Alternating self-assembling morphologies of diblock copolymers controlled by variations in surfaces

- Micron Technology, Inc.

Methods for fabricating sublithographic, nanoscale microstructures arrays including openings and linear microchannels utilizing self-assembling block copolymers, and films and devices formed from these methods are provided. In some embodiments, the films can be used as a template or mask to etch openings in an underlying material layer.

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Description
TECHNICAL FIELD

Embodiments of the invention relate to methods of fabricating nanostructures by use of thin films of self-assembling block copolymers, and devices resulting from those methods.

BACKGROUND OF THE INVENTION

As the development of nanoscale mechanical, electrical, chemical and biological devices and systems increases, new processes and materials are needed to fabricate nanoscale devices and components. Optical lithographic processing methods are not able to accommodate fabrication of structures and features at the nanometer level. The use of self assembling diblock copolymers presents another route to patterning at nanometer dimensions. Diblock copolymer films spontaneously assembly into periodic structures by microphase separation of the constituent polymer blocks after annealing, for example by thermal annealing above the glass transition temperature of the polymer or by solvent annealing, forming ordered domains at nanometer-scale dimensions. Following self assembly, one block of the copolymer can be selectively removed and the remaining patterned film used, for example, as an etch mask for patterning nanosized features into the underlying substrate. Since the domain sizes and periods (Lo) involved in this method are determined by the chain length of a block copolymer (MW), resolution can exceed other techniques such as conventional photolithography, while the cost of the technique is far less than electron beam (E-beam) lithography or EUV photolithography, which have comparable resolution.

The film morphology, including the size and shape of the microphase-separated domains, can be controlled by the molecular weight and volume fraction of the AB blocks of a diblock copolymer to produce lamellar, cylindrical, or spherical morphologies, among others. For example, for volume fractions at ratios greater than about 80:20 of the two blocks (AB) of a diblock polymer, a block copolymer film will microphase separate and self-assemble into a periodic spherical domains with spheres of polymer B surrounded by a matrix of polymer A. For ratios of the two blocks between about 60:40 and 80:20, the diblock copolymer assembles into periodic cylindrical domains of polymer B within a matrix of polymer A. For ratios between about 50:50 and 60:40, lamellar domains or alternating stripes of the blocks are formed. Domain size typically ranges from 5-50 nm.

Researchers have demonstrated the ability to chemically differentiate a surface such that some areas are preferentially wetting to one domain of a block copolymer and other areas are neutral wetting to both blocks. Periodic cylindrical structures have been grown in parallel and perpendicular orientations to substrates within trenches by thermal annealing cylindrical-phase block copolymers. A primary requirement for producing perpendicular cylinders is that the trench floor must be non-preferential or neutral wetting to both blocks of the copolymer. For producing parallel-oriented half-cylinders, the trench floor must by preferentially wetting by the minor copolymer block.

A film composed of periodic hexagonal close-packed cylinders, for example, can be useful in forming an etch mask to make structures in an underlying substrate for specific applications such as magnetic storage devices. However, many applications require a more complex layout of elements for forming contacts, conductive lines and/or other elements such as DRAM capacitors.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention are described below with reference to the following accompanying drawings, which are for illustrative purposes only. Throughout the following views, the reference numerals will be used in the drawings, and the same reference numerals will be used throughout the several views and in the description to indicate same or like parts.

FIG. 1 illustrates a diagrammatic top plan view of a portion of a substrate at a preliminary processing stage according to an embodiment of the present disclosure. FIG. 1A is an elevational, cross-sectional view of the substrate depicted in FIG. 1 taken along lines 1A-1A.

FIGS. 2-3 are diagrammatic top plan views of the substrate of FIG. 1 at subsequent processing steps according an embodiment of the invention. FIGS. 2A-3A illustrate elevational, cross-sectional views of a portion of the substrate depicted in FIGS. 2-3 taken, respectively, along lines 2A-2A and 3A-3A. FIGS. 2B-3B illustrate elevational, cross-sectional views of another portion of the substrate depicted in FIGS. 2-3 taken, respectively, along lines 2B-2B and 3B-3B.

FIG. 4 is a diagrammatic top plan view of a portion of a substrate at a preliminary processing stage according to another embodiment of the disclosure. FIGS. 4A-4B are elevational, cross-sectional views of portions of the substrate depicted in FIG. 4 taken, respectively, along lines 4A-4A and 4B-4B. FIGS. 5-6 illustrate diagrammatic top plan views of the substrate depicted in FIG. 4 at subsequent processing stages. FIGS. 5A-6A are elevational, cross-sectional views of a portion of the substrates depicted in FIGS. 5-6, respectively, taken along lines 5A-5A and 6A-6A. FIGS. 5B-6B are elevational, cross-sectional views of another portion of the substrate depicted in FIGS. 5-6, respectively, taken along lines 5B-5B and 6B-6B.

FIGS. 7-8 are diagrammatic top plan views of the substrate of FIG. 2 at subsequent processing steps according to another embodiment of the invention. FIGS. 7A-8A illustrate elevational, cross-sectional views of a portion of the substrate depicted in FIGS. 7-8 taken, respectively, along lines 7A-7A and 8A-8A. FIGS. 7B-8B are elevational, cross-sectional views of a portion of the substrate depicted in FIGS. 7-8 taken, respectively, along lines 7B-7B and 8B-8B.

FIG. 9 is a diagrammatic top plan view of the substrate of FIG. 2 at a subsequent processing step according to another embodiment of the invention to form preferential and neutral wetting surfaces. FIGS. 9A-9B illustrate elevational, cross-sectional views of a portion of the substrate depicted in FIG. 9 taken, respectively, along lines 9A-9A and 9B-9B.

FIG. 10 is a diagrammatic top plan view of the substrate of FIG. 2 at a subsequent processing step according to another embodiment of the disclosure. FIGS. 10A-10B depict elevational, cross-sectional view of a portion of the substrate depicted in FIG. 10 taken, respectively, along lines 10A-10A and 10B-10B.

FIG. 11 is a diagrammatic top plan view of the substrate of FIG. 2 at a subsequent processing step according to another embodiment of the invention to form roughened trench floors for a preferential wetting surface. FIGS. 11A-11B illustrate elevational, cross-sectional views of a portion of the substrate depicted in FIG. 11 taken, respectively, along lines 11A-11A and 11B-11B.

FIGS. 12-13 are diagrammatic top plan views of the substrate of FIG. 3 at subsequent stages in the fabrication of a film composed of arrays of cylindrical domains according to an embodiment of the present disclosure FIGS. 14 and 16 are top plan views of the substrate of FIG. 13 at subsequent processing steps according to an embodiment of the invention to form a mask and arrays of conductive contacts and lines in a substrate.

FIGS. 12A-14A and 16A are elevational, cross-sectional views of a portion of the substrate depicted in FIGS. 12-14 and 16 taken, respectively, along lines 12A-12A to 14A-14A and 16A-16A. FIGS. 12B-14B and 16B are elevational, cross-sectional views of a portion of the substrate depicted in FIGS. 12-14 and 16 taken, respectively, along lines 12B-12B to 14B-14B and 16B-16B. FIGS. 15A-15B are cross-sectional views of the substrate depicted in FIGS. 14A-14B, respectively, at a subsequent processing stage.

 DETAILED DESCRIPTION OF THE INVENTION

The following description with reference to the drawings provides illustrative examples of devices and methods according to embodiments of the invention. Such description is for illustrative purposes only and not for purposes of limiting the same.

In the context of the current application, the term “semiconductor substrate” or “semiconductive substrate” or “semiconductive wafer fragment” or “wafer fragment” or “wafer” will be understood to mean any construction comprising semiconductor material, including but not limited to bulk semiconductive materials such as a semiconductor wafer (either alone or in assemblies comprising other materials thereon), and semiconductive material layers (either alone or in assemblies comprising other materials). The term “substrate” refers to any supporting structure including, but not limited to, the semiconductive substrates, wafer fragments or wafers described above.

“Lo” is the inherent pitch (bulk period or repeat unit) of structures that self assemble upon annealing from a self-assembling (SA) block copolymer or a blend of a block copolymer with one or more of its constituent homopolymers.

In embodiments of the invention, processing conditions utilize graphoepitaxy techniques that use topographical features, e.g., the sidewalls and ends of trenches, as constraints to induce the formation and registration of polymer domains of cylindrical-phase diblock copolymers in one dimension (e.g., hexagonal close-packed (honeycomb) array or single row of perpendicular cylinders) and chemically or structurally (topographically) differentiated trench floors to provide a wetting pattern to control orientation of the microphase separated and self-assembling cylindrical domains in a second dimension (e.g., parallel lines of half-cylinders or perpendicular-oriented cylinders). The trench floors are structured or composed of surface materials to provide a neutral wetting surface or preferential wetting surface to impose ordering on a block copolymer film that is then cast on top of the substrate and annealed to produce desired arrays of nanoscale cylinders.

Embodiments of the invention provide a means of generating self-assembled diblock copolymer structures wherein perpendicular cylinders are formed in some trenches and parallel-oriented half-cylinders are formed in other trenches. Control of the orientation of the cylinders is provided by the nature of the trench floor surface. Graphoepitaxy is used to provide parallel lines of half-cylinders, hexagonal close-packed arrays of perpendicular cylinders, or a single row of perpendicular cylinders within lithographically defined trenches. A desired pattern of cylinders on a substrate, e.g., a wafer, can be prepared by providing trenches having walls that are selective to one polymer block of a block copolymer and a floor composed either of a material that is block-sensitive or preferentially wetting to one of the blocks of the block copolymer in trenches where lines of parallel half-cylinders are desired, or a material that is neutral wetting to both blocks in trenches where an array of perpendicular cylinders are desired. Embodiments of the invention can be used to pattern lines and openings (holes) in the same patterning step at predetermined locations on a substrate.

Embodiments of the invention of methods for fabricating arrays of cylinders from thin films of cylindrical-phase self assembling (SA) block copolymers are described with reference to the figures. As shown in FIGS. 1-1A, a substrate 10 to be etched is provided, being silicon in the illustrated embodiment. Overlying the substrate 10 is a material layer 12. As illustrated in FIGS. 2-2B, the material layer 12 is etched to form a desired pattern of trenches shown as trenches 14a, 14b and 14c.

The trenches can be formed using a lithographic tool having an exposure system capable of patterning at the scale of Lo (10-100 nm). Such exposure systems include, for example, extreme ultraviolet (EUV) lithography, dry lithography (e.g., 248 nm, 193 nm), immersion lithography (e.g., 193 nm), and electron beam lithography, as known and used in the art. Conventional photolithography can attain about 58 nm features. A method called “pitch doubling” or “pitch multiplication” can also be used for extending the capabilities of photolithographic techniques beyond their minimum pitch, as described, for example, in U.S. Pat. No. 5,328,810 (Lowrey et al.), U.S. Pat. No. 7,115,525 (Abatchev, et al.), US 2006/0281266 (Wells) and US 2007/0023805 (Wells), the disclosures of which are incorporated by reference herein. Briefly, a pattern of lines is photolithographically formed in a photoresist layer overlying a layer of an expendable material, which in turn overlies a substrate, the expendable material layer is etched to form placeholders or mandrels, the photoresist is stripped, spacers are formed on the sides of the mandrels, and the mandrels are then removed leaving behind the spacers as a mask for patterning the substrate. Thus, where the initial photolithography formed a pattern defining one feature and one space, the same width now defines two features and two spaces, with the spaces defined by the spacers. As a result, the smallest feature size possible with a photolithographic technique is effectively decreased down to about 30 nm or more.

The trenches 14a-14c are structured with opposing sidewalls 16, opposing ends 18, a floor 20, a width (wt), a length (lt) and a depth (Dt). Trench 14c is also structured with the trench ends 18 angled to the sidewalls 16, for example, at an about 60° angle, and in some embodiments, the trench ends are slightly rounded. Portions of the material layer 12 form a spacer 12a between the trenches.

The trench sidewalls, edges and floors influence the self-assembly of the polymer blocks and the structuring of the array of nanostructures within the trenches. The boundary conditions of the trench sidewalls 16 impose order in the x-direction (x-axis) and the ends 18 impose order in the y-direction (y-axis) to impose a structure wherein each trench contains n number of features (i.e., cylinders). Other factors that influence the formation and alignment of elements within the trench include the width (wt) of the trench, the formulation of the block copolymer to achieve the desired pitch (Lo), the thickness (t) of the block copolymer film, and the wetting nature of the trench surfaces.

Entropic forces drive the wetting of a neutral wetting surface by both blocks, and enthalpic forces drive the wetting of a preferential-wetting surface by the preferred block (e.g., the minority block). The trench sidewalls 16 and ends 18 are structured to be preferential wetting such that upon annealing, the preferred block of the block copolymer will segregate to the sidewalls and edges of the trench to assemble into a thin (e.g., ¼ pitch) interface (wetting) layer, and will self-assemble to form cylinders in the center of a polymer matrix within each trench, the cylinders being in a perpendicular orientation on neutral wetting floor surfaces and half-cylinders in a parallel orientation in relation to preferential wetting floor surfaces.

As illustrated in FIGS. 2-2B, trenches 14a are constructed with a width (wt) of about 2*Lo or less, e.g., about 1.5*Lo to about 2*Lo (e.g., about 1.75*Lo) (Lo being the inherent periodicity or pitch value of the block copolymer) for forming a 1-D array of cylinders with a center-to-center pitch of at or about Lo (e.g., a width of about 65-75 nm for a Lo value of about 36-42 nm). Trenches 14b, 14c have a width (wt) at or about an integer multiple of the Lo value or nLo where n=3, 4, 5, etc. (e.g., a width of about 120-2,000 nm for a Lo value of about 36-42 nm). The length (l) of the trenches is at or about nLo where n is an integer multiple of Lo, typically within a range of about n*10−n*100 nm (with n being the number of features or structures (i.e., cylinders)). The depth (Dt) of the trenches generally over a range of about 50-500 nm. The width of the spacer 12a between adjacent trenches can vary and is generally about Lo to about nLo.

As shown in FIGS. 3-3B, the floors 20 of trenches 14a, 14c have a neutral wetting surface (layer 22) to induce formation of perpendicular cylinders within those trenches, and the floors 20 of trenches 14b are preferential wetting by one block of a self-assembling block copolymer to induce formation of parallel half-cylinders in those trenches. The application and annealing of a cylindrical-phase block copolymer material having an inherent pitch value of about Lo in the trenches will result in a single row of “n” perpendicular cylinders in trenches 14a for the length of the trenches, “n” rows or lines of half-cylinders (parallel to the sidewalls and trench floor) extending the length (lt) and spanning the width (wt) of trenches 14b, and a periodic hexagonal close-pack or honeycomb array of perpendicular cylinders within trench 14c. The cylindrical domains are separated by a center-to-center distance (pitch distance (p)) of at or about Lo.

For example, a block copolymer having a 35-nm pitch (Lo value) deposited into a 75-nm wide trench having a neutral wetting floor will, upon annealing, result in a zigzag pattern of 35-nm diameter perpendicular cylinders that are offset by a half distance for the length (lb) of the trench, rather than a single line of perpendicular cylinders aligned with the sidewalls down the center of the trench. As the Lo value of the copolymer is increased, for example, by forming a ternary blend by the addition of both constituent homopolymers, there is a shift from two rows to one row of the perpendicular cylinders within the center of the trench.

In some embodiments, the substrate 10 can be a material that is inherently preferential wetting to one of the blocks, and a neutral wetting surface layer 22 can be provided by applying a neutral wetting polymer (e.g., a neutral wetting random copolymer) onto the substrate 10 and then selectively removing the layer 22 to expose portions of the preferential wetting surface of the substrate. For example, in the use of a poly(styrene-block-methyl methacrylate) block copolymer (PS-b-PMMA), a random PS:PMMA copolymer (PS-r-PMMA) which exhibits non-preferential or neutral wetting toward PS and PMMA can be applied. The polymer layer can be affixed by grafting (on an oxide substrate) or by cross-linking (any surface) using UV radiation or thermal processing.

As shown in FIGS. 4-4B, in some embodiments, a neutral wetting layer 22′ can be formed on the substrate 10′ prior to forming the overlying material layer 12′. For example, a blanket layer 22′ of a photo-crosslinkable random copolymer (e.g., PS-r-PMMA) can be spin coated onto the substrate 10′ and photo-crosslinked (arrows ↓↓↓) in select areas 22a′ using a reticle 24′, for example. The material layer 12′ can then be formed over layer 22′ and the trenches etched to expose the neutral wetting layer 22′ at the trench floors 20′, as depicted in FIGS. 5-5B, including crosslinked sections 22a′. As shown in FIGS. 6-6B, non-crosslinked and exposed regions of the neutral wetting layer 22′ can then be selectively removed, e.g., by a solvent rinse, to expose the substrate 10′ (e.g., silicon with native oxide) as a preferential wetting surface 20b′ in trenches 14b′, with the crosslinked neutral wetting layer 22a′ providing a neutral wetting surface 20a′ in trenches 14a′, 14c′.

In another embodiment depicted in FIGS. 7-7B, a neutral wetting random copolymer can be applied after forming the trenches, for example, as a blanket coat by spin-coating into each of the trenches 14a″-14c″ and thermally processed (↓↓↓) to flow the material into the bottom of the trenches by capillary action, which can result in crosslinking the neutral wetting polymer layer 22″. To remove the crosslinked polymer layer 22″ from selected regions, a photoresist layer 24″ can be coated over the structure, patterned and developed as shown in FIGS. 8-8B, and an oxygen (O2) dry etch (arrows ↓↓↓) can be conducted to remove the crosslinked random copolymer layer 22″ from trenches 14b″ where a preferential wetting floor is desired, by exposing the substrate 10″ (e.g., silicon with native oxide). The photoresist 24″ can then be removed, resulting in the structure shown in FIGS. 3-3B.

For example, a neutral wetting polymer (NWP) such as a random copolymer of polystyrene (PS), polymethacrylate (PMMA) with hydroxyl group(s) (e.g., 2-hydroxyethyl methacrylate (P(S-r-MMA-r-HEMA)) (e.g., about 58% PS) can be can be selectively grafted to a material layer (e.g., an oxide floor) as a layer 22″ of about 5-10 nm thick by heating at about 160° C. for about 48 hours (FIGS. 7-7B). See, for example, In et al., Langmuir, 2006, 22, 7855-7860, the disclosure of which is incorporated by reference herein. The grafted polymer can then be removed from trenches 14b″ by applying and developing a photoresist layer 24″ and etching (e.g., O2 dry etch) the exposed polymer layer 22″ to produce preferential wetting floors (e.g., substrate 10″ of silicon with native oxide) in trenches 14b″ (FIGS. 8-8B).

A surface that is neutral wetting to PS-b-PMMA can also be prepared by spin coating a blanket layer of a photo- or thermally cross-linkable random copolymer such as a benzocyclobutene- or azidomethylstyrene-functionalized random copolymer of styrene and methyl methacrylate (e.g., poly(styrene-r-benzocyclobutene-r-methyl methacrylate (PS-r-PMMA-r-BCB)). For example, such a random copolymer can comprise about 42% PMMA, about (58-x) % PS and x % (e.g., about 2-3%) of either polybenzocyclobutene or poly(para-azidomethylstyrene)). An azidomethylstyrene-functionalized random copolymer can be UV photo-crosslinked (e.g., 1-5 MW/cm^2 exposure for about 15 seconds to about 30 minutes) or thermally crosslinked (e.g., at about 170° C. for about 4 hours) to form a crosslinked polymer mat as a neutral wetting layer 22″. A benzocyclobutene-functionalized random copolymer can be thermally cross-linked (e.g., at about 200° C. for about 4 hours or at about 250° C. for about 10 minutes). The layer 22″ can be globally photo- or thermal-crosslinked (FIGS. 7-7B), masked using a patterned photoresist 24″ (FIGS. 8-8B), and the unmasked sections can be selectively removed by etching (arrows ↓↓↓) (e.g., O2 etch) to expose preferential-wetting floors 20″, e.g., substrate 10″ of silicon with native oxide, in trenches 14b″.

In other embodiments, as illustrated in FIGS. 9-9B, portions of the neutral wetting layer 22′″ in trenches 14a′″, 14c′″ can be photo-crosslinked through a reticle 24′″ (arrows ↓↓↓) and the non-crosslinked material in trenches 14b′″ can be removed, for example, using a solvent rinse, resulting in the structure shown in FIGS. 3-3B.

Referring now to FIGS. 10-10B, in another embodiment in which the substrate 10″″ is silicon (with native oxide), another neutral wetting surface for PS-b-PMMA can be provided by hydrogen-terminated silicon. For example, the floors 20″″ of trenches 14b″″ can be masked, e.g., using a patterned photoresist layer 24″″, and the floors 20″″ of trenches 14a″″, 14c″″ can be selectively etched (arrows ↓↓↓), for example, with a hydrogen plasma, to remove the oxide material and form hydrogen-terminated silicon 22″″, which is neutral wetting with equal affinity for both blocks of a block copolymer material such as PS-b-PMMA. H-terminated silicon can be prepared by a conventional process, for example, by a fluoride ion etch of a silicon substrate (with native oxide present, about 12-15 Å) by exposure to an aqueous solution of hydrogen fluoride (HF) and buffered HF or ammonium fluoride (NH4F), by HF vapor treatment, or by a hydrogen plasma treatment (e.g., atomic hydrogen). The photoresist layer 24″″ can then be removed, resulting in a structure as shown in FIGS. 3-3B.

In other embodiments, a neutral wetting layer (22) can be provided by grafting a random copolymer such as PS-r-PMMA selectively onto an H-terminated silicon substrate (e.g., 20′″ floor) in FIGS. 10-10B by an in situ free radical polymerization of styrene and methyl methacrylate using a di-olefinic linker such divinyl benzene which links the polymer to the surface to produce an about 10-15 nm thick film.

In other embodiments, a layer of a preferential wetting material can be applied onto the surface of the substrate exposed as the floors of trenches 14b. For example, a layer of oxide or silicon nitride, etc. can be deposited as a blanket layer into the trenches (e.g., as shown in FIGS. 7-7B), followed by selective removal of the material from the floor of trenches 14a″, 14c″ to expose a neutral wetting surface or, in other embodiments, a neutral wetting material (e.g., a random copolymer) can then be selectively applied onto the exposed floors of trenches 14a″, 14c″.

In yet another embodiment, the floors of the trenches can be made neutral or preferential wetting by varying the roughness of the surface of the trenches floor, as described, for example, in Sivaniah et al., Macromolecules 2005, 38, 1837-1849, and Sivaniah et al., Macromolecules 2003, 36, 5894-5896, the disclosure of which are incorporated by reference herein. A grooved or periodic grating-like substrate topography having a lateral periodicity and structure at or above a critical roughness value (e.g., qsR where qs=2π/λs, R is the (root-mean-square) vertical displacement of the surface topography about a mean horizontal plane, and λs is the lateral periodicity in the surface topography) can be provided to form a neutral wetting surface (e.g., trenches 14a, 14c) for formation of perpendicular cylinders (under conditions of a neutral wetting air surface). The floors of trenches 14b can be provided with a low surface roughness below the critical qsR, value for formation of parallel-oriented half-cylinders in those trenches. The critical roughness of the floor surface topography can also be adjusted according to the molecular weight of the block copolymer to achieve a perpendicular orientation of cylinders. The roughness of the substrate surface can be characterized using atomic force microscopy (AFM).

For example, as shown in FIGS. 11-11B, in some embodiments, the floors of trenches 14av, 14cv can be selectively etched (arrows ↓↓↓) to provide a pattern of grooves 26v at or above a critical roughness (qsR), the floors being sufficiently rough to form a neutral wetting surface to induce formation of perpendicular-oriented cylinders within those trenches. In other embodiments, a material 26v such as indium tin oxide (ITO), can be e-beam deposited (arrows ↓↓↓) onto the surface of floors 20v of trenches 14av, 14cv to form a sufficiently rough and neutral wetting surface and, in some embodiments, sputter coated onto the surface of floors 20v of trenches 14bv to form a relatively smooth and preferential wetting surface.

Referring now to FIGS. 3-3B, the sidewalls 16 and ends 18 of the trenches are preferential wetting by one block of the copolymer. The material layer 12 defining the trench surfaces can be an inherently preferential wetting material, or in other embodiments, a layer of a preferential wetting material can be applied onto the surfaces of the trenches. For example, in the use of a PS-b-PMMA block copolymer, the material layer 12 can be composed of silicon (with native oxide), oxide (e.g., silicon oxide, SiOx), silicon nitride, silicon oxycarbide, ITO, silicon oxynitride, and resist materials such as such as methacrylate-based resists, among other materials, which exhibit preferential wetting toward the PMMA block. In other embodiments, a layer of a preferential wetting material such as a polymethylmethacrylate (PMMA) polymer modified with an —OH containing moiety (e.g., hydroxyethylmethacrylate) can be applied onto the surfaces of the trenches, for example, by spin coating and then heating (e.g., to about 170° C.) to allow the terminal OH groups to end-graft to oxide sidewalls 16 and ends 18 of the trenches. Non-grafted material can be removed by rinsing with an appropriate solvent (e.g., toluene). See, for example, Mansky et al., Science, 1997, 275, 1458-1460, and In et al., Langmuir, 2006, 22, 7855-7860, the disclosures of which are incorporated by reference herein.

Referring now to FIGS. 12-12B, a cylindrical-phase self-assembling block copolymer material 28 having an inherent pitch at or about Lo (or a ternary blend of block copolymer and homopolymers blended to have a pitch at or about Lo) is then deposited, typically by spin casting or spin-coating into the trenches 14a-14c and onto the floors 20. The block copolymer material can be deposited onto the patterned surface by spin casting from a dilute solution (e.g., about 0.25-2 wt % solution) of the copolymer in an organic solvent such as dichloroethane (CH2Cl2) or toluene, for example.

The copolymer material layer 28 is deposited into the trenches 14a-14c to a thickness (t) such that during an anneal, the capillary forces pull excess material (e.g., greater than a monolayer) into the trench. The resulting thickness of layer 28 in the trench is at about the Lo value of the copolymer material such that the copolymer film layer will self assemble upon annealing to form an array of cylindrical elements, for example, perpendicular cylindrical domains having a diameter at or about 0.5 Lo (e.g., about 20 nm) over the neutral wetting surface 22 of trenches 14a, 14c, and a single layer of lines of parallel-oriented half-cylinders with a diameter at or about 0.5 Lo over the preferential wetting floor 20 of trenches 14b. The film thickness can be measured, for example, by ellipsometry. Depending on the depth (Dt) of the trenches, the cast block copolymer material 28 can fill the trenches where the trench depth is about equal to Lo (Dt˜L0), or form a thinner film over the trench floor where the trench depth (Dt) is greater than Lo (Dt>L0) as depicted. A thin film of the copolymer material 28 generally less than Lo can be deposited on the spacers 12a, this material will not self-assemble, as it is not thick enough to form structures.

Although diblock copolymers are used in the illustrative embodiment, other types of block copolymers (i.e., triblock or triblock or multiblock copolymers) can be used. Examples of diblock copolymers include poly(styrene-block-methyl methacrylate) (PS-b-PMMA), polyethyleneoxide-polyisoprene, polyethyleneoxide-polybutadiene, polyethyleleoxide-polystyrene, polyetheleneoxide-polymethylmethacrylate, polystyrene-polyvinylpyridine, polystyrene-polyisoprene (PS-b-PI), polystyrene-polybutadiene, polybutadiene-polyvinylpyridine, and polyisoprene-polymethylmethacrylate, among others. Examples of triblock copolymers include poly(styrene-block methyl methacrylate-block-ethylene oxide). An example of a PS-b-PMMA copolymer material (Lo=35 nm) is composed of about 70% PS and 30% PMMA with a total molecular weight (Me) of 67 kg/mol, to form 20 nm diameter cylindrical PMMA domains in a matrix of PS.

The block copolymer material can also be formulated as a binary or ternary blend comprising a SA block copolymer and one or more homopolymers of the same type of polymers as the polymer blocks in the block copolymer, to produce blends that swell the size of the polymer domains and increase the Lo value of the polymer. The volume fraction of the homopolymers can range from 0 to about 40%. An example of a ternary diblock copolymer blend is a PS-b-PMMA/PS/PMMA blend, for example, 46K/21K PS-b-PMMA containing 40% 20K polystyrene and 20K poly(methylmethacrylate). The Lo value of the polymer can also be modified by adjusting the molecular weight of the block copolymer.

Optionally, ellipticity (“bulging”) can be induced in the structures by creating a slight mismatch between the trench and the spacer widths and the inherent pitch (Lo) of the block copolymer or ternary blend, as described, for example, by Cheng et al., “Self-assembled One-Dimensional Nanostructure Arrays,”, Nano Lett., 6 (9), 2099-2103 (2006), which then reduces the stresses that result from such mismatches.

Referring now to FIGS. 13-13B, the block copolymer film 28 is then annealed to cause the component polymer blocks to phase separate and self assemble according to the wetting material on the trench floors 20 and the preferential wetting surfaces of the trench sidewalls 16 and ends 18. This imposes ordering on the block copolymer film as it is annealed and the blocks self-assemble, resulting in a 1-D array of perpendicular-oriented cylinders 30 (minority block) in a matrix 34 (majority block) for the length (nLo) of each trench 14a (neutral wetting floor), parallel-oriented half-cylinder(s) 32 in a matrix 34 for the length of each trench 14b, and a hexagonal close pack array of perpendicular cylinders 30 in trench 14c. A layer 30a, 32a of the minority block wets the preferential wetting sidewalls 16 and ends 18 of the trenches.

The copolymer film can be thermally annealed to above the glass transition temperature of the component blocks of the copolymer material. For example, a PS-b-PMMA copolymer film can be annealed at a temperature of about 180-285° C. in a vacuum oven for about 1-24 hours to achieve the self-assembled morphology. The resulting morphologies of the block copolymer (i.e., perpendicular and parallel orientation of cylinders) can be examined, for example, using atomic force microscopy (AFM), transmission electron microscopy (TEM), and scanning electron microscopy (SEM).

The diameter of the perpendicular cylinders 30 and width of the half-cylinders 32 is generally about 0.5 Lo (e.g., about 20 nm). The center-to-center distance (pitch distance, p) between adjacent cylindrical domains within a trench is generally at or about Lo (e.g., about 40 nm for a 46/21 PS/PMMA block copolymer).

The hexagonal array of perpendicular cylinders 30 in trench 14c contains n rows of cylinders according to the width (wt) of the trench with the cylinders in each row being offset by about Lo (pitch distance (p) or center-to-center distance) from the cylinders in the adjacent rows. Each row contains “in” number of cylinders according to the length (lt) of the trench and the shape of the trench ends 18 (e.g., rounded, angled, etc.), with some rows having greater or less than m cylinders. The perpendicular cylinders 30 are spaced apart at a pitch distance (p) at or about Lo between cylinders in the same row and an adjacent row, and at a pitch distance (p) at or about Lo*cos(π/6) or about 0.866*Lo distance between two parallel lines where one line bisects the cylinders in a given row and the other line bisects the cylinders in an adjacent row.

The annealed and ordered film may then be treated to crosslink the polymer segments (e.g., the PS matrix 34) to fix and enhance the strength of the self-assembled polymer blocks within the trenches. The polymers can be structured to inherently crosslink (e.g., upon exposure to ultraviolet (UV) radiation, including deep ultraviolet (DUV) radiation), or one or both of the polymer blocks of the copolymer material can be formulated to contain a crosslinking agent. Non-ordered material outside the trenches (e.g., on spacers 12a) may then be removed.

For example, in one embodiment, the trench regions can be selectively exposed through a reticle (not shown) to crosslink only the self-assembled films within the trenches, and optionally, a wash can then be applied with an appropriate solvent (e.g., toluene) to remove non-crosslinked portions of the film 28 (e.g., on the spacers 12a). In another embodiment, the annealed films can be crosslinked globally, a photoresist layer can be applied to pattern and expose the areas of the film outside the trench regions (e.g., over the spacers 12a), and the exposed portions of the film can be removed, for example by an oxygen (O2) plasma treatment. In other embodiments, the spacers 12a are narrow in width, for example, a width (ws) of one of the copolymer domains (e.g., about Lo) such that the non-crosslinked block copolymer material 28 on the spacers is minimal and no removal is required. Material on the spacers 12a that is generally featureless need not be removed.

After annealing and the copolymer material is ordered, the minority polymer domains can be selectively removed from the films to produce a template for use in patterning the substrate 10. For example, as shown in FIGS. 14-14B, selective removal of the cylindrical domains 30, 32 (e.g., of PMMA) will produce an array of openings 36, 38 within the polymer matrix 34 (e.g., of PS), with the openings varying according to the orientation of the cylindrical domains within the trenches. Only openings 36 will extend to the trench floors 20, with the majority block matrix component 34 (e.g., PS) remaining underneath the lines of half-cylinder openings 38.

As shown in FIGS. 15A-15B, the half-cylinder openings 38 can be extended to expose the underlying substrate 10 by removing the underlying matrix component 34 (e.g., PS), for example, by a plasma O2 etch. The cylindrical openings 36 generally have a diameter of about 5-50 nm and an aspect ratio of about 1:1 to about 1:2, and the lined openings (grooves) 38 have a width of about 5-50 nm and an aspect ratio of about 1:1. The resulting film 40 can then be used in patterning (arrows ↓↓) the substrate 10 to form a configuration of cylindrical openings 42 and grooves (lines) 44 (shown in phantom) extending to active areas or elements 46. The residual matrix 34 (film 40) can be removed and the openings 42, 44 filled with a material 48 e.g., a metal or conductive alloy such as Cu, Al, W, Si, and Ti3N4, among others, as shown in FIGS. 16-16B to form arrays of cylindrical contacts 50 and parallel conductive lines 52, for example, to an underlying active area, contact, or conductive line 46. The cylindrical openings 42 can also be filled with a metal-insulator-metal-stack to form capacitors with an insulating material such as SiO2, Al2O3, HfO2, ZrO2, SrTiO3, and the like. Further processing can be conducted as desired.

Methods of the disclosure provide a means of generating self-assembled diblock copolymer structures where perpendicular cylinders preferentially form on some regions on a substrate and parallel cylinders form on other regions. In some embodiments, the desired orientation is controlled by the structure of the substrate (e.g., wafer) and/or the nature of the surface material. The methods provide ordered and registered elements on a nanometer scale that can be prepared more inexpensively than by electron beam lithography or EUV photolithography. The feature sizes produced and accessible by this invention cannot be prepared by conventional photolithography. Embodiments of the invention can be used to pattern lines and openings (holes) on a substrate in the same patterning step, thus eliminating processing steps compared to conventional process flows. The described methods can be readily employed and incorporated into existing semiconductor manufacturing process flows.

Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that any arrangement which is calculated to achieve the same purpose may be substituted for the specific embodiments shown. This application is intended to cover any adaptations or variations that operate according to the principles of the invention as described. Therefore, it is intended that this invention be limited only by the claims and the equivalents thereof. The disclosures of patents, references and publications cited in the application are incorporated by reference herein.

Claims

1. A method for fabricating nanoscale microstructures, comprising:

forming a film comprising a cylindrical-phase block copolymer within a plurality of trenches to a thickness of about Lo, each trench having a width, length, sidewalls, ends and a floor, wherein the sidewalls and ends of the trenches are preferential wetting to a first block of the block copolymer, the floor of at least one trench is preferential wetting to said first block and the floor of another trench is neutral wetting to a second block of the block copolymer; and
causing the block copolymer film to self-assemble to form perpendicularly-oriented cylindrical domains of the minority block of the block copolymer in a matrix of a majority block within trenches having said neutral wetting floor, and parallel-oriented half-cylindrical domains of the minority block in a matrix of the majority block within trenches having said preferential wetting floor.

2. The method of claim 1, wherein the at least one trench with a neutral wetting floor has a width of about 1.5*Lo to about 2*Lo.

3. The method of claim 1, wherein the at least one trench with a neutral wetting floor has a width of about nLo where n is an integer multiple greater than one.

4. The method of claim 3, wherein the ends of said trench are curved.

5. The method of claim 1, wherein the preferential wetting floor comprises a material selected from the group consisting of silicon (with native oxide), oxide, silicon nitride, silicon oxycarbide, silicon oxynitride, indium tin oxide, and methacrylate-based resists.

6. The method of claim 1, wherein the preferential wetting floor comprises a material having a surface roughness below a critical roughness for preferential wetting of the block copolymer.

7. The method of claim 6, wherein the preferential wetting floor induces a parallel orientation of cylindrical domains on said floor.

8. The method of claim 1, wherein the neutral wetting floor comprises a layer of a random copolymer.

9. The method of claim 1, wherein the neutral wetting floor comprises a layer of hydrogen-terminated silicon.

10. The method of claim 1, wherein the sidewalls and ends comprise a preferential wetting material selected from the group consisting of silicon (with native oxide), oxide, silicon nitride, silicon oxycarbide, silicon oxynitride, and methacrylate-based resists.

11. The method of claim 1, further comprising applying a preferential wetting material to the sidewalls and ends of the trenches.

12. The method of claim 1, further comprising crosslinking the self-assembled film.

13. The method of claim 1, further comprising, after causing the block copolymer film to self-assemble, selectively removing the minority polymer block to provide an array of perpendicular-oriented cylindrical openings and parallel-oriented half-cylindrical openings within the matrix of the majority polymer block.

14. The method of claim 13, further comprising extending the half-cylindrical openings to expose the floor of the trench.

15. A method for fabricating nanoscale microstructures, comprising:

forming a material layer on a substrate, the material layer and the substrate being preferential wetting to a first block of a block copolymer;
forming a plurality of trenches in the material layer, each trench having a width, length, sidewalls, ends and a floor, wherein the sidewalls and ends of the trenches are preferential wetting to said first block of the block copolymer;
forming a neutral wetting layer on the floor of at least one trench wherein at least one other trench has a preferential wetting floor;
forming a film comprising a cylindrical-phase block copolymer within the trenches to a thickness of about Lo; and
annealing the block copolymer film to form perpendicularly-oriented cylindrical domains of a minority block of the block copolymer in a matrix of a majority block within trenches having the neutral wetting layer on the floor of said trench, and parallel-oriented half-cylindrical domains of the minority block in a matrix of the majority block within trenches having a preferential wetting floor.

16. A method for fabricating nanoscale microstructures, comprising:

forming a material layer on a substrate;
forming a plurality of trenches in the material layer, each trench having a width, length, sidewalls, ends and a floor, wherein the sidewalls and ends of the trenches are preferential wetting to a first block of a block copolymer;
etching the floor of a first trench to a critical roughness for neutral wetting of said firstblock of the block copolymer;
forming a preferential wetting layer on the floor of a second trench;
forming a film comprising a cylindrical-phase block copolymer within the trenches to a thickness of about Lo; and
annealing the block copolymer film to form perpendicularly-oriented cylindrical domains of a minority block of the block copolymer in a matrix of a majority block within the first trench having a neutral wetting floor, and parallel-oriented half-cylindrical domains of the minority block in a matrix of the majority block within the second trench having said preferential wetting layer on the floor of said trench.

17. The method of claim 16, wherein forming the preferential wetting layer comprises forming a layer of a material selected from the group consisting of oxide, nitride, silicon oxycarbide, silicon oxynitride, indium tin oxide, and a resist, selectively on the floor of the second trench.

18. A method for fabricating nanoscale microstructures, comprising:

forming a neutral wetting layer on a substrate, the substrate being preferential wetting to a first block of a block copolymer and the neutral wetting layer being wetting to blocks a second block of the block copolymer;
forming a material layer on the neutral wetting layer;
forming a plurality of trenches in the material layer, each trench having a width, length, sidewalls, ends and a floor exposing the neutral wetting layer, wherein the sidewalls and ends of the trenches are preferential wetting to said first block of the block copolymer;
removing the neutral wetting layer from the floor of at least one trench to expose the preferential wetting substrate as the floor of said trench wherein at least one trench retains the neutral wetting layer as the floor of said trench;
forming a film comprising a cylindrical-phase block copolymer within the trenches to a thickness of about Lo; and
annealing the block copolymer film to form perpendicularly-oriented cylindrical domains of a minority block of the block copolymer in a matrix of a majority block within said trenches having the neutral wetting layer as the floor of said trench, and parallel-oriented half-cylindrical domains of the minority block in a matrix of the majority block within trench having the preferential wetting substrate as the floor of said trench.

19. A method of etching a substrate, comprising:

forming an etch mask, comprising: forming a film comprising a cylindrical-phase block copolymer within a plurality of trenches to a thickness of about Lo, each trench having a width, length, sidewalls, ends and a floor, wherein the sidewalls and ends of the trenches are preferential wetting to a first block of the block copolymer, and the floor of at least one trench is preferential wetting to said first block and the floor of another trench is neutral wetting to a second block of the block copolymer; annealing the film to cause the copolymer to self-assemble to form perpendicularly-oriented cylindrical domains of a minority block of the block copolymer in a matrix of a majority block within said trench having a neutral wetting floor, and parallel-oriented half-cylindrical domains of the minority block in a matrix of the majority block within said trench having a preferential wetting floor; and selectively removing the minority polymer block to provide an array of perpendicular-oriented cylindrical openings and parallel-oriented half-cylindrical openings within the matrix of the majority polymer block; and
etching the substrate through the openings of the etch mask.

20. The method of claim 19, further comprising extending the half-cylindrical openings to expose the floor of the trench.

21. The method of claim 19, wherein the perpendicular-oriented cylindrical openings extend the length of at least one trench in a single array.

22. The method of claim 19, wherein the perpendicular-oriented cylindrical openings in at least one trench are in a hexagonal array.

Referenced Cited
U.S. Patent Documents
4623674 November 18, 1986 Bailey, Jr.
4877647 October 31, 1989 Klabunde
5328810 July 12, 1994 Lowrey et al.
5482656 January 9, 1996 Hiraoka et al.
5538655 July 23, 1996 Fauteux et al.
5622668 April 22, 1997 Thomas
5904824 May 18, 1999 Oh
5948470 September 7, 1999 Harrison et al.
6111323 August 29, 2000 Carter et al.
6143647 November 7, 2000 Pan et al.
6368871 April 9, 2002 Christel et al.
6403382 June 11, 2002 Zhu et al.
6423465 July 23, 2002 Hawker et al.
6503841 January 7, 2003 Criscuolo
6506660 January 14, 2003 Holmes et al.
6548830 April 15, 2003 Noguchi et al.
6565763 May 20, 2003 Asakawa
6566248 May 20, 2003 Wang et al.
6569528 May 27, 2003 Nam et al.
6689473 February 10, 2004 Guire et al.
6699797 March 2, 2004 Morris et al.
6713238 March 30, 2004 Chou et al.
6746825 June 8, 2004 Nealey et al.
6781166 August 24, 2004 Lieber et al.
6890624 May 10, 2005 Kambe et al.
6890703 May 10, 2005 Hawker et al.
6913697 July 5, 2005 Lopez et al.
6924341 August 2, 2005 Mays
6926953 August 9, 2005 Nealey et al.
6949456 September 27, 2005 Kumar
6962823 November 8, 2005 Empedocles et al.
6989426 January 24, 2006 Hu et al.
6992115 January 31, 2006 Hawker et al.
7030495 April 18, 2006 Colburn et al.
7037744 May 2, 2006 Colburn et al.
7045851 May 16, 2006 Black et al.
7056455 June 6, 2006 Matyjasewski et al.
7056849 June 6, 2006 Wan et al.
7115525 October 3, 2006 Abatchev et al.
7115995 October 3, 2006 Wong
7118784 October 10, 2006 Xie
7132370 November 7, 2006 Paraschiv
7135144 November 14, 2006 Christel et al.
7135388 November 14, 2006 Ryu et al.
7135523 November 14, 2006 Ho et al.
7163712 January 16, 2007 Chilkoti et al.
7172953 February 6, 2007 Lieber et al.
7186613 March 6, 2007 Kirner
7189430 March 13, 2007 Ajayan et al.
7189435 March 13, 2007 Tuominen et al.
7190049 March 13, 2007 Tuominen et al.
7202308 April 10, 2007 Boussand et al.
7291284 November 6, 2007 Mirkin et al.
7347953 March 25, 2008 Black et al.
7407887 August 5, 2008 Guo
7408186 August 5, 2008 Merkulov et al.
7514339 April 7, 2009 Yang et al.
7521090 April 21, 2009 Cheng et al.
7553760 June 30, 2009 Yang et al.
7592247 September 22, 2009 Yang et al.
7605081 October 20, 2009 Yang et al.
7767099 August 3, 2010 Li et al.
20030077452 April 24, 2003 Guire et al.
20030091752 May 15, 2003 Nealey et al.
20030100822 May 29, 2003 Lew et al.
20030143375 July 31, 2003 Noguchi et al.
20030185741 October 2, 2003 Matyjaszewski
20040084298 May 6, 2004 Yao et al.
20040124092 July 1, 2004 Black et al.
20040125266 July 1, 2004 Miyauchi et al.
20040127001 July 1, 2004 Colburn
20040142578 July 22, 2004 Wiesner et al.
20040192013 September 30, 2004 Ryu et al.
20040222415 November 11, 2004 Chou
20040254317 December 16, 2004 Hu
20040256615 December 23, 2004 Sirringhaus et al.
20040256662 December 23, 2004 Black et al.
20040265548 December 30, 2004 Ho et al.
20050062165 March 24, 2005 Saenger et al.
20050074706 April 7, 2005 Bristol
20050100830 May 12, 2005 Xu et al.
20050124135 June 9, 2005 Ayazi et al.
20050147841 July 7, 2005 Tavkhelidze et al.
20050167651 August 4, 2005 Merkulov et al.
20050208752 September 22, 2005 Colburn et al.
20050238889 October 27, 2005 Iwamoto
20050250053 November 10, 2005 Marsh et al.
20050271805 December 8, 2005 Kambe et al.
20050272341 December 8, 2005 Colburn et al.
20060013956 January 19, 2006 Angelescu et al.
20060014001 January 19, 2006 Zhang et al.
20060038182 February 23, 2006 Rogers et al.
20060046079 March 2, 2006 Lee
20060046480 March 2, 2006 Guo
20060060863 March 23, 2006 Lu et al.
20060062867 March 23, 2006 Choi
20060078681 April 13, 2006 Hieda et al.
20060105562 May 18, 2006 Yi
20060124467 June 15, 2006 Ho et al.
20060134556 June 22, 2006 Nealey et al.
20060163646 July 27, 2006 Black
20060192283 August 31, 2006 Benson
20060205875 September 14, 2006 Cha et al.
20060217285 September 28, 2006 Destarac
20060231525 October 19, 2006 Asakawa et al.
20060249784 November 9, 2006 Black et al.
20060249796 November 9, 2006 Tavkhelidze et al.
20060258159 November 16, 2006 Colburn et al.
20060278158 December 14, 2006 Tolbert et al.
20060281266 December 14, 2006 Wells
20070020749 January 25, 2007 Nealey et al.
20070023805 February 1, 2007 Wells
20070045562 March 1, 2007 Parekh
20070071881 March 29, 2007 Chua et al.
20070072403 March 29, 2007 Sakata
20070122932 May 31, 2007 Kodas et al.
20070161237 July 12, 2007 Lieber et al.
20070175859 August 2, 2007 Black et al.
20070181870 August 9, 2007 Libertino et al.
20070200477 August 30, 2007 Tuominen et al.
20070208159 September 6, 2007 McCloskey et al.
20070218202 September 20, 2007 Ajayan et al.
20070222995 September 27, 2007 Lu
20070224819 September 27, 2007 Sandhu
20070227383 October 4, 2007 Decre et al.
20070249117 October 25, 2007 Kang et al.
20070281220 December 6, 2007 Sandhu et al.
20070293041 December 20, 2007 Yang et al.
20080083991 April 10, 2008 Yang et al.
20080093743 April 24, 2008 Yang et al.
20080103256 May 1, 2008 Kim et al.
20080164558 July 10, 2008 Yang et al.
20080176767 July 24, 2008 Millward
20080193658 August 14, 2008 Millward
20080217292 September 11, 2008 Millward et al.
20080233323 September 25, 2008 Cheng et al.
20080257187 October 23, 2008 Millward
20080260941 October 23, 2008 Jin
20080274413 November 6, 2008 Millward
20080286659 November 20, 2008 Millward
20080315270 December 25, 2008 Marsh et al.
20080318005 December 25, 2008 Millward
20090062470 March 5, 2009 Millward et al.
20090200646 August 13, 2009 Millward et al.
20090206489 August 20, 2009 Li et al.
20090236309 September 24, 2009 Millward et al.
20090240001 September 24, 2009 Regner
20090263628 October 22, 2009 Millward
20090274887 November 5, 2009 Millward et al.
20100092873 April 15, 2010 Sills et al.
20100102415 April 29, 2010 Millward et al.
20100124826 May 20, 2010 Millward et al.
20100137496 June 3, 2010 Millward et al.
20100163180 July 1, 2010 Millward
20100204402 August 12, 2010 Millward et al.
20100279062 November 4, 2010 Millward et al.
20100316849 December 16, 2010 Millward et al.
20100323096 December 23, 2010 Sills et al.
Foreign Patent Documents
1562730 January 2005 CN
0784543 April 2000 EP
1416303 May 2004 EP
1593164 June 2010 EP
11080414 March 1999 JP
2005008882 January 2005 JP
2006036923 February 2005 JP
2006055982 March 2006 JP
200419017 October 2004 TW
200511364 March 2005 TW
256110 June 2006 TW
9007575 July 1990 WO
97/06013 February 1997 WO
99/47570 September 1999 WO
02081372 October 2002 WO
2005/122285 December 2005 WO
2006/076016 July 2006 WO
2006/078952 July 2006 WO
2007/019439 February 2007 WO
2007013889 February 2007 WO
2007/024241 March 2007 WO
2007/024323 March 2007 WO
2007/055041 May 2007 WO
2008/091741 July 2008 WO
2008/097736 August 2008 WO
2008096335 August 2008 WO
2008/124219 October 2008 WO
2008118635 October 2008 WO
2008130847 October 2008 WO
2008145268 December 2008 WO
2008156977 December 2008 WO
2009099924 August 2009 WO
2009102551 August 2009 WO
2009117238 September 2009 WO
2009117243 September 2009 WO
2009134635 November 2009 WO
Other references
  • Bae, Joonwon, “Surface Modification Using Photo-Crosslinkable Random Copolymers”, Abstract submitted for the Mar. 2006 meeting of the American Physical Society, submitted Nov. 30, 2005.
  • Bang, Joona, “The Effect of Humidity on the Ordering of Tri-block Copolymer Thin Films,” Abstract submitted for the Mar. 2007 meeting of the American Physical Society, submitted Nov. 20, 2006.
  • Bass, Robert B., et al., “Microcontact Printing with Octadecanethiol”, Applied Surface Science, 226(4), pp. 335-340, Apr. 2004, http://www.ece.virginia.edu/UVML/sis/Papers/rbbpapers/assoct.pdf.
  • Bearinger, J.P., et al., Nature Materials 2, 259-264, 2003, published online Mar. 23, 2003.
  • Black, C.T., IEEE 2005 Custom Integrated Circuits Conference, pp. 87-91.
  • Black, C.T., et al., IBM J. Res. & Dev., vol. 51, No. 5, Sep. 2007, pp. 605-633.
  • Black, Charles T., ACSNano, vol. 1, No. 3, 2007, American Chemical Society, pp. 147-150, published online Oct. 31, 2007.
  • Black, Charles T., et al., IEEE Electronon Device Letters, vol. 25, No. 9, Sep. 2004, pp. 622-624.
  • Botelho do Rego, A.M., et al., Surface Science, 482-485 (2001), pp. 1228-1234.
  • Brydson, Rik M., et al. (chapter authors), “Generic Methodologies for Nanotechnology: Classification and Fabrication”, Nanoscale Science and Technology, edited by R.W. Kelsall, et al., 2005 John Wiley & Sons, Ltd., (published online: Dec. 20, 2005) (http://www3.interscience.wiley.com/cgi-bin/summary/112217550/Summary).
  • Canaria, Christi A., et al., “Formation and Removal of Alkylthiolate Self-Assembled Monolayers on Gold in Aqueous Solutions”, Lab Chip 6, 289-295 (2006), http://www.rsc.org/publishing/journals/LC/article.asp?doi=b51066c) (Abstract).
  • Chandekar, Amol, et al., “Template-Directed Adsorption of block Copolymers on Alkanethiol-Patterned Gold Surfaces,” (circa 2006), http://www.nano.neu.edu/industry/industry—showcase/industry—day/documents/Chandekar.pdf) (Powerpoint template for scientific posters (Swarthmore College)).
  • Cheng, Joy T., et al., Nano Letters, vol. 0, No. 0, A-E, published on Web Aug. 16, 2006.
  • Daoulas Kostas Ch., et al., Physical Review Letters 96, week ending Jan. 27, 2006, pp. 036104-1-3.
  • Desai, Dr. Trejal A., et al., Business Briefing: Medical Device Manufacturing & Technology, 2002.
  • Edwards, Erik W., et al., Journal of Polymer Science: Part B Polymer Physics, vol. 43, 3444-3459, 2005.
  • Edwards, Erik W., et al., Advanced Mater, 16, No. 15, Aug. 4, 2004, pp. 1315-1319.
  • Fasolka, Michael J. et al., Macromolecules 2000, vol. 33, No. 15, pp. 5702-5712, published on the web Jun. 29, 2000.
  • Gates, Byron D., et al., Annu. Rev. Mater. Res. 2004, 34:339-72, published online Mar. 26, 2004.
  • Ge, Zhenbin, et al., PRL 96, 186101-1-186101-4, The American Physical Society, week ending May 12, 2006.
  • Genua, A., et al., Nanotechnology, 18 (2007), pp. 1-7, published Apr. 27, 2007.
  • Gillmor, S.D., et al., Langmuir 2000, vol. 16, No. 18, 2000, pp. 7223-7228, published on Web Aug. 5, 2000.
  • Hamley, I. W., “Introduction to Block Copolymers”, Developments in Block Copolymers Science and Technology, 2004, John Wiley & Sons, Ltd., pp. 1-29.
  • Hermans, Thomas M., et al., “Application of Solvent-Directed Assembly of Block Copolymers to the Synthesis of Nanostructured Materials with Low Dielectric Constants”, Angewandte Chem. Int. Ed. 2006, 45, pp. 6648-6652.
  • Hutchison, J. Brian, et al., Chem. Mater., vol. 17, No. 19, 2005, pp. 4789-4797, published on Web Aug. 25, 2005.
  • In, Insik, et al., Langmuir, vol. 22, No. 18, 2006, pp. 7855-7860, published on Web Aug. 1, 2006.
  • Kim, Sang Ouk, et al., Nature, vol. 424, Jul. 24, 2003, pp. 411-414.
  • Kim, Sang Ouk, et al., Adv. Mater., 2007, 19, pp. 3271-3275.
  • Kim, Seung Hyun, et al., Macromolecules 2006, vol. 39, No. 24, 2006, pp. 8473-8479, published on Web Oct. 25, 2006.
  • Kim, Seung Hyun, et al., Advanced Mater., vol. 16, No. 23-24, pp. 2119-2123, Dec. 17, 2004.
  • Krishnamoorthy, Sivashankar, et al., MaterialsToday, vol. 9, No. 9, Sep. 2006, pp. 40-47.
  • La, Young-Hye, et al., Chem. Mater, 2007, vol. 19, No. 18, pp. 4538-4544, published on Web Jul. 28, 2007.
  • Laracuente, A.R., et al., Surface Science 545, 2003, pp. 70-84.
  • Lentz, David, et al., “Whole Wafer Imprint Patterning Using Step and Flash Imprint Lithography: A Manufacturing Solution for Sub 100 nm Patterning”, SPIE Advanced Lithography Paper, http://molecularimprints.com/NewsEvents/tech—articles/new—articles/SPIE —07—MII—WW—Paper.pdf), Feb. 2007, pp. 1-10.
  • Li, Mingqi, et al., MaterialsToday, vol. 9, No. 9, Sep. 2006, pp. 30-39.
  • Li, Xue, et al., Polymer 48 (2007), pp. 2434-2443, available online Feb. 25, 2007.
  • Lin, Zhiqun, et al., Adv. Mater. 2002, 14 No. 19, Oct. 2, pp. 1373-1376.
  • Lin-Gibson, Sheng, et al., Macromolecules 2005, 38, pp. 2897-2902, published on Web Mar. 8, 2005.
  • Malkoch, Michael, et al., Chem. Commun., 2006, pp. 2774-2776, published on the web Jun. 1, 2006.
  • Mansky, P., et al., Science, vol. 275, Mar. 7, 1997, pp. 1458-1460.
  • Maye, Mathew A., et al., Journal of Chemical Education, vol. 79, No. 2, Feb. 2002, pp. 207-210.
  • Metters, Andrew, et al., Biomacromolecules 2005, 6, pp. 290-301, 2005, published on Web Nov. 13, 2004.
  • Meyer, Evelyn, et al., Macromollecular Mater. Eng., 276/277, 2000, pp. 44-50.
  • Mezzenga, Raffaele, et al., Langmuir 2003, vol. 19, No. 20, 2003, pp. 8144-8147, published on Web Aug. 29, 2003.
  • Mindel, Joseph., et.al., “A Study of Bredig Platinum Sols”, The Chemical Laboratories of New York University, vol. 65 pp. 2112.
  • Naito, et al., IEEE Transactions on Magnetics, vol. 38, No. 5, Sep. 2002, pp. 1949-1951.
  • Nealey, Paul F., et al., “Self-Assembling Resists for Nanolithography”, IEEE 2005.
  • Nguyen, Kytai, et al., Biomaterials 23, 2002, pp. 4307-4314.
  • Wang, C., et al., Electrochimica Acta 52 (2006), pp. 704-709, available online Jul. 12, 2006.
  • Black, C.T., Proc. of SPIE, vol. 6153, 615302 (2006).
  • Darling, S.B., Progress in Polymer Science, vol. 32, No. 10, Sep. 28, 2007, pp. 1152-1204.
  • Harrison, Christopher et al., Polymer, vol. 39, No. 13, pp. 2733-2744, 1998.
  • Kim, Su-Jin, et al., J. Vac. Sci. Technol. B26(1), Jan./Feb. 2008, 189-194.
  • La, Young-Hye, et al., J. Vac. Sci. Technol. B 25(6), Nov./Dec. 2007, pp. 2508-2513.
  • Olayo-Valles, Roberto et al., J. Mater. Chem, 2004, 14, 2729-2731, published on web Aug. 18, 2004.
  • Yang, XiaoMin, et al., J. Vac. Sci. Technol. B 22(6), Nov./Dec. 2004, 3331-3334.
  • Berry, B.C., et al., “Effects of Zone Annealing on Thin Films of Block Copolymers”, National Institute of Standard and Technology, Polymers Division, Gaithersburg, MD., 2007.
  • Black, C.T., Applied Physics Letters 87, 163116-1 to 1163116-3, 2005, published online Oct. 13, 2005.
  • Black, Charles T., IEEE Transactions on Nanotechnology, vol. 3, No. 3, Sep. 2004, pp. 412-415.
  • Cavicchi, Kevin A., et al., Macromolecules 2007, vol. 40, 2007, pp. 1181-1186, published on the web Jan. 24, 2007.
  • Gudipati, Chakravarthy S., et al., Journal of Polymer Science Part A: Polymer Chemistry, vol. 42, pp. 6193-6208.
  • Guo, Kai, et al., Abstract of “Synthesis and Characterization of Novel Biodegradable Unsaturated Poly(ester amide)/Poly(ethylene glycol) Diacrylate Hydrogels”, Journal of Polymer Science Part A: Polymer Chemistry, vol. 43, Issue 17, pp. 3932-3944, 2005 Wiley Periodicals, Inc.
  • Karim, Alamgir et al., “Control of Ordering Kinetics and Morphology Using Zone Annealing of Thin Block Copolymer Filmes”, Abstract submitted for the Mar. 2007 Meeting of The American Physical Society, Nov. 20, 2006.
  • Kim, Seung Hyun, et al., Adv. Mater. 2004, 16, No. 3, Feb. 3, pp. 226-231.
  • Park, Dae-Ho, Nanotechnology 18, 2007, 355304, pp. 1-7, Aug. 8, 2007.
  • Peng, Juan et al., Macromol. Rapid Commun. 2007, 28, 1422-1428.
  • Rogers, John A., ACS Nano, vol. 1, No. 3, pp. 151-153, 2007.
  • Rozkiewicz, Dorota I., et al., Angew. Chem. Int. Ed., 2006, 45, pp. 5292-5296.
  • Ruiz, Ricardo et al., Science, vol. 321, Aug. 15, 2008, pp. 936-939.
  • Segalman, Rachel A., Materials Science and Engineering R 48 (2005), pp. 191-226.
  • Srinvivasan, Charan, et al., ACS Nano, vol. 1, No. 3, pp. 191-201, 2007, published online Oct. 17, 2007.
  • Xiao, Shuaigang et al., Nanotechnology 16 (2005) S324-S329, Apr. 15, 2005.
  • Jun, et al., Langmuir, 2002, 18(9), pp. 3415-3417, Abstract only, Web publication date Apr. 3, 2002.
  • Balsara et al, CPIMA, IRG Technical Programs, Synthesis and application of Nanostructured Materials, Leland Stanford Junior Univ., 2006, http://www.stanford.edu/group/cpima/irg/irg—1.htm, printed Jul. 1, 2009.
  • Bulpitt, Paul et al, Journal of Biomedical Materials Research, vol. 47, Issue 2, pp. 152-169, Abstract only, published online Aug. 13, 1999.
  • Elisseeff J., et al., Journal of Biomedical Materials Research, 51(2): 164-171, Aug. 2000, Abstract only.
  • Gelest Inc., Silane Coupling Agents: Connecting Across Boundaries, pp. 1-56, 2006.
  • Ji, Shengxiang, et al., Preparation of Neutral Wetting Brushes for Block Copolymer Films from Homopolymer Blends, submitted to Advanced Materials, 20(16): 3054-3060; published online Jul. 7, 2008.
  • Ji, Shengxiang, et al., Macromolecules, 2008, 41(23): 9098-9103.
  • Kim, SH, J Biomater Appl., Jul. 2000; 15(1): 23-46 Abstract only.
  • Kim, SH, J Biomater Res., Mar. 15, 2000; 49(4): 517-27 Abstract only.
  • Kim, IS, et al., Int J Pharm., Sep. 15, 2000; 205(1-2): 109-16, Abstract only.
  • Li, Wai-kin, et al, J. Vac. Sci. Technol. B 25(6), Nov./Dec. 2007, pp. 1982-1984, published Dec. 6, 2007.
  • Lutolf, M.P., et al, Nature Biotechnology, 23, 47-55 (2005), Abstract only, published online Jan. 6, 2005.
  • Martens, P., et al., Polymer, vol. 41, Issue 21, Oct. 2000, pp. 7715-7722, Abstract only.
  • Matsuda, T., et al., ASAIO J, Jul.-Sep. 1992; 38(3): M154-7, Abstract only.
  • Sawhney, Amarpreet S., et al., Macromolecules 1993, 26, 581-587, Abstract only.
  • Walthier, Michel, et al., J. Am. Chem. Soc., 2004, 126 (40), pp. 12744-12745, Abstract only, web publication date Sep. 21, 2004.
  • Truskett, Van N., et al., Trends in Biotechnology, vol. 24, No. 7, Jul. 2006, pp. 312-315.
  • Cheng, Joy Y., et al., Nano Letters, vol. 6, No. 9, 2006, pp. 2099-2103, publ on Web Aug. 16, 2006.
  • Cheng, Joy Y., et al., Adv. Mater. 2003, vol. 15, No. 19, pp. 1599-1602, Oct. 2, 2003.
  • Cheng, Joy Y., et al., Applied Physics Letters, 91, 143106-143106-3 (2007), publ online Oct. 1, 2007.
  • Niu, Sanjun, et al., Macromolecules, 36(7), 2428-2440, 2003 (web release date: Mar. 13, 2003) http:// digitalcommons.uni.edu/cgi/viewcontent.cgi?article+1005&contect=chemeng—nanotechnology).
  • Parejo, Pilar Garcia, et al., J. Mater. Chem., 2006, 16, pp. 2165-2169.
  • Park, Cheolmin, et al., Polymer 44, 2003, 6725-6760.
  • Park, Miri, et al., Science, v. 276, No. 5317, p. 1401-1404, May 30, 1997.
  • Park, Sang-Min, et al., Adv. Mater., 2007, 19, pp. 607-611.
  • Park, Sung Chan, et al., Macromolecules 2007, vol. 40, No. 22, pp. 8119-8124, published on Web Oct. 4, 2007.
  • Peters, Richard D., et al., J. Vac. Sci. Technol. B, vol. 18, No. 6, Nov./Dec. 2000, pp. 3530-3532.
  • Peters, Richard D., et al., Macromolecules, vol. 35, No. 5, 2002, pp. 1822-1834, published on Web Jan. 26, 2002.
  • Potemkin, Igor I., et al., Macromol. Rapid Commun., 2007, 28, pp. 579-584.
  • Resnick, Douglas, J., et al., J. Microlith., Microfab., Microsyst., vol. 3, No. 2, Apr. 2004, pp. 316-321.
  • Ruiz, Ricardo, et al., Adv. Mater, 2007, 19, pp. 587-591.
  • Ryu, Du Yeol, et al., Macromolecules, vol. 40, No. 12, 2007, pp. 4296-4300, published on Web May 19, 2007.
  • Saraf, Ravi R., et al., Applied Physics Letters, vol. 80, No. 23, Jun. 10, 2002, pp. 4425-4427.
  • Shahrjerdi, Davood, et al., IEEE Electron Device Letters, vol. 28, No. 9, Sep. 2007, pp. 793-796.
  • Sharma, Sadhana, et al., Applied Surface Science, 206 (2003), pp. 218-229.
  • Sivaniah, E., et al., Macromolecules 2003, 36, pp. 5894-5896, publ on Web Jul. 15, 2003.
  • Sivaniah, et al., Macromolecules 2005, 38, 1837-1849, publ on Web Feb. 2, 2005.
  • Solak, Harun H., Journal of Physics D: Applied Physics, 2006, pp. R171-188, published May 5, 2006.
  • Stoykovich, Mark P., et al., Science, vol. 308, Jun. 3, 2005, pp. 1442-1446.
  • Stoykovich, Mark P., et al., ACS Nano, vol. 1, No. 3, 2007, pp. 168-175, published online Oct. 6, 2007.
  • Sundrani, Deepak, et al., Nano Lett., vol. 4, No. 2, 2004, pp. 273-276, published on Web Dec. 25, 2003.
  • Sundrani, Deepak, et al., Langmuir 2004, vol. 20, No. 12, 2004, pp. 5091-5099, published on Web Mar. 11, 2004.
  • Sigma-Aldrich, Tutorial regarding Materials for Lithography/Nanopatterning, http://www.sigmaaldrich.com/Area—of—Interest/Chemistry/Materials—Science/Micro—and—Nanoelectronic website, retrieved Aug. 27, 2007.
  • Van Poll, Maaike L., et al., Angew. Chem. Int. Ed. 2007, 46, pp. 6634-6637.
  • Winesett, D.A., et al., Langmuir 2003, 19, pp. 8526-8535, published on Web Aug. 22, 2003.
  • Xu, Ting et al., Polymer 42, (2001) 9091-9095.
  • Wu, C.Y., et al., IEEE, 2007, pp. 153-154.
  • Yamaguchi, Toru, et al., Journal of Photopolymer Science and Technology, vol. 19, No. 3, 2006, pp. 385-388.
  • Yan, Xiaohu, et al., J. Am. Chem. Soc., vol. 126, No. 32, 2004, pp. 10059-10066.
  • Yang, Xiao M., et al., Macromolecules 2000, vol. 33, No. 26, 2000, pp. 9575-9582, published on Web Dec. 26, 2000.
  • Yurt, Serkan, et al., Macromolecules 2006, vol. 39, No. 5, 2006, published on Web Feb. 2, 2006.
  • Zhang, Mingfu, et al., Adv. Mater. 2007, 19, pp. 1571-1576, published online May 15, 2007.
  • Arshady et al., Makromol. Chem., 1976, vol. 177, p. 2911-2918.
  • Bang, J. Abstract submitted for the Mar. 2006 meeting of the American Physical Society, submitted Nov. 2005 [online], accessed via the Internet [retrieved on Apr. 5, 2010], URL: <http://absimage.aps.org/image/MWS—MAR06-2005-003641.pdf>.
  • Candau et al., Polymer, 1977, vol. 18, p. 1253-1257.
  • Hawker et al., Facile Synthesis of Block Copolymers for Nanolithographic Applications; Polymer Reprints, 2005.
  • Nishikubo, T., American Chemical Society Symposium Series, 1997, p. 214-230.
  • He, Yiyong et al., J. Am. Chem. Soc. 2006, 128, pp. 2745-2750, web publication Feb. 2, 2006.
  • Ali, H.A., et al., Solid-State Electronics 46 (2002), 1639-1642.
  • Berry et al., Orientational Order in Block Copolymer Films Zone Annealed below the Order-Disorder Transition Temperature , Nano Letters vol. 7, No. 9 Aug. 2007, p. 2789-2794.
  • Fukunaga et al., Self-Assembly of Block Copolymer Thin Films Having a Half-Domain-Spacing Thickness: Nonequilibrium Pathways to Achieve Equilibrium Brush Layers Parallel to Substrate, Macromolecules vol. 39, Aug. 2006, p. 6171-6179.
  • Hammond et al., Temperature Dependence of Order, Disorder, and Defects in Laterally Confined Diblock Copolymer Cylinder Monolayers, Macromolecules vol. 38, Jul. 2005; p. 6575-6585.
  • Knoll et al., Phase Behavior in Thin Films of Cylinder-Forming Block Copolymers, Physical Review Letters vol. 89, No. 3 Jul. 2002.
  • Zehner, Robert W. et al., Langmuir, vol. 14, No. 2, pp. 241-244, Jan. 20, 1998.
Patent History
Patent number: 8123962
Type: Grant
Filed: Jun 12, 2007
Date of Patent: Feb 28, 2012
Patent Publication Number: 20080311347
Assignee: Micron Technology, Inc. (Boise, ID)
Inventors: Dan B. Millward (Boise, ID), Donald Westmoreland (Boise, ID), Gurtej Sandhu (Boise, ID)
Primary Examiner: Anita K Alanko
Attorney: Whyte Hirschboeck Dudek SC
Application Number: 11/761,589