Neutral Layer and Hydrophobic Pinned MAT Materials for Use in DSA with Improved Substrate Compatibility

Abstract

The present invention relates to a random copolymer of structure (A) comprising repeat units of structure (I) having a carboxylic acid, repeat units of structure (II) derived from 4-vinylbenzocyclobutene, styrenic repeat units of structure (III), repeat units of structure (IV) derived from an alkyl acrylate or alkyl 2-methylenealkanoate, repeat units of structure (V) derived from a hydroxy-functionalized alkyl acrylate or alkyl 2-methylenealkanoate, and repeat units of structure (V) substituted with methyl moieties, one of which is H and the other of which is Rr, Rrl, and Rr2. the random copolymer includes two end groups shown in structure (A), which are moieties, wherein Rr1 is a C1-C8 alkyl and Rr2 is selected from a C1-C8 alkyl, a C1-C8 alkylene hydroxy moiety (-alkylene-OH), a C1-C8 alkylene carboxylic acid moiety (-alkylene-COH), or a benzylic alcohol-containing moiety of structure (B), and Rr is a cyano moiety (-CN) or a carbonyl alkyl moiety (-C(=O)-Ri), where Ri is a C1-C8 alkyl or aryl moiety.

Description

[Technical field]

[0001] The present invention relates to neutral layer and pinned mat compositions for use in directed self-assembly processes. [Background technology]

[0002] Self-assembly of block copolymers is a useful method for generating ever smaller patterned features for the manufacture of microelectronic devices, which can achieve critical dimensions (CD) of features on the nanoscale order. Self-assembly methods are desirable for extending the resolution capabilities of microlithography techniques for repeating features such as arrays of contact holes or posts. In conventional lithography approaches, ultraviolet (UV) radiation can be used to expose through a mask onto a photoresist layer coated on a substrate or layered substrate. Positive or negative photoresists are useful, and they can also contain refractory elements such as silicon to allow dry development using conventional integrated circuit (IC) plasma processing techniques. In positive photoresists, UV radiation passing through the mask causes a photochemical reaction in the photoresist that renders the exposed areas removable with a developer solution or by conventional IC plasma processing. Conversely, in negative photoresists, UV radiation passing through the mask renders the exposed areas less removable with a developer solution or by conventional IC plasma processing. Integrated circuit features such as gates, vias or interconnects are then etched into the substrate or layered substrate, and the remaining photoresist is removed. With conventional lithographic exposure processes, there is a limit to the feature size of integrated circuit features. Further reduction in pattern size is difficult to achieve with radiation exposure due to limitations related to aberrations, focus, proximity effects, minimum achievable exposure wavelength, and maximum achievable numerical aperture. Due to the need for large scale integration, device circuit dimensions and features have been continually reduced. In the past, the final resolution of features has depended on the wavelength of light used to expose the photoresist, which is itself limited. Guided self-assembly techniques such as graphoepitaxy and chemoepitaxy using block copolymer imaging with patterned areas on the substrate are highly desirable techniques used to improve resolution while reducing CD variation.These techniques can be used to augment conventional UV lithography techniques or to enable higher resolution and CD control in approaches using EUV, e-beam, deep UV or immersion lithography. Directed self-assembling block copolymers contain blocks of etch-resistant and easily etched copolymer units that, when coated, aligned and etched on a substrate, provide areas of very dense patterns.

[0003] For guided or unguided self-assembly of block copolymer films on patterned or unpatterned substrate regions, respectively, the self-assembly process of the block copolymer layer typically occurs during annealing of the film over a neutral layer. The neutral layer on the semiconductor substrate may be an unpatterned neutral layer, or in chemoepitaxy or graphoepitaxy, the neutral layer may include graphoepitaxy or chemoepitaxy guided features (formed via UV lithography techniques as described above), respectively. While the block copolymer film is annealed, the underlying neutral layer induces nanophase separation of the block copolymer domains. An example is the formation of phase-separated domains that are lamellae or cylinders perpendicular to the underlying neutral layer surface. These nanophase-separated block copolymer domains form pre-patterns (e.g., lines and spaces L / S), which can be transferred into the substrate via an etching process (e.g., plasma etching). In graphoepitaxy or chemoepitaxy, these guiding features can induce both pattern modification and pattern multiplication. In the case of unpatterned neutral layers, this produces repeating arrays of L / S or CH, for example. For example, in conventional block copolymers such as poly(styrene-b-methyl methacrylate) (P(Sb-MMA)), where both blocks have similar surface energies at the BCP-air interface, this can be achieved by coating and thermal annealing the block copolymer onto a layer of non-preferential or neutral material that is grafted or crosslinked at the polymer-substrate interface.

[0004] In the graphoepitaxy-induced self-assembly method, block copolymers self-assemble on substrates that have been pre-patterned using conventional lithography (ultraviolet, deep UV, e-beam, extreme UV (EUV) exposure sources) to form repeating topographical features such as line / space (L / S) or contact hole (CH) patterns. In one example of an L / S-induced self-assembly array, block copolymers can form self-aligned lamellar regions that can form parallel line-space patterns of different pitches in the trenches between the pre-patterned lines to enhance pattern resolution by dividing the spaces in the trenches between the topographical lines into finer patterns. For example, diblock or triblock copolymers capable of microphase separation, including carbon-rich blocks (e.g., styrene or containing some other element such as Si, Ge, Ti) that are resistant to plasma etching, and blocks that are highly etchable or removable by plasma, can provide high-resolution pattern definition. An example of a highly etchable block may include a monomer (e.g., methyl methacrylate) that is oxygen-rich, does not contain refractory elements, and can form a highly etchable block. The plasma etch gases used in the etching process that defines the self-assembled pattern are typically those used in processes used in the manufacture of integrated circuits (ICs). In this manner, very fine patterns can be created in typical IC substrates compared to those that can be defined by conventional lithographic techniques, thus achieving pattern multiplication. Similarly, graphoepitaxy can be used to create a higher density of features such as contact holes. In graphoepitaxy, a suitable block copolymer aligns itself by directed self-assembly around an array of contact holes or posts defined by conventional lithography to form a higher density array of regions of etchable and etch-resistant domains, which when etched, gives a higher density array of contact holes. As a result, graphoepitaxy has the potential to provide both pattern modification and pattern multiplication.

[0005] In chemical epitaxy or pinned chemical epitaxy, the self-assembly of block copolymers is formed on a surface with guide features that are regions of different chemical affinity that have no or no significant topography on which to base the guided self-assembly process (in other words, non-guided topography). For example, the surface of a substrate can be patterned with conventional lithography (UV, deep UV, e-beam, EUV) to create a line-and-space (L / S) pattern of surfaces of different chemical affinity in which exposed regions, where the surface chemistry has been modified by irradiation, alternate with unexposed regions that show no chemical change. These regions do not provide topographical differences, but rather surface chemical differences or pinning that guide the self-assembly of the block copolymer segments. Specifically, the directed self-assembly of block copolymers with block segments containing etch-resistant repeat units (e.g., styrene repeat units) and fast-etching repeat units (e.g., methyl methacrylate repeat units) allows for precise placement of the etch-resistant and fast-etching block segments on a pattern. This technique allows for precise placement of these block copolymers and subsequent pattern transfer to a substrate after plasma or wet etching processing. Chemical epitaxy has the advantage that it can be fine-tuned by changing chemical differences, which helps improve line edge roughness and CD control, thus allowing pattern modification. Other types of patterns, such as repeating contact hole (CH) arrays, can also be pattern modified using chemoepitaxy.

[0006] These neutral layers are layers on the substrate or surfaces of the treated substrate that have no affinity for any of the block segments of the block copolymers used for directed self-assembly. Neutral layers are useful in graphoepitaxy methods of directed self-assembly of block copolymers because they allow for the proper placement or orientation of the block polymer segments for directed self-assembly, which results in the proper placement of the etch-resistant and highly etchable block polymer segments relative to the substrate. For example, in a surface containing line-and-space features defined by conventional radiation lithography, the neutral layer allows for the orientation of the block segments such that they are oriented perpendicular to the surface of the substrate, which is an ideal orientation for both pattern modification and pattern multiplication depending on the length of the block segments in the block copolymer relative to the length between the lines defined by conventional lithography. If the substrate interacts too strongly with one of the block segments, the segment will lie flat on its surface, maximizing the contact area between the segment and the substrate; such a surface will disrupt the desired vertical alignment that can be used to achieve either pattern modification or pattern multiplication based on features generated by conventional lithography. Modification of selected small regions or pinning of the substrate to make them interact strongly with one block of the block copolymer, while leaving the remainder of the substrate coated with a neutral layer, can be useful to align the domains of the block copolymer in a desired direction, and this is the basis of pinned chemoepitaxy or graphoepitaxy used for pattern multiplication. The pinned regions can be hydrophilic, with a relatively large affinity for polar block copolymer segments, such as, for example, polymethylmethacrylate block segments in a block copolymer of styrene and methylmethacrylate, or alternatively, the pinned regions can be hydrophobic, with a relatively large affinity for, for example, polystyrene block segments in a block copolymer of styrene and methylmethacrylate.

[0007] Directed self-assembly using PS-b-PMMA type block copolymers requires a neutral underlayer for chemoepitaxy growth of line-and-space patterns that can work on many different substrates. Crosslinkable terpolymers such as P(Sr-VBCB-r-MMA) (i.e., poly(styrene-co-4-vinylbenzocyclobutene-co-methylmethacrylate) have been used as crosslinkable neutral mat layer compositions in DSA processes. Although this terpolymer works effectively as a neutral layer on oxide and nitride-based substrates such as SiOx (silicon oxynitride) and SiN (silicon nitride), this terpolymer, due to its hydrophobic nature, causes severe de-wetting defects on SiARC (silicon antireflective coating) substrates, leading to defects in the subsequent DSA process. Therefore, there is a need to develop new crosslinkable neutral mat materials that are specifically suitable for SiARC substrates.

[0008] There is also a need to develop a non-polar (in other words hydrophobic) pinning mat layer for directed self-assembly using PS-b-PMMA type block copolymers, which require robust PS pinning patterns for chemoepitaxy growth of line-and-space patterns. In general, crosslinkable PS copolymers such as P(Sr-VBCB)-H (i.e., poly(styrene-co-4-vinylbenzocyclobutene)) are the hydrophobic crosslinkable pinning mat compositions that are widely used in LiNe-flow DSA processes. This copolymer works effectively for oxide- and nitride-based substrates such as SiOx and SiN. However, due to its hydrophobicity, this copolymer causes severe dewetting defects on SiARC substrates, which leads to defects in the subsequent DSA process. There is a need to develop new crosslinkable hydrophobic mat materials that are specifically suitable for SiARC substrates. The mat material is a crosslinked layer that is insoluble in any layer coated on top of it and can be used as a DSA neutral or pinning layer material. [Brief description of the drawings]

[0009] [Figure 1] Representative structures of tetracopolymers capable of forming a neutral layer. [Diagram 2] Representative structures of pentacopolymers capable of forming a neutral layer. [Diagram 3] 1H NMR spectrum of P(Sr-VBCB-r-MMA-r-VBA)-OH, a representative terpolymer capable of forming a neutral layer. [Figure 4] 1H NMR spectrum of P(Sr-VBCB-r-MMA-r-VBA)-COOH, a representative tetracopolymer capable of forming a neutral layer. [Diagram 5] 1H NMR spectrum of P(Sr-VBCB-r-MMA-r-HEMA-r-VBA), a representative pentacopolymer capable of forming a neutral layer. [Figure 6] Coating defect analysis of neutral matte on SiARC by LPC (FOV100). [Figure 7] Representative examples of terpolymers that can form non-polar crosslinked pinned mats include P(Sr-VBCB-r-VBA)-R (R=H, OH, COOH). [Figure 8] 1H NMR spectrum of P(Sr-VBCB-r-VBA)-COOH of Example 14. [Figure 9] 1H NMR spectrum of P(Sr-VBCB-r-VBA)-OH of Example 15. [Figure 10] Coating defect analysis of hydrophobic mat on SiARC by LPC. [Figure 11] PS5 SEM images of various defects in Comparative Example 2. [Figure 12] PS5 SEM images of various defects in Example 15. [Figure 13] PS5 SEM images of various defects in Example 14. [Figure 14] IMEC self-assembled defect verification template, key to graytone defect designation in Figs. 15-17 [Figure 15]IMEC Defect Verification (SOL COMP2) [Figure 16] IMEC Defect Verification DO1:(SOL15) [Figure 17] IMEC Defect Verification DO1:(SOL14) [Figure 18] Examples of coating defect types for the coatings in Table 6 for neutral layer membranes using P(Sr-VBCB-r-MMA-r-VBA)-OH membranes cast on ISX302 and ISX304. [Figure 19] Example of contact hole self-assembly of neutral layer film coating in Table 6 using P(Sr-VBCB-r-MMA-r-VBA)-OH film cast on ISX302 and ISX304. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] US9574104B1 [Non-patent literature]

[0011] [Non-Patent Document 1] Macromolecules 2019,52,2987-2994 [Non-Patent Document 2] Macromol.Rapid Commun.2018,39,1800479 [Non-Patent Document 3] A.Deiter Shluter et al Synthesis of Polymers,2014,Volume 1,p315 [Non-Patent Document 4] Encyclopedia of Polymer Science and Technology,2014,Vol 7,p 625 Summary of the Invention

[0012] One aspect of the present invention is improved crosslinkable neutral tetra- and pentapolymers compatible with SiARCs as well as SiOx and SiN substrates. One aspect of this is novel tetra- and pentapolymers of styrene (S), 4-vinylbenzocyclobutene (VBCB), methyl methacrylate (MMA), 2-hydroxyethyl methacrylate (HEMA) and 4-vinylbenzoic acid (VBA) initiated by 4,4'-azobis(4-cyanopentanol) (AIBN-OH) or 4,4'-azobis(4-cyanovaleric acid) (AIBN-COOH). P(Sr-VBCB-r-MMA-r-VBA-r-HEMA)-OH [i.e., hydroxyl-terminated poly(styrene-co-4-vinylbenzocyclobutene-co-methyl methacrylate-co-4-vinylbenzoic acid-co-2-hydroxyethyl methacrylate] or P(Sr-VBCB-r-MMA-r-VBA-r-HEMA)-COOH [i.e., carboxylic acid-terminated poly(styrene-co-4-vinylbenzocyclobutene-co-methyl methacrylate-co-4-vinylbenzoic acid-co-2-hydroxyethyl methacrylate)]. Improvements in the composition to hydroxyethyl methacrylate) gave a neutral crosslinkable mat with fewer coating defects. The S and MMA components give the polymer the necessary neutrality. The VBCB component allows the polymer to be crosslinked into an insoluble film when baked. The VBA and HEMA components make the polymer more compatible with SiARC substrates. The hydroxyl- or carboxylic acid-terminated end groups from the initiator graft the polymer onto the substrate and hold the polymer in place when a high temperature bake crosslinks the polymer.

[0013] Another aspect of this improved crosslinkable hydrophobic copolymer is its compatibility with SiARC as well as SiOx and SiN substrates. The novel copolymer is initiated with styrene (S), 4-vinylbenzocyclobutene (VBCB) and 4-vinylbenzoic acid (VBA) with either 4,4'-azobis(4-cyanopentanol) (AIBN-OH) or 4,4'-azobis(4-cyanovaleric acid) (AIBN-COOH). The modification of the composition to P(Sr-VBCB-r-VBA)-OH [i.e., hydroxyl-terminated poly(styrene-co-4-vinylbenzocyclobutene-co-4-vinylbenzoic acid)] or P(Sr-VBCB-r-VBA)-COOH [i.e., carboxylic acid-terminated poly(styrene-co-4-vinylbenzocyclobutene-co-4-vinylbenzoic acid)] provided hydrophobic crosslinkable pinning mats with fewer coating defects. The S component provides pinning hydrophobicity to the polymer. The VBCB component allows the polymer to be crosslinked into an insoluble film when baked. The VBA component makes the polymer more compatible with SiARC substrates. The hydroxyl- or carboxylic acid-terminated end groups from the initiator graft the polymer onto the substrate and hold the polymer in place when a high temperature bake crosslinks the polymer.

[0014] The present invention relates to a random copolymer of structure (A): A repeating unit of structure (I) having a carboxylic acid, provided that R m1 is H or C1-C4 alkyl, and n1 is the total number of said repeat units, and said repeat units range from about 1.0 mol % to about 5.0 mol % in said copolymer; A repeating unit of structure (II) derived from 4-vinylbenzocyclobutene, where R m2 is H or C1-C4 alkyl, and n2 is the total number of said repeat units, and said repeat units range from about 5.0 mol % to about 35.0 mol % in said copolymer; Styrenic repeating units of structure (III), where R m3 is H or C1-C4 alkyl, R styis selected from H, C1-C8 alkyl, and C1-C4 alkyloxy, and n3 is the total number of such repeat units, and such repeat units range from about 25 mol % to about 94.0 mol % in said copolymer; Repeating units of structure (IV) derived from alkyl acrylate or alkyl 2-methylene alkanoate, where R m4 is H or C1-C4 alkyl, R I is a C1-C8 alkyl, and n4 is the total number of such repeat units, and such repeat units range from 0 mol % to about 64 mol % in the copolymer; Repeating units of structure (V) derived from hydroxy-functionalized alkyl acrylate or alkyl 2-methylene alkanoate, where R m5 is H or C1-C4 alkyl, L1 is a C2-C8 alkylene moiety, and n5 is the total number of this repeat unit, and this repeat unit ranges from 0 mol % to about 3 mol % in the copolymer; and two end groups as shown in structure (A), one of which is H and the other of which is a methyl moiety substituted with Rr, Rrl, and Rr2, where Rrl is a C1-C8 alkyl and Rr2 is selected from a C1-C8 alkyl, a C1-C8 alkylene hydroxy moiety (-alkylene-OH), a C1-C8 alkylene carboxylic acid moiety (-alkylene-CO2H), or a benzylic alcohol containing moiety of structure (B), where ni is an integer ranging from 0 to 5, nia is an integer from 1 to 5, nib is an integer from 1 to 5, and "*" represents the point of attachment of the moiety, and Rr is a cyano moiety (-CN) or a carbonyl alkyl moiety (-C(=O)-Ri), where Ri is a C1-C8 alkyl or aryl moiety; and further comprising the sum of the individual mole percent of repeat units of structures (I), (II), (III), (IV) and (V) is less than or equal to 100 mole percent of the total repeat units present in said copolymer; Random copolymers are described.

[0015] [ka] Another aspect of the invention is a composition comprising one of these polymers and an organic spin-coating solvent.

[0016] Another aspect of the invention is a method of coating these compositions and thermally generating either a crosslinked non-polar (alternatively, hydrophobic) pinning mat or a crosslinked neutral layer and using them in lithographic DSA processing. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] It is to be understood that both the general description above and the detailed description below are exemplary and explanatory, and are not intended to be limiting with respect to the invention as claimed. In this application, unless specifically stated otherwise, the use of the singular includes the plural, the singular means "at least one," and the use of "or" means "and / or." Furthermore, the use of the term "comprises" as well as other verb forms such as "comprises" is not limiting. Also, the use of terms such as "element" or "component" includes both elements and components that contain one unit, and elements or components that contain more than one unit, unless specifically stated otherwise. Unless otherwise indicated, the conjunction "and" as used herein is intended to be inclusive, and the conjunction "or" is not intended to be exclusive. For example, the phrase "or instead of" is intended to be exclusive. As used herein, the conjunction "and / or" refers to any combination of the aforementioned elements, including the use of a single element.

[0018] The term "C1-C4 alkyl" includes methyl and C2-C4 linear alkyl and C3-C4 branched alkyl moieties, such as methyl (-CH3), ethyl (-CH2-CH3), n-propyl (-CH2-CH2-CH3), isopropyl (-CH(CH3)2, n-butyl (-CH2-CH2-CH2-CH3), tert-butyl (-C(CH3)3), isobutyl (CH2-CH(CH3)2, 2-butyl (-CH(CH3)CH2-CH3). Similarly, the term C1-C8 includes methyl, C2-C8 linear alkyl, C3-C8 branched alkyl, C4-C8 cycloalkyl (e.g., cyclopentyl, cyclohexyl, etc.) or C5-C8 alkylenecycloalkyl (e.g., -CH2-cyclohexyl, CH2-CH2-cyclopentyl, etc.).

[0019] The term "C2-C5 alkylene" includes C2-C5 linear alkylene moieties (e.g., ethylene, propylene, etc.) and C3-C5 branched alkylene moieties (e.g., -CH(CH3)-, -CH(CH3)-CH2-, etc.).

[0020] Diblock and triblock copolymers of styrenic repeat units and repeat units derived from alkyl 2-methylene alkanoates, useful as components in the compositions of the invention described herein, can be prepared by a variety of methods, such as anionic polymerization, atom transfer radical polymerization (ATRP), reversible addition-fragmentation chain transfer (RAFT) polymerization, and living radical polymerization (Macromolecules 2019, 52, 2987-2994 (Non-Patent Document 1); Macromol. Rapid Commun. 2018, 39, 1800479 (Non-Patent Document 2); A. Deiter Shluter et al Synthesis of Polymers, 2014, Volume 1, p 315 (Non-Patent Document 3); Encyclopedia of Polymer Science and Technology, 2014, Vol 7, p 625 (Non-Patent Document 4)).

[0021] The random copolymer poly(styrene-co-methyl methacrylate) is abbreviated as "P(S-co-MMA)" and the oligomeric form of this material is abbreviated as oligo(S-co-MMA). Similarly, the block copolymer poly(styrene-block-methyl methacrylate) is abbreviated as P(Sb-MMA) while the oligomer of this material is abbreviated as oligo(Sb-MMA). The oligomer oligo(styrene-co-p-octylstyrene)-block-(methyl methacrylate-co-di(ethylene glycol) methyl ether methacrylate) uses the same abbreviations to designate the building blocks of a random block copolymer, specifically, oligo(S-co-p-OS)-bP(MMA-co-DEGMEMA) (S=styrene, p-OS=para-octylstyrene, MMA=methyl methacrylate, DEGMEMA=di(ethylene glycol) methyl ether methacrylate) to designate the repeating units in this block copolymer where both blocks are random copolymers.

[0022] FOV is an abbreviation for "field of view" in a top-down scanning electron microscope (SEM) in SEM images in this application. "L / S" is an abbreviation for "line and space" lithography features.

[0023] PGMEA and PGME are abbreviations for 1-methoxypropan-2-yl acetate and 1-methoxypropan-2-ol, respectively.

[0024] The section headings used herein are for organizational purposes only and should not be construed as limiting the subject matter described. All references or portions of references cited herein, including but not limited to patents, patent applications, papers, books, and treatises, are incorporated herein in their entirety for all purposes. In the event that the definition of a term in one or more of the references and similar materials incorporated herein conflicts with that herein, the definition in the present application shall control.

[0025] Unless otherwise indicated, "alkyl" refers to a hydrocarbon group that can be linear or branched (e.g., methyl, ethyl, propyl, isopropyl, tert-butyl, and similar groups) or cyclic (e.g., cyclohexyl, cyclopropyl, cyclopentyl, and similar groups) or polycyclic (e.g., norbornyl, adamantyl, and similar groups). These alkyl moieties can be substituted or unsubstituted as described below. The term "alkyl" refers to such moieties having C1 to C8 carbons. For structural reasons, it is understood that linear alkyls start at C1, while branched and cyclic alkyls start at C3, and polycyclic alkyls start at C5. Furthermore, moieties derived from alkyls described below, such as alkyloxy and perfluoroalkyl, are understood to have the same carbon number range, unless otherwise stated. In the event that a different alkyl group length is specified, the above definition of alkyl is still valid in that it encompasses all types of alkyl moieties described above, and the above structural considerations regarding the minimum carbon number of a given type of alkyl group still apply.

[0026] Alkyloxy (also known as alkoxy) refers to an alkyl group attached through an oxy (-O-) moiety (e.g., methoxy, ethoxy, propoxy, butoxy, 1,2-isopropoxy, cyclopentyloxy, cyclohexyloxy, and similar groups). These alkyloxy moieties may be substituted or unsubstituted as described below.

[0027] Halo or halide refers to a halogen, F, Cl, Br, or I, attached to an organic moiety by one bond.

[0028] As used herein, the term lactone includes both monolactones (eg, caprolactone) and dilactones (eg, lactide).

[0029] Haloalkyl refers to a saturated linear, cyclic or branched alkyl group, such as those described above, in which at least one of the hydrogens is replaced by a halide selected from the group F, Cl, Br, I, or mixtures thereof when more than one halo moiety is present. Fluoroalkyl is a specific subgroup of these moieties.

[0030] Perfluoroalkyl refers to a linear, cyclic or branched saturated alkyl group as defined above in which all of the hydrogens have been replaced by fluorine (eg, trifluoromethyl, perfluoroethyl, perfluoroisopropyl, perfluorocyclohexyl, and similar groups).

[0031] Copolymer of structure (A) One embodiment of the present invention is the inventive random copolymer of structure (A): A repeating unit of structure (I) having a carboxylic acid, provided that R m1 is H or C1-C4 alkyl, and n1 is the total number of said repeat units, and said repeat units range from about 1.0 mol % to about 5.0 mol % in said copolymer; A repeating unit of structure (II) derived from 4-vinylbenzocyclobutene, where R m2 is H or C1-C4 alkyl, and n2 is the total number of said repeat units, and said repeat units range from about 5.0 mol % to about 35.0 mol % in said copolymer; Styrenic repeating units of structure (III), where R m3 is H or C1-C4 alkyl, R sty is selected from H, C1-C8 alkyl, and C1-C4 alkyloxy, and n3 is the total number of such repeat units, and such repeat units range from about 25 mol % to about 94.0 mol % in said copolymer; Repeating units of structure (IV) derived from alkyl acrylate or alkyl 2-methylene alkanoate, where R m4 is H or C1-C4 alkyl, R Iis a C1-C8 alkyl, and n4 is the total number of such repeat units, and such repeat units range from 0 mol % to about 64 mol % in the copolymer; Repeating units of structure (V) derived from hydroxy-functionalized alkyl acrylate or alkyl 2-methylene alkanoate, where R m5 is H or C1-C4 alkyl, L1 is a C2-C8 alkylene moiety, and n5 is the total number of this repeat unit, and this repeat unit ranges from 0 mol % to about 3 mol % in the copolymer; and two end groups shown in structure (A), one of which is H and the other of which is a methyl moiety substituted with Rr, Rrl, and Rr2, where Rrl is a C1-C8 alkyl and Rr2 is selected from a C1-C8 alkyl, a C1-C8 alkylene hydroxy moiety (-alkylene-OH), a C1-C8 alkylene carboxylic acid moiety (-alkylene-CO2H), or a benzylic alcohol containing moiety of structure (B), where ni is an integer ranging from 0 to 5, nia is an integer from 1 to 5, nib is an integer from 1 to 5, and "*" represents the point of attachment of the moiety; Rr is a cyano moiety (-CN) or a carbonylalkyl moiety (-C(=O)-Ri), where Ri is a C1-C8 alkyl or aryl moiety; and further comprising the sum of the individual mole percent of repeat units of structures (I), (II), (III), (IV) and (V) is less than or equal to 100 mole percent of the total repeat units present in said copolymer; It is a random copolymer.

[0032] [ka] In another aspect of the random copolymer of the present invention of structure (A) described above, the repeat units of structure (III) range from about 30 mol % to about 60 mol %, and the repeat units of structure (IV) range from 0 mol % to about 45 mol %.

[0033] A copolymer comprising repeating units (I), (II) and (III) In one aspect of the copolymer of the invention of structure (A), the repeating units consist essentially of repeating units of structures (I), (II), and (III). In another aspect of this embodiment, the copolymer is one in which the repeating units consist of repeating units of structures (I), (II), and (III).

[0034] In another aspect of the inventive copolymer of Structure (A) described herein, the repeat units of Structure (I) range from about 1 mol % to about 5 mol %, the repeat units of Structure (II) range from about 5 mol % to about 9 mol %, the repeat units of Structure (III) range from about 90 mol % to about 94 mol %, and further, the sum of the individual mol % of repeat units of Structures (I), (II) and (III) equals 100 mol % of the total repeat units of the copolymer.

[0035] In another aspect of the copolymer of the present invention having structure (A) described herein, R m1 , R m2 and R m3 is H.

[0036] In another aspect of the copolymer of the present invention having structure (A), R sty is H.

[0037] In another aspect of the copolymer of the present invention described herein above with structure (A), it has the structure (A-1).

[0038] [ka] In another aspect of the copolymer of the invention of structure (A), in said end group which is a methyl moiety substituted with Rr, Rrl and Rr2, Rrl is methyl. In another aspect, Rr2 is a C1-C8 alkyl. In yet another aspect, Rr2 is a C1-C8 alkylene hydroxy moiety. In yet another aspect, Rr2 is a C1-C8 alkylene carboxylic acid moiety. In yet another aspect, Rr2 is a benzylic alcohol containing moiety of structure (B), and in another aspect of this embodiment, structure (B) has structure (B-1). In another aspect of this embodiment, Rr is CN. In another aspect of this embodiment, Rr is said carbonyl alkyl moiety.

[0039] [ka] A copolymer comprising repeating units (I), (II), (III) and (IV) In another aspect of the copolymer of the present invention having structure (A), it has structure (A-2): said repeat units of structure (I) range from about 1 mol % to about 5 mol %; said repeat units of structure (II) range from about 15 mol % to about 35 mol %; the repeat units of structure (III) range from about 25 mol % to about 69 mol %, and said repeat units of structure (IV) range from about 5 mol % to about 49 mol %.

[0040] In another aspect of this embodiment, the copolymer of the present invention having structure (A-2) is said repeat units of structure (I) range from about 1 mol % to about 5 mol %; the repeat units of structure (II) range from about 15 mol % to about 35 mol %; the repeat units of structure (III) range from about 30 mol % to about 60 mol %, and the repeat units of structure (IV) range from about 15 mol % to about 45 mol %; It is something.

[0041] In one aspect of the copolymer of structure (A-2), its repeat units consist essentially of repeat units of structures (I), (II), (III), and (IV). In another aspect of this embodiment, it consists of repeat units of structures (I), (II), (III), and (IV). In another aspect of this embodiment, the sum of the individual mole percents of repeat units of structures (I), (II), (III), and (IV) equals 100 mole percent of all repeat units in the copolymer.

[0042] [ka] In one aspect of the copolymer of the present invention having structure (A-2), R m1 , R m2 and R m3 is H and R m4 is H. In another view, R m1 , R m2 and R m3 is H and R m4 is methyl. In yet another aspect, R sty is H.

[0043] In one aspect of the inventive copolymer of structure (A-2) described herein, it has the structure (A-3).

[0044] [ka] In another aspect of the copolymer of the invention of structure (A-2) or (A-3) described herein, in the end group which is a methyl moiety substituted with Rr, Rrl, and Rr2, Rrl is methyl. In another aspect of this embodiment, Rr2 is a C1-C8 alkyl. In another aspect, Rr2 is a C1-C8 alkylene hydroxy moiety. In yet another aspect, Rr2 is a C1-C8 alkylene carboxylic acid moiety. In yet another aspect, Rr2 is a benzylic alcohol-containing moiety of structure (B), which in another aspect of this embodiment has structure (B-1). In another aspect of this embodiment, Rr is CN. In another aspect, Rr is the carbonyl alkyl moiety.

[0045] [ka] Copolymers containing structures (I), (II), (III), (IV) and (V) In one aspect of the inventive copolymer of structure (A): said repeat units of structure (I) range from about 1 mol % to about 5 mol %; said repeat units of structure (II) range from about 15 mol % to about 35 mol %; said repeat units of structure (III) range from about 30 mol % to about 60 mol %; said repeat units of structure (IV) range from about 15 mol % to about 45 mol %; said repeat units of structure (V) range from about 1 mol % to about 3 mol %.

[0046] In one aspect of this embodiment, the repeat units consist essentially of repeat units of structures (I), (II), (III), (IV), and (V). In another aspect of this embodiment, it consists of repeat units of structures (I), (II), (III), (IV), and (V). In another aspect of this embodiment, the sum of the individual mole percents of repeat units of structures (I), (II), (III), (IV), and (V) equals 100 mole percent of all repeat units in the copolymer. In another aspect of this embodiment, R m1 , R m2 , R m3 , R m4 and R m5 is H. In another aspect of this embodiment, R m1 , R m2 and R m3 is H and R m4 and R m5 is methyl. In another aspect of this embodiment, R sty is H.

[0047] [ka] In one aspect of the embodiments described herein, where all of the repeat units of structures (I), (II), (III), (IV) and (V) are present in a single polymer described herein, it has the more specific structure (A-4).

[0048] [ka] In another aspect of the embodiment described herein, where all of the repeat units of structures (I), (II), (III), (IV) and (V) are present in a polymer and have either structure (A) or (A-4), in said end group which is a methyl moiety substituted with Rr, Rrl and Rr2, Rrl is methyl. In another aspect of this embodiment, Rr2 is a C1-C8 alkyl. In yet another aspect of this embodiment, Rr2 is a C1-C8 alkylene hydroxy moiety. In yet another aspect of this embodiment, Rr2 is a C1-C8 alkylene carboxylic acid moiety. In yet another aspect of this embodiment, Rr2 is a benzylic alcohol containing moiety of structure (B), which in another aspect of this embodiment has structure (B-1). In yet another aspect, Rr is CN. In yet another aspect, Rr is said carbonyl alkyl moiety.

[0049] [ka] Compositions Comprising the Copolymers of the Invention Compositions containing copolymers of structure (A) Another aspect of the present invention is a composition, which may be crosslinked or a combination of crosslinking and grafting, comprising a copolymer of structure (A) described herein and an organic spin-casting solvent.

[0050] A composition comprising a copolymer of structure (A) containing as repeating units only repeating units of structures (I), (II) and (III), which can be crosslinked or combined with crosslinking and grafting to form a non-polar pinning layer.

[0051] Another aspect of the invention is a crosslinkable or combined crosslinkable and graftable composition comprising a copolymer and an organic spin-casting solvent, the copolymer comprising only repeat units of structures (I), (II) and (III) or the more specific structure (A-1) as described herein, capable of forming a non-polar pinning layer as described herein.

[0052] A composition comprising a copolymer of structure (A) containing only repeating units of structures (I), (II) and (III) as repeating units that can be combined with crosslinking and grafting to form a non-polar pinning layer.

[0053] Another aspect of the invention is a combined crosslinking and grafting composition comprising a copolymer and an organic spin-casting solvent, said copolymer containing only repeat units of Structures (I), (II) and (III) or having the more specific Structure (A-1), where Rr2 is selected from the group consisting of C1-C8 alkylene hydroxy moieties, C1-C8 alkylene carboxylic acid moieties, benzylic alcohol containing moieties of Structure (B), and benzylic alcohol containing moieties of Structure (B-1), and capable of forming a non-polar pinning layer as described herein.

[0054] A composition comprising a copolymer of structure (A) containing only repeating units of structures (I), (II), and (III) as repeating units, which can only be crosslinked, thus forming a non-polar pinning layer. Another aspect of the present invention is a crosslinkable composition comprising a copolymer and an organic spin-casting solvent, the copolymer containing only repeat units of structures (I), (II) and (III) or having the more specific structure (A-1), where Rr2 is C1-C8 alkyl, and capable of forming a non-polar pinned layer as described herein.

[0055] A composition comprising a copolymer of structure (A) containing as repeating units only repeating units of structures (I), (II) and (III), which can be crosslinked or a combination of crosslinking and grafting.

[0056] Another aspect of the present invention is a composition comprising a copolymer and an organic spin-casting solvent, which can be crosslinked or a combination of crosslinking and grafting, said copolymer comprising only repeat units of structures (I), (II), (III) and (IV) or having the more specific structures (A-2) or (A-3), and which can form a non-polar pinning layer as described herein.

[0057] A composition comprising a copolymer of structure (A) containing as repeating units only repeating units of structures (I), (II), (III) and (IV), which can be crosslinked or a combination of crosslinking and grafting, thus forming a neutral layer.

[0058] Another aspect of the invention is a composition capable of combining crosslinking and grafting comprising a copolymer and an organic spin-casting solvent, wherein the copolymer contains only repeat units of Structures (I), (II), (III) and (IV) as described herein or has the more specific Structures (A-2) or (A-3), where Rr2 is selected from the group consisting of a C1-C8 alkylene hydroxy moiety, a C1-C8 alkylene carboxylic acid moiety, a benzylic alcohol containing moiety of Structure (B), and a benzylic alcohol containing moiety of Structure (B-1).

[0059] A composition comprising a copolymer of structure (A) which contains as repeating units only repeating units of structures (I), (II), (III) and (IV) which can be combined with crosslinking and grafting to form a neutral layer.

[0060] Another aspect of the present invention is a crosslinkable composition comprising a copolymer and an organic spin-casting solvent, the copolymer comprising only repeat units of structures (I), (II), (III) and (IV) or having the more specific structures (A-2) or (A-3), where Rr2 is a C1-C8 alkyl, and capable of forming a neutral layer as described herein.

[0061] A composition comprising a copolymer of structure (A) containing, as repeating units, only repeating units of structures (I), (II), (III) and (IV), which can only be crosslinked, thus forming a neutral phase.

[0062] Another aspect of the present invention is a crosslinkable or combined crosslinkable and graftable composition comprising a copolymer and an organic spin-casting solvent, said copolymer comprising repeating units of structures (I), (II), (III), (IV) and (V) or having the more specific structure (A-4), capable of forming a neutral layer as described herein.

[0063] A composition comprising a copolymer of structure (A) containing as repeating units only repeating units of structures (I), (II), (III), (IV) and (V), which can be crosslinked or can be crosslinked in combination with grafting, thus forming a neutral layer.

[0064] Another aspect of the present invention is a composition that can be crosslinked or combined with crosslinking and grafting, where the copolymer comprises repeating units of structures (I), (II), (III), (IV) and (V) or has the more specific structure (A-4), and can form a neutral layer as described herein.

[0065] A composition comprising a copolymer of structure (A) which comprises as repeating units repeating units of structures (I), (II), (III), (IV) and (V) that have been crosslinked and grafted in combination to form a neutral layer.

[0066] Another aspect of the present invention is a composition which can be combined with crosslinking and grafting, where the copolymer comprises repeating units of Structures (I), (II), (III), (IV) and (V) or has the more specific Structure (A-4), where Rr2 is selected from the group consisting of C1-C8 alkylene hydroxy moieties, C1-C8 alkylene carboxylic acid moieties, benzylic alcohol containing moieties of Structure (B), and benzylic alcohol containing moieties of Structure (B-1), and can form a neutral layer as described herein.

[0067] A composition comprising a copolymer of structure (A) containing as repeating units repeating units of structures (I), (II), (III), (IV) and (V) which can only be crosslinked, thus forming a neutral phase.

[0068] Another aspect of the present invention is a crosslinkable composition comprising a copolymer and an organic spin-casting solvent, the copolymer comprising repeat units of structures (I), (II), (III), (IV) and (V) or having the more specific structure (A-4), where Rr2 is C1-C8 alkyl, capable of forming a neutral layer as described herein.

[0069] Methods of Using Compositions Containing the Copolymers of the Invention Another aspect of the present invention is a method for forming a crosslinked or grafted and crosslinked coating of a copolymer on a substrate, comprising the steps of: i) forming a coating on a substrate using any one of the compositions described herein, comprising any one of the copolymers of the present invention having structure (A) described herein; ii) heating the coating at a temperature of from about 90° C. to about 180° C. to remove the solvent and form a crosslinked or grafted and crosslinked coating of the copolymer; iii) heating the crosslinked or grafted and crosslinked coating of step ii) to about 200° C. to about 250° C. to form a fully crosslinked or fully crosslinked and grafted copolymer coating; The method includes:

[0070] Method for forming a non-polar pinning layer Another aspect of the present invention is a method for forming a crosslinked or grafted and crosslinked non-polar pinning coating on a substrate, comprising the steps of: ia) forming a coating on a substrate using any one of the compositions described herein, comprising any one of the inventive copolymers described herein that contain only repeat units of structures (I), (II), and (III) as described herein; iia) heating the coating at a temperature of from about 90° C. to about 180° C. to remove the solvent and form a crosslinked or grafted and crosslinked coating; iiia) heating the crosslinked or grafted and crosslinked coating of step iia) at a temperature of from about 200° C. to about 250° C. to form a fully crosslinked or fully crosslinked and grafted non-polar pinning coating; The method includes:

[0071] Another aspect of the present invention is a method for forming a grafted and crosslinked non-polar pinning coating on a substrate, comprising the steps of: ib) forming a coating on a substrate using any one of the compositions described herein comprising any one of the copolymers of the invention described herein that contain only repeat units of Structures (I), (II), and (III) as described herein, where Rr2 is selected from the group consisting of C1-C8 alkylene hydroxy moieties, C1-C8 alkylene carboxylic acid moieties, benzylic alcohol-containing moieties of Structure (B), and benzylic alcohol-containing moieties of Structure (B-1); iib) heating the coating at a temperature of from about 90° C. to about 180° C. to remove the solvent and form a crosslinked or grafted and crosslinked coating; iiib) heating the crosslinked or grafted and crosslinked coating of step iib) at a temperature of about 200° C. to about 250° C. to form a fully crosslinked and grafted non-polar pinning coating; The method includes:

[0072] Another aspect of the present invention is a method of forming a crosslinked non-polar pinning coating on a substrate, comprising the steps of: ic) forming a coating on a substrate using any one of the compositions described herein, comprising any one of the copolymers of the invention described herein that contain only repeat units of structures (I), (II), and (III) described herein, where Rr2 is C1-C8 alkyl; iic) heating the coating at a temperature of from about 90° C. to about 180° C. to remove the solvent and form a crosslinked coating; iiic) heating the crosslinked coating of step iic) at a temperature of about 200° C. to about 250° C. to form a fully crosslinked non-polar pinned coating; The method includes:

[0073] Method for forming a neutral layer using a copolymer containing only repeat units of structures (I), (II), (III) and (IV) Another aspect of the present invention is a method for forming a crosslinked or grafted and crosslinked neutral coating on a substrate, comprising the steps of: id) forming a coating on a substrate using any one of the compositions described herein, comprising any one of the inventive copolymers described herein that contain only repeat units of structures (I), (II), (III) and (IV) as described herein; iid) heating the coating at a temperature of from about 90° C. to about 180° C. to remove the solvent and form a crosslinked or grafted and crosslinked coating; iiid) heating the crosslinked coating of step iid) at a temperature of about 200° C. to about 250° C. to form a fully crosslinked non-polar pinned coating; The method includes:

[0074] Another aspect of the present invention is a method for forming a grafted and crosslinked neutral coating on a substrate, comprising the steps of: ie) forming a coating on a substrate using any one of the compositions described herein comprising any one of the inventive copolymers described herein that contain only repeat units of Structures (I), (II), (III), and (IV) as described herein, wherein Rr2 is selected from the group consisting of C1-C8 alkylene hydroxy moieties, C1-C8 alkylene carboxylic acid moieties, benzylic alcohol-containing moieties of Structure (B), and benzylic alcohol-containing moieties of Structure (B-1). iie) heating the coating at a temperature of from about 90° C. to about 180° C. to remove the solvent and form a grafted and crosslinked coating; iiie) heating the crosslinked coating of step iie) at a temperature of about 200° C. to about 250° C. to form a fully grafted and crosslinked neutral coating; The method includes:

[0075] Another aspect of the present invention is a method for forming a crosslinked neutral coating on a substrate, comprising the steps of: if) forming a coating on a substrate using any one of the compositions described herein comprising any one of the copolymers of the invention described herein that contain only repeat units of structures (I), (II), (III) and (IV) described herein, where Rr2 is C1-C8 alkyl; iif) heating the coating at a temperature of from about 90° C. to about 180° C. to remove the solvent and form a crosslinked or grafted and crosslinked coating; iiif) heating the crosslinked or grafted and crosslinked coating of step iif) at a temperature of about 200° C. to about 250° C. to form a fully crosslinked neutral coating; The method includes:

[0076] Method for forming a neutral layer using a copolymer containing only repeat units of structures (I), (II), (III), (IV) and (V) Another aspect of the present invention is a method for forming a crosslinked or grafted and crosslinked neutral coating on a substrate, comprising the steps of: ig) forming a coating on a substrate using any one of the compositions described herein, comprising any one of the inventive copolymers described herein that contain only repeat units of structures (I), (II), (III), (IV) and (V) as described herein; iig) heating the coating at a temperature of from about 90° C. to about 180° C. to remove the solvent and form a crosslinked or grafted and crosslinked coating; iiig) heating the crosslinked or grafted and crosslinked coating of step iig) at a temperature of about 200° C. to about 250° C. to form a fully crosslinked or fully grafted and crosslinked neutral coating; The method includes:

[0077] Another aspect of the present invention is a method for forming a crosslinked and grafted neutral coating on a substrate, comprising the steps of: ih) forming a coating on a substrate using any one of the compositions described herein comprising any one of the copolymers of the invention described herein that contain only repeat units of Structures (I), (II), (III), (IV) and (V) described herein, wherein Rr2 is selected from the group consisting of C1-C8 alkylene hydroxy moieties, C1-C8 alkylene carboxylic acid moieties, benzylic alcohol containing moieties of Structure (B), and benzylic alcohol containing moieties of Structure (B-1). iih) heating the coating at a temperature of from about 90° C. to about 180° C. to remove the solvent and form a grafted and crosslinked coating; iiih) heating the grafted and crosslinked coating of step iih) at a temperature of about 200° C. to about 250° C. to form a fully grafted and crosslinked neutral coating; The method includes:

[0078] Another aspect of the present invention is a method for forming a crosslinked neutral coating on a substrate, comprising the steps of: i') forming a coating on a substrate using any one of the compositions described herein, comprising any one of the copolymers of the invention described herein that contain only repeat units of structures (I), (II), (III), (IV) and (V) described herein, where Rr2 is C1-C8 alkyl; ii') heating the coating at a temperature of from about 90°C to about 180°C to remove the solvent and form a crosslinked coating; iii') heating the crosslinked coating of step ii') at a temperature of about 200°C to about 250°C to form a fully crosslinked neutral coating; The method includes:

[0079] Method for self-assembly of block copolymers using neutral layers of the present invention Another aspect of the present invention is a method for forming a self-assembled block copolymer coating on a neutral coating, comprising the steps of: ij) forming a neutral coating according to any of the methods of the invention described herein for forming a neutral layer coating; iij) applying a block copolymer onto said neutral coating and annealing until induced self-assembly of the block copolymer coating occurs; The method includes:

[0080] Graphoepitaxy-directed self-assembly method using neutral layers of the present invention Another aspect of the invention is a method for graphoepitaxy-directed self-assembly of a block copolymer coating used to form an image, comprising the steps of: ik) forming a neutral coating according to any of the methods of the invention described herein for forming a neutral layer coating; iik) providing a coating of a photoresist coating over said neutral coating and forming a pattern in said photoresist coating; iiik) applying a block copolymer comprising an etch-resistant block and a highly etchable block onto the photoresist pattern and annealing until induced self-assembly occurs; and ivk) etching the block copolymer, thereby removing highly etchable blocks of said copolymer covering areas of the substrate and at the same time forming a pattern in the substrate selectively in these areas; The method includes:

[0081] In another aspect of the method, the pattern in the photoresist coating is formed by imaging lithography selected from the group consisting of electron beam lithography, broadband UV lithography, 193 nm immersion lithography, 13.5 nm EUV lithography, 193 nm deep UV lithography, 248 nm deep UV lithography, 365 nm UV lithography, and 436 nm UV lithography.

[0082] Chemo-epitaxy directed self-assembly method using neutral layers of the present invention Another aspect of the invention is a method for chemoepitaxy-directed self-assembly of block copolymer coatings used to form images, comprising the steps of: il) forming a neutral coating on the substrate according to any of the methods of the invention described herein for forming a neutral layer coating; iil) providing a coating of a photoresist coating over said neutral coating and forming a pattern in the photoresist coating, thereby forming areas of the neutral coating that are not covered with resist; iiil) treating the uncovered neutral coating to remove it and form a pinning region; ivl) removing the photoresist to expose the untreated neutral coating and form a chemo-epitaxy pattern including neutral and pinned regions; vl) applying a block copolymer comprising an etch-resistant block and a highly etchable block onto the neutral coating and annealing until induced self-assembly occurs; and vil) etching the block copolymer, thereby removing highly etchable blocks of the block copolymer covering areas of the substrate and simultaneously forming a pattern in the substrate selectively in these areas; The method includes:

[0083] In another aspect of the method, the pattern in the photoresist coating is formed by imaging lithography selected from the group consisting of electron beam lithography, broadband UV lithography, 193 nm immersion lithography, 13.5 nm EUV lithography, 193 nm deep UV lithography, 248 nm deep UV lithography, 365 nm UV lithography, and 436 nm UV lithography.

[0084] Chemo-epitaxy directed self-assembly method using non-polar pinning layers of the present invention Another aspect of the invention is a method for chemoepitaxy-directed self-assembly of block copolymer coatings used to form images, comprising the steps of: im) forming a non-polar pinning coating on the substrate according to any one of the methods of the invention described herein for forming a non-polar pinning coating; iim) providing a coating of a photoresist coating onto the pinning coating; iiim) forming a pattern in said photoresist coating, thereby forming areas of the pinning coating that are not covered by resist; ivm) treating and removing the uncovered pinning coating to form a bare substrate area; vm) removing the photoresist to expose both the untreated pinning coating and the bare areas of the substrate; vim) applying a neutral coating in areas of the bare substrate to form a chemo-epitaxy pattern comprising neutral and pinned regions; viim) applying a block copolymer comprising an etch-resistant block and a highly etchable block onto the chemo-epitaxy pattern and annealing until guided self-assembly occurs; and viiim) etching the block copolymer, thereby removing highly etchable blocks of said copolymer covering areas of the substrate and simultaneously forming a pattern in the substrate selectively in these areas; The method includes:

[0085] In another aspect of the method, the pattern in the photoresist coating is formed by imaging lithography selected from the group consisting of electron beam lithography, broadband UV lithography, 193 nm immersion lithography, 13.5 nm EUV lithography, 193 nm deep UV lithography, 248 nm deep UV lithography, 365 nm UV lithography, and 436 nm UV lithography.

[0086] Another aspect of the invention is a microelectronic device fabricated using patterns formed by any one of the following methods: self-assembly, graphoepitaxy-directed self-assembly, and chemoepitaxy.

[0087] Yet another aspect of the present invention is the use of the compositions disclosed or claimed herein in the manufacture of coated substrates or electronic devices. EXAMPLES

[0088] Chemicals and characterization equipment Unless otherwise indicated, chemicals were obtained from Millipore-Sigma Corporation (St. Louis, Missouri).

[0089] 1 1 H NMR spectra were recorded on a Bruker Advance III 400 MHz spectrometer.

[0090] Lithography experiments were performed using a TEL Clean ACT8 track. SEM images were taken using an Applied Materials NanoSEM_3D scanning electron microscope. Images are shown at either 5 FOV magnification or 100 FOV magnification (field of view (FOV) = 5 μm using 1, 2 and 5 FOV). Etching experiments were performed using standard isotropic oxygen etch conditions for self-assembled film block copolymers of methyl methacrylate and styrene.

[0091] Unless otherwise specified, molecular weight determination (also called M n Polydispersity) is 100Å, 500Å, 10 3 Å, 10 5 Å and 10 6 The analysis was carried out by gel permeation chromatography (PSS Inc., Germany) equipped with a Åμ-Ultrastyragel column using THF solvent as the eluent. Polystyrene polymer standards were used for calibration. GPC was performed at 100 Å, 500 Å, 10 3 Å, 105 Å and 10 6 The measurements were performed using an Agilent gel permeation chromatography system equipped with an Åμ-Ultrastyragel column. The first P(SDPE) block was M n (GPC) = 45,048 g / mol and M w / M n = 1.04. Gel Permeation Chromatography: 1 mg / mL in THF solution was injected using 0.1 μL into a polystyrene calibrated GPC tool with 1 mL / min THF flow.

[0092] Synthesis of test polymer materials Reference Block Copolymer Synthesis Example 1 Synthesis of P(Sb-MMA)(26k-b-30k) P(Sb-MMA) (26K-b-30K) was synthesized using the same procedure as in Example 2. The amount of initiator and monomer were varied to achieve the desired Mn and composition of PS and PMMA blocks. Briefly, 20 g (192 mmol) of styrene was polymerized with 0.55 mL (1.4 M solution) of sec-butyllithium. Then, 0.16 g (0.7 mmol) of 1,1'-diphenylethylene (DPE) in 2.5 mL of anhydrous toluene was added into the reactor via an ampoule. The orange color of the reaction mixture changed to a dark brick red color, suggesting that the styryllithium active center was converted to a delocalized DPE-added carbanion. After stirring for 2 min, a small amount (2 mL) of the reaction mixture was taken for PS block molecular weight analysis. Then, methyl methacrylate (22.85 g, 230 mmol) was added via an ampoule. The reaction was quenched after 30 min with 1 mL of degassed methanol. The block copolymer was recovered by precipitation into excess isopropanol (5 times the polymer solution) containing 10% water, filtered, and dried under vacuum at 55° C. for 12 h to give 40 g of P(Sb-MMA) (94% yield) consisting of 46.9 mol % polystyrene blocks and 53.1 mol % polymethyl methacrylate blocks. The diblock copolymer molecular weight obtained from GPC was M n,PS-b-PMMA= 46,978 g / mol and M w / M n =1.02.

[0093] Reference block copolymer solution (Ref SOL1) Reference Block Copolymer Synthesis Example 1 was dissolved in PGMEA as a 1.7 wt % solution and filtered through a 0.2 micron PTFE filter. This solution was used in the neutrality experiments conducted to evaluate both the inventive neutral layer and the inventive non-polar pinned layer, as described below.

[0094] Neutral layer test of the present invention for L / S and contact hole self-assembly Neutral Layer Examples and Testing Overview of the Invention Herein, crosslinkable neutral tetra- and pentapolymers are disclosed that have been found to be compatible with SiARCs as well as SiOx and SiN substrates. These novel tetra- and pentapolymers, starting with either 2,2'-azobis(2-methylpropionitrile) (AIBN), 4,4'-azobis(4-cyanopentanol) (AIBN-OH) or 4,4'-azobis(4-cyanovaleric acid) (AIBN-COOH), from styrene (S), 4-vinylbenzocyclobutene (VBCB), methyl methacrylate (MMA), 2-hydroxyethyl methacrylate (HEMA) and 4-vinylbenzoic acid (VBA), were prepared to verify this point. The following polymers were also prepared: P(Sr-VBCB-r-MMA-r-VBA-r-HEMA) [i.e., poly(styrene-co-vinylbenzocyclobutene-co-methyl methacrylate-co-4-vinylbenzoic acid-co-2-hydroxyethyl methacrylate)], P(Sr-VBCB-r-MMA-r-VBA)-OH [i.e., hydroxyl-terminated poly(styrene-co-4-vinylbenzocyclobutene-co-methyl methacrylate-co-4-vinylbenzoic acid)], or P(Sr-VBCB-r-MMA-r-VBA)-COOH [i.e., carboxylic acid-terminated poly(styrene-co-4-vinylbenzocyclobutene-co-methyl methacrylate-co-4-vinylbenzoic acid)], which when coated and crosslinked gave crosslinkable neutral mats with fewer coating defects. Depending on the block copolymer (BCP) used, these neutral layers were shown to be capable of leading to self-assembly that produced either an L / S self-assembled fingerprint pattern (i.e., with BCP ref SOL1) or a contact hole self-assembled pattern (e.g., with ref SOL2). These neutral layers showed good compatibility with a variety of SiARC substrates and also led to the above self-assemblies with few, if any, defects compared to the reference materials.

[0095] In these materials, the S component provided the necessary hydrophobicity to the polymer, the VBCB hydrophobic component allowed the polymer to crosslink into an insoluble film when baked, the MMA component provided the necessary hydrophobicity for neutrality, and surprisingly, the inclusion of VBA (1-5 wt%) provided good compatibility with SiARC. The introduction of relatively large amounts of VBA at the expense of PMMA was shown to adversely affect neutrality, but the combination of the VBA and HEMA components proved effective in rendering the polymer more hydrophilic and compatible with SiARC substrates. The presence of hydroxyl or carboxylic acid terminating end groups from the radical initiator aided in grafting the polymer chains onto the substrate when the VBCB crosslinked upon heating.

[0096] First, the analysis of the crosslinked films was checked for film retention by immersion test and neutrality by fingerprint test. The new tetra- or pentapolymer solution was spin-coated and baked on the wafer. The newly formed film was immersed in EBR solvent (70 / 30 PGME / PGMEA) and then rinsed off. Film retention was determined by measuring the film thickness before and after the immersion test. A solution of diblock copolymer ref SOL1 (Block Copolymer Example 1) of styrene and methyl methacrylate was coated on these test films and annealed on the new tetra- or pentapolymer films to verify neutrality by fingerprint appearance. This non-bias towards either block of the diblock copolymer allows the self-assembly of BCP into lines. The coating was then analyzed for defects using SEM method (VM277). It showed improved coatings with only minor defects.

[0097] FIG. 1 shows a non-limiting representative structure for the tetrapolymer type material P(Sr-VBCB-r-MMA-r-VBA)-X (X=HO, COOH) of the present invention. FIG. 2 shows a non-limiting representative example for the pentapolymer type material P(Sr-VBCB-r-MMA-r-VBA-r-HEMA). These types of materials, such as P(Sr-VBCB-r-MMA-r-HEMA-r-VBA), P(Sr-VBCB-r-MMA-VBA)-OH and P(Sr-VBCB-r-MMA-r-VBA)-COOH, incorporate additional hydrophilic functionality not typically used in neutral crosslinkable mat compositions. Surprisingly, the introduction of these hydrophilic groups improves the compatibility of the polymer film on the SiARC substrate and, upon crosslinking, results in a very large reduction in the number of dewetting defects in the resulting crosslinked neutral layer. All of these inventive compositions exhibited fewer defects as crosslinked neutral layers on SiARCs compared to the crosslinked neutral layer formed from the reference neutral layer formed from the VBA-free terpolymer P(Sr-VBCB-MMA).

[0098] It was also found that the combination of 4-vinylbenzoic acid (VBA) and 2-hydroxyethyl methacrylate (HEMA) was useful in these novel compositions by reducing dewetting defects of hydrophobic films on SiARCs compared to neutral layers formed from the reference terpolymer P(Sr-VBCB-MMA). Since SiARCs are commonly used in microchip architectures, the observed improvement in compatibility of crosslinked films formed from the materials of the present invention satisfies a need. Surprisingly, the polar functionality of VBA and HEMA improved the adhesion of the hydrophobic film to any surface, reducing dewetting defects.

[0099] In addition, functionalized radical initiators such as AIBN-OH or AIBN-COOH were used in terpolymer compositions containing 4-vinylbenzoic acid (VBA) to produce derivatives of P(Sr-VBCB-r-MMA-r-VBA)-, which after heat treatment gave neutral layers that were both crosslinked and grafted, and these neutral layers showed very few defects. The end group functionalization of these polymers allowed for grafting reactions on the substrate, which pinned these terpolymers to SiARCs while simultaneously crosslinking them.

[0100] The optimum content of VBA in these copolymers was found to be 1-3 mole %, which provided neutrality in these compositions. Increasing the incorporation of VBA to 5 mole % started to result in a loss of neutrality. However, countering this, increasing amounts of VBA also reduced the overall number of defects (see, for example, SOL8 and SOL9 in Table 2).

[0101] The combination of hydroxyl and carboxyl functionalities generally gave better defectivity than either single functionality, and as seen in the comparison of SOL2 and SOL3, the combination of hydroxyl end groups and VBA gave better defectivity than carboxylic acid end groups and VBA (Table 2).

[0102] It was observed that as the amount of VBCB was reduced, the overall number of defects also decreased (Table 2). Higher amounts of VBCB make the film less flexible and more rigid once crosslinked. Without being bound by theory, it is believed that this phenomenon increases the defect level because the crosslinked network becomes denser when baked. Conversely, reducing the amount of VBCB may also result in a loss of neutrality.

[0103] These copolymers of the invention containing VBA for use as low defect forming neutral underlayers have been reproducibly prepared by a controllable synthesis using free radical polymerization conditions.

[0104] To summarize the advantages of these new materials, the neutral crosslinked MAT produced from these materials provided significantly better conformability on SiARC substrates with fewer defects when used in DSA processing. The moderate contact angles and low film loss observed in the neutral layers produced from these new polymers were ideal for DSA processing. As a result of these moderate contact angles, coating with photoresist and photolithographic processing provided better desired patterns required for the DSA process. The neutral layer films produced from coating and crosslinking on SiARC produced films on the neutral mat with significantly reduced levels of particles and dewetting defects, which results in an improved DSA process by reducing defects overall. Finally, the conformability of the neutral layers formed from the polymers of the present invention on SiARC allows for the application of multiple layers via spin-on processes (2D stacking).

[0105] Example 1: Synthesis of poly(styrene-co-4-vinylbenzocyclobutene-co-methyl methacrylate-co-4-vinylbenzoic acid)-hydroxyl terminated type Styrene (12.2 g, 120 mmol), 4-vinylbenzocyclobutene (13.9 g, 110 mmol), methyl methacrylate (12.5 g, 120 mmol), 4-vinylbenzoic acid (1.05 g, 7.1 mmol), 4,4'-azobis(4-cyanopentanol) (0.40 g, 1.57 mmol) and 2-butanone (60 g) were added to a flask and purged with nitrogen for 30 minutes. The mixture was heated in a 90°C oil bath for 16 hours. The mixture was cooled to room temperature, diluted with THF and precipitated in isopropanol. The polymer was collected, redissolved in THF to a 15% solids solution and precipitated in isopropanol. The polymer was collected and dried in vacuum overnight at 70°C. 18.0 g (65.3%) white powder, GPC: 14,446 g / mol Mn, 24,748 g / mol Mw, 1.71 PDI.

[0106] Example 2: Synthesis of poly(styrene-co-4-vinylbenzocyclobutene-co-methyl methacrylate-co-4-vinylbenzoic acid)-hydroxyl terminated type Styrene (12.2 g, 120 mol), 4-vinylbenzocyclobutene (13.9 g, 110 mmol), methyl methacrylate (12.5 g, 120 mmol), 4-vinylbenzoic acid (1.05 g, 7.1 mmol), 4,4'-azobis(4-cyanopentanol) (0.40 g, 1.57 mmol) and 2-butanone (60 g) were added to a flask and purged with nitrogen for 30 minutes. The mixture was heated in a 90°C oil bath for 16 hours. The mixture was cooled to room temperature, diluted with THF and precipitated in isopropanol. The polymer was collected, redissolved in THF to a 15% solids solution and precipitated in isopropanol. The polymer was collected and dried in vacuum overnight at 70°C. 18.2 g (66.1%) white powder, GPC: 13,391 g / mol Mn, 24,461 g / mol Mw, 1.83 PDI.

[0107] Example 3: Synthesis of poly(styrene-co-4-vinylbenzocyclobutene-co-methyl methacrylate-co-4-vinylbenzoic acid) - Carboxylic acid terminated Styrene (12.2 g, 120 mol), 4-vinylbenzocyclobutene (13.9 g, 110 mmol), methyl methacrylate (12.5 g, 120 mmol), 4-vinylbenzoic acid (1.05 g, 7.1 mmol), 4,4'-azobis(4-cyanovaleric acid) (0.40 g, 1.41 mmol) and 2-butanone (60 g) were added to a flask and purged with nitrogen for 30 minutes. The mixture was heated in a 90°C oil bath for 16 hours. The mixture was cooled to room temperature, diluted with THF and precipitated in isopropanol. The polymer was collected, redissolved in THF to a 15% solids solution and precipitated in isopropanol. The polymer was collected and dried in vacuum overnight at 70°C. 18.1 g (65.7%) white powder, GPC: 12,831 g / mol Mn, 23,805 g / mol Mw, 1.86 PDI.

[0108] Example 4: Synthesis of poly(styrene-co-4-vinylbenzocyclobutene-co-methyl methacrylate-co-4-vinylbenzoic acid-co-2-hydroxyethyl methacrylate) Styrene (15.62 g, 150 mmol), 4-vinylbenzocyclobutene (19.53 g, 180 mmol), methyl methacrylate (18.02 g, 180 mmol), 4-vinylbenzoic acid (2.22 g, 15 mmol), 2-hydroxyethyl methacrylate (0.65 g, 5 mmol), 4,4'-azobis(2-methylpropionitrile) (0.41 g, 2.5 mmol), and anisole (100 g) were added to a flask and degassed by freeze-thawing three times. The mixture was heated in a 90° C. oil bath for 16 hours. The mixture was cooled to room temperature, diluted two-fold with THF, and precipitated in isopropanol. The polymer was collected, redissolved in THF to a 15% solids solution, and precipitated in isopropanol. The polymer was collected and dried overnight at 70° C. in vacuum. 37.7 g (67.0%) white powder, GPC: 29,448 g / mol Mn, 48,053 g / mol Mw, 1.63 PDI.

[0109] Example 5: Synthesis of poly(styrene-co-4-vinylbenzocyclobutene-co-methyl methacrylate-co-4-vinylbenzoic acid-co-2-hydroxyethyl methacrylate) Styrene (13.02 g, 125 mmol), 4-vinylbenzocyclobutene (19.53 g, 150 mmol), methyl methacrylate (20.53 g, 205 mmol), 4-vinylbenzoic acid (2.22 g, 15 mmol), 2-hydroxyethyl methacrylate (0.65 g, 5 mmol), 4,4'-azobis(2-methylpropionitrile) (0.41 g, 2.5 mmol), and anisole (100 g) were added to a flask and degassed by freeze-thawing three times. The mixture was heated in a 90° C. oil bath for 16 hours. The mixture was cooled to room temperature and diluted two-fold with THF, then precipitated in isopropanol. The polymer was collected, redissolved in THF to a 15% solids solution, and precipitated in isopropanol. The polymer was collected and dried overnight at 70° C. in vacuum. 38.0 g (67.7%) white powder, GPC: 28,750 g / mol Mn, 46,102 g / mol Mw, 1.60 PDI.

[0110] Example 6: Synthesis of poly(styrene-co-4-vinylbenzocyclobutene-co-methyl methacrylate-co-4-vinylbenzoic acid-co-2-hydroxyethyl methacrylate) Styrene (20.83 g, 200 mmol), 4-vinylbenzocyclobutene (13.02 g, 100 mmol), methyl methacrylate (18.02 g, 180 mmol), 4-vinylbenzoic acid (2.22 g, 15 mmol), 2-hydroxyethyl methacrylate (0.65 g, 5 mmol), 4,4'-azobis(2-methylpropionitrile) (0.41 g, 2.5 mmol), and anisole (100 g) were added to a flask and degassed by freeze-thawing three times. The mixture was heated in a 90° C. oil bath for 16 hours. The mixture was cooled to room temperature and diluted two-fold with THF, then precipitated in isopropanol. The polymer was collected, redissolved in THF to a 15% solids solution, and precipitated in isopropanol. The polymer was collected and dried in vacuum overnight at 70° C. 36.9 g (67.2%) white powder, GPC: 46,809 g / mol Mn, 66,245 g / mol Mw, 1.41 PDI.

[0111] Example 7: Synthesis of poly(styrene-co-4-vinylbenzocyclobutene-co-methyl methacrylate-co-4-vinylbenzoic acid-co-2-hydroxyethyl methacrylate) Styrene (21.35 g, 205 mmol), 4-vinylbenzocyclobutene (11.72 g, 90 mmol), methyl methacrylate (18.72 g, 187 mmol), 4-vinylbenzoic acid (2.00 g, 14 mmol), 2-hydroxyethyl methacrylate (0.59 g, 4.5 mmol), 4,4'-azobis(2-methylpropionitrile) (0.41 g, 2.5 mmol), and anisole (100 g) were added to a flask and degassed by freeze-thawing three times. The mixture was heated in a 90° C. oil bath for 16 hours. The mixture was cooled to room temperature and diluted two-fold with THF, then precipitated in isopropanol. The polymer was collected, redissolved in THF to a 15% solids solution, and precipitated in isopropanol. The polymer was collected and dried overnight at 70° C. in vacuum. 38.4 g (70.4%) white powder, GPC: 46,699 g / mol Mn, 66,453 g / mol Mw, 1.42 PDI.

[0112] Example 8: Synthesis of poly(styrene-co-4-vinylbenzocyclobutene-co-methyl methacrylate-co-methyl methacrylate-co-4-vinylbenzoic acid-co-2-hydroxyethyl methacrylate) Styrene (20.83 g, 200 mmol), 4-vinylbenzocyclobutene (9.77 g, 75 mmol), methyl methacrylate (19.52 g, 195 mmol), 4-vinylbenzoic acid (3.70 g, 25 mmol), 2-hydroxyethyl methacrylate (0.65 g, 5 mmol), 4,4'-azobis(2-methylpropionitrile) (0.41 g, 2.5 mmol), and anisole (100 g) were added to a flask and degassed by freeze-thawing three times. The mixture was heated in a 90° C. oil bath for 16 hours. The mixture was cooled to room temperature and diluted two-fold with THF, then precipitated in isopropanol. The polymer was collected, redissolved in THF to a 15% solids solution, and precipitated in isopropanol. The polymer was collected and dried overnight at 70° C. in vacuum. 37.9 g (69.3%) white powder, GPC: 28,313 g / mol Mn, 47,107 g / mol Mw, 1.66 PDI.

[0113] Example 9: Synthesis of poly(styrene-co-4-vinylbenzocyclobutene-co-methyl methacrylate-co-methyl methacrylate-co-4-vinylbenzoic acid-co-2-hydroxyethyl methacrylate) Styrene (26.04 g, 250 mmol), 4-vinylbenzocyclobutene (9.76 g, 75 mmol), methyl methacrylate (14.52 g, 145 mmol), 4-vinylbenzoic acid (3.70 g, 25 mmol), 2-hydroxyethyl methacrylate (0.65 g, 5 mmol), 4,4'-azobis(2-methylpropionitrile) (0.41 g, 2.5 mmol), and anisole (100 g) were added to a flask and degassed by freeze-thawing three times. The mixture was heated in a 90° C. oil bath for 16 hours. The mixture was cooled to room temperature and diluted two-fold with THF, then precipitated in isopropanol. The polymer was collected, redissolved in THF to a 15% solids solution, and precipitated in isopropanol. The polymer was collected and dried overnight at 70° C. in vacuum. 37.6 g (68.5%) white powder, GPC: 32,692 g / mol Mn, 51,032 g / mol Mw, 1.56 PDI.

[0114] Comparative Example 1: Synthesis of poly(styrene-co-4-vinylbenzocyclobutene-co-methyl methacrylate) terminated with benzyl alcohol The synthesis of the azo initiator as described in US9574104B1 was used in this polymerization. In a 2 L four-neck round bottom flask equipped with a stir bar, reflux condenser, temperature controller and nitrogen purge, styrene (143.8 g, 1.38 mol), methyl methacrylate (184.9 g, 1.84 mol), 4-vinylbenzocyclobutene (180.0 g, 1.38 mol) and 2-butanone (620 g) were added. The reaction mixture was stirred while purging with nitrogen for 20 minutes. The mixture was heated in a heating mantle with the temperature controller set at 80° C. At 80° C., a solution of the azo initiator (3.05 g, 5.07 mmol) in 2-butanone (12.2 g) was added over 1 minute. The mixture was heated at 80° C. for 20 hours. An additional solution of azo initiator (1.22 g) in 2-butanone (4.88 g) was added over 1 min. Heating of the mixture was continued at 80° C. for 24 h. The mixture was cooled, diluted with 2-butanone (900 g), and then slowly precipitated into IPA (15 L). The precipitate was collected by suction filtration and dried in an oven. The residue was redissolved in THF (15% solids) and precipitated once more into MeOH (15 L). The precipitate was collected by suction filtration and dried in an oven. The solid was redissolved in 2-butanone (1900 g), filtered through a 0.2 μm nylon filter, and slowly precipitated into IPA (15 L). The precipitate was collected by suction filtration and dried in an oven. The polymer is an off-white solid (290 g (57.0%)). GPC: 38,842g / mol Mn, 90,053g / mol Mw, 2.30 PDI.

[0115] 3, 4 and 5 show representative results of P(Sr-VBCB-r-MMA-r-VBA)-OH (Examples 1 and 2), P(Sr-VBCB-r-MMA-r-VBA)-COOH (Example 3) and P(Sr-VBCB-r-MMA-r-HEMA-r-VBA) (Examples 4 to 9), respectively. 1The H NMR spectrum is shown.

[0116] Table 1 summarizes the characterization data for both inventive polymers 1-9 and Comparative Example 1.

[0117] [Table 1]

[0118] Processing conditions: Test solutions were prepared by dissolving the polymers of Examples 1-10 (SOL1-10) and Comparative Example 1 (SOL COMP1) individually in PGMEA as 0.3 wt% solutions and filtering them through a 0.2 micron PTFE filter. These solutions were coated onto SiARC substrates and baked at 220°C / 90 seconds, then baked in N2 at 250°C / 5 minutes, followed by coating with the reference block copolymer solution (ref SOL1) and then baking in air at 250°C / 2 minutes. The naming of the solutions reflects the naming of the examples, so SOL1 through SOL10 are solutions prepared from Examples 1-10 and SOL COMP1 is the sample prepared from Comparative Example 1.

[0119] Data Analysis: Defect analysis was performed by collecting 277 SEM images for two fields of view (FOV5 & FOV100) by scanning with Applied Materials NanoSem 3D tool. Defect images were evaluated as dewet spots, black or white dots or particles (shown in black). Comparing SOL2 to SOL3, a significant reduction in the number of defects was observed when increasing the %VBA from 1% to 2%. In Figure 6, the following non-polar pinned layers were compared: 1)SOL COMP1, P(Sr-VBCB-r-MMA)(30 / 30 / 40) 2)SOL1, P(Sr-VBCB-r-MMA-r-VBA)-OH(34 / 30 / 35 / 1) 3)SOL2, P(Sr-VBCB-r-MMA-r-VBA)-OH(33 / 30 / 35 / 2) 4)SOL3, P(Sr-VBCB-r-MMA-r-VBA)-COOH(33 / 30 / 35 / 2) From Table 2, it can be seen that the samples made with the comparative examples show both a very high degree of dewetting and a high degree of defects compared to the new compositions. Table 2 shows that most of the new compositions retain their neutrality against the block copolymer of styrene and methyl methacrylate ref SOL1 (Reference Block Copolymer Synthesis Example 1) coated as an overlayer, while the loss of neutrality only occurred in Examples 8 and 9 where VBA was >3 mol%. Above 3 mol% VBA, the neutral surface became a hydrophilic pinning surface and a loss of neutrality was observed. Figure 6 shows in more detail what was observed in the defect analysis, where the comparative terpolymer SOL COMP1 gives a significantly higher number of defects, indicated by dark gray squares, compared to either the tetrapolymer or pentapolymer of the present invention, indicated by the samples prepared with SOL2 and SOL3, respectively.

[0120] Table 2 summarizes the performance of compositions containing these materials as neutral layers processed as described above.

[0121] Table 2. Performance and test summary of neutral surfaces P(Sr-VBCB-r-MMA-r-VBA)-X and P(Sr-VBCB-r-MMA-r-VBA-r-HEMA)

[0122] [Table 2]

[0123] Examples and Testing of Hydrophobic (Non-Polar) Matte Layers of the Present Invention Disclosed herein are novel hydrophobic pinning mats that have been reproducibly produced using a controllable synthesis method compatible with free radical polymerization. The following are the demonstrated advantages of these inventive materials: Highly hydrophobic crosslinkable pinning mat for DSA processing. High contact angle and low film loss characterize this mat as ideal for DSA pinning. · Less defect undercoat. Less particles and dewetting defects improve the DSA process and widen its process window. · The compatibility of hydrophobic pinning underlayer films on SiARCs allows for multilayer application of line multiplication using spin-on processes.

[0124] The new copolymers investigated to enable robust hydrophobic mats for use in DSA were copolymers of styrene (S), 4-vinylbenzocyclobutene (VBCB), and 4-vinylbenzoic acid (VBA) initiated with either 4,4'-azobis(4-cyanopentanol) (AIBN-OH) or 4,4'-azobis(4-cyanovaleric acid) (AIBN-COOH). Modification of the composition to P(Sr-VBCB-r-VBA)-OH [i.e., hydroxyl-terminated poly(styrene-co-4-vinylbenzocyclobutene-co-4-vinylbenzoic acid)] or P(Sr-VBCB-r-VBA)-COOH [i.e., carboxylic acid-terminated poly(styrene-co-4-vinylbenzocyclobutene-co-4-vinylbenzoic acid)] provided hydrophobic crosslinkable pinned mats with fewer coating defects. The S component provided the pinning hydrophobicity to the polymer. Figure 7 shows a representative example of one of the copolymers of the invention that was produced. The VBCB component allowed the polymer to crosslink into an insoluble film when baked during processing. Surprisingly, the VBA component made these copolymers more compatible with SiARC substrates. In addition, when terminal hydroxyl or carboxylic acid terminated end groups were introduced into these copolymers from initiators containing these moieties, this allowed the copolymer to graft onto the substrate, retaining the copolymer to the substrate and also allowing the copolymer to better adhere to the substrate during high temperature bake crosslinking of the copolymer, further reducing dewetting and reducing defect levels.

[0125] Analysis of the crosslinked films was performed to check for non-neutrality or pinning of the hydrophobic blocks, especially for the homopolystyrene blocks. This was done by annealing a coating of reference block copolymer synthesis example 1 (ref SOL1) onto the film to verify the self-assembly of the block copolymer. This analysis showed that the block copolymer did not produce a fingerprint, suggesting that it adopted a parallel shape on these new non-polar pinning surfaces. This bias of the top layer block copolymer allowed for preferential interaction with the PS block of the diblock copolymer. The coating on the SiARC was then analyzed for defects using SEM method (VM277). This showed an improved coating with only minor defects. SEM method VM277 is a process of taking 277 images per wafer and visually inspecting each image for coating defects such as pinholes, black or white spots, and particles. These defects were further analyzed at IMEC (Kapeldreef 75, 3001, Leuven, Belgium) for better characterization.Finally, the pinning properties of these novel non-polar mats were examined by patterning them by radiation lithography and subjecting them to LiNe flow for guided self-assembly of BCPs for line multiplication, which resulted in pattern multiplication as shown in Figures 15-17.

[0126] The novel hydrophobic crosslinkable pinning mat compositions P(Sr-VBCB-r-VBA)-OH and P(Sr-VBCB-r-VBA)-COOH (Figure 7) begin with AIBN-OH and AIBN-COOH, respectively, which are not commonly used in crosslinkable mats. This end group functionality allows for increased interaction with the substrate in the grafting capacity prior to crosslinking. When AIBN-OH was used as the initiator instead of AIBN, the defect improved from 277 / 277 to 26 / 158 (Figure 10, SOL COMP2 vs. SOL10). When AIBN-COOH was used as the initiator instead of AIBN, the defect improved from 277 / 277 to 4 / 0 (Figure 10, SOL11).

[0127] 4-Vinylbenzoic acid (VBA) was added to the composition to reduce dewetting defects of hydrophobic films on SiARCs. Since SiARCs are commonly used in microchip architectures, film compatibility is important. The polar functionality of VBA improves adhesion of hydrophobic films on any surface, reducing dewetting defects. Adding 0.5 mol% VBA to the composition improved the defect from 277 / 277 to 83 / 9 (Figure 10, SOL12). Adding 1.0 mol% VBA to the composition improved the defect from 277 / 277 to 3 / 3 (Figure 10, SOL13).

[0128] The use of the functionalized radical initiators AIBN-OH or AIBN-COOH in (1) in combination with 4-vinylbenzoic acid in composition (2) gave polymers that exhibited very few defects when coated onto SiARC substrates. Adding 1.5 mol% VBA to the composition starting with AIBN-COOH improved the defectivity from 277 / 277 to 0 / 1 (Figure 10, SOL14). Adding 1 mol% VBA to the composition starting with AIBN-OH improved the defectivity from 277 / 277 to 0 / 0 (Figure 10, SOL15).

[0129] SEM images of the new composition show improved dewetting defects when coated using the procedure previously described for coating, compared to Comparative Example 2 (COMP SOL2) (Figure 11, Bin 1 and Bin 2, large defects). It should be noted that the reference was treated with UV exposure to reduce its defects on the SiARC. When coated using the procedure previously described for coating, SOL15 shows an overall improvement in Bin 1 and Bin 2 defects compared to Comparative Example 2, since no UV treatment was applied to this sample (Figure 12).

[0130] When coated using the procedure described above for coating, SOL14 shows equal or better improvement in Bin1 and Bin2 defects compared to SOL COMP2 (FIG. 11), since no UV treatment was applied to this sample either.

[0131] SOL15 (FIG. 12) shows an overall improvement for most dies with perfect line multiplication set compared to SOL COMP2 (FIG. 11) since no UV treatment was applied to this sample.

[0132] FIG. 14 (FIG. 13) shows better performance when comparing the number of dies with perfect line multiplication sets compared to SOL COMP2 (FIG. 11) since no UV treatment was applied to this sample.

[0133] Directed self-assembly (DSA) performance on guided line prepatterns generated with the novel underlayer pinning mat showed a better process window (FIGS. 16 and 17).

[0134] Example 10 Synthesis of poly(styrene-co-4-vinylbenzocyclobutene-co-4-vinylbenzoic acid)-hydroxyl terminated type Styrene (25.0 g, 230 mmol), 4-vinylbenzocyclobutene (2.35 g, 20 mmol), 4,4'-azobis(4-cyanopentanol) (0.63 g, 2.5 mmol), and methyl isobutyl ketone (42 g) were added to a flask and degassed three times using the freeze-thaw technique. The mixture was heated in an 85° C. oil bath for 16 hours. The mixture was cooled to room temperature and diluted with THF, then precipitated in isopropanol. The polymer was collected, redissolved in THF to a 15% solids solution, and precipitated in isopropanol. The polymer was collected and dried overnight in vacuum at 70° C. 18.0 g (65.3%) white powder, GPC: 12,992 g / mol Mn, 22,621 g / mol Mw, 1.74 PDI.

[0135] Example 11 Synthesis of poly(styrene-co-4-vinylbenzocyclobutene-co-4-vinylbenzoic acid)-carboxylic acid terminated Styrene (24.8 g, 240 mmol), 4-vinylbenzocyclobutene (2.34 g, 20 mmol), 4,4'-azobis(4-cyanovaleric acid) (0.84 g, 3 mmol), and methyl isobutyl ketone (42 g) were added to a flask and degassed three times using the freeze-thaw technique. The mixture was heated in an 85° C. oil bath for 16 hours. The mixture was cooled to room temperature and diluted with THF, then precipitated in isopropanol. The polymer was collected, redissolved in THF to a 15% solids solution, and precipitated in isopropanol. The polymer was collected and dried overnight in vacuum at 70° C. 18.0 g (65.3%) white powder, GPC: 8,571 g / mol Mn, 14,280 g / mol Mw, 1.67 PDI.

[0136] Example 12 Synthesis of poly(styrene-co-4-vinylbenzocyclobutene-co-4-vinylbenzoic acid) Styrene (35.7 g, 340 mmol), 4-vinylbenzocyclobutene (3.37 g, 30 mmol), 4-vinylbenzoic acid (0.27 g, 1.9 mmol), 4,4'-azobis(2-methylpropionitrile) (0.69 g, 4.2 mmol) and methyl isobutyl ketone (60 g) were added to a flask and degassed three times using the freeze-thaw technique. The mixture was heated in an 85° C. oil bath for 16 hours. The mixture was cooled to room temperature and diluted with THF, then precipitated in isopropanol. The polymer was collected, redissolved in THF to a 15% solids solution, and precipitated in isopropanol. The polymer was collected and dried overnight in vacuum at 70° C. 18.0 g (65.3%) white powder, GPC: 10,711 g / mol Mn, 17,888 g / mol Mw, 1.67 PDI.

[0137] Example 13 Synthesis of poly(styrene-co-4-vinylbenzocyclobutene-co-4-vinylbenzoic acid) Styrene (35.4 g, 340 mmol), 4-vinylbenzocyclobutene (3.37 g, 30 mmol), 4-vinylbenzoic acid (0.55 g, 3.7 mmol), 4,4'-azobis(2-methylpropionitrile) (0.69 g, 4.2 mmol) and methyl isobutyl ketone (60 g) were added to a flask and degassed three times using the freeze-thaw technique. The mixture was heated in an 85° C. oil bath for 16 hours. The mixture was cooled to room temperature and diluted with THF, then precipitated in isopropanol. The polymer was collected, redissolved in THF to a 15% solids solution, and precipitated in isopropanol. The polymer was collected and dried overnight in vacuum at 70° C. 18.0 g (65.3%) white powder, GPC: 9,719 g / mol Mn, 17,591 g / mol Mw, 1.81 PDI.

[0138] Example 14 Synthesis of poly(styrene-co-4-vinylbenzocyclobutene-co-4-vinylbenzoic acid)-carboxylic acid terminated Styrene (24.3 g, 230 mol), 4-vinylbenzocyclobutene (2.32 g, 20 mmol), 4-vinylbenzoic acid (0.57 g, 3.8 mmol), 4,4'-azobis(4-cyanovaleric acid) (0.82 g, 2.9 mmol) and methyl isobutyl ketone (42 g) were added to a flask and degassed three times using the freeze-thaw technique. The mixture was heated in an 85° C. oil bath for 16 hours. The mixture was cooled to room temperature and diluted with THF, then precipitated in isopropanol. The polymer was collected, redissolved in THF to a 15% solids solution, and precipitated in isopropanol. The polymer was collected and dried overnight in vacuum at 70° C. 18.0 g (65.3%) white powder, GPC: 12,311 g / mol Mn, 20,879 g / mol Mw, 1.696 PDI.

[0139] Example 15 Synthesis of poly(styrene-co-4-vinylbenzocyclobutene-co-4-vinylbenzoic acid)-hydroxyl terminated type Styrene (24.6 g, 240 mmol), 4-vinylbenzocyclobutene (2.34 g, 20 mmol), 4-vinylbenzoic acid (0.38 g, 2.6 mmol), 4,4'-azobis(4-cyanopentanol) (0.70 g, 2.8 mmol) and methyl ethyl ketone (42 g) were added to a flask and degassed by purging with nitrogen for 30 minutes. The mixture was heated to reflux in a 90°C oil bath for 16 hours. The mixture was cooled to room temperature, diluted two-fold with THF and precipitated in isopropanol. The polymer was collected, redissolved in THF to a 15% solids solution and precipitated in isopropanol. The polymer was collected and dried overnight in vacuum at 70°C. 14.4 g (52.3%) white powder, GPC: 13,236 g / mol Mn, 25,535 g / mol Mw, 1.93 PDI.

[0140] Example 16 Synthesis of poly(styrene-co-4-vinylbenzocyclobutene-co-4-vinylbenzoic acid)-hydroxyl terminated type Styrene (23.1 g, 220 mmol), 4-vinylbenzocyclobutene (1.56 g, 10 mmol), 4-vinylbenzoic acid (0.35 g, 2.4 mmol), methacryloisobutyl POSS (2.25 g, 2.4 mmol), 4,4'-azobis(4-cyanopentanol) (0.70 g, 2.8 mmol) and methyl ethyl ketone (42 g) were added to a flask and degassed by purging with nitrogen for 30 minutes. The mixture was heated to reflux in a 90° C. oil bath for 16 hours. The mixture was cooled to room temperature, diluted two-fold with THF and precipitated in isopropanol. The polymer was collected, redissolved in THF to a 15% solids solution and precipitated in isopropanol. The polymer was collected and dried overnight in vacuum at 70° C. 14.2 g (52.1%) white powder, GPC: 14,148 g / mol Mn, 23,558 g / mol Mw, 1.67 PDI.

[0141] Examples and Testing of Neutral Layers of the Present Invention for Block Copolymer Contact Hole Self-Assembly Reference block copolymer synthesis example 2 of P(Sb-MMA)(62k-b-25k) P(Sb-MMA) (62K-b-25K) was synthesized using the same procedure as in Example 2. The amount of initiator and the amount of monomer were varied to achieve the desired Mn and composition of the PS and PMMA blocks. Briefly, 20 g (192 mmol) of styrene was polymerized with 4.38 mL (1.4 M solution) of sec-butyllithium. Then, 0.07 g (0.38 mmol) of 1,1'-diphenylethylene (DPE) in 2.5 ml of anhydrous toluene was added to the reactor via an ampoule. The orange color of the reaction mixture changed to a dark brick red color, suggesting that the styryllithium active center was converted to a delocalized DPE-added carbanion. After stirring for 2 min, a small amount (2 mL) of the reaction mixture was taken for PS block molecular weight analysis. Then, methyl methacrylate (8.10 g, 81 mmol) was added via an ampoule. The reaction was stopped after 30 min with 1 mL of degassed methanol. The block copolymer was recovered by precipitation in excess isopropanol (5 times the volume of the polymer solution) containing 10% water, filtration, and drying under vacuum at 55° C. for 12 h to give 26.5 g of P(Sb-MMA) (94% yield) consisting of 70.1 mol % polystyrene blocks and 29.9 mol % polymethyl methacrylate blocks. The diblock copolymer molecular weight obtained from GPC is Mn=86,518 g / mol and Mw / Mn=1.01.

[0142] Reference block copolymer solution (Ref SOL2) Reference block copolymer synthesis example 2 was dissolved in PGMEA as a 1.7 wt % solution and filtered through a 0.2 micron PTFE filter. This solution was used to test neutral layer compositions of the invention, as described below, for their effect on contact hole self-assembly (e.g., Examples 17-25 reported in Tables 5 and 6).

[0143] Example 17: Synthesis of poly(styrene-co-4-vinylbenzocyclobutene-co-methyl methacrylate-co-4-vinylbenzoic acid)-hydroxyl terminated (feed ratio 39 / 35 / 25 / 1) Styrene (35.7 g, 0.34 mol), 4-vinylbenzocyclobutene (40.0 g, 0.31 mol), methyl methacrylate (22.0 g, 0.22 mol), 4-vinylbenzoic acid (1.30 g, 8.80 mmol), 4,4'-azobis(4-cyanopentanol) (0.99 g, 3.92 mmol) and 2-butanone (150 g) were added to a flask and purged with nitrogen for 30 minutes. The mixture was heated in an 85°C oil bath for 16 hours. The mixture was cooled to room temperature, diluted with THF and precipitated in isopropanol. The polymer was collected, redissolved in THF to a 15% solids solution and precipitated in isopropanol. The polymer was collected and dried in vacuum overnight at 70°C. 18.0 g (65.3%) white powder, GPC: 21,270 g / mol, Mn 47,875 g / mol, Mw, 2.25 PDI.

[0144] Example 18: Synthesis of poly(styrene-co-4-vinylbenzocyclobutene-co-methyl methacrylate-co-4-vinylbenzoic acid)-hydroxyl terminated (feed ratio 33 / 30 / 35 / 1) Styrene (18.3 g, 0.18 mol), 4-vinylbenzocyclobutene (20.8 g, 0.16 mol), methyl methacrylate (18.7 g, 0.19 mol), 4-vinylbenzoic acid (1.58 g, 10.7 mmol), 4,4'-azobis(4-cyanopentanol) (0.59 g, 2.35 mmol) and 2-butanone (90 g) were added to a flask and purged with nitrogen for 30 minutes. The mixture was heated in an 85°C oil bath for 16 hours. The mixture was cooled to room temperature, diluted with THF and precipitated in isopropanol. The polymer was collected, redissolved in THF to a 15% solids solution and precipitated in isopropanol. The polymer was collected and dried overnight in vacuum at 70°C. 32.0 g (54%) white powder, GPC: 13,391 g / mol Mn, 24,461 g / mol Mw, 1.83 PDI.

[0145] Example 19: Synthesis of poly(styrene-co-4-vinylbenzocyclobutene-co-methyl methacrylate-co-4-vinylbenzoic acid)-hydroxyl terminated (feed ratio 38 / 35 / 25 / 2) Styrene (34.1 g, 0.33 mol), 4-vinylbenzocyclobutene (39.4 g, 0.30 mol), methyl methacrylate (21.6 g, 0.22 mol), 4-vinylbenzoic acid (3.84 g, 17.3 mmol), 4,4'-azobis(4-cyanopentanol) (0.99 g, 3.92 mmol) and 2-butanone (150 g) were added to a flask and purged with nitrogen for 30 minutes. The mixture was heated in an 85° C. oil bath for 16 hours. The mixture was cooled to room temperature, diluted with THF and precipitated in isopropanol. The polymer was collected, redissolved in THF to a 15% solids solution and precipitated in isopropanol. The polymer was collected and dried overnight in vacuum at 70° C. 64 g (64%) white powder, GPC: 13,256 g / mol Mn, 24,824 g / mol Mw, 1.95 PDI.

[0146] Example 20: Synthesis of poly(styrene-co-4-vinylbenzocyclobutene-co-methyl methacrylate-co-4-vinylbenzoic acid)-hydroxyl terminated (feed ratio 48 / 35 / 15 / 2) Styrene (43.0 g, 0.41 mol), 4-vinylbenzocyclobutene (39.2 g, 0.30 mol), methyl methacrylate (12.9 g, 0.13 mol), 4-vinylbenzoic acid (3.83 g, 17.2 mmol), 4,4'-azobis(4-cyanopentanol) (0.99 g, 3.92 mmol) and 2-butanone (150 g) were added to a flask and purged with nitrogen for 30 minutes. The mixture was heated in an 85° C. oil bath for 16 hours. The mixture was cooled to room temperature and diluted two-fold with THF, then precipitated in isopropanol. The polymer was collected, redissolved in THF to a 15% solids solution, and precipitated in isopropanol. The polymer was collected and dried overnight in vacuum at 70° C. 53 g (53%) white powder, GPC: 10,572 g / mol Mn, 22,685 g / mol Mw, 2.15 PDI.

[0147] Example 21: Synthesis of poly(styrene-co-4-vinylbenzocyclobutene-co-methyl methacrylate-co-4-vinylbenzoic acid)-hydroxyl terminated (feed ratio 48 / 35 / 15 / 2) Styrene (43.6 g, 0.42 mol), 4-vinylbenzocyclobutene (39.7 g, 0.31 mol), methyl methacrylate (13.1 g, 0.13 mol), 4-vinylbenzoic acid (2.58 g, 17.4 mmol), 4,4'-azobis(4-cyanopentanol) (0.99 g, 3.92 mmol) and 2-butanone (60 g) were added to a flask and purged with nitrogen for 30 minutes. The mixture was heated in an 85°C oil bath for 16 hours. The mixture was cooled to room temperature and diluted two-fold with THF, then precipitated in isopropanol. The polymer was collected, redissolved in THF to a 15% solids solution, and precipitated in isopropanol. The polymer was collected and dried overnight in vacuum at 70°C. 41 g (41%) white powder, GPC: 16,902 g / mol Mn, 40,958 g / mol Mw, 2.42 PDI.

[0148] Example 22: Synthesis of poly(styrene-co-4-vinylbenzocyclobutene-co-methyl methacrylate-co-4-vinylbenzoic acid)-hydroxyl terminated (feed ratio 68 / 15 / 15 / 2) Styrene (64.7 g, 0.62 mol), 4-vinylbenzocyclobutene (17.9 g, 0.14 mol), methyl methacrylate (13.7 g, 0.14 mol), 4-vinylbenzoic acid (2.71 g, 18.3 mmol), 4,4'-azobis(4-cyanopentanol) (0.99 g, 3.92 mmol) and 2-butanone (150 g) were added to a flask and purged with nitrogen for 30 minutes. The mixture was heated in an 85°C oil bath for 16 hours. The mixture was cooled to room temperature and diluted two-fold with THF, then precipitated in isopropanol. The polymer was collected, redissolved in THF to a 15% solids solution, and precipitated in isopropanol. The polymer was collected and dried overnight in vacuum at 70°C. 45 g (45%) white powder, GPC: 23,381 g / mol Mn, 42,354 g / mol Mw, 1.81 PDI.

[0149] Example 23 Synthesis of poly(styrene-co-4-vinylbenzocyclobutene-co-methyl methacrylate-co-4-vinylbenzoic acid)-hydroxyl terminated (feed ratio 35 / 53 / 10 / 2) Styrene (30.1 g, 0.29 mol), 4-vinylbenzocyclobutene (57.0 g, 0.44 mol), methyl methacrylate (8.27 g, 0.08 mol), 4-vinylbenzoic acid (3.67 g, 16.5 mmol), 4,4'-azobis(4-cyanopentanol) (0.99 g, 3.92 mmol) and 2-butanone (150 g) were added to a flask and purged with nitrogen for 30 minutes. The mixture was heated in an 85°C oil bath for 16 hours. The mixture was cooled to room temperature and diluted two-fold with THF, then precipitated in isopropanol. The polymer was collected, redissolved in THF to a 15% solids solution, and precipitated in isopropanol. The polymer was collected and dried overnight in vacuum at 70°C. 49 g (49%) white powder, GPC: 14,246 g / mol Mn, 26,302 g / mol Mw, 1.84 PDI.

[0150] Example 24 Synthesis of poly(styrene-co-4-vinylbenzocyclobutene-co-methyl methacrylate-co-4-vinylbenzoic acid)-hydroxyl terminated (feed ratio 13 / 30 / 55 / 2) Styrene (12.1 g, 0.12 mol), 4-vinylbenzocyclobutene (35.0 g, 0.27 mol), methyl methacrylate (49.3 g, 0.49 mol), 4-vinylbenzoic acid (2.65 g, 17.9 mmol), 4,4'-azobis(4-cyanopentanol) (0.99 g, 3.92 mmol) and 2-butanone (150 g) were added to a flask and purged with nitrogen for 30 minutes. The mixture was heated in an 85°C oil bath for 16 hours. The mixture was cooled to room temperature, diluted with THF and precipitated in isopropanol. The polymer was collected, redissolved in THF to a 15% solids solution and precipitated in isopropanol. The polymer was collected and dried overnight in vacuum at 70°C. 28 g (59%) white powder, GPC: 14,877 g / mol Mn, 32,134 g / mol Mw, 2.16 PDI.

[0151] Example 25: Synthesis of poly(styrene-co-4-vinylbenzocyclobutene-co-methyl methacrylate-co-4-vinylbenzoic acid)-hydroxyl terminated (feed ratio 33 / 30 / 34 / 3) Styrene (29.8 g, 0.29 mol), 4-vinylbenzocyclobutene (33.9 g, 0.26 mol), methyl methacrylate (29.5 g, 0.30 mol), 4-vinylbenzoic acid (3.86 g, 26.0 mmol), 4,4'-azobis(4-cyanopentanol) (2.91 g, 1.15 mmol) and 2-butanone (150 g) were added to a flask and purged with nitrogen for 30 minutes. The mixture was heated in an 85°C oil bath for 16 hours. The mixture was cooled to room temperature and diluted two-fold with THF, then precipitated in isopropanol. The polymer was collected, redissolved in THF to a 15% solids solution, and precipitated in isopropanol. The polymer was collected and dried overnight in vacuum at 70°C. 52 g (52%) white powder, GPC: 14,277 g / mol Mn, 23,518 g / mol Mw, 1.65 PDI.

[0152] Comparative Example 2: Synthesis of poly(styrene-co-4-vinylbenzocyclobutene) To a 250 mL 4-neck round bottom flask equipped with a stir bar, reflux condenser, temperature controller and nitrogen purge was added styrene (630 g, 6.05 mol), 4-vinylbenzocyclobutene (59.30 g, 0.46 mol), 2,2'-azobis(2-methylpropionitrile) (10.35 g, 63 mmol) and 2-butanone (MEK, 1050 g). The reaction mixture was stirred with nitrogen purging for 1.0 h. The mixture was heated in a 90°C oil bath and stirred for 20 h. The mixture was cooled and then slowly precipitated into iPrOH (15 L). The precipitate was collected by suction filtration and dried in an oven. The residue was redissolved in THF (15% solids) and precipitated once more into MeOH (15 L). The precipitate was collected by suction filtration and dried in an oven. The polymer is an off-white solid, 450 g (64.0% yield). GPC: 9,452 g / mol Mn, 18,053 g / mol Mw, 1.91 PDI.

[0153] Comparative Example 3: Synthesis of poly(styrene-co-4-vinylbenzocyclobutene-co-methyl methacrylate)-hydroxyl terminated (feed ratio 30 / 30 / 40) Styrene (28.0 g, 0.27 mol), 4-vinylbenzocyclobutene (35.0 g, 0.27 mol), methyl methacrylate (35.9 g, 0.36 mol), 4,4'-azobis(4-cyanopentanol) (0.99 g, 3.92 mmol) and 2-butanone (150 g) were added to a flask and purged with nitrogen for 30 minutes. The mixture was heated in an 85° C. oil bath for 16 hours. The mixture was cooled to room temperature, diluted two-fold with THF and precipitated in isopropanol. The polymer was collected, redissolved in THF to a 15% solids solution and precipitated in isopropanol. The polymer was collected and dried overnight in vacuum at 70° C. 26 g (26%) white powder, GPC: 26,113 g / mol Mn, 43,631 g / mol Mw, 1.67 PDI. This comparative example demonstrated the effectiveness of excluding repeat units derived from 4-vinylbenzoic acid.

[0154] Polymer characterization FIG. 8 shows a representative graph of the P(Sr-VBCB-r-VBA)-COOH polymer (i.e., Examples 11 and 14). 1 The H NMR spectrum is shown. This spectrum is from Example 14.

[0155] FIG. 9 shows a representative graph of the P(Sr-VBCB-r-VBA)-OH polymer (i.e., Examples 10, 15, and 16). 1 The H NMR spectrum is shown. This spectrum is from Example 15.

[0156] Table 3 summarizes the property data for both the inventive polymers 10-16 and Comparative Example 2.

[0157] Table 3. Summary of polymer characterization of P(Sr-VBCB-r-VBA)-X and P(Sr-VBCB-r-VBA-r-POSS-MA)

[0158] [Table 3]

[0159] Testing of novel non-polar pinning layers Table 4 summarizes the defectivity testing performed on non-polar pinned layers formed using the VBA-containing polymers of the present invention described in Examples 12-17, and layers prepared using the copolymer of Comparative Example 2.

[0160] In the experiments outlined in Table 4, test solutions were prepared by dissolving the copolymers of Examples 12-17 and Comparative Example 2 individually in PGMEA as 0.3 wt % solutions and filtering them through a 0.2 μm PTFE filter. The naming of the solutions reflects the naming of the examples, so SOL12 through SOL17 are solutions prepared from Examples 12-17 and SOL COMP2 is the sample prepared from Comparative Example 2.

[0161] Film thickness (FT) was measured using a JA Woollam M-2000 ellipsometer. Film thickness pre- and post-rinse measurements with PGMEA determine film robustness. Neutrality test-processing conditions are solution coated on SiARC and baked at 220°C / 90s, new mat coated and baked in N2 at 250°C / 5min, ref SOL1 coated and baked in N2 at 250°C / 5min. Neutrality was determined by the presence (neutral) or absence (non-neutral) of vertical morphology (fingerprint) of BCP. Details of processing conditions are given in the section entitled "General Processing Conditions".

[0162] Coating defect analysis of non-polar pinning layers by LPC FIG. 10 shows the results obtained in the coating defect analysis using SOL10-16 and COMP SOL2. The dark grey-black color indicates areas with defects. This analysis involved coating SiARC and baking at 220°C / 90s, then separately coating with SOL10-16 or with COMP SOL2, and separately baking the copolymer coating at 250°C / 5min in N2 to form crosslinked non-polar pinned layer test samples. These wafers were then subjected to the VM277 SEM method to analyze for coating defects. These non-polar pinned test samples were finally coated with block copolymer solution (ref SOL1) and baked at 250°C / 5min in N2 to check for neutrality.

[0163] Defect analysis was performed by scanning with Applied Materials NanoSem 3D tool in a procedure of collecting 277 images in two fields of view (FOV5 & FOV100). Defect images were evaluated as dewet spots, black or white dots or particles (shown in black). Suspected small defects are shown in light grey in Figure 10. Significant improvement in defects was observed by changing to hydroxyl and carboxylic acid termination as initiator end groups (SOL10 and SOL11, respectively). Gradually increasing %VBA to 0.5% and 1.0% in the hydrophobic composition improved the defect count (SOL12 and SOL13, respectively). The combination of these factors gave very few defects (SOL14-SOL16). In Figure 10, the following non-polar pinning layers were compared: 1)SOL COMP2, P(Sr-VBCB)(93 / 7) 2) SOL10, P(Sr-VBCB)-OH(93 / 7) 3)SOL11, P(Sr-VBCB)-COOH(93 / 7) 4)SOL12, P(Sr-VBCB-r-VBA)(92.5 / 7 / 0.5) 5)SOL13, P(Sr-VBCB-r-VBA)(92 / 7 / 1) 6)SOL14, P(Sr-VBCB-r-VBA)-COOH(91.5 / 7 / 1.5) 7)SOL15, P(Sr-VBCB-r-VBA)-OH(92 / 7 / 1) 8)SOL16,P(Sr-VBCB-r-VBA-r-POSSMA)-OH(95 / 5 / 1 / 1) Details regarding the procedures used for defect analysis are provided in the section entitled "General Defect Analysis Procedures."

[0164] Table 4 summarizes the performance of compositions containing these materials as hydrophobic pinning layers processed as described above.

[0165] The VBA-containing composition improved the surface of the neutral film on the SiARC, as shown in FIG. 10 by the number of defects observable on the surface of this novel pinning mat.

[0166] [Table 4]

[0167] Table 5 summarizes the property data for both inventive polymers 17-25 and Comparative Example 3.

[0168] [Table 5]

[0169] Defect counts were also obtained in IMEC using the SP5 defect tool, as shown in Figures 11, 12, and 13 for SOL COMP2, SOL15, and SOL14, respectively. SEM images of the defects were taken to analyze the type of defects detected by the SP5 tool. The largest Bin1 defect was due to dewetting defects of the hydrophobic film on the SiARC. Overall, the novel inventive polymers show fewer defects compared to the reference polymers. Details on the procedure used for defect analysis are provided in the section entitled "General Defect Analysis Procedure."

[0170] The process used at IMEC for Figures 11-13 is as follows: SiARC was coated on clean bare Si wafers and baked at 220°C / 90s, and the SOL materials used in Figures 11 and 13 (i.e., Comp SOL2 and SOL14) were coated, respectively, and baked in N2 at 250°C / 90min. Defect Analysis: The wafers were scanned with a KLA Tencor 2935 as an optical defect inspection tool. The inspected defects were reviewed by a KLA Tencor EDR7380, and the defect images were evaluated as dewet spots, protrusions, recesses, or particles. The dewet spots are shown in red.

[0171] Figure 14 shows a key to the grey-tone color scheme of the defect status shown in Figure 15 (SOL COMP2), Figure 16 (SOL15) and Figure 17 (SOL14). Black squares indicate no alignment, light grey squares indicate mostly aligned lines and grey squares indicate perfectly aligned lines. These figures show the alignment quality of the novel non-polar pinning compositions SOL15 and SOL14 compared to the reference SOL COMP2.

[0172] The processing used at IMEC for Figures 15-17 was as follows: Coat SOC (spin-on carbon material) and then SiARC, bake in air at 250° C. / 90 sec and 220° C. / 90 sec, coat the SOL materials used in FIGS. 15 and 17 (i.e., SOL COMP2 and SOL14), respectively, bake in N2 at 250° C. / 90 min, coat photoresist, bake at 120° C. / 60 sec, expose with ASML iArF scanner, develop with 2.38 wt % TMAH, coat SOL COMP2 or SOL14 separately, etch with N2 / O2 chemistry in LAM E5 dry etcher, strip photoresist with DNS cleaning tool, coat neutral layer, bake in N2 at 250° C. / 5 min, rinse neutral layer with PGMEA, and ref Coat with a solution of SOL1 (Reference Block Copolymer Synthesis Example 1) (BCP) and bake in N2 at 250°C / 30 min.

[0173] DSA process window analysis: The wafers were scanned on a Hitachi CD-SEM with a means of collecting 169 images. The DSA images were evaluated as complete clusters, partial clusters, or no clusters (shown in black, light gray, or gray). Figure 14 shows the key to the gray-tone color scheme of the defect status shown in Figure 15 (SOL COMP2), Figure 16 (SOL15), and Figure 17 (SOL14). These figures define the DSA process window by checking the pattern CD on the complete cluster die to understand the capability of the new underlayer as a pinning material. The new underlayer pinning mat was coated on SiARC and patterned using ArF lithography to generate the pinning line guide pattern. A neutral brush polymer was then coated on the wafer to introduce a non-partial surface. A diblock copolymer was then annealed on the patterned wafer to generate a 3x line multiplication of 90nm 1:1 L / S features.

[0174] General processing conditions: Test solutions were prepared by dissolving the polymers of Examples 1 and 17-25 (SOL1 and SOL17-25) and Comparative Example 3 (SOL COMP3) individually as 0.3 wt% solutions in PGMEA and filtering them through a 0.2 micron PTFE filter. Two different SiARCs (ISX302 and ISX304) were used in this evaluation. Each SOL was cast onto a coupon of ISX302 and ISX304 fixed onto a wafer to form Film 1 and Film 2, respectively. These coupons were evaluated for coating defects as dewet spots, black spots, or white spots using a SEM tool (Figure 18). JSR ISX302 or ISX304 SiARCs were coated onto a Si wafer and baked at 220°C / 90 seconds in N2. The wafer was separated into smaller coupon pieces and fixed onto the Si wafer. These new solutions were then coated as 8 nmFT onto the coupons with SiARC films and baked in air at 250°C / 2 min. A reference block copolymer solution (ref SOL2) was coated as 47 nmFT and baked in N2 at 250°C / 30 min. The naming of these solutions reflects the naming of the examples, thus SOL1, SOL17-SOL25 are solutions prepared from Examples 1 and 17-25, and SOL COMP3 is the sample prepared from Comparative Example 3.

[0175] General Defect Analysis Procedure: Defect analysis was performed by scanning with Applied Materials NanoSem 3D tool in a procedure that collected SEM images for two fields of view (FOV0.5 & FOV10). Two sets of SEM analysis were performed. Figure 18 shows SEM images of the novel composition coated on SiARC film. Defect images were evaluated as dewet white spots, bright color spots, barely visible white spots, or no visible white spots. Figure 19 shows SEM images of ref SOL2 coated on the novel composition film. Defect images were evaluated as good, partial or poor formation of contact hole features as a result of film neutrality. SOL COMP3 was prepared with AIBN-OH initiator to be comparable to the novel composition, but without VBA added. The inclusion of VBA showed improved dewetting performance on both SiARC coatings for all the novel compositions except SOL24. The low hydrophobicity of SOL24 may be responsible for this observation. A change in VBA content from 1% to 3% showed that the coating on the SiARC became defect-free. The quality of the contact hole morphology depends on the overall neutrality of the composition. 1% VBA is sufficient to give defect-free coating on the SiARC (SOL17 and SOL18), but stronger hydrophobicity is required for better contact holes. Too much VBA in the composition, such as SOL25, was observed to increase the collapse of the contact holes. A relatively stronger hydrophobicity when 2% VBA was added to the composition showed better performance in both SiARC defects and contact hole morphology (SOL20, SOL21, and SOL22).

[0176] Table 6 summarizes the performance of compositions containing these materials as neutral layers processed as described above.

[0177] Two different SiARCs (ISX302 and ISX304) were used in this evaluation. Each SOL was cast onto a coupon of ISX302 and ISX304 fixed on a wafer to form Film 1 and Film 2, respectively. These coupons were evaluated for coating defects as dewet spots, black spots, or white spots using a SEM tool, as shown in FIG. 18. In Table 6, the coatability ratings on the new neutral layer on SiARC are shown in FIG. 18 and are as follows: SEM images with white spots were rated as dewet defects (X). SEM images with bright color spots were rated as slight defects (∇). SEM images with barely discernible white spots were rated as very slight defects (Δ). SEM images with no discernible spots were rated as no defects (O).

[0178] In Table 6, the block copolymer solutions for Reference Block Copolymer Synthesis Example 2 were separately coated onto coupons of Film 1 and Film 2 fixed on a wafer to give the morphology of Coating 1 and Coating 2, respectively. These coupons were evaluated for morphology using a SEM tool.

[0179] Table 6 summarizes the results observed when forming SEM images with respect to coatability of the new neutral layers on various SiARC coatings and the ability of the formed neutral layers to induce contact hole self-assembly in the overlying block copolymer (ref SOL2). In this table, observed SEM images with >90% contact hole morphology were graded as good C / H (A). SEM images with 50-89% contact hole morphology were graded as partial C / H (B). SEM images with 0-49% contact hole morphology were graded as poor C / H (C). These grades of contact morphology are illustrated with representative examples in FIG. 19.

[0180] As can be seen in this table, the tetrapolymer of P(Sr-VBCB-r-MMA-r-VBA)-OH generally gives better compatibility with various types of SiARCs compared to SOL COM3 in terms of both coating defects and contact hole assembly in the annealed film on top of ref SOL2 (Reference Block Copolymer Synthesis Example 2). Also, SOL24, which contains 13 mol% repeat units derived from styrene, gave very poor coating compatibility with all SiARCs tested, as well as poor self-assembly in the annealed film on top of Reference Block Copolymer Synthesis Example 2. This proves the need for a high content of styrene in the P(Sr-VBCB-r-MMA-r-VBA)-OH polymer. Also seen in Table 3 is that the SOL COMP3 formulation, which excludes the 4-vinylbenzoic acid based repeat units, gave poorer compatibility with various SiARCs.

[0181] [Table 6]

[0182] While the disclosed and claimed invention has been described and illustrated with a certain degree of detail, it will be apparent that this disclosure is made by way of example only, and that those skilled in the art may resort to numerous variations in the conditions and sequence of steps without departing from the spirit and scope of the disclosed and claimed invention.

Claims

1. A random copolymer of structure (A): A repeating unit of structure (I) having a carboxylic acid, wherein R ｍ１ is H or C1-C4 alkyl, and n1 is the total number of repeat units, and this repeat unit ranges from 1.0 mol % to 5.0 mol % in said copolymer; A repeating unit of structure (II) derived from 4-vinylbenzocyclobutene, wherein R ｍ２ is H or C1-C4 alkyl, and n2 is the total number of repeat units, and the repeat units range from 5.0 mol % to 35.0 mol % in the copolymer; Styrenic repeat units of structure (III), wherein R ｍ３ is H or C1-C4 alkyl, and R ｓｔｙ is selected from H, C2-C8 linear alkyl, and C1-C4 alkyloxy, and n3 is the total number of such repeat units, which range from 25 mol % to 94 mol % in said copolymer; Repeating units of structure (IV) derived from alkyl acrylate or alkyl 2-methylene alkanoate, wherein R ｍ４ is H or C1-C4 alkyl, and R Ｉ is a C1-C8 alkyl, and n4 is the total number of repeat units, and the repeat units range from 0 mol % to 64 mol % in the copolymer; Repeating units of structure (V) derived from hydroxy-functionalized alkyl acrylate or alkyl 2-methylene alkanoate, wherein R ｍ５ is H or C1-C4 alkyl, and L １ is a C2-C8 alkylene moiety, and n5 is the total number of repeat units, and the repeat units range from 0 mol % to 3 mol % in the copolymer; and One is H and the other is Rr, Rr １ and Rr ２ the two terminal groups shown in structure (A) being methyl moieties substituted with Rr １ is C1-C8 alkyl, and Rr ２ represents a C1-C8 alkyl, a C1-C8 alkylene hydroxy moiety (-alkylene-OH), a C1-C8 alkylene carboxylic acid moiety (-alkylene-CO ２ H), or a benzylic alcohol-containing moiety of structure (B), wherein ni is an integer ranging from 0 to 5, nia is an integer from 1 to 5, nib is an integer from 1 to 5, and "*" represents the point of attachment for the moiety; Rr is a cyano moiety (—CN) or a carbonylalkyl moiety (—C(═O)—Ri), where Ri is a C1-C8 alkyl or aryl moiety; and further comprising the sum of the individual mole percents of repeat units of structures (I), (II), (III), (IV) and (V) is less than or equal to 100 mole percent of the total repeat units present in said copolymer; Random copolymer. 【Chemistry 1】

2. 10. The copolymer of claim 1, wherein the styrenic repeat units of structure (III) range from 30.0 mol % to 94.0 mol % in said copolymer; and said repeat units of structure (IV) derived from alkyl acrylate or alkyl 2-methylene alkanoate range from 0 mol % to 45 mol %.

3. The copolymer of claim 1, wherein the repeating units consist of repeating units of structures (I), (II), and (III): said repeat units of structure (I) range from 1 mol % to 5 mol %; said repeat units of structure (II) range from 5 mol % to 9 mol %; said repeat units of structure (III) range from 90 mol % to 94 mol %, and further The copolymer wherein the sum of the individual mole percent of repeat units of structures (I), (II) and (III) equals 100 mole percent of all repeat units in said copolymer.

4. R ｓｔｙ The copolymer of claim 1 , wherein

5. The copolymer of claim 1 having the structure (A-1): 【Chemistry 2】

6. Rr ２ 10. The copolymer of claim 1, wherein is a C1-C8 alkylene hydroxy moiety.

7. Rr ２ 2. The copolymer of claim 1, wherein is a C1-C8 alkylene carboxylic acid moiety.

8. Rr ２ The copolymer of claim 1 , wherein is the benzylic alcohol-containing moiety of structure (B).

9. 10. The copolymer of claim 1 having the structure (A-2): said repeat units of structure (I) range from 1 mol % to 5 mol %; said repeat units of structure (II) range from 15 mol % to 35 mol %; the repeat units of structure (III) range from 25 mol % to 69 mol %; and said repeat units of structure (IV) range from 5 mol % to 49 mol %; Further, the repeating units are composed of repeating units (I), (II), (III) and (IV). Copolymer. 【Transformation 3】

10. The copolymer of claim 9 having the structure (A-3): 【Chemistry 4】

11. Rr ２ is a C1-C8 alkylene hydroxy moiety.

12. Rr ２ is a C1 to C8 alkylene carboxylic acid moiety.

13. Rr ２ is the benzylic alcohol-containing moiety of structure (B).

14. 10. The copolymer of claim 1 having the structure (A): said repeat units of structure (I) range from 1 mol % to 5 mol %; said repeat units of structure (II) range from 15 mol % to 35 mol %; said repeat units of structure (III) range from 30 mol % to 60 mol %; said repeat units of structure (IV) range from 15 mol % to 45 mol %; the repeating units of structure (V) range from 1 mol % to 3 mol %; Copolymer. 【Transformation 5】

15. The copolymer of claim 14 having the structure (A-4): 【Transformation 6】

16. Rr ２ The copolymer of claim 14, wherein is a C1 to C8 alkyl.

17. Rr ２ is a C8 alkylene hydroxy moiety.

18. Rr ２ is a C1 to C8 alkylene carboxylic acid moiety.

19. Rr ２ is the benzylic alcohol-containing moiety of structure (B).

20. A composition comprising the copolymer of claim 1 and an organic spin-casting solvent.

21. A composition comprising the copolymer of claim 6 and an organic spin-casting solvent.

22. 10. A composition comprising the copolymer of claim 9 and an organic spin-casting solvent, wherein Rr 2 is either a C1-C8 alkylene hydroxy moiety, a C1-C8 alkylene carboxylic acid moiety, or a benzylic alcohol-containing moiety of structure (B).

23. 10. A composition comprising the copolymer of claim 9 and an organic spin-casting solvent, wherein Rr 2 is a C1-C8 alkyl.

24. A composition comprising the copolymer of claim 14 and an organic spin-casting solvent.

25. 15. A composition comprising the copolymer of claim 14, wherein Rr 2 in the copolymer is either a C8 alkylene hydroxy moiety, a C1-C8 alkylene carboxylic acid moiety, or a benzylic alcohol-containing moiety of structure (B), and an organic spin-casting solvent.

26. A composition comprising the copolymer of claim 16 and an organic spin-casting solvent.

27. 1. A method for forming a crosslinked or grafted and crosslinked coating of a copolymer on a substrate, comprising the steps of: i) forming a coating of the composition of claim 20 on a substrate; ii) heating the coating at a temperature of from 90°C to 180°C to remove the solvent and form a crosslinked or grafted and crosslinked coating of the copolymer; iii) heating the crosslinked or grafted and crosslinked coating of step ii) to 200°C to 250°C to form a fully crosslinked or fully crosslinked and grafted copolymer coating; A method comprising:

28. 1. A method for forming a crosslinked or grafted and crosslinked non-polar pinning coating on a substrate, comprising the steps of: ia) forming a coating of the composition of claim 20 on a substrate, wherein the copolymer is a copolymer whose repeating units consist of repeating units of structures (I), (II), and (III); iia) heating the coating at a temperature of from 90°C to 180°C to remove the solvent and form a crosslinked or grafted and crosslinked coating; iiia) heating the crosslinked or grafted and crosslinked coating of step iia) at a temperature of from 200° C. to 250° C. to form a fully crosslinked or fully crosslinked and grafted non-polar pinning coating; A method comprising:

29. 1. A method for forming a grafted and crosslinked non-polar pinning coating on a substrate, comprising the steps of: ib) forming a coating of the composition of claim 20 on a substrate, wherein the copolymer is a copolymer whose repeating units consist of repeating units of structures (I), (II), and (III); iib) heating the coating at a temperature of from 90°C to 180°C to remove the solvent and form a crosslinked or grafted and crosslinked coating; iiib) heating the crosslinked or grafted and crosslinked coating of step iib) at a temperature of from 200°C to 250°C to form a fully crosslinked and grafted non-polar pinning coating; A method comprising:

30. 1. A method of forming a crosslinked non-polar pinning coating on a substrate, comprising the steps of: ic) forming a coating of the composition of claim 20 on a substrate, wherein the copolymer is one in which Rr 2 is a C1-C8 alkyl; iic) heating the coating at a temperature of from 90°C to 180°C to remove the solvent and form a crosslinked coating; iiiic) heating the crosslinked coating of step iic) at a temperature of from 200°C to 250°C to form a fully crosslinked non-polar pinned coating; A method comprising:

31. 1. A method for forming a crosslinked or grafted and crosslinked neutral coating on a substrate, comprising the steps of: id) forming a coating of the composition of claim 20 on a substrate, wherein the copolymer has the structure (A-2): said repeat units of structure (I) range from 1 mol % to 5 mol %; said repeat units of structure (II) range from 15 mol % to 35 mol %; the repeat units of structure (III) range from 25 mol % to 69 mol %; and the repeat units of structure (IV) range from 5 mol % to 49 mol %; Step, 【Transformation 7】 iid) heating the coating at a temperature of from 90°C to 180°C to remove the solvent and form a crosslinked or grafted and crosslinked coating; iiid) heating the crosslinked coating of step iid) at a temperature of from 200°C to 250°C to form a fully crosslinked non-polar pinned coating; A method comprising:

32. 1. A method for forming a grafted and crosslinked neutral coating on a substrate, comprising the steps of: ie) forming a coating of the composition of claim 22 on a substrate; iii) heating the coating at a temperature of from 90°C to 180°C to remove the solvent and form a grafted and crosslinked coating; iii) heating the crosslinked coating of step iii) at a temperature of 200°C to 250°C to form a fully grafted and crosslinked neutral coating; A method comprising:

33. 1. A method for forming a crosslinked neutral coating on a substrate, comprising the steps of: if) forming a coating of the composition of claim 23 on a substrate; iif) heating the coating at a temperature of from 90°C to 180°C to remove the solvent and form a crosslinked or grafted and crosslinked coating; iiif) heating the crosslinked or grafted and crosslinked coating of step iif) at a temperature of 200°C to 250°C to form a fully crosslinked neutral coating; A method comprising:

34. 1. A method for forming a crosslinked or grafted and crosslinked neutral coating on a substrate, comprising the steps of: ig) forming a coating of the composition of claim 24 on a substrate; iig) heating the coating at a temperature of from 90°C to 180°C to remove the solvent and form a crosslinked or grafted and crosslinked coating; iiig) heating the crosslinked or grafted and crosslinked coating of step iig) at a temperature of 200°C to 250°C to form a fully crosslinked or fully grafted and crosslinked neutral coating; A method comprising:

35. 1. A method for forming a grafted and crosslinked neutral coating on a substrate, comprising the steps of: ih) forming a coating of the composition of claim 25 on a substrate; iih) heating the coating at a temperature of from 90°C to 180°C to remove the solvent and form a grafted and crosslinked coating; iiih) heating the grafted and crosslinked coating of step iih) at a temperature of 200°C to 250°C to form a fully grafted and crosslinked neutral coating; A method comprising:

36. 1. A method for forming a crosslinked neutral coating on a substrate, comprising the steps of: i') forming a coating of the composition of claim 26 on a substrate; ii') heating the coating at a temperature of from 90°C to 180°C to remove the solvent and form a crosslinked coating; iii') heating the crosslinked coating of step ii') at a temperature of 200°C to 250°C to form a fully crosslinked neutral coating; A method comprising:

37. 1. A method of forming a self-assembled block copolymer coating on a neutral coating, comprising the steps of: ij) forming a neutral coating according to any one of claims 32; iij) applying a block copolymer onto the neutral coating and annealing until directed self-assembly of the block copolymer coating occurs; A method comprising:

38. 1. A graphoepitaxy-directed self-assembly method for a block copolymer coating used to form an image, comprising the steps of: ik) forming a neutral coating according to claim 32; iik) applying a coating of a photoresist coating onto the neutral coating and forming a pattern in the photoresist coating; iiik) applying a block copolymer comprising an etch-resistant block and a highly etchable block onto the photoresist pattern and annealing until directed self-assembly occurs; and ivk) etching the block copolymer, thereby removing highly etchable blocks of said copolymer covering areas of the substrate and simultaneously forming a pattern in the substrate selectively in these areas; A method comprising:

39. 1. A method for chemoepitaxy-directed self-assembly of a block copolymer coating used to form an image, comprising the steps of: il) forming a neutral coating on the substrate according to claim 32; iil) applying a coating of photoresist coating onto the neutral coating and forming a pattern in the photoresist coating, thereby forming areas of the neutral coating that are not covered with resist; iii) treating the uncovered neutral coating to remove it and form a pinning region; ivl) removing the photoresist to expose the untreated neutral coating and form a chemo-epitaxy pattern comprising neutral and pinned regions; vl) applying a block copolymer comprising an etch-resistant block and a highly etchable block onto the neutral coating and annealing until directed self-assembly occurs; and vii) etching the block copolymer, thereby removing highly etchable blocks of the copolymer that cover areas of the substrate and simultaneously forming a pattern in the substrate selectively in these areas; A method comprising:

40. 1. A method for chemoepitaxy-directed self-assembly of a block copolymer coating used to form an image, comprising the steps of: im) forming a non-polar pinning coating on the substrate according to claim 28; iim) providing a coating of a photoresist coating over the pinning coating; iii) forming a pattern in said photoresist coating, thereby forming areas of the pinning coating that are not covered by resist; ivm) treating the uncovered pinning coating to remove it and form a bare substrate area; vm) removing the photoresist to expose both the untreated pinning coating and the bare areas of the substrate; vim) applying a neutral coating in areas of the bare substrate to form a chemo-epitaxy pattern comprising neutral and pinned areas; viim) applying a block copolymer comprising an etch-resistant block and a highly etchable block onto the chemo-epitaxy pattern and annealing until directed self-assembly occurs; and viii) etching the block copolymer, thereby removing highly etchable blocks of the copolymer that cover areas of the substrate and simultaneously forming a pattern in the substrate selectively in these areas; A method comprising:

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