer covalently attached to “B” homopolymer, which are coated over a lithographically defined guide pattern on a semiconductor substrate.
- BCPs block copolymers
- the lithographically defined guide pattern is a pre-pattern that is encoded with spatial chemical and/or topographical information and serves to direct the self-assembly process and the pattern formed by the self-assembling materials.
- a method for fabricating an integrated circuit includes forming a bifunctional brush layer of a polymeric material overlying an anti-reflective coating on a semiconductor substrate.
- the polymeric material has a neutral polymeric block portion and a pinning (non-neutral) polymeric block portion that are covalently bonded together.
- the bifunctional brush layer includes a neutral layer that is formed of the neutral polymeric block portion and a pinning layer that is formed of the pinning polymeric block portion.
- a portion of the neutral layer or the pinning layer is selectively removed to define a chemical guide pattern.
- a block copolymer layer is deposited overlying the chemical guide pattern.
- the block copolymer layer is phase separated to define a nanopattern that is registered to the chemical guide pattern.
- a method for fabricating an integrated circuit includes forming a bifunctional brush layer of a polymeric material overlying an anti-reflective coating on a semiconductor substrate.
- the bifunctional brush layer is formed such that a pinning layer of the bifunctional brush layer is disposed adjacent to the anti-reflective coating and a neutral layer of the bifunctional brush layer is disposed adjacent to the pinning layer on a side opposite the anti-reflective coating.
- the polymeric material includes a neutral polymeric block portion and a pinning polymeric block portion that form the neutral layer and the pinning layer, respectively.
- a portion of the neutral layer is selectively removed to define a chemical guide pattern.
- a block copolymer layer is deposited overlying the chemical guide pattern.
- the block copolymer layer is phase separated to define a nanopattern that is registered to the chemical guide pattern.
- a method for fabricating an integrated circuit includes forming a bifunctional brush layer of a polymeric material overlying an anti-reflective coating on a semiconductor substrate.
- the bifunctional brush layer is formed such that a neutral layer of the bifunctional brush layer is disposed adjacent to the anti-reflective coating and a pinning layer of the bifunctional brush layer is disposed adjacent to the neutral layer on a side opposite the anti-reflective coating.
- the polymeric material includes a neutral polymeric block portion and a pinning polymeric block portion that form the neutral layer and the pinning layer, respectively.
- a portion of the pinning layer is selectively removed to define a chemical guide pattern.
- a block copolymer layer is deposited overlying the chemical guide pattern.
- the block copolymer layer is phase separated to define a nanopattern that is registered to the chemical guide pattern.
- FIGS. 1-8 illustrate, in cross-sectional views, fabrication of the chemical guide pattern and a method for forming this structure during intermediate stages of its fabrication in accordance with an exemplary embodiment.
- FIGS. 9-16 illustrate, in cross-sectional views, fabrication of the chemical guide pattern and a method for forming this structure during intermediate stages of its fabrication in accordance with another exemplary embodiment.
- FIGS. 17-24 illustrate, in cross-sectional views, fabrication of the chemical guide pattern and a method for forming this structure during intermediate stages of its fabrication in accordance with another exemplary embodiment.
- the exemplary embodiments taught herein form a bifunctional brush layer of a polymeric material overlying an anti-reflective coating on a semiconductor substrate.
- the polymeric material includes polymer chains each having a neutral polymeric block and a pinning polymeric block that is coupled to an end of the neutral polymeric block.
- the neutral polymeric blocks together form the neutral polymeric block portion of the polymeric material and the pinning polymeric blocks together form the pinning polymeric block portion of the polymeric material.
- the neutral polymeric blocks are random copolymers that have no preferential affinity for the individual polymeric block components of a block copolymer layer that will be subsequently deposited over the polymeric material as part of a DSA process.
- the pinning polymeric blocks are polymers with functionality to facilitate preferential interaction (pinning) with one of the components of the polymeric material of the subsequently deposited block copolymer layer.
- the polymer chains that form the bifunctional brush layer are chemically attached (grafted) at one end to the anti-reflective coating by incorporating additional functionality, for example monohydroxy moieties or cyclic ethers, within the pinning brush polymeric block.
- a portion of the neutral layer or the pinning layer is selectively removed, e.g., using acid scissioning or ultraviolet (UV) lithography or electron beam lithography (EBL), to define a chemical guide pattern.
- a block copolymer layer is deposited overlying the chemical guide pattern as part of the DSA process.
- the block copolymer layer is heated to a temperature near or above its glass transition temperature (Tg) to phase separate the block copolymer into a first polymeric block portion and a second polymeric block portion.
- the chemical guide pattern has portions that consists of the neutral layer and portions that consists of the pinning layer, various areas of the chemical guide pattern have differing affinities towards the first polymeric block portion and independently towards the second polymeric block portion such that when the block copolymer is phase separated, it forms a nanopattern that is registered to the chemical guide pattern.
- the first or second polymeric block portion is removed to form a mask for transferring the nanopattern to the semiconductor substrate.
- This exemplary embodiment makes use of a polymeric material that has both a neutral polymeric block portion and a pinning polymeric block portion to create a bifunctional brush layer that can be formed simply from a single layer of the polymeric material to facilitate forming the chemical guide pattern, thereby reducing complexity and cost for large scale manufacturing of the integrated circuits using DSA.
- FIGS. 1-24 illustrate methods for fabricating an integrated circuit 10 in accordance with various embodiments.
- the described process steps, procedures, and materials are to be considered only as exemplary embodiments designed to illustrate to one of ordinary skill in the art methods for practicing the invention; the invention is not limited to these exemplary embodiments.
- Various steps in the manufacture of integrated circuits are well known and so, in the interest of brevity, many conventional steps will only be mentioned briefly herein or will be omitted entirely without providing the well-known process details.
- FIGS. 1-8 illustrate, in cross-sectional views, the integrated circuit 10 during intermediate stages of its fabrication in accordance with an exemplary embodiment.
- the integrated circuit includes an anti-reflective coating 12 disposed on a semiconductor substrate 14 .
- the semiconductor substrate 14 can be, for example, a bulk semiconductor substrate or silicon-on-insulator (SOI) semiconductor substrate as are well known in the art.
- the anti-reflective coating 12 which is commonly referred to as ARC or BARC (bottom anti-reflective coating), may be a polymer and/or silicon (Si) containing material that is used to absorb and/or control light to dampen or eliminate light reflection during photolithography to improve the photolithography process window for producing smaller features.
- the anti-reflective coating 12 is formed of a Si-containing polymer(s) (SiARC) that may be cross-linked.
- SiARC materials are commercially available from several manufacturers including Shin Etsu Chemical Co., Ltd., which is headquartered in Japan.
- the anti-reflective coating 12 may be formed by depositing an anti-reflective material onto the semiconductor substrate 14 using a spin coating process, for example, and heating the semiconductor substrate 14 to cross-link the anti-reflective material.
- the semiconductor substrate 14 with the anti-reflective material is heated to a temperature of from about 150° C. to about 350° C. to cross-link the anti-reflective material.
- the method continues as illustrated in FIGS. 2A-2C by depositing a polymeric material 16 overlying the anti-reflective coating 12 .
- the polymeric material 16 is deposited onto the anti-reflective coating 12 using, for example, a spin coating process. Other processes known to those skilled in the art may also be used for depositing the polymeric material 16 onto the anti-reflective coating 12 .
- the polymeric material 16 includes a plurality of polymer chains 18 each having a neutral polymeric block 20 , a pinning polymeric block 22 , and a chemically or photochemically cleavable junction 24 that couples the neutral polymeric block 20 to the pinning polymeric block 22 .
- the neutral polymeric components 20 together form a neutral polymeric block portion 26 of the polymeric material 16
- the pinning polymeric components 22 together form a pinning polymeric component portion 28 of the polymeric material 16
- the cleavable junctions 24 together form a cleavable link portion 30 of the polymeric material 16 .
- the neutral polymeric block 20 includes a random copolymer of polystyrene and polymethylmethacrylate (e.g., Formula I) with monohydroxy functional groups.
- the pinning polymeric block 22 has chemical cross-linkable functionality and includes styrene (e.g., polystyrene) with hydroxyethyl methacrylate (HEMA) (e.g., Formula II) such as styrene (e.g., polystyrene) with about 1 to about 3 mole % (mol. %) of HEMA, for example about 2 mol.
- HEMA hydroxyethyl methacrylate
- HEMA hydroxyethacrylate
- styrene e.g., polystyrene
- GMA glycol methacrylate
- styrene e.g., polystyrene
- GMA glycol methacrylate
- styrene e.g., polystyrene
- polystyrene with a terminal hydroxyl moiety e.g., Formula IV
- methylmethacrylate with HEMA e.g., Formula V
- methylmethacrylate with about 1 to about 3 mol. % of HEMA for example about 2 mol.
- the cleavable link includes trityl ether (e.g., Formula VII) and/or nitro benzyl ether (e.g., Formula VIII).
- the polymeric material 16 is heated at a predetermined temperature for a predetermined time to at least partially cross-link the pinning polymeric block portion 28 (e.g., via the HEMA moieties or the GMA moieties) and form a bifunctional brush layer 32 that is coupled, affixed, and/or otherwise attached to the anti-reflective coating 12 .
- the polymeric material 16 is heated to a temperature of from about 200 to about 350° C. for a time of from about 60 to about 600 seconds.
- FIG. 3 illustrates the bifunctional brush layer 32 including the polymer chains 18 that are coupled to surface of the anti-reflective coating 12 .
- the bifunctional brush layer 32 has a neutral layer 34 that is formed of the neutral polymeric block portion 26 and a pinning layer 36 that is formed of the pinning polymeric block portion 28 .
- the pinning layer 36 is disposed adjacent to the anti-reflective coating 12 and the neutral layer 34 is coupled to the pinning layer 36 on a side opposite the anti-reflective coating 12 via the cleavable link portion 30 .
- a photoresist layer 38 is deposited overlying the bifunctional brush layer 32 and is patterned using lithographic techniques to form an exposed photoresist portion 40 and an unexposed photoresist portion 42 .
- ultraviolet light e.g., from a lithographical process including an ultraviolet light source
- the photoresist layer 38 is patterned using ultraviolet light at a wavelength of about 193 nm with an exposure dose of about 5 to about 40 mJ/cm 2 , for example about 20 mJ/cm 2 .
- portions of the neutral layer 34 are selectively cleaved (e.g., separated, scissioned, removed, or the like) from and/or during patterning the photoresist layer 38 , leaving remaining portions 44 of the neutral layer 34 spaced apart from each other and intermittently disposed overlying the pinning layer 36 .
- the cleavable link portion 30 is cleaved by exposure to ultraviolet light.
- the cleavable link portion 30 is nitro benzyl ether, which is an ultraviolet responsive junction that is cleaved by exposure to ultraviolet light.
- the photoresist layer 38 is a chemically amplified photoresist layer that forms an acid when exposed to ultraviolet light and the cleavable link portion 30 is cleaved by exposure to the acid.
- the cleavable link portion 30 is trityl ether, which is an acid responsive junction that is cleaved by exposure to acid.
- Chemically amplified (CA) photoresist materials are well known and are commercially available from JSR Micro Inc. and Shin-Etsu Chemical Co., Ltd.
- the photoacid generators (PAG) within the CA photoresists decompose to produce photoacid species. These acid species cleave deprotection groups within the CA photoresist, changing the solubility of the exposed region, which can then be removed in a development step.
- the chemically amplified photoresist layer is heated to a temperature of from about 90 to about 130° C. contemporaneously with or subsequent to patterning the chemically amplified photoresist layer to facilitate forming the acid.
- FIGS. 5A-5B illustrate, in cross-sectional views, the integrated circuit 10 during a later fabrication stage in accordance with an exemplary embodiment.
- the exposed and unexposed photoresist portions 40 and 42 and the portions of the neutral layer 34 (see FIGS. 3-4 ) that have been cleaved are removed from the semiconductor substrate 14 with a solvent to expose a chemical guide pattern 46 .
- the solvent is an organic solvent such as propylene glycol methyl ether acetate (PGMEA), 4-Methyl-2-pentanol (4M2P), n-Butyl acetate (nBA), gamma-Butyrolactone (GBA), toluene, acetone, and/or the like.
- the chemical guide pattern 46 is a recessed topographical chemical guide pattern 47 that has recessed pinning guide features 48 defined by the exposed portion of the pinning layer 36 and protruding neutral fields 50 defined by the remaining portion 44 of the neutral layer 34 .
- FIGS. 6-8 illustrate, in cross-sectional views, the integrated circuit 10 during later fabrication stages in accordance with an exemplary embodiment.
- the method continues by depositing a block copolymer layer 52 overlying the chemical guide pattern 46 .
- the block copolymer layer 52 may be deposited, for example, using a spin coating process or the like.
- the block copolymer layer 52 has A polymer blocks and B polymer blocks.
- the block copolymer layer 52 is a block copolymer of polystyrene that forms the A polymer blocks and polymethylmethacrylate that forms the B polymer blocks.
- the pinning layer acts to guide the polystyrene component of the block copolymer.
- the pinning layer could also be PMMA based.
- the block copolymer layer 52 is heated at a predetermined temperature for a predetermined time to phase separate the block copolymer layer 52 and form a phase separated block copolymer 53 .
- the phase separated block copolymer 53 has A polymer block regions 54 formed from the A polymer blocks and B polymer block regions 56 formed from the B polymer blocks.
- the recessed pinning guide features 48 and the protruding neutral fields 50 of the chemical guide pattern 46 have different affinities towards the A polymer blocks and independently towards the B polymer blocks of the block copolymer layer 52 .
- the block copolymer layer 52 phase separates, the A polymer block regions 54 and the B polymer block regions 56 are registered to the chemical guide pattern 46 so as to produce a nanopattern 58 .
- the block copolymer layer 52 is heated at a temperature of from about 200 to about 350° C. for about 60 to about 600 seconds in a nitrogen-rich (N 2 ) atmosphere.
- the nanopattern 58 allows for resolution in the nanometer range beyond that of conventional optical lithography techniques.
- the method continues as illustrated in FIG. 8 by removing the B polymer block regions 56 .
- the remaining A polymer block regions 54 defines a mask 60 for transferring the nanopattern 58 to the semiconductor substrate 14 .
- the B polymer block regions 56 are polymethylmethacrylate and are removed by exposing the phase separated block copolymer 53 (see FIG. 7 ) to a dry etching process, such as reactive-ion etching (RIE) plasma.
- RIE reactive-ion etching
- FIGS. 9-16 illustrate, in cross-sectional views, the integrated circuit 10 during intermediate stages of its fabrication in accordance with another exemplary embodiment.
- the bifunctional brush layer 32 of the polymeric material 16 is formed overlying the anti-reflective coating 12 including depositing and heating of the polymeric material 16 similarly as described above in relation to FIGS. 1-2C except that the neutral layer 34 is disposed adjacent to the anti-reflective coating 12 and the pinning layer 36 is coupled to the neutral layer 34 on a side opposite the anti-reflective coating 12 via the cleavable link portion 30 .
- FIG. 11 illustrates, in cross-sectional view, the integrated circuit 10 during a later fabrication stage in accordance with an exemplary embodiment.
- the photoresist layer 38 is deposited overlying the bifunctional brush layer 32 and is patterned as described above in relation to FIG. 3 to form the exposed photoresist portion 40 and the unexposed photoresist portion 42 .
- portions of the pinning layer 36 are selectively cleaved (e.g., separated, scissioned, removed, or the like) from and/or during patterning the photoresist layer 38 , leaving remaining portions 62 of the pinning layer 36 spaced apart from each other and intermittently disposed overlying the neutral layer 34 .
- the cleavable link portion 30 is cleaved by exposure to ultraviolet light.
- the cleavable link portion 30 is nitro benzyl ether and is cleaved by exposure to ultraviolet light.
- patterning the photoresist layer 38 with ultraviolet light causes scissioning of the portions of the pinning layer 36 from the neutral layer 34 in areas where the cleavable link portion 30 is selectively exposed to ultraviolet light.
- the photoresist layer 38 is a chemically amplified photoresist layer and the cleavable link portion 30 is trityl ether that is cleaved by exposure to acid produced from the chemically amplified photoresist layer during ultraviolet light exposure.
- the chemically amplified photoresist layer is heated to a temperature of from about 90 to about 130° C. contemporaneously with or subsequent to patterning the chemically amplified photoresist layer to facilitate forming the acid.
- FIGS. 13A-13B illustrate, in cross-sectional views, the integrated circuit 10 during a later fabrication stage in accordance with an exemplary embodiment.
- the exposed and unexposed photoresist portions 40 and 42 and the portions of the pinning layer 36 (see FIGS. 11-12 ) that have been cleaved are removed from the semiconductor substrate 14 with a solvent to expose a chemical guide pattern 64 .
- the solvent is an organic solvent such as propylene glycol methyl ether acetate (PGMEA), 4-Methyl-2-pentanol (4M2P), n-Butyl acetate (nBA), gamma-Butyrolactone (GBA), toluene, acetone, and/or the like.
- the chemical guide pattern 64 is a protruding topographical chemical guide pattern 66 that has protruding pinning guide features 68 defined by the remaining portions 62 of the pinning layer 36 and recessed neutral fields 70 defined by the exposed portion 72 of the neutral layer 34 .
- FIGS. 14-16 illustrate, in cross-sectional views, the integrated circuit 10 during later fabrication stages in accordance with an exemplary embodiment.
- the method continues by depositing the block copolymer layer 52 as described above in relation to FIG. 6 overlying the chemical guide pattern 64 .
- the block copolymer layer 52 is heated to phase separate the block copolymer layer 52 and form the phase separated block copolymer 53 .
- the phase separated block copolymer 53 has A polymer block regions 54 formed from the A polymer blocks and B polymer block regions 56 formed from the B polymer blocks.
- the protruding pinning guide features 68 and the recessed neutral fields 70 of the chemical guide pattern 64 have different affinities towards the A polymer blocks and independently towards the B polymer blocks of the block copolymer layer 52 .
- the block copolymer layer 52 phase separates, the A polymer block regions 54 and the B polymer block regions 56 are registered to the chemical guide pattern 64 so as to produce the nanopattern 58 .
- the block copolymer layer 52 is heated at a temperature of from about 200 to about 350° C. for about 60 to about 600 seconds in a nitrogen-rich (N 2 ) atmosphere.
- the method continues as illustrated in FIG. 16 by removing the B polymer block regions 56 as discussed above in relation to FIG. 8 . As illustrated, the remaining A polymer block regions 54 defines the mask 60 for transferring the nanopattern 58 to the semiconductor substrate 14 in a conventional manner.
- FIGS. 17-24 illustrate, in cross-sectional views, the integrated circuit 10 during intermediate stages of its fabrication in accordance with a further exemplary embodiment.
- the bifunctional brush layer 32 is formed overlying the anti-reflective coating 12 including depositing and heating of the polymeric material 16 similarly as described above in relation to FIGS. 1-2C with the exception that the polymer chains 18 of the polymeric material 16 each have the neutral polymeric block 20 coupled directly to the pinning polymeric block 22 .
- the neutral polymeric components 20 together form the neutral polymeric block portion 26 of the polymeric material 16 and the pinning polymeric components 22 together form the pinning polymeric block portion 28 of the polymeric material 16 without a cleavable link portion 30 (see FIGS.
- the neutral polymeric block 20 includes a random copolymer of polystyrene and polymethylmethacrylate (e.g., Formula I) and the pinning polymeric block 22 does not include polymethylmethacrylate. Rather, for example, the pinning polymeric block 22 includes polystyrene with HEMA (e.g., Formula II), polystyrene with GMA (e.g., Formula III), and/or polystyrene with a terminal hydroxyl moiety (e.g., Formula IV).
- HEMA e.g., Formula II
- GMA e.g., Formula III
- Formula IV polystyrene with a terminal hydroxyl moiety
- FIG. 19 illustrates, in cross-sectional view, the integrated circuit 10 during a later fabrication stage in accordance with an exemplary embodiment.
- a photoresist layer 38 is deposited overlying the bifunctional brush layer 32 and is patterned using electron beam lithography (ELB) to form the exposed photoresist portion 40 and the unexposed photoresist portion 42 .
- ELB electron beam lithography
- portions of the neutral layer 34 are selectively removed during patterning of the photoresist layer 38 , leaving the remaining portion 44 of the neutral layer 34 spaced apart from each other and intermittently disposed overlying the pinning layer 36 .
- the electron beam degrades polymethylmethacrylate contained in the neutral layer 34 and the degraded portions of the neutral layer 34 can be selectively removed while not degrading the pinning layer 36 , which does not contain polymethylmethacrylate.
- the method continues as illustrated in FIGS. 21-24 and as described above in relation to FIGS. 5A-8 to form the mask 60 for transferring the nanopattern 58 to the semiconductor substrate 14 .
- the exemplary embodiments taught herein form a bifunctional brush layer from a polymeric material.
- the bifunctional brush layer includes a neutral layer and a pinning layer. A portion of the neutral layer or the pinning layer is selectively removed, e.g., using ultraviolet (UV) lithography or electron beam lithography (EBL), to define a chemical guide pattern.
- a block copolymer layer is deposited overlying the chemical guide pattern as part of a DSA process.
- the block copolymer layer is heated to phase separate the block copolymer into a first polymeric block portion and a second polymeric block portion.
- the chemical guide pattern has portions that are defined by the neutral layer and portions that are defined by the pinning layer, various areas of the chemical guide pattern have differing affinities towards the first polymeric block portion and independently towards the second polymeric block portion such that when the block copolymer is phase separated, it forms a nanopattern that is registered to the chemical guide pattern.
- the first or second polymeric block portion is removed to form a mask for transferring the nanopattern to the semiconductor substrate.
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Microelectronics & Electronic Packaging (AREA)
- General Physics & Mathematics (AREA)
- Physics & Mathematics (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- Computer Hardware Design (AREA)
- Power Engineering (AREA)
- Chemical & Material Sciences (AREA)
- Inorganic Chemistry (AREA)
- Nanotechnology (AREA)
- Analytical Chemistry (AREA)
- Exposure Of Semiconductors, Excluding Electron Or Ion Beam Exposure (AREA)
- Photosensitive Polymer And Photoresist Processing (AREA)
Abstract
Description
- The technical field relates generally to methods for fabricating integrated circuits, and more particularly relates to methods for fabricating integrated circuits including formation of chemical guide patterns for directed self-assembly lithography.
- Decreasing device size and increasing device density has traditionally been a high priority for the manufacturing of the integrated circuits. Optical lithography has been the driving force for device scaling. Conventional optical lithography is limited to about 80 nm pitch for single exposure patterning whilst double and other multi-patterning processes can realize smaller pitch, these approaches are expensive and more complex.
- Directed self-assembly (DSA), a technique which aligns self-assembling polymeric materials on a lithographically defined guide pattern, is a potential option for extending current optical lithography beyond its pitch and resolution limits. The self-assembling materials, for example, are block copolymers (BCPs) which consist of “A” homopolymer covalently attached to “B” homopolymer, which are coated over a lithographically defined guide pattern on a semiconductor substrate. The lithographically defined guide pattern is a pre-pattern that is encoded with spatial chemical and/or topographical information and serves to direct the self-assembly process and the pattern formed by the self-assembling materials. Subsequently, by annealing the DSA polymers, the A polymer chains and the B polymer chains undergo phase separation to form an A polymer region and a B polymer region that are registered to the underlying guide pattern. Then, by removing either the A polymer block or the B polymer block by wet chemical or plasma-etch techniques, a mask is formed for transferring the nanopattern to the underlying substrate. Unfortunately, current processes for forming chemical guide patterns for DSA are complicated, costly, and/or not practical for large scale manufacturing.
- Accordingly, it is desirable to provide methods for fabricating integrated circuits including formation of chemical guide patterns for directed self-assembly lithography with reduced complexity and cost and that are practical for large scale manufacturing. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and this background.
- Methods for fabricating integrated circuits are provided herein. In accordance with an exemplary embodiment, a method for fabricating an integrated circuit includes forming a bifunctional brush layer of a polymeric material overlying an anti-reflective coating on a semiconductor substrate. The polymeric material has a neutral polymeric block portion and a pinning (non-neutral) polymeric block portion that are covalently bonded together. The bifunctional brush layer includes a neutral layer that is formed of the neutral polymeric block portion and a pinning layer that is formed of the pinning polymeric block portion. A portion of the neutral layer or the pinning layer is selectively removed to define a chemical guide pattern. A block copolymer layer is deposited overlying the chemical guide pattern. The block copolymer layer is phase separated to define a nanopattern that is registered to the chemical guide pattern.
- In accordance with another exemplary embodiment, a method for fabricating an integrated circuit is provided. The method includes forming a bifunctional brush layer of a polymeric material overlying an anti-reflective coating on a semiconductor substrate. The bifunctional brush layer is formed such that a pinning layer of the bifunctional brush layer is disposed adjacent to the anti-reflective coating and a neutral layer of the bifunctional brush layer is disposed adjacent to the pinning layer on a side opposite the anti-reflective coating. The polymeric material includes a neutral polymeric block portion and a pinning polymeric block portion that form the neutral layer and the pinning layer, respectively. A portion of the neutral layer is selectively removed to define a chemical guide pattern. A block copolymer layer is deposited overlying the chemical guide pattern. The block copolymer layer is phase separated to define a nanopattern that is registered to the chemical guide pattern.
- In accordance with another exemplary embodiment, a method for fabricating an integrated circuit is provided. The method includes forming a bifunctional brush layer of a polymeric material overlying an anti-reflective coating on a semiconductor substrate. The bifunctional brush layer is formed such that a neutral layer of the bifunctional brush layer is disposed adjacent to the anti-reflective coating and a pinning layer of the bifunctional brush layer is disposed adjacent to the neutral layer on a side opposite the anti-reflective coating. The polymeric material includes a neutral polymeric block portion and a pinning polymeric block portion that form the neutral layer and the pinning layer, respectively. A portion of the pinning layer is selectively removed to define a chemical guide pattern. A block copolymer layer is deposited overlying the chemical guide pattern. The block copolymer layer is phase separated to define a nanopattern that is registered to the chemical guide pattern.
- The various embodiments will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and wherein:
-
FIGS. 1-8 illustrate, in cross-sectional views, fabrication of the chemical guide pattern and a method for forming this structure during intermediate stages of its fabrication in accordance with an exemplary embodiment. -
FIGS. 9-16 illustrate, in cross-sectional views, fabrication of the chemical guide pattern and a method for forming this structure during intermediate stages of its fabrication in accordance with another exemplary embodiment. -
FIGS. 17-24 illustrate, in cross-sectional views, fabrication of the chemical guide pattern and a method for forming this structure during intermediate stages of its fabrication in accordance with another exemplary embodiment. - The following Detailed Description is merely exemplary in nature and is not intended to limit the various embodiments or the application and uses thereof. Furthermore, there is no intention to be bound by any theory presented in the preceding background or the following detailed description.
- Various embodiments described herein relate to methods for fabricating integrated circuits. The exemplary embodiments taught herein form a bifunctional brush layer of a polymeric material overlying an anti-reflective coating on a semiconductor substrate. The polymeric material includes polymer chains each having a neutral polymeric block and a pinning polymeric block that is coupled to an end of the neutral polymeric block. The neutral polymeric blocks together form the neutral polymeric block portion of the polymeric material and the pinning polymeric blocks together form the pinning polymeric block portion of the polymeric material. In an exemplary embodiment, the neutral polymeric blocks are random copolymers that have no preferential affinity for the individual polymeric block components of a block copolymer layer that will be subsequently deposited over the polymeric material as part of a DSA process. In an exemplary embodiment, the pinning polymeric blocks are polymers with functionality to facilitate preferential interaction (pinning) with one of the components of the polymeric material of the subsequently deposited block copolymer layer. The polymer chains that form the bifunctional brush layer are chemically attached (grafted) at one end to the anti-reflective coating by incorporating additional functionality, for example monohydroxy moieties or cyclic ethers, within the pinning brush polymeric block.
- A portion of the neutral layer or the pinning layer is selectively removed, e.g., using acid scissioning or ultraviolet (UV) lithography or electron beam lithography (EBL), to define a chemical guide pattern. As discussed above, a block copolymer layer is deposited overlying the chemical guide pattern as part of the DSA process. In an exemplary embodiment, the block copolymer layer is heated to a temperature near or above its glass transition temperature (Tg) to phase separate the block copolymer into a first polymeric block portion and a second polymeric block portion. Because the chemical guide pattern has portions that consists of the neutral layer and portions that consists of the pinning layer, various areas of the chemical guide pattern have differing affinities towards the first polymeric block portion and independently towards the second polymeric block portion such that when the block copolymer is phase separated, it forms a nanopattern that is registered to the chemical guide pattern. In an exemplary embodiment, the first or second polymeric block portion is removed to form a mask for transferring the nanopattern to the semiconductor substrate. This exemplary embodiment makes use of a polymeric material that has both a neutral polymeric block portion and a pinning polymeric block portion to create a bifunctional brush layer that can be formed simply from a single layer of the polymeric material to facilitate forming the chemical guide pattern, thereby reducing complexity and cost for large scale manufacturing of the integrated circuits using DSA.
-
FIGS. 1-24 illustrate methods for fabricating an integratedcircuit 10 in accordance with various embodiments. The described process steps, procedures, and materials are to be considered only as exemplary embodiments designed to illustrate to one of ordinary skill in the art methods for practicing the invention; the invention is not limited to these exemplary embodiments. Various steps in the manufacture of integrated circuits are well known and so, in the interest of brevity, many conventional steps will only be mentioned briefly herein or will be omitted entirely without providing the well-known process details. -
FIGS. 1-8 illustrate, in cross-sectional views, the integratedcircuit 10 during intermediate stages of its fabrication in accordance with an exemplary embodiment. Referring toFIG. 1 , the integrated circuit includes ananti-reflective coating 12 disposed on asemiconductor substrate 14. Thesemiconductor substrate 14 can be, for example, a bulk semiconductor substrate or silicon-on-insulator (SOI) semiconductor substrate as are well known in the art. Theanti-reflective coating 12, which is commonly referred to as ARC or BARC (bottom anti-reflective coating), may be a polymer and/or silicon (Si) containing material that is used to absorb and/or control light to dampen or eliminate light reflection during photolithography to improve the photolithography process window for producing smaller features. In one embodiment, theanti-reflective coating 12 is formed of a Si-containing polymer(s) (SiARC) that may be cross-linked. SiARC materials are commercially available from several manufacturers including Shin Etsu Chemical Co., Ltd., which is headquartered in Japan. Theanti-reflective coating 12 may be formed by depositing an anti-reflective material onto thesemiconductor substrate 14 using a spin coating process, for example, and heating thesemiconductor substrate 14 to cross-link the anti-reflective material. In an exemplary embodiment, thesemiconductor substrate 14 with the anti-reflective material is heated to a temperature of from about 150° C. to about 350° C. to cross-link the anti-reflective material. - The method continues as illustrated in
FIGS. 2A-2C by depositing apolymeric material 16 overlying theanti-reflective coating 12. Thepolymeric material 16 is deposited onto theanti-reflective coating 12 using, for example, a spin coating process. Other processes known to those skilled in the art may also be used for depositing thepolymeric material 16 onto theanti-reflective coating 12. - In an exemplary embodiment, the
polymeric material 16 includes a plurality ofpolymer chains 18 each having aneutral polymeric block 20, a pinningpolymeric block 22, and a chemically or photochemicallycleavable junction 24 that couples theneutral polymeric block 20 to the pinningpolymeric block 22. The neutralpolymeric components 20 together form a neutralpolymeric block portion 26 of thepolymeric material 16, the pinningpolymeric components 22 together form a pinningpolymeric component portion 28 of thepolymeric material 16, and thecleavable junctions 24 together form acleavable link portion 30 of thepolymeric material 16. In an exemplary embodiment, theneutral polymeric block 20 includes a random copolymer of polystyrene and polymethylmethacrylate (e.g., Formula I) with monohydroxy functional groups. In another exemplary embodiment, the pinningpolymeric block 22 has chemical cross-linkable functionality and includes styrene (e.g., polystyrene) with hydroxyethyl methacrylate (HEMA) (e.g., Formula II) such as styrene (e.g., polystyrene) with about 1 to about 3 mole % (mol. %) of HEMA, for example about 2 mol. % of HEMA, styrene (e.g., polystyrene) with glycol methacrylate (GMA) (e.g., Formula III) such as styrene (e.g., polystyrene) with about 1 to about 3 mol. % of GMA, for example about 2 mol. % of GMA, polystyrene with a terminal hydroxyl moiety (e.g., Formula IV), methylmethacrylate with HEMA (e.g., Formula V) such as methylmethacrylate with about 1 to about 3 mol. % of HEMA, for example about 2 mol. % of HEMA, and/or methylmethacrylate with GMA (e.g., Formula VI) such as methylmethacrylate with about 1 to about 3 mol. % of GMA, for example about 2 mol. % of GMA. In another exemplary embodiment, the cleavable link includes trityl ether (e.g., Formula VII) and/or nitro benzyl ether (e.g., Formula VIII). - In an exemplary embodiment, the
polymeric material 16 is heated at a predetermined temperature for a predetermined time to at least partially cross-link the pinning polymeric block portion 28 (e.g., via the HEMA moieties or the GMA moieties) and form abifunctional brush layer 32 that is coupled, affixed, and/or otherwise attached to theanti-reflective coating 12. In one example, thepolymeric material 16 is heated to a temperature of from about 200 to about 350° C. for a time of from about 60 to about 600 seconds. -
FIG. 3 illustrates thebifunctional brush layer 32 including thepolymer chains 18 that are coupled to surface of theanti-reflective coating 12. Thebifunctional brush layer 32 has aneutral layer 34 that is formed of the neutralpolymeric block portion 26 and a pinninglayer 36 that is formed of the pinningpolymeric block portion 28. The pinninglayer 36 is disposed adjacent to theanti-reflective coating 12 and theneutral layer 34 is coupled to the pinninglayer 36 on a side opposite theanti-reflective coating 12 via thecleavable link portion 30. - As illustrated, a
photoresist layer 38 is deposited overlying thebifunctional brush layer 32 and is patterned using lithographic techniques to form an exposedphotoresist portion 40 and anunexposed photoresist portion 42. In an exemplary embodiment, ultraviolet light (e.g., from a lithographical process including an ultraviolet light source) is used to pattern thephotoresist layer 38. In one example, thephotoresist layer 38 is patterned using ultraviolet light at a wavelength of about 193 nm with an exposure dose of about 5 to about 40 mJ/cm2, for example about 20 mJ/cm2. - As illustrated in
FIG. 4 , portions of theneutral layer 34 are selectively cleaved (e.g., separated, scissioned, removed, or the like) from and/or during patterning thephotoresist layer 38, leaving remainingportions 44 of theneutral layer 34 spaced apart from each other and intermittently disposed overlying the pinninglayer 36. In an exemplary embodiment, thecleavable link portion 30 is cleaved by exposure to ultraviolet light. In one example, thecleavable link portion 30 is nitro benzyl ether, which is an ultraviolet responsive junction that is cleaved by exposure to ultraviolet light. As such, patterning thephotoresist layer 38 with ultraviolet light causes scissioning of the portions of theneutral layer 34 from the pinninglayer 36 in areas where thecleavable link portion 30 is selectively exposed to ultraviolet light. In another embodiment, thephotoresist layer 38 is a chemically amplified photoresist layer that forms an acid when exposed to ultraviolet light and thecleavable link portion 30 is cleaved by exposure to the acid. In one example, thecleavable link portion 30 is trityl ether, which is an acid responsive junction that is cleaved by exposure to acid. Chemically amplified (CA) photoresist materials are well known and are commercially available from JSR Micro Inc. and Shin-Etsu Chemical Co., Ltd. After the post exposure bake, the photoacid generators (PAG) within the CA photoresists decompose to produce photoacid species. These acid species cleave deprotection groups within the CA photoresist, changing the solubility of the exposed region, which can then be removed in a development step. In an exemplary embodiment, the chemically amplified photoresist layer is heated to a temperature of from about 90 to about 130° C. contemporaneously with or subsequent to patterning the chemically amplified photoresist layer to facilitate forming the acid. -
FIGS. 5A-5B illustrate, in cross-sectional views, theintegrated circuit 10 during a later fabrication stage in accordance with an exemplary embodiment. The exposed andunexposed photoresist portions FIGS. 3-4 ) that have been cleaved are removed from thesemiconductor substrate 14 with a solvent to expose achemical guide pattern 46. In an exemplary embodiment, the solvent is an organic solvent such as propylene glycol methyl ether acetate (PGMEA), 4-Methyl-2-pentanol (4M2P), n-Butyl acetate (nBA), gamma-Butyrolactone (GBA), toluene, acetone, and/or the like. As illustrated, thechemical guide pattern 46 is a recessed topographicalchemical guide pattern 47 that has recessed pinning guide features 48 defined by the exposed portion of the pinninglayer 36 and protrudingneutral fields 50 defined by the remainingportion 44 of theneutral layer 34. -
FIGS. 6-8 illustrate, in cross-sectional views, theintegrated circuit 10 during later fabrication stages in accordance with an exemplary embodiment. The method continues by depositing ablock copolymer layer 52 overlying thechemical guide pattern 46. Theblock copolymer layer 52 may be deposited, for example, using a spin coating process or the like. Theblock copolymer layer 52 has A polymer blocks and B polymer blocks. In an exemplary embodiment, theblock copolymer layer 52 is a block copolymer of polystyrene that forms the A polymer blocks and polymethylmethacrylate that forms the B polymer blocks. As shown inFIG. 8 , the pinning layer acts to guide the polystyrene component of the block copolymer. In another embodiment, the pinning layer could also be PMMA based. - The
block copolymer layer 52 is heated at a predetermined temperature for a predetermined time to phase separate theblock copolymer layer 52 and form a phase separatedblock copolymer 53. The phase separatedblock copolymer 53 has Apolymer block regions 54 formed from the A polymer blocks and Bpolymer block regions 56 formed from the B polymer blocks. In an exemplary embodiment, the recessed pinning guide features 48 and the protrudingneutral fields 50 of thechemical guide pattern 46 have different affinities towards the A polymer blocks and independently towards the B polymer blocks of theblock copolymer layer 52. As such, when theblock copolymer layer 52 phase separates, the Apolymer block regions 54 and the Bpolymer block regions 56 are registered to thechemical guide pattern 46 so as to produce ananopattern 58. In an exemplary embodiment, theblock copolymer layer 52 is heated at a temperature of from about 200 to about 350° C. for about 60 to about 600 seconds in a nitrogen-rich (N2) atmosphere. In an exemplary embodiment, thenanopattern 58 allows for resolution in the nanometer range beyond that of conventional optical lithography techniques. - The method continues as illustrated in
FIG. 8 by removing the Bpolymer block regions 56. As illustrated, the remaining Apolymer block regions 54 defines amask 60 for transferring thenanopattern 58 to thesemiconductor substrate 14. In an exemplary embodiment, the Bpolymer block regions 56 are polymethylmethacrylate and are removed by exposing the phase separated block copolymer 53 (seeFIG. 7 ) to a dry etching process, such as reactive-ion etching (RIE) plasma. Thenanopattern 58 can be transferred to thesemiconductor substrate 14 to form device features, for example, using themask 60 and a conventional wet or dry etching process. -
FIGS. 9-16 illustrate, in cross-sectional views, theintegrated circuit 10 during intermediate stages of its fabrication in accordance with another exemplary embodiment. Referring toFIGS. 9-10C , thebifunctional brush layer 32 of thepolymeric material 16 is formed overlying theanti-reflective coating 12 including depositing and heating of thepolymeric material 16 similarly as described above in relation toFIGS. 1-2C except that theneutral layer 34 is disposed adjacent to theanti-reflective coating 12 and the pinninglayer 36 is coupled to theneutral layer 34 on a side opposite theanti-reflective coating 12 via thecleavable link portion 30. -
FIG. 11 illustrates, in cross-sectional view, theintegrated circuit 10 during a later fabrication stage in accordance with an exemplary embodiment. Thephotoresist layer 38 is deposited overlying thebifunctional brush layer 32 and is patterned as described above in relation toFIG. 3 to form the exposedphotoresist portion 40 and theunexposed photoresist portion 42. As illustrated inFIG. 12 , portions of the pinninglayer 36 are selectively cleaved (e.g., separated, scissioned, removed, or the like) from and/or during patterning thephotoresist layer 38, leaving remainingportions 62 of the pinninglayer 36 spaced apart from each other and intermittently disposed overlying theneutral layer 34. In an exemplary embodiment, thecleavable link portion 30 is cleaved by exposure to ultraviolet light. In one example, thecleavable link portion 30 is nitro benzyl ether and is cleaved by exposure to ultraviolet light. As such, patterning thephotoresist layer 38 with ultraviolet light causes scissioning of the portions of the pinninglayer 36 from theneutral layer 34 in areas where thecleavable link portion 30 is selectively exposed to ultraviolet light. In another embodiment, thephotoresist layer 38 is a chemically amplified photoresist layer and thecleavable link portion 30 is trityl ether that is cleaved by exposure to acid produced from the chemically amplified photoresist layer during ultraviolet light exposure. In an exemplary embodiment, the chemically amplified photoresist layer is heated to a temperature of from about 90 to about 130° C. contemporaneously with or subsequent to patterning the chemically amplified photoresist layer to facilitate forming the acid. -
FIGS. 13A-13B illustrate, in cross-sectional views, theintegrated circuit 10 during a later fabrication stage in accordance with an exemplary embodiment. The exposed andunexposed photoresist portions FIGS. 11-12 ) that have been cleaved are removed from thesemiconductor substrate 14 with a solvent to expose achemical guide pattern 64. The solvent is an organic solvent such as propylene glycol methyl ether acetate (PGMEA), 4-Methyl-2-pentanol (4M2P), n-Butyl acetate (nBA), gamma-Butyrolactone (GBA), toluene, acetone, and/or the like. As illustrated, thechemical guide pattern 64 is a protruding topographicalchemical guide pattern 66 that has protruding pinning guide features 68 defined by the remainingportions 62 of the pinninglayer 36 and recessedneutral fields 70 defined by the exposedportion 72 of theneutral layer 34. -
FIGS. 14-16 illustrate, in cross-sectional views, theintegrated circuit 10 during later fabrication stages in accordance with an exemplary embodiment. The method continues by depositing theblock copolymer layer 52 as described above in relation toFIG. 6 overlying thechemical guide pattern 64. Theblock copolymer layer 52 is heated to phase separate theblock copolymer layer 52 and form the phase separatedblock copolymer 53. The phase separatedblock copolymer 53 has Apolymer block regions 54 formed from the A polymer blocks and Bpolymer block regions 56 formed from the B polymer blocks. In an exemplary embodiment, the protruding pinning guide features 68 and the recessedneutral fields 70 of thechemical guide pattern 64 have different affinities towards the A polymer blocks and independently towards the B polymer blocks of theblock copolymer layer 52. As such, when theblock copolymer layer 52 phase separates, the Apolymer block regions 54 and the Bpolymer block regions 56 are registered to thechemical guide pattern 64 so as to produce thenanopattern 58. In an exemplary embodiment, theblock copolymer layer 52 is heated at a temperature of from about 200 to about 350° C. for about 60 to about 600 seconds in a nitrogen-rich (N2) atmosphere. - The method continues as illustrated in
FIG. 16 by removing the Bpolymer block regions 56 as discussed above in relation toFIG. 8 . As illustrated, the remaining Apolymer block regions 54 defines themask 60 for transferring thenanopattern 58 to thesemiconductor substrate 14 in a conventional manner. -
FIGS. 17-24 illustrate, in cross-sectional views, theintegrated circuit 10 during intermediate stages of its fabrication in accordance with a further exemplary embodiment. Referring toFIGS. 17-18C , thebifunctional brush layer 32 is formed overlying theanti-reflective coating 12 including depositing and heating of thepolymeric material 16 similarly as described above in relation toFIGS. 1-2C with the exception that thepolymer chains 18 of thepolymeric material 16 each have theneutral polymeric block 20 coupled directly to the pinningpolymeric block 22. As such, the neutralpolymeric components 20 together form the neutralpolymeric block portion 26 of thepolymeric material 16 and the pinningpolymeric components 22 together form the pinningpolymeric block portion 28 of thepolymeric material 16 without a cleavable link portion 30 (seeFIGS. 2A-2C ). In an exemplary embodiment, theneutral polymeric block 20 includes a random copolymer of polystyrene and polymethylmethacrylate (e.g., Formula I) and the pinningpolymeric block 22 does not include polymethylmethacrylate. Rather, for example, the pinningpolymeric block 22 includes polystyrene with HEMA (e.g., Formula II), polystyrene with GMA (e.g., Formula III), and/or polystyrene with a terminal hydroxyl moiety (e.g., Formula IV). -
FIG. 19 illustrates, in cross-sectional view, theintegrated circuit 10 during a later fabrication stage in accordance with an exemplary embodiment. In an exemplary embodiment, aphotoresist layer 38 is deposited overlying thebifunctional brush layer 32 and is patterned using electron beam lithography (ELB) to form the exposedphotoresist portion 40 and theunexposed photoresist portion 42. - As illustrated in
FIG. 20 , portions of theneutral layer 34 are selectively removed during patterning of thephotoresist layer 38, leaving the remainingportion 44 of theneutral layer 34 spaced apart from each other and intermittently disposed overlying the pinninglayer 36. In an exemplary embodiment, the electron beam degrades polymethylmethacrylate contained in theneutral layer 34 and the degraded portions of theneutral layer 34 can be selectively removed while not degrading the pinninglayer 36, which does not contain polymethylmethacrylate. The method continues as illustrated inFIGS. 21-24 and as described above in relation toFIGS. 5A-8 to form themask 60 for transferring thenanopattern 58 to thesemiconductor substrate 14. - Accordingly, methods for fabricating integrated circuits have been described. The exemplary embodiments taught herein form a bifunctional brush layer from a polymeric material. The bifunctional brush layer includes a neutral layer and a pinning layer. A portion of the neutral layer or the pinning layer is selectively removed, e.g., using ultraviolet (UV) lithography or electron beam lithography (EBL), to define a chemical guide pattern. A block copolymer layer is deposited overlying the chemical guide pattern as part of a DSA process. In an exemplary embodiment, the block copolymer layer is heated to phase separate the block copolymer into a first polymeric block portion and a second polymeric block portion. Because the chemical guide pattern has portions that are defined by the neutral layer and portions that are defined by the pinning layer, various areas of the chemical guide pattern have differing affinities towards the first polymeric block portion and independently towards the second polymeric block portion such that when the block copolymer is phase separated, it forms a nanopattern that is registered to the chemical guide pattern. The first or second polymeric block portion is removed to form a mask for transferring the nanopattern to the semiconductor substrate.
- While at least one exemplary embodiment has been presented in the foregoing detailed description of the disclosure, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the disclosure in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment of the disclosure. It being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope of the disclosure as set forth in the appended claims.
Claims (20)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US13/841,694 US8853101B1 (en) | 2013-03-15 | 2013-03-15 | Methods for fabricating integrated circuits including formation of chemical guide patterns for directed self-assembly lithography |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US13/841,694 US8853101B1 (en) | 2013-03-15 | 2013-03-15 | Methods for fabricating integrated circuits including formation of chemical guide patterns for directed self-assembly lithography |
Publications (2)
Publication Number | Publication Date |
---|---|
US20140273511A1 true US20140273511A1 (en) | 2014-09-18 |
US8853101B1 US8853101B1 (en) | 2014-10-07 |
Family
ID=51529009
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US13/841,694 Active 2033-03-29 US8853101B1 (en) | 2013-03-15 | 2013-03-15 | Methods for fabricating integrated circuits including formation of chemical guide patterns for directed self-assembly lithography |
Country Status (1)
Country | Link |
---|---|
US (1) | US8853101B1 (en) |
Cited By (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20140370712A1 (en) * | 2013-06-12 | 2014-12-18 | Eunsung KIM | Methods of forming a pattern and devices formed by the same |
US9371427B2 (en) * | 2014-09-03 | 2016-06-21 | Kabushiki Kaisha Toshiba | Pattern forming method |
CN105731371A (en) * | 2014-12-30 | 2016-07-06 | 罗门哈斯电子材料有限责任公司 | Copolymer Formulation For Directed Self Assembly, Methods Of Manufacture Thereof And Articles Comprising The Same |
CN106847676A (en) * | 2015-12-03 | 2017-06-13 | 中芯国际集成电路制造(上海)有限公司 | The patterning method and forming method of semiconductor devices |
US9881793B2 (en) | 2015-07-23 | 2018-01-30 | International Business Machines Corporation | Neutral hard mask and its application to graphoepitaxy-based directed self-assembly (DSA) patterning |
US10011713B2 (en) | 2014-12-30 | 2018-07-03 | Dow Global Technologies Llc | Copolymer formulation for directed self assembly, methods of manufacture thereof and articles comprising the same |
US20180323078A1 (en) * | 2015-12-24 | 2018-11-08 | Intel Corporation | Pitch division using directed self-assembly |
US10294359B2 (en) | 2014-12-30 | 2019-05-21 | Rohm And Haas Electronic Materials Llc | Copolymer formulation for directed self assembly, methods of manufacture thereof and articles comprising the same |
US10351727B2 (en) | 2015-02-26 | 2019-07-16 | Dow Global Technologies Llc | Copolymer formulation for directed self-assembly, methods of manufacture thereof and articles comprising the same |
US10854465B2 (en) | 2015-05-19 | 2020-12-01 | Samsung Electronics Co., Ltd. | Method of fabricating pattern structure |
US11021630B2 (en) | 2014-12-30 | 2021-06-01 | Rohm And Haas Electronic Materials Llc | Copolymer formulation for directed self assembly, methods of manufacture thereof and articles comprising the same |
JP2021524150A (en) * | 2018-03-26 | 2021-09-09 | インテル・コーポレーション | Multifunctional molecules for selective polymer formation on conductive surfaces and structures obtained from selective polymer formation on conductive surfaces |
WO2023021016A3 (en) * | 2021-08-18 | 2023-04-13 | Merck Patent Gmbh | Development of novel hydrophilic pinning mat |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US9129909B2 (en) * | 2013-11-08 | 2015-09-08 | Kabushiki Kaisha Toshiba | Method of patterning |
US9911608B2 (en) * | 2016-01-26 | 2018-03-06 | Micron Technology, Inc. | Method of forming patterns |
KR102611450B1 (en) | 2016-01-26 | 2023-12-08 | 삼성전자주식회사 | Method of forming patterns |
TWI805617B (en) | 2017-09-15 | 2023-06-21 | 南韓商Lg化學股份有限公司 | Laminate |
Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7237221B2 (en) * | 2003-01-02 | 2007-06-26 | Yuri Granik | Matrix optical process correction |
US8114573B2 (en) * | 2006-06-02 | 2012-02-14 | Micron Technology, Inc. | Topography based patterning |
US8222154B2 (en) * | 2009-02-10 | 2012-07-17 | International Business Machines Corporation | Fin and finFET formation by angled ion implantation |
US8287749B2 (en) * | 2008-12-22 | 2012-10-16 | Hitachi, Ltd. | High-molecular thin film, pattern medium and manufacturing method thereof |
US8336003B2 (en) * | 2010-02-19 | 2012-12-18 | International Business Machines Corporation | Method for designing optical lithography masks for directed self-assembly |
US8574950B2 (en) * | 2009-10-30 | 2013-11-05 | International Business Machines Corporation | Electrically contactable grids manufacture |
US8667430B1 (en) * | 2012-10-24 | 2014-03-04 | GlobalFoundries, Inc. | Methods for directed self-assembly process/proximity correction |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20110076623A1 (en) | 2009-09-29 | 2011-03-31 | Tokyo Electron Limited | Method for reworking silicon-containing arc layers on a substrate |
JP5484373B2 (en) | 2011-02-14 | 2014-05-07 | 東京エレクトロン株式会社 | Pattern formation method |
-
2013
- 2013-03-15 US US13/841,694 patent/US8853101B1/en active Active
Patent Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7237221B2 (en) * | 2003-01-02 | 2007-06-26 | Yuri Granik | Matrix optical process correction |
US8114573B2 (en) * | 2006-06-02 | 2012-02-14 | Micron Technology, Inc. | Topography based patterning |
US8287749B2 (en) * | 2008-12-22 | 2012-10-16 | Hitachi, Ltd. | High-molecular thin film, pattern medium and manufacturing method thereof |
US8222154B2 (en) * | 2009-02-10 | 2012-07-17 | International Business Machines Corporation | Fin and finFET formation by angled ion implantation |
US8574950B2 (en) * | 2009-10-30 | 2013-11-05 | International Business Machines Corporation | Electrically contactable grids manufacture |
US8336003B2 (en) * | 2010-02-19 | 2012-12-18 | International Business Machines Corporation | Method for designing optical lithography masks for directed self-assembly |
US8667430B1 (en) * | 2012-10-24 | 2014-03-04 | GlobalFoundries, Inc. | Methods for directed self-assembly process/proximity correction |
Cited By (15)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US9564324B2 (en) * | 2013-06-12 | 2017-02-07 | Samsung Electronics Co., Ltd. | Methods of forming a pattern and devices formed by the same |
US20140370712A1 (en) * | 2013-06-12 | 2014-12-18 | Eunsung KIM | Methods of forming a pattern and devices formed by the same |
US9371427B2 (en) * | 2014-09-03 | 2016-06-21 | Kabushiki Kaisha Toshiba | Pattern forming method |
US10011713B2 (en) | 2014-12-30 | 2018-07-03 | Dow Global Technologies Llc | Copolymer formulation for directed self assembly, methods of manufacture thereof and articles comprising the same |
CN105731371A (en) * | 2014-12-30 | 2016-07-06 | 罗门哈斯电子材料有限责任公司 | Copolymer Formulation For Directed Self Assembly, Methods Of Manufacture Thereof And Articles Comprising The Same |
US10294359B2 (en) | 2014-12-30 | 2019-05-21 | Rohm And Haas Electronic Materials Llc | Copolymer formulation for directed self assembly, methods of manufacture thereof and articles comprising the same |
US11021630B2 (en) | 2014-12-30 | 2021-06-01 | Rohm And Haas Electronic Materials Llc | Copolymer formulation for directed self assembly, methods of manufacture thereof and articles comprising the same |
US10351727B2 (en) | 2015-02-26 | 2019-07-16 | Dow Global Technologies Llc | Copolymer formulation for directed self-assembly, methods of manufacture thereof and articles comprising the same |
US10854465B2 (en) | 2015-05-19 | 2020-12-01 | Samsung Electronics Co., Ltd. | Method of fabricating pattern structure |
US9881793B2 (en) | 2015-07-23 | 2018-01-30 | International Business Machines Corporation | Neutral hard mask and its application to graphoepitaxy-based directed self-assembly (DSA) patterning |
CN106847676A (en) * | 2015-12-03 | 2017-06-13 | 中芯国际集成电路制造(上海)有限公司 | The patterning method and forming method of semiconductor devices |
US20180323078A1 (en) * | 2015-12-24 | 2018-11-08 | Intel Corporation | Pitch division using directed self-assembly |
JP2021524150A (en) * | 2018-03-26 | 2021-09-09 | インテル・コーポレーション | Multifunctional molecules for selective polymer formation on conductive surfaces and structures obtained from selective polymer formation on conductive surfaces |
US11398428B2 (en) | 2018-03-26 | 2022-07-26 | Intel Corporation | Multifunctional molecules for selective polymer formation on conductive surfaces and structures resulting therefrom |
WO2023021016A3 (en) * | 2021-08-18 | 2023-04-13 | Merck Patent Gmbh | Development of novel hydrophilic pinning mat |
Also Published As
Publication number | Publication date |
---|---|
US8853101B1 (en) | 2014-10-07 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US8853101B1 (en) | Methods for fabricating integrated circuits including formation of chemical guide patterns for directed self-assembly lithography | |
US8828493B2 (en) | Methods of directed self-assembly and layered structures formed therefrom | |
US9159558B2 (en) | Methods of reducing defects in directed self-assembled structures | |
CN102428022B (en) | Directed self-assembly of block copolymers using segmented prepatterns | |
US8715917B2 (en) | Simultaneous photoresist development and neutral polymer layer formation | |
KR101800996B1 (en) | Method for patterning contact openings on a substrate | |
US8623458B2 (en) | Methods of directed self-assembly, and layered structures formed therefrom | |
US20100068656A1 (en) | High etch resistant material for double patterning | |
US8993221B2 (en) | Block co-polymer photoresist | |
US8728714B2 (en) | Methods for adhering materials, for enhancing adhesion between materials, and for patterning materials, and related semiconductor device structures | |
WO2006057745A2 (en) | Direct imprinting of etch barriers using step and flash imprint lithography | |
US10056256B2 (en) | Method of priming photoresist before application of a shrink material in a lithography process | |
US9640410B2 (en) | Pattern formation method | |
US20150303055A1 (en) | Methods for fabricating integrated circuits including surface treating for directed self-assembly | |
US10915027B2 (en) | Post development treatment method and material for shrinking critical dimension of photoresist layer | |
KR102107227B1 (en) | Structure and method for forming pattern using block copolymer, and method of fabricating semiconductor device using the same | |
US11300881B2 (en) | Line break repairing layer for extreme ultraviolet patterning stacks | |
CN106024592B (en) | Layer composition and correlation technique in silicon substrate | |
US9881793B2 (en) | Neutral hard mask and its application to graphoepitaxy-based directed self-assembly (DSA) patterning | |
US9613807B2 (en) | Methods for fabricating integrated circuits using directed self-assembly chemoepitaxy | |
US10727078B2 (en) | Methods of forming fine patterns | |
CN109471329A (en) | The method for carrying out photoetching process | |
US20080102648A1 (en) | Method and System For Making Photo-Resist Patterns | |
US10186542B1 (en) | Patterning for substrate fabrication | |
CN108231550B (en) | Method for manufacturing semiconductor device |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: GLOBALFOUNDRIES INC., CAYMAN ISLANDS Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:FARRELL, RICHARD A.;SCHMID, GERARD M.;JI, XU;REEL/FRAME:030021/0837 Effective date: 20130313 |
|
STCF | Information on status: patent grant |
Free format text: PATENTED CASE |
|
CC | Certificate of correction | ||
CC | Certificate of correction | ||
MAFP | Maintenance fee payment |
Free format text: PAYMENT OF MAINTENANCE FEE, 4TH YEAR, LARGE ENTITY (ORIGINAL EVENT CODE: M1551) Year of fee payment: 4 |
|
AS | Assignment |
Owner name: WILMINGTON TRUST, NATIONAL ASSOCIATION, DELAWARE Free format text: SECURITY AGREEMENT;ASSIGNOR:GLOBALFOUNDRIES INC.;REEL/FRAME:049490/0001 Effective date: 20181127 |
|
AS | Assignment |
Owner name: GLOBALFOUNDRIES U.S. INC., CALIFORNIA Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:GLOBALFOUNDRIES INC.;REEL/FRAME:054633/0001 Effective date: 20201022 |
|
AS | Assignment |
Owner name: GLOBALFOUNDRIES INC., CAYMAN ISLANDS Free format text: RELEASE BY SECURED PARTY;ASSIGNOR:WILMINGTON TRUST, NATIONAL ASSOCIATION;REEL/FRAME:054636/0001 Effective date: 20201117 |
|
AS | Assignment |
Owner name: GLOBALFOUNDRIES U.S. INC., NEW YORK Free format text: RELEASE BY SECURED PARTY;ASSIGNOR:WILMINGTON TRUST, NATIONAL ASSOCIATION;REEL/FRAME:056987/0001 Effective date: 20201117 |
|
MAFP | Maintenance fee payment |
Free format text: PAYMENT OF MAINTENANCE FEE, 8TH YEAR, LARGE ENTITY (ORIGINAL EVENT CODE: M1552); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY Year of fee payment: 8 |