Alkali-soluble gap filling material forming composition for lithography

Abstract

This gap filling material forming composition is used in manufacturing a semiconductor device by a method for coating a substrate having a hole having an aspect ratio represented by height / diameter of 1 or more with a photoresist and transferring an image onto the substrate using a lithography process, and is coated on the substrate before the substrate is coated with the photoresist. The gap filling material forming composition is characterized by containing a polymer and one or more types selected from a cross-linker and a curing catalyst, the polymer including at least one type of polymer selected from a polymer having a specific partial structure, a polymer having a specific structural unit, and a polyamic acid.

Description

Gap fill material forming composition for alkali-soluble lithography

[0001] The present invention relates to a novel gap fill material forming composition for lithography. More specifically, it provides a gap fill material for lithography that exhibits excellent planarization properties on substrates with irregularities such as holes and trenches, is soluble in alkaline aqueous solutions, does not undergo intermixing with the photoresist layer, and yields excellent resist patterns.

[0002] Conventionally, in the manufacturing of semiconductor devices, microfabrication is performed by lithography using photoresist compositions. This microfabrication method involves forming a thin film of photoresist composition on a silicon wafer, and then irradiating it with active light such as ultraviolet light through a mask pattern on which the semiconductor device pattern is drawn, developing the photoresist pattern, and using the resulting photoresist pattern as a protective film to etch the silicon wafer. However, in recent years, as the integration density of semiconductor devices has increased, the active light used has tended to become shorter wavelength, from i-line (365 nm) to KrF excimer laser (248 nm). Along with this, the effects of diffuse reflection and standing waves of the active light from the substrate have become a major problem. Therefore, a method of providing an anti-reflective coating (Bottom Anti-Reflective Coating, BARC) between the photoresist and the substrate has been widely investigated.

[0003] As anti-reflective coatings, inorganic anti-reflective coatings such as titanium, titanium dioxide, titanium nitride, chromium oxide, carbon, and α-silicon, and organic anti-reflective coatings composed of absorbent substances and polymer compounds are known. The former requires equipment such as vacuum deposition apparatus, CVD apparatus, and sputtering apparatus for film formation, while the latter is advantageous because it does not require special equipment, and numerous studies have been conducted on it. Examples include acrylic resin type anti-reflective coatings having a hydroxyl group (a crosslinking reactive group) and an absorbent group in the same molecule, and novolac resin type anti-reflective coatings having a hydroxyl group (a crosslinking reactive group) and an absorbent group in the same molecule (see, for example, Patent Documents 1 and 2).

[0004] Desired properties for organic anti-reflective coating materials include high absorbance to light and radiation, no intermixing with the photoresist layer (insolubility in photoresist solvent), no low-molecular-weight diffusers from the anti-reflective coating material into the topcoat photoresist during coating or heat drying, and a higher dry etching rate compared to photoresist (see, for example, Non-Patent Documents 1, 2, and 3).

[0005] However, when it comes to LSI pattern rules with a fineness of 0.13 μm or less, wiring delay has a greater impact on the LSI's speed, making it difficult to advance the performance of LSIs with current LSI process technology. One material used to reduce wiring delay is the wiring material Cu. The technology introduced to change the wiring material from Al to Cu is the dual damascene process (see, for example, Patent Document 3). In this process, an anti-reflective coating is used on a substrate with a larger aspect ratio (roughness) compared to a conventional Al wiring material substrate.

[0006] In addition to the properties described above, the required characteristics for anti-reflective coating materials for dual damascene processes include controlling the coverage of the anti-reflective coating on the substrate around the holes. Furthermore, when the anti-reflective coating is applied to a constant thickness, it must have high absorbance to light and radiation, and high planarity that is independent of the uneven shape of the substrate. However, it is becoming increasingly difficult to use organic anti-reflective coating materials as anti-reflective coating materials for dual damascene processes.

[0007] Therefore, a process using two layers has been proposed: an inorganic or organic anti-reflective coating with high absorbance to light and radiation, and a lithography gap-fill material for planarization. The lithography gap-fill material is a gap-filling material, that is, a filler or planarizing material. Gap-fill material forming compositions using polymer solutions effective for the dual damascene process are known (see, for example, Patent Document 4). In addition, certain types of filling compositions are known (see, for example, Patent Document 5).

[0008] In processes using gap fill materials, a gap fill material composition is generally applied to a substrate with irregularities such as holes, fired, and a gap fill material layer is formed. After that, excess gap fill material layer is removed by etching, i.e., etch-back. Etching-back allows for obtaining a gap fill material layer of the desired thickness and also makes it possible to flatten the surface of the gap fill material layer. Then, a photoresist layer is formed either directly on this gap fill material layer or after forming an anti-reflective film layer, and the substrate is processed by a subsequent lithography process.

[0009] Etching back is generally performed by dry etching. In this case, the substrate with the gap fill material layer formed on it must first be moved from the coat and developer equipment (coating and developing equipment) to the dry etching equipment for dry etching back, and then returned to the coat and developer equipment for the formation of the anti-reflective film or photoresist layer. In other words, the need to move the substrate between two pieces of equipment for etch-back has been cited as a drawback of this process, as it leads to a decrease in production efficiency.

[0010] U.S. Patent No. 5,919,599, U.S. Patent No. 5,693,691, U.S. Patent No. 6,057,239, International Publication No. 02 / 05035, Japanese Patent Publication No. 2002-47430, International Publication No. 2004 / 061526

[0011] Tom Lynch et al., "Properties and Performance of Near UV Reflectivity Control Layers," (USA), in Advances in Resist Technology and Processing XI, edited by Omkaram Nalamasu, Proceedings of SPIE, 1994, Vol. 2195, p. 225-229 G. Taylor et al., "Methacrylate Resist and Antireflective Coatings for 193nm Lithography," (USA), in Microlithography 1999: Advances in Resist Technology and Processing XVI, edited by Will Conley, Proceedings of SPI SPIE), 1999, Vol. 3678, p. 174-185 Jim D. Meador et al., "Recent Progress in 193nm Antireflective Coatings," (USA), in Microlithography 1999: Advances in Resist Technology and Processing XVI, edited by Will Conley, Proceedings of SPISPIE), 1999, Vol. 3678, pp. 800-809

[0012] Therefore, a process has been proposed in which the etch-back of the gap fill material layer is performed using an alkaline aqueous solution (see, for example, Patent Document 6). This process makes it possible to perform a series of steps, from coating the gap fill material composition to etch-back and formation of the photoresist layer, using a coat and developer device (coating and developing device), thereby significantly improving production efficiency.

[0013] The required properties for gap fill materials that enable etch-back with alkaline aqueous solutions, i.e., gap fill materials for alkaline lithography, include the ability to flatten substrates with a large aspect ratio (roughness), the gap fill material layer having appropriate solubility (etch-back properties) in alkaline aqueous solutions, the gap fill material layer being insoluble in the solvent used in the anti-reflective film or photoresist composition after etch-back (no intermixing with the anti-reflective film layer or photoresist layer), the absence of low-molecular-weight diffusers from the gap fill material layer to the topcoat anti-reflective film or photoresist layer during heat drying, and having a higher dry etching rate compared to photoresist.

[0014] The object of the present invention is to provide a novel gap fill material forming composition for lithography that can fully satisfy the above requirements. Furthermore, the present invention is to provide a novel gap fill material forming composition for lithography that has excellent planarization properties on substrates with irregularities such as holes and trenches, is soluble in alkaline aqueous solutions, does not undergo intermixing with the photoresist layer, and yields an excellent resist pattern.

[0015] In order to solve the above problems, the present inventors conducted intensive studies and as a result, found that the above problems can be solved, and completed the present invention having the following gist. That is, the present invention includes the following. [1] In the manufacture of a semiconductor device by a method of coating a substrate having a hole with an aspect ratio of height / diameter of 1 or more with a photoresist and transferring an image onto the substrate using a lithography process, a gap filling material forming composition coated on the substrate before coating the photoresist, which contains one or more selected from a polymer, a crosslinking agent, and a curing catalyst, and the polymer contains at least one polymer selected from a polymer having a partial structure represented by the following formula (A), a polymer having a structural unit represented by the following formula (B), and a polyamic acid. A gap filling material forming composition characterized by the above. [In formula (A), R １１ represents a single bond or a divalent group having 1 to 4 carbon atoms. R １２ and R １３ each independently represent a hydrogen atom, a hydroxy group, or a methyl group. * represents a bond. ] [In formula (B), R １ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R ２ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, R ３ represents an optionally substituted alkyl group having 1 to 10 carbon atoms, R ２ and R ３ are R ２ and R ３[1] The gap fill material forming composition according to [1], wherein the carbon atoms and oxygen atoms between them may form a ring, and the ring may contain heteroatoms other than the oxygen atoms. [2] The gap fill material forming composition according to [1], wherein the weight-average molecular weight of the polymer is 500 to 30000. [3] The gap fill material forming composition according to [1] or [2], wherein the polymer having the substructure represented by formula (A) has the substructure represented by formula (A) in its main chain. [4] The gap fill material forming composition according to [1] or [2], wherein the polymer having the substructure represented by formula (A) has the substructure represented by formula (A) in its side chain. [5] The gap fill material forming composition according to any one of [1] to [4], wherein the polymer does not have an aromatic ring structure in its structure. [6] The gap fill material forming composition according to any one of [1] to [5], wherein the crosslinking agent or curing catalyst has at least two crosslinking functional groups. [7] The gap fill material forming composition according to any one of [1] to [6], further containing an alkaline dissolution rate modifier. [8] A method for forming a gap fill material layer for use in the manufacture of a semiconductor device, comprising coating a gap fill material forming composition according to any one of [1] to [7] onto a substrate and firing it. [9] A gap fill material layer obtained by coating a gap fill material forming composition according to any one of [1] to [7] onto a semiconductor substrate and firing it, wherein the dissolution rate in an alkaline aqueous solution with a concentration of 0.1% to 20% is 3 to 500 nm per second.

[0016] The present invention relates to a gap fill material forming composition for lithography, aimed at providing planarity to hole substrates. The gap fill material layer obtained from the gap fill material forming composition of the present invention has not only a suitable alkaline dissolution rate for substrate planarization and etch-back with an alkaline aqueous solution, but also a high etching rate. Furthermore, the gap fill material layer of the present invention can fill in the irregularities of a hole substrate and planarize it, and the planarity can be enhanced by etch-back with an alkaline aqueous solution, thereby increasing the uniformity of the film thickness of a coating film such as a photoresist applied thereon. The gap fill material forming composition of the present invention provides an excellent lithography gap fill material layer that has a large dry etching rate compared to a photoresist layer, does not cause intermixing with the photoresist layer, and does not contain diffused material into the photoresist during heat drying.In addition, since the gap fill material layer formed from the gap fill material forming composition of the present invention can be etch-backed with an alkaline aqueous solution, the process from gap fill material layer formation to photoresist layer formation can be performed using a coat and developer device (coating and developing device). This eliminates the need for the conventional step of transferring the material to a dry etching apparatus for etch-back. Therefore, by using the gap fill material composition of the present invention, it is possible to improve production efficiency.

[0017] This figure shows the manufacturing process using the gap fill material forming composition of the present invention. This figure shows one of the states of the gap fill material layer after etch-back with an alkaline aqueous solution. This figure shows one of the states of the gap fill material layer after etch-back with an alkaline aqueous solution. This figure shows one of the states of the gap fill material layer after etch-back with an alkaline aqueous solution. This is a schematic diagram showing the cross-sectional shape of the hole substrate used in the example. This is an SEM image showing the cross-section of the hole substrate in which the gap fill material forming composition of Example 1 is embedded. This is an SEM image showing the cross-section of the hole substrate in which the gap fill material forming composition of Example 1 is embedded after being immersed in an alkaline solvent.

[0018] (Gap Fill Material Forming Composition) The present invention relates to a gap fill material forming composition used in the manufacture of a semiconductor device by a method of coating a substrate having holes with an aspect ratio of 1 or more, indicated by height / diameter, with a photoresist and transferring an image onto the substrate using a lithography process, and is coated onto the substrate before coating with the photoresist, characterized in that it contains one or more selected from a polymer, a crosslinking agent and a curing catalyst. The lithography gap fill material forming composition of the present invention may also be used in a dual damascene process for introducing Cu (copper) wiring material used to reduce wiring delay in semiconductor devices.

[0019] The gap-fill material forming composition of the present invention basically contains a polymer and one or more selected from a crosslinking agent and a curing catalyst, and optionally contains a solvent, surfactant, alkali dissolution rate modifier, etc.

[0020] The solid content of the gap fill material forming composition of the present invention is, for example, 0.1 to 70% by mass, 0.1 to 50% by mass, and also, for example, 0.5 to 50% by mass. Here, the solid content is the total components of the gap fill material forming composition excluding the solvent components.

[0021] The content of the polymer component in the gap fill material forming composition of the present invention is, for example, 1 to 99% by mass, for example, 20 to 80% by mass, and for example, 30 to 70% by mass, based on the solid content.

[0022] <Polymers> The polymer includes at least one polymer selected from a polymer having a substructure represented by the following formula (A) (hereinafter also referred to as "polymer (A)"), a polymer having a structural unit represented by the following formula (B) (hereinafter also referred to as "polymer (B)"), and polyamic acid (hereinafter also referred to as "polymer (C)"). [In formula (A), R １１ R represents a single bond or a divalent group with 1 to 4 carbon atoms. １２ and R １３ Each of these independently represents a hydrogen atom, a hydroxyl group, or a methyl group. * represents a bonding bond. [In formula (B), R １ R represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. ２ R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. ３ R represents an alkyl group having 1 to 10 carbon atoms, which may be substituted. ２ and R ３ R ２ and R ３ The carbon and oxygen atoms between them may form a ring, and this ring may contain heteroatoms other than the oxygen atoms.

[0023] <<Polymer (A)>> Polymer (A) has a substructure represented by the following formula (A). [In formula (A), R １１ R represents a single bond or a divalent group with 1 to 4 carbon atoms. １２ and R １３ Each of these independently represents a hydrogen atom, a hydroxyl group, or a methyl group. * represents a bonding bond.

[0024] Polymer (A) may have a substructure represented by formula (A) in its main chain, or it may have a substructure represented by formula (A) in its side chains.

[0025] The polymer (A) preferably has a structural unit represented by the following formula (A-1). For example, the substructure represented by formula (A) is a part of the structural unit represented by the following formula (A-1). [In formula (A-1), A １ A ２ A ３ A ４ A ５ and A ６ Each of these independently represents a hydrogen atom, a methyl group, or an ethyl group, and Q represents a divalent organic group. １１ R represents a single bond or a divalent group with 1 to 4 carbon atoms. １２ and R １３ Each of these independently represents a hydrogen atom, a hydroxyl group, or a methyl group.

[0026] <<<R １１ >>> In equations (A) and (A-1), R １１R represents a single bond or a divalent group with 1 to 4 carbon atoms. １１ The number of carbon atoms in R is 1 to 4, and may be 1 to 3, 1 or 2, or 1. １１ Examples include divalent hydrocarbon groups having 1 to 4 carbon atoms, which may be substituted with a hydroxyl group. １１ If R has a hydroxyl group, １１ The number of hydroxyl groups it has is, for example, R １１ It is less than or equal to the number of carbon atoms it has. １１ From the viewpoint of suitably obtaining the effects of the present invention, it is preferable that the group represents a divalent group having 1 to 4 carbon atoms, and that the divalent group has a hydroxyl group.

[0027] <<<R １２ and R １３ >>> In equations (A) and (A-1), R １２ and R １３ Each of these independently represents a hydrogen atom, a hydroxyl group, or a methyl group, preferably a hydrogen atom or a hydroxyl group.

[0028] Examples of substructures represented by formula (A) include the following: * represents a combination.

[0029] <<<Q>>> In formula (A-1), Q represents a divalent organic group. The divalent organic group is not particularly limited, but a divalent organic group having a heteroatom is preferred, and a divalent organic group having a nitrogen atom and an oxygen atom is more preferred. Examples of heteroatoms include a nitrogen atom, an oxygen atom, and a sulfur atom. The number of carbon atoms in the divalent organic group is not particularly limited, but 3 to 30 carbon atoms is preferred, and 3 to 20 carbon atoms is more preferred.

[0030] As for Q, from the viewpoint of suitably obtaining the effects of the present invention, it is preferable that it be represented by either formula (A-11) or formula (A-12) below. (In formula (A-11), X １ This represents a divalent group represented by the following formula (A-11-1), formula (A-11-2), or formula (A-11-3). １ and Z２ Each of these independently represents a single bond or a divalent group represented by the following formula (A-11-4). * represents a bond. In formula (A-12), Q １ represents a divalent group having an aromatic hydrocarbon ring or an aliphatic hydrocarbon ring. n1 and n2 each independently represent 0 or 1. * represents a bond. (In formulas (A-11-1) to (A-11-3), R １ ~R ５ Each independently represents a C1-C10 alkyl group that may be interrupted by a hydrogen atom, an oxygen atom, or a sulfur atom, a C2-C10 alkenyl group that may be interrupted by an oxygen atom or a sulfur atom, an alkynyl group that may be interrupted by an oxygen atom or a sulfur atom, a benzyl group, or a phenyl group, wherein the phenyl group may be substituted with at least one monovalent group selected from the group consisting of C1-C6 alkyl groups, halogen atoms, C1-C6 alkoxy groups, nitro groups, cyano groups, and C1-C6 alkylthio groups. １ and R ２ These may be bonded to each other to form a ring with 3 to 6 carbon atoms. ３ and R ４ These atoms may bond to each other to form a ring with 3 to 6 carbon atoms. * represents a bond. *1 represents a bond to a carbon atom. *2 represents a bond to a nitrogen atom. (In formula (A-11-4), m1 is an integer from 1 to 4, and m2 is 0 or 1. *3 represents a bond to the nitrogen atom. *4 represents a bond to the carbon atom.)

[0031] Q in equation (A-12) １ It is preferable that it be represented by any of the following formulas (A-12-1) to (A-12-4). (In formulas (A-12-1) to (A-12-4), R ３１ ~R ３６Each of these independently represents a halogen atom, a hydroxyl group, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkenyloxy group having 2 to 6 carbon atoms, an alkynyloxy group having 2 to 6 carbon atoms, an acyl group having 2 to 6 carbon atoms, an aryloxy group having 6 to 12 carbon atoms, an arylcarbonyl group having 7 to 13 carbon atoms, or an aralkyl group having 7 to 13 carbon atoms. * represents a bond. In formula (A-12-1), n3 represents 0 or 1. When n3 is 0, n11 represents an integer from 0 to 4. When n3 is 1, n11 represents an integer from 0 to 6. R ３１ When R is 2 or more, ３１ They may be the same or they may be different. In equation (A-12-2), Z １ n12 and n13 each independently represent integers from 0 to 4. ３２ When R is 2 or more, ３２ They may be the same or they may be different. ３３ When R is 2 or more, ３３ They may be the same or they may be different. In equation (A-12-3), Y １ and Y ２ Each of these independently represents a single bond or an alkylene group with 1 to 6 carbon atoms. n14 represents an integer from 0 to 4. ３４ When R is 2 or more, ３４ They may be the same or they may be different. In equation (A-12-4), Z ２ n15 and n16 each independently represent integers from 0 to 4. ３５ When R is 2 or more, ３５ They may be the same or they may be different. ３６ When R is 2 or more, ３６ They may be the same or they may be different.

[0032] For example, Q in equation (A-11) can be represented by the following structure. * represents a coupling.

[0033] When polymer (A) has a structural unit represented by formula (A-1), the mass percentage of the structural unit represented by formula (A-1) in polymer (A) is not particularly limited, but is preferably 50% to 100% by mass, more preferably 75% to 100% by mass, and particularly preferably 90% to 100% by mass.

[0034] The method for producing polymer (A) is not particularly limited, but one example is a method of reacting a dicarboxylic acid represented by the following formula (A1) with a diexope compound represented by the following formula (A2). In this case, a polymer having a structural unit represented by formula (A-1) is obtained.

[0035] Catalysts that activate epoxy groups include, for example, quaternary phosphonium salts such as tetrabutylphosphonium bromide and ethyltriphenylphosphonium bromide, and quaternary ammonium salts such as benzyltriethylammonium chloride. The amount of catalyst used can be selected from a range of 0.1 to 10% by mass relative to the total mass of the polymer raw materials used in the reaction. The temperature and time for the polymerization reaction can be selected to the optimal conditions, for example, from a range of 80 to 160°C and 2 to 50 hours.

[0036] (In formula (A1), R １１ , R １２ and R １３ These are R in equation (A-1), respectively. １１ , R １２ and R １３ (This is synonymous.)

[0037] Examples of the dicarboxylic acid represented by the formula (A1) include tartaric acid, malic acid, tartronic acid, citramalic acid, dioxymaleic acid, mucic acid and the like.

[0038] (In the formula (A2), A １ , A ２ , A ３ , A ４ , A ５ , A ６ and Q are respectively synonymous with A １ , A ２ , A ３ , A ４ , A ５ , A ６ and Q in the formula (A-1).)

[0039] <<Polymer (B)>> The polymer (B) has a structural unit represented by the following formula (B). [In the formula (B), R １ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R ２ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, R ３ represents an optionally substituted alkyl group having 1 to 10 carbon atoms, R ２ and R ３ may together with the carbon and oxygen atoms between R ２ and R ３ form a ring, and the ring may contain a hetero atom other than the oxygen atom.]

[0040] Examples of the alkyl group having 1 to 3 carbon atoms in R １ include a methyl group, an ethyl group, and a propyl group. Examples of the alkyl group having 1 to 4 carbon atoms in R ２ include a methyl group, an ethyl group, a propyl group, and a butyl group. R ３Examples of substituents in the C1-C10 alkyl group, which may be substituted, include halogen atoms, C1-C6 alkoxy groups, and aromatic groups. Examples of aromatic groups include aromatic hydrocarbon groups. Examples of aromatic hydrocarbon groups include phenyl groups and naphthyl groups. In the present invention, examples of halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms.

[0041] R ２ and R ３ R ２ and R ３ The carbon and oxygen atoms between them may form a ring, and this ring may contain heteroatoms other than the oxygen atom. Examples of such rings include 4-membered to 7-membered rings. Examples of such rings include cyclic ethers, lactone rings, and cyclic carbonates. Examples of heteroatoms that the ring may contain include oxygen atoms, nitrogen atoms, and sulfur atoms.

[0042] R １ Hydrogen atoms and methyl groups are preferred. ２ As such, methyl groups and ethyl groups are preferred. ３ Preferably, the alkyl group has 1 to 6 carbon atoms, and more preferably, an alkyl group has 1 to 4 carbon atoms.

[0043] The inventors believe that the acetal structure of formula (B) acts as a protecting group for carboxyl groups, imparting solubility to the polymer in solvents while improving the coatability of the gap fill material forming composition. On the other hand, during the process of forming a gap fill material layer from the gap fill material forming composition, the acetal structure is removed (for example, by heat or catalyst), generating carboxyl groups. The generated carboxyl groups, by reacting with each other or with the crosslinking agent in the presence of a crosslinking agent, impart solvent resistance to the gap fill material layer. Furthermore, the generated carboxyl groups facilitate the removal of the gap fill material layer by an alkaline aqueous solution. Therefore, the gap fill material layer obtained from the gap fill material forming composition exhibits good solvent resistance. In addition, the gap fill material layer obtained from the gap fill material forming composition can be removed by an alkaline aqueous solution.

[0044] Examples of structural units represented by formula (B) include the following structural units. Among the following structural units, R １ This represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, preferably a hydrogen atom or a methyl group.

[0045] The structural unit represented by formula (B) originates, for example, from the compound represented by the following formula (B1). [In formula (B1), R １ , R ２ , and R ３ These are R in equation (B), respectively. １ , R ２ , and R ３ This is synonymous with [the above].

[0046] Polymer (B) may contain structural units other than the structural unit represented by formula (B). Examples of such structural units include structural units derived from (meth)acrylic acid ester compounds, (meth)acrylamide compounds, or styrene compounds. In this invention, (meth)acrylic acid ester compounds mean acrylic acid ester compounds or methacrylic acid ester compounds. The same applies to (meth)acrylamide compounds.

[0047] Examples of structural units derived from (meth)acrylic acid ester compounds include the structural unit represented by the following formula (B-1). Examples of structural units derived from (meth)acrylamide compounds include the structural unit represented by the following formula (B-2). Examples of structural units derived from styrene compounds include the structural unit represented by the following formula (B-3). [In formulas (B-1) to (B-3), R １１ R represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. １２ R represents a monovalent group with 1 to 20 carbon atoms. １３ R represents a hydrogen atom or a monovalent group having 1 to 20 carbon atoms. １４ Each of these independently represents a halogen atom, a hydroxyl group, a carboxyl group, a cyano group, a nitro group, or a monovalent group with 1 to 10 carbon atoms. m represents an integer from 0 to 5.

[0048] R １２ and R １３ The number of carbon atoms in R may be 1 to 20 or 1 to 10. １２ and R １３ The monovalent group having 1 to 20 carbon atoms in the compound may have a heteroatom. Examples of heteroatoms include oxygen atoms and nitrogen atoms. １２ and R １３ The monovalent group having 1 to 20 carbon atoms in the compound may have an aromatic ring. Examples of aromatic rings include aromatic hydrocarbon rings and aromatic heterocycles. Examples of aromatic hydrocarbon rings include benzene rings and naphthalene rings. １２ and R １３The monovalent group having 1 to 20 carbon atoms in R may, for example, have a halogen atom, a hydroxyl group, a carboxyl group, a cyano group, a nitro group, an epoxy group, etc. １２ and R １３ Examples of monovalent groups having 1 to 20 carbon atoms include optionally substituted alkyl groups and optionally substituted aromatic groups. Examples of substituents on optionally substituted alkyl groups include halogen atoms, hydroxyl groups, carboxyl groups, cyano groups, nitro groups, epoxy groups, and optionally substituted aromatic groups. Examples of substituents on optionally substituted aromatic groups include halogen atoms, hydroxyl groups, carboxyl groups, cyano groups, nitro groups, epoxy groups, optionally substituted C1 to C6 alkyl groups, and optionally substituted C1 to C6 alkoxy groups. Examples of C1 to C6 alkyl groups include methyl groups, ethyl groups, propyl groups, and butyl groups. Examples of C1 to C6 alkoxy groups include methoxy groups, ethoxy groups, propoxy groups, and butoxy groups.

[0049] R １４ The monovalent group having 1 to 10 carbon atoms in R may have a heteroatom. Examples of heteroatoms include oxygen atoms and nitrogen atoms. １４ The monovalent group having 1 to 10 carbon atoms in R may, for example, have a halogen atom, a hydroxyl group, a carboxyl group, a cyano group, a nitro group, an epoxy group, and the like. １４ Examples of monovalent groups having 1 to 10 carbon atoms include alkyl groups having 1 to 6 carbon atoms that may be substituted with halogen atoms, and alkoxy groups having 1 to 6 carbon atoms that may be substituted with halogen atoms. Examples of alkyl groups having 1 to 6 carbon atoms include methyl groups, ethyl groups, propyl groups, and butyl groups. Examples of alkoxy groups having 1 to 6 carbon atoms include methoxy groups, ethoxy groups, propoxy groups, and butoxy groups.

[0050] Specific examples of acrylic acid ester compounds include, but are not limited to, methyl acrylate, ethyl acrylate, n-hexyl acrylate, i-propyl acrylate, cyclohexyl acrylate, benzyl acrylate, phenyl acrylate, 4-hydroxyphenyl acrylate, anthyl methyl acrylate, 2,2,2-trifluoroethyl acrylate, 2,2,2-trichloroethyl acrylate, 2-bromoethyl acrylate, 2-methoxyethyl acrylate, tetrahydrofurfuryl acrylate, 2-methyl-2-adamantyl acrylate, 3-acryloxypropyltriethoxysilane, and glycidyl acrylate.

[0051] Specific examples of methacrylic acid ester compounds include, but are not limited to, methyl methacrylate, ethyl methacrylate, n-hexyl methacrylate, i-propyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, phenyl methacrylate, 4-hydroxyphenyl acrylate, anthyl methyl methacrylate, 2,2,2-trifluoroethyl methacrylate, 2,2,2-trichloroethyl methacrylate, 2-bromoethyl methacrylate, 2-methoxyethyl methacrylate, tetrahydrofurfuryl methacrylate, 2-methyl-2-adamantyl methacrylate, 3-methacryloxypropyltriethoxysilane, glycidyl methacrylate, 2-phenylethyl methacrylate, and bromophenyl methacrylate.

[0052] Specific examples of acrylamide compounds include, but are not limited to, acrylamide, N-methylacrylamide, N-ethylacrylamide, N-benzylacrylamide, N-phenylacrylamide, N-(4-hydroxyphenyl)acrylamide, N,N-dimethylacrylamide, and N-antrylcrylamide.

[0053] Specific examples of methacrylamide compounds include, but are not limited to, methacrylamide, N-methylmethacrylamide, N-ethylmethacrylamide, N-benzylmethacrylamide, N-phenylmethacrylamide, N-(4-hydroxyphenyl)methacrylamide, N,N-dimethylmethacrylamide, and N-antlylmethacrylamide.

[0054] Specific examples of styrene compounds include, but are not limited to, styrene, chlorostyrene, bromostyrene, methoxystyrene, cyanostyrene, and acetylstyrene.

[0055] Polymer (B) may further have other structural units. Examples of monomers that induce such structural units include, but are not limited to, acrylic acid, methacrylic acid, vinyl compounds, maleimide compounds, maleic anhydride, and acrylonitrile.

[0056] Specific examples of vinyl compounds include, but are not limited to, vinyl alcohol, 2-hydroxyethyl vinyl ether, methyl vinyl ether, ethyl vinyl ether, benzyl vinyl ether, vinyl acetic acid, vinyl trimethoxysilane, 2-chloroethyl vinyl ether, 2-methoxyethyl vinyl ether, vinyl naphthalene, and vinyl anthracene.

[0057] Examples of maleimide compounds include, but are not limited to, maleimide, N-methylmaleimide, N-phenylmaleimide, N-cyclohexylmaleimide, N-benzylmaleimide, and N-hydroxyethylmaleimide.

[0058] The lower limit of the molar ratio of structural units represented by formula (B) to the total structural units of polymer (B) is not particularly limited, but from the viewpoint of suitably obtaining the effects of the present invention, the molar ratio of structural units represented by formula (B) is preferably 20 mol% or more, more preferably 45 mol% or more, and particularly preferably 65 mol% or more. The upper limit of the molar ratio of structural units represented by formula (B) to the total structural units of polymer (B) is not particularly limited, but from the viewpoint of suitably obtaining the effects of the present invention, the molar ratio of structural units represented by formula (B) is preferably 100 mol% or less, more preferably 95 mol% or less, and particularly preferably 90 mol% or less.

[0059] The lower limit of the molar ratio of the total structural units derived from (meth)acrylic acid ester compounds, (meth)acrylamide compounds, and styrene compounds (hereinafter sometimes referred to as "total structural units (B2)") relative to the total structural units of polymer (B) is not particularly limited, but from the viewpoint of suitably obtaining the effects of the present invention, the molar ratio of total structural units (B2) is preferably greater than 0 mol%, and more preferably 10 mol% or more. The upper limit of the molar ratio of total structural units (B2) relative to the total structural units of polymer (B) is not particularly limited, but from the viewpoint of suitably obtaining the effects of the present invention, the molar ratio of total structural units (B2) is preferably 60 mol% or less, and more preferably 45 mol% or less.

[0060] The molar ratio of the total structural units (B2) represented by formula (B) to the total structural units (B2) of polymer (B) is not particularly limited, but from the viewpoint of suitably obtaining the effects of the present invention, 80 mol% to 100 mol% is preferred, and 90 mol% to 100 mol% is more preferred.

[0061] Polymer (B) may be a homopolymer or a copolymer. If polymer (B) is a copolymer, polymer (B) may be a random copolymer or a block copolymer.

[0062] The method for producing polymer (B) is not particularly limited. Polymer (B) can be produced by polymerizing monomers by conventional methods, such as bulk polymerization, solution polymerization, suspension polymerization, or emulsion polymerization. Solution polymerization is particularly preferred, in which case monomers can be polymerized using, for example, a polymerization initiator. Organic peroxides and diazo compounds can be used as polymerization initiators.

[0063] Examples of organic peroxides include diacyl peroxides, peroxydicarbonates, peroxyesters, and sulfonate peroxides. Examples of diacyl peroxides include diacetyl peroxide, diisobutyl peroxide, didecanoyl peroxide, benzoyl peroxide, and succinate peroxide. Examples of peroxydicarbonates include diisopropyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, and diallyl peroxydicarbonate. Examples of peroxyesters include tert-butyl peroxyisobutyrate, tert-butyl neodecanate, and cumene peroxyneodecanate. Examples of sulfonate peroxides include acetylcyclohexylsulfonyl peroxide.

[0064] Examples of diazo compounds include 2,2'-azobisisobutyronitrile, 2,2'-azobis(isobutyrate)dimethyl, 4,4'-azobis(4-cyanovaleric acid), 2,2'-azobis(4-methoxy-2,4-dimethoxyvaleronitrile), and 2,2'-azobis(2-cyclopropylpropionitrile).

[0065] If polymerization is to be completed in a short time, it is preferable to use a polymerization initiator that has a decomposition half-life of 10 hours or less at 80°C. Suitable polymerization initiators include benzoyl peroxide and 2,2'-azobisisobutyronitrile, with 2,2'-azobisisobutyronitrile being more preferred.

[0066] The amount of polymerization initiator used is, for example, 0.0001 to 0.2 equivalents, preferably 0.0005 to 0.1 equivalents, relative to the total amount of monomer used.

[0067] The solvent used for polymerization is not particularly limited as long as it does not participate in the polymerization reaction and is compatible with the resulting polymer. Examples include aromatic hydrocarbons, alicyclic hydrocarbons, aliphatic hydrocarbons, ketones, ethers, esters, amides, sulfoxides, alcohols, and polyhydric alcohol derivatives. Examples of aromatic hydrocarbons include benzene, toluene, and xylene. Examples of alicyclic hydrocarbons include cyclohexane. Examples of aliphatic hydrocarbons include n-hexane and n-octane. Examples of ketones include acetone, methyl ethyl ketone, and cyclohexanone. Examples of ethers include tetrahydrofuran and dioxane. Examples of esters include ethyl acetate and butyl acetate. Examples of amides include N,N-dimethylformamide and N,N-dimethylacetamide. Examples of sulfoxides include dimethyl sulfoxide. Examples of alcohols include methanol and ethanol. Examples of polyhydric alcohol derivatives include ethylene glycol monomethyl ether, propylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate, and propylene glycol monomethyl ether acetate. These can be used individually or in combination of two or more.

[0068] The polymerization temperature is not particularly limited as long as it is within a temperature range where side reactions such as transfer reactions and termination reactions do not occur, and the monomer is consumed and polymerization is completed. However, it is preferable that the polymerization is carried out in a temperature range of -100°C or higher and below the boiling point of the solvent. The concentration of monomer in the solvent is not particularly limited, but is usually 1 to 40% by mass, and preferably 10 to 30% by mass. The polymerization reaction time can be appropriately selected, but is usually in the range of 2 to 50 hours.

[0069] <<Polymer (C)>> Polymer (C) is a polyamic acid. A polyamic acid has a structure represented by, for example, the following formula (1).

[0070] [In formula (1), A １ represents a tetravalent organic group, B １ This represents a trivalent organic group.

[0071] Furthermore, polymer (C) may be a polymer having a structure represented by formula (1) above and a structure represented by formula (2) below.

[0072] [In formula (2), A ２ represents a tetravalent organic group, B ２ This represents a divalent organic group.

[0073] In equation (1), A １ represents a tetravalent organic group, B １ represents a trivalent organic group. A １ Examples include formulas (3) to (10) (wherein X represents an alkyl group having 1 to 5 carbon atoms, a chlorine atom, a bromine atom, a fluorine atom, an alkoxy group having 1 to 5 carbon atoms, a hydroxyl group, a carboxyl group, a phenoxy group, a trifluoromethyl group, or a nitro group, and m represents the number 0, 1, or 2).

[0074] * represents a coupling.

[0075] B １ Examples include formulas (11) to (18) (wherein Y represents an alkyl group having 1 to 5 carbon atoms, a chlorine atom, a bromine atom, a fluorine atom, an alkoxy group having 1 to 5 carbon atoms, a hydroxyl group, a carboxyl group, a phenoxy group, a trifluoromethyl group, or a nitro group, and m represents the number 0, 1, or 2).

[0076] * represents a coupling.

[0077] In equation (2), A ２ represents a tetravalent organic group, B ２ This represents a divalent organic group. A ２ Examples include equations (3) to (10). B２ Examples include formulas (19) to (28) (wherein Z represents an alkyl group having 1 to 5 carbon atoms, a chlorine atom, a bromine atom, a fluorine atom, an alkoxy group having 1 to 5 carbon atoms, a hydroxyl group, a carboxyl group, a phenoxy group, a trifluoromethyl group, or a nitro group, and m represents the number 0, 1, or 2).

[0078] * represents a coupling.

[0079] The method for obtaining polymer (C) contained in the gap fill material forming composition of the present invention is not particularly limited and can be produced by existing methods. For example, polymer (C) can be produced by reacting and polymerizing a diamine compound with a tetracarboxylic acid or its derivative, such as a tetracarboxylic dianhydride compound or a dicarboxylic acid dihalide. Alternatively, polymer (C) can be produced by synthesizing a polymer (C) silyl ester by polymerization using a bissilylated diamine compound and a tetracarboxylic dianhydride compound, and then decomposing the silyl ester portion with an acid.

[0080] The polymer (C) contained in the gap fill material forming composition of the present invention can be produced from (a) a tetracarboxylic dianhydride compound and (b) a diamine compound having at least one carboxyl group, or from (a) a tetracarboxylic dianhydride compound, (b) a diamine compound having at least one carboxyl group, and (c) a diamine compound.

[0081] The (a) tetracarboxylic dianhydride compounds used in the production of polymer (C) in the present invention are not particularly limited, and may be used individually or two or more simultaneously. Specific examples include aromatic tetracarboxylic acids such as pyromellitic dianhydride, 3,3'-,4,4'-biphenyltetracarboxylic dianhydride, 3,3'-,4,4'-benzophenonetetracarboxylic dianhydride, 3,3'-,4,4'-diphenylethertetracarboxylic dianhydride, and 3,3'-,4,4'-diphenylsulfonetetracarboxylic dianhydride, as well as 1,2,3,4-cyclobutanetetracarboxylic dianhydride and 1,2-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid Examples include alicyclic tetracarboxylic dianhydrides such as dianhydrides, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,3,4-cyclohexanetetracarboxylic dianhydride, and 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalenesuccinic acid dianhydride, as well as aliphatic tetracarboxylic dianhydrides such as 1,2,3,4-butanetetracarboxylic dianhydride.

[0082] The diamine compounds (b) having at least one carboxyl group used in the production of the polymer (C) used in the present invention are not particularly limited, and may be used individually or two or more simultaneously. Specific examples include 2,4-diaminobenzoic acid, 2,5-diaminobenzoic acid, 3,5-diaminobenzoic acid, 4,6-diamino-1,3-benzenedicarboxylic acid, 2,5-diamino-1,4-benzenedicarboxylic acid, bis(4-amino-3-carboxyphenyl) ether, bis(4-amino-3,5-dicarboxyphenyl) ether, bis(4-amino-3-carboxyphenyl) sulfone, bis(4-amino-3,5-dicarboxyphenyl) sulfone, 4,4'-diamino-3,3'-dicarboxybiphenyl, 4,4'-diamino-3,3' Examples include -dicarboxy-5,5'-dimethylbiphenyl, 4,4'-diamino-3,3'-dicarboxy-5,5'-dimethoxybiphenyl, 1,4-bis(4-amino-3-carboxyphenoxy)benzene, 1,3-bis(4-amino-3-carboxyphenoxy)benzene, bis[4-(4-amino-3-carboxyphenoxy)phenyl]sulfone, bis[4-(4-amino-3-carboxyphenoxy)phenyl]propane, and 2,2-bis[4-(4-amino-3-carboxyphenoxy)phenyl]hexafluoropropane.

[0083] Furthermore, there are no particular limitations on the (c) diamine compound used in the production of polymer (C) used in the present invention, but it is a diamine compound different from (b) a diamine compound having at least one carboxyl group. It is preferable that the (c) diamine compound does not have a carboxyl group. Also, one of these may be used, or two or more may be used simultaneously. Specific examples include 2,4-diaminophenol, 3,5-diaminophenol, 2,5-diaminophenol, 4,6-diaminoresorcinol, 2,5-diaminohydroquinone, bis(3-amino-4-hydroxyphenyl) ether, bis(4-amino-3-hydroxyphenyl) ether, bis(4-amino-3,5-dihydroxyphenyl) ether, bis(3-amino-4-hydroxyphenyl)methane, bis(4-amino-3-hydroxyphenyl)methane, bis(4-amino-3,5-dihydroxyphenyl)methane, bis(3-amino-4-hydroxyphenyl)sulfone, bis(4-amino-3-hydroxyphenyl)sulfone, bis(4-amino-3,5-dihydroxyphenyl)sulfone, 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane, 2,2-bis(4-amino-3-hydroxyphenyl)hexafluoropropane, 2,2-bis(4-amino-3, 5-dihydroxyphenyl)hexafluoropropane, 4,4'-diamino-3,3'-dihydroxybiphenyl, 4,4'-diamino-3,3'-dihydroxy-5,5'-dimethylbiphenyl, 4,4'-diamino-3,3'-dihydroxy-5,5'-dimethoxybiphenyl, 1,4-bis(3-amino-4-hydroxyphenoxy)benzene, 1,3-bis(3-amino-4-hydroxyphenoxy)benzene, 1,4-bis(4-amino-3-H Diamine compounds having phenolic hydroxyl groups such as hydroxyphenoxybenzene, 1,3-bis(4-amino-3-hydroxyphenoxy)benzene, bis[4-(3-amino-4-hydroxyphenoxy)phenyl]sulfone, bis[4-(3-amino-4-hydroxyphenoxy)phenyl]propane, 2,2-bis[4-(3-amino-4-hydroxyphenoxy)phenyl]hexafluoropropane, 1,3-diamino-4-mercaptobenzene, 1,Examples include diamine compounds having a thiophenol group, such as 3-diamino-5-mercaptobenzene, 1,4-diamino-2-mercaptobenzene, bis(4-amino-3-mercaptophenyl) ether, and 2,2-bis(3-amino-4-mercaptophenyl)hexafluoropropane; and diamine compounds having a sulfonic acid group, such as 1,3-diaminobenzene-4-sulfonic acid, 1,3-diaminobenzene-5-sulfonic acid, 1,4-diaminobenzene-2-sulfonic acid, bis(4-aminobenzene-3-sulfonic acid) ether, 4,4'-diaminobiphenyl-3,3'-disulfonic acid, and 4,4'-diamino-3,3'-dimethylbiphenyl-6,6'-disulfonic acid. Also, p-phenylenediamine, m-phenylenediamine, 4,4'-methylene-bis(2,6-ethylaniline), 4,4'-methylene-bis(2-isopropyl-6-methylaniline), 4,4'-methylene-bis(2,6-diisopropylaniline), 2,4,6-trimethyl-1,3-phenylenediamine, 2,3,5,6-tetramethyl-1,4-phenylenediamine, o-tolidine, m-tolidine, 3,3'-,5,5'-tetramethylbenzidine, bis[4-(3-aminophenoxy)phenyl]sulfone, 2,2-bis[4-(3-aminophenoxy)phenyl]propane, 2,2-bis[4-(3-aminophenoxy)phenyl]hexafluoropropane, 4,4'-diamino-3,3 Examples of diamine compounds include '-dimethyldicyclohexylmethane, 4,4'-diaminodiphenyl ether, 3,4-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane, 2,2-bis(4-anilino)hexafluoropropane, 2,2-bis(3-anilino)hexafluoropropane, 2,2-bis(3-amino-4-toluyl)hexafluoropropane, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, bis[4-(4-aminophenoxy)phenyl]sulfone, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, and 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane.

[0084] When (b) a diamine compound having at least one carboxyl group and (c) a diamine compound are used in the production of polymer (C) used in the present invention, the proportion of (b) a diamine compound having at least one carboxyl group to the total diamine compounds is, for example, 1 to 99% by mass, or for example, 5 to 80% by mass, or 10 to 60% by mass. If the proportion of (b) a diamine compound having at least one carboxyl group is less than this, the solubility of the formed gap fill material layer in the developer will be insufficient.

[0085] When the polymer (C) used in the present invention is produced from (a) a tetracarboxylic dianhydride compound and (b) at least one carboxyl group, or from (a) a tetracarboxylic dianhydride compound, (b) a diamine compound having at least one carboxyl group, and (c) a diamine compound, it is desirable that the ratio of the total number of moles of the diamine compound to the total number of moles of the tetracarboxylic dianhydride compound is 0.8 to 1.2. Similar to ordinary polycondensation reactions, the closer this molar ratio is to 1, the higher the degree of polymerization of the resulting polymer (C) and the greater the molecular weight.

[0086] In the production of polymer (C), the reaction temperature for the reaction between the diamine compound and the tetracarboxylic dianhydride compound can be selected from any temperature between -20°C and +150°C, preferably between -5°C and +100°C. A high molecular weight polymer (C) can be obtained at a reaction temperature of 5°C to 40°C for a reaction time of 1 to 48 hours. To obtain a low molecular weight polymer (C) with high storage stability, a reaction temperature of 40°C to 80°C for a reaction time of 10 hours or more is more preferable.

[0087] The reaction between diamine compounds and tetracarboxylic dianhydride compounds can be carried out in a solvent. Suitable solvents include N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, N-vinylpyrrolidone, N-methylcaprolactam, dimethyl sulfoxide, tetramethylurea, pyridine, dimethyl sulfone, hexamethyl sulfoxide, m-cresol, γ-butyrolactone, ethyl acetate, butyl acetate, ethyl lactate, methyl 3-methoxypropionate, methyl 2-methoxypropionate, ethyl 3-methoxypropionate, ethyl 2-methoxypropionate, ethyl 3-ethoxypropionate, ethyl 2-ethoxypropionate, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, and ethyl ethylene glycol dimethyl ether. Examples include ethylene glycol methyl ethyl ether, propylene glycol dimethyl ether, dipropylene glycol dimethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, propylene glycol monomethyl ether acetate, carbitol acetate, ethyl cellosolve acetate, cyclohexanone, methyl ethyl ketone, methyl isobutyl ketone, 2-heptanone, etc. These may be used individually or in combination. Furthermore, even solvents that do not dissolve polymer (C) may be mixed with the above solvents, as long as the polymer (C) produced by the polymerization reaction does not precipitate.

[0088] The solution containing the polymer (C) obtained in this way can be used directly in the preparation of a gap fill material forming composition. Alternatively, the polymer (C) can be precipitated and isolated in a poor solvent such as methanol or ethanol, and then recovered for use.

[0089] Examples of polymers (C) contained in the gap fill material forming composition of the present invention include the following polymers (C) (29) to (41) (wherein p １ , p ２ , p ３ and p ４ (where represents the proportion of each structure in polymer (C)). Here, (29) to (36) are polymers (C) produced from one tetracarboxylic dianhydride compound and two diamine compounds, (37) and (38) are polymers (C) produced from two tetracarboxylic dianhydride compounds and one diamine compound, (39) is polymer (C) produced from two tetracarboxylic dianhydride compounds and two diamine compounds, and (40) and (41) are polymers (C) produced from one tetracarboxylic dianhydride compound and one diamine compound.

[0090]

[0091]

[0092]

[0093]

[0094]

[0095]

[0096]

[0097] The weight-average molecular weight of the polymer used in the gap-fill material forming composition of the present invention is, for example, 500 to 30,000, for example, 500 to 20,000, and for example, 1,000 to 15,000. The weight-average molecular weight is a value obtained by gel permeation chromatography (GPC) using polystyrene as a standard sample.

[0098] If the weight-average molecular weight is less than 500, it is difficult to obtain an amorphous gap fill material layer. Furthermore, there is a high possibility of sublimation during the firing process after coating the gap fill material composition, which may lead to disadvantages such as insufficient formation of the gap fill material layer and contamination of the equipment. If the weight-average molecular weight exceeds 30,000, the fluidity of the gap fill material composition decreases, resulting in insufficient filling of holes formed in the substrate, which may cause voids and gaps within the holes, hindering the final processing of the substrate.

[0099] The polymer content in the gap fill material forming composition is not particularly limited, but is preferably 1 to 99% by mass, more preferably 20 to 80% by mass, and particularly preferably 30 to 70% by mass, relative to the solid content. Here, the solid content is the total components of the gap fill material forming composition excluding the solvent components.

[0100] <Crosslinking agents> Typical crosslinking agents include aminoplast crosslinking agents and phenoplast crosslinking agents.

[0101] Such crosslinking agents can undergo crosslinking reactions with each other or with the polymer components during the formation of the gap fill material layer by firing after coating the gap fill material forming composition onto the substrate, thereby reducing the solubility of the formed gap fill material layer in organic solvents.

[0102] As the crosslinking agent, a crosslinking agent with high heat resistance can be used. Preferably, a crosslinking agent with high heat resistance is a compound containing a crosslinking substituent having an aromatic ring (e.g., a benzene ring, a naphthalene ring) in its molecule.

[0103] Examples of aminoplast crosslinking agents include highly alkylated, alkoxylated, or alkoxyalkylated melamine, benzoguanamine, glycoluryl, urea, and polymers thereof. Preferably, the crosslinking agent has at least two crosslinking functional groups and is a compound such as methoxymethylated glycoluryl, butoxymethylated glycoluryl, methoxymethylated melamine, butoxymethylated melamine, methoxymethylated benzoguanamine, butoxymethylated benzoguanamine, methoxymethylated urea, butoxymethylated urea, methoxymethylated thiourea, or methoxymethylated thiourea. Condensates of these compounds can also be used.

[0104] Preferably, it is at least one selected from the group consisting of tetramethoxymethylglycoluryl and hexamethoxymethylmelamine.

[0105] Here are a few specific examples:

[0106]

[0107] Examples of phenoplast crosslinking agents include highly alkylated, alkoxylated, or alkoxyalkylated aromatics and polymers thereof. Preferably, the crosslinking agent has at least two crosslinking functional groups in one molecule, and is a compound such as 2,6-dihydroxymethyl-4-methylphenol, 2,4-dihydroxymethyl-6-methylphenol, bis(2-hydroxy-3-hydroxymethyl-5-methylphenyl)methane, bis(4-hydroxy-3-hydroxymethyl-5-methylphenyl)methane, 2,2-bis(4-hydroxy-3,5-dihydroxymethylphenyl)propane, bis(3-formyl-4-hydroxyphenyl)methane, bis(4-hydroxy-2,5-dimethylphenyl)formylmethane, or α,α-bis(4-hydroxy-2,5-dimethylphenyl)-4-formyltoluene. Condensates of these compounds can also be used.

[0108] Examples of such compounds include compounds having the substructure of formula (4) below, and polymers or oligomers having the repeating unit of formula (5) below.

[0109] The above R １１ , R １２ , R １３ , and R １４ n1 is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and the alkyl groups described above can be used. n1 is an integer from 1 to 4, n2 is an integer from 1 to (5-n1), and (n1+n2) is an integer from 2 to 5. n3 is an integer from 1 to 4, n4 is from 0 to (4-n3), and (n3+n4) is an integer from 1 to 4. The oligomers and polymers can be used with a number of repeating unit structures ranging from 2 to 100, or from 2 to 50.

[0110] Here are a few specific examples:

[0111]

[0112]

[0113]

[0114]

[0115] Crosslinking agents such as aminoplast crosslinking agents and phenoplast crosslinking agents may be used individually or in combination of two or more. Aminoplast crosslinking agents can be manufactured by known methods or similar methods, or commercially available products may be used.

[0116] The crosslinking agent preferably has at least two crosslinking functional groups. Examples of crosslinking functional groups include hydroxyl groups, amino groups, carboxyl groups, epoxy groups, and the like.

[0117] The crosslinking agent content in the gap fill material forming composition of the present invention is, for example, 1 to 99% by mass, for example, 1 to 50% by mass, and for example, 2 to 30% by mass, based on the solid content.

[0118] <Curing Catalyst> In the gap fill material forming composition of the present invention, either a thermal acid generator or a photoacid generator can be used as the curing catalyst, but it is preferable to use a thermal acid generator.

[0119] Examples of thermal acid generating agents include sulfonic acid compounds and carboxylic acid compounds such as p-toluenesulfonic acid, trifluoromethanesulfonic acid, pyridinium-p-toluenesulfonate (pyridinium-p-toluenesulfonic acid), pyridinium phenolsulfonic acid, pyridinium-p-hydroxybenzenesulfonic acid (pyridinium salt of p-phenolsulfonic acid), pyridinium-trifluoromethanesulfonic acid, salicylic acid, camphorsulfonic acid, 5-sulfosalicylic acid, 4-chlorobenzenesulfonic acid, 4-hydroxybenzenesulfonic acid, benzenedisulfonic acid, 1-naphthalenesulfonic acid, citric acid, benzoic acid, hydroxybenzoic acid, N-methylmorpholine-p-toluenesulfonic acid, N-methylmorpholine-p-hydroxybenzenesulfonic acid, and N-methylmorpholine-5-sulfosalicylic acid.

[0120] Examples of photoacid generators include onium salt compounds, sulfonimide compounds, and disulfonyldiazomethane compounds.

[0121] Examples of iodonium salt compounds include iodonium salt compounds such as diphenyliodonium hexafluorophosphate, diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoron-butanesulfonate, diphenyliodonium perfluoron-octanesulfonate, diphenyliodonium camphorsulfonate, bis(4-tert-butylphenyl)iodonium camphorsulfonate and bis(4-tert-butylphenyl)iodonium trifluoromethanesulfonate, and sulfonium salt compounds such as triphenylsulfonium hexafluoroantimonate, triphenylsulfonium nonafluoron-butanesulfonate, triphenylsulfonium camphorsulfonate and triphenylsulfonium trifluoromethanesulfonate.

[0122] Examples of sulfonimide compounds include N-(trifluoromethanesulfonyloxy)succinimide, N-(nonafluoron-butanesulfonyloxy)succinimide, N-(camphorsulfonyloxy)succinimide, and N-(trifluoromethanesulfonyloxy)naphthalimide.

[0123] Examples of disulfonyl diazomethane compounds include bis(trifluoromethylsulfonyl)diazomethane, bis(cyclohexylsulfonyl)diazomethane, bis(phenylsulfonyl)diazomethane, bis(p-toluenesulfonyl)diazomethane, bis(2,4-dimethylbenzenesulfonyl)diazomethane, and methylsulfonyl-p-toluenesulfonyldiazomethane.

[0124] Only one type of curing catalyst may be used, or two or more types may be used in combination.

[0125] When a curing catalyst is used, the content of the curing catalyst is, for example, 0.01% to 50% by mass relative to the crosslinking agent, preferably 0.1% to 30% by mass.

[0126] The gap fill material forming composition of the present invention comprises at least one of a crosslinking agent and a curing catalyst. Preferably, the gap fill material forming composition of the present invention comprises both a crosslinking agent and a curing catalyst.

[0127] <Alkali Dissolution Rate Adjuster> An alkali dissolution rate adjuster can be added to the gap fill material forming composition of the present invention. An alkali dissolution rate adjuster is a compound that can adjust the dissolution rate of the gap fill material layer formed from the gap fill material forming composition in an alkaline aqueous solution. By adjusting the type and amount of alkali dissolution rate adjuster added, it is possible to control the dissolution rate of the gap fill material layer in an alkaline aqueous solution.

[0128] Examples of such alkali dissolution rate modifiers include naphthoquinone compounds, t-butoxycarbonyl group-containing compounds, hydroxyl group-containing compounds, carboxyl group-containing compounds, and phenyl-containing compounds. The amount of alkali dissolution rate modifier added is 100 parts by mass or less, preferably 80 parts by mass or less, or 50 parts by mass or less, per 100 parts by mass of polymer.

[0129] <Additives> In addition to the above, the lithography gap fill material forming composition of the present invention may contain further additives such as rheological modifiers, adhesion aids, and surfactants as needed.

[0130] Rheology modifiers are added primarily to improve the fluidity of gap-fill material forming compositions, and especially to enhance the filling ability of the gap-fill material forming composition into holes during the firing process. Specific examples include phthalate derivatives such as dimethyl phthalate, diethyl phthalate, diisobutyl phthalate, dihexyl phthalate, and butyl isodecyl phthalate; adipic acid derivatives such as dinormal butyl adipate, diisobutyl adipate, diisooctyl adipate, and octyldecyl adipate; maleic acid derivatives such as dinormal butyl malate, diethyl malate, and dinonyl malate; oleic acid derivatives such as methyl oleate, butyl oleate, and tetrahydrofurfuryl oleate; or stearic acid derivatives such as normal butyl stearate and glyceryl stearate. These rheology modifiers are usually added in a proportion of less than 30% by mass per gap-fill material forming composition.

[0131] Adhesion aids are added primarily to improve the adhesion between the substrate or anti-reflective film or photoresist layer and the gap fill material layer formed from the gap fill material forming composition, and especially to prevent peeling during development. Specific examples include chlorosilanes such as trimethylchlorosilane, dimethylvinylchlorosilane, methyldiphenylchlorosilane, and chloromethyldimethylchlorosilane; alkoxysilanes such as trimethylmethoxysilane, dimethyldiethoxysilane, methyldimethoxysilane, dimethylvinylethoxysilane, γ-methacryloxypropyltrimethoxysilane, diphenyldimethoxysilane, and phenyltriethoxysilane; silazanes such as hexamethyldisilazane, N,N'-bis(trimethylsilyl)urea, dimethyltrimethylsilylamine, and trimethylsilylimidazole; and vinyltrichlorosilane. Examples of adhesive aids include silanes such as rosilane, γ-chloropropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, and γ-methacryloxypropyltrimethoxysilane; heterocyclic compounds such as benzotriazole, benzimidazole, indazole, imidazole, 2-mercaptobenzimidazole, 2-mercaptobenzothiazole, 2-mercaptobenzoxazole, urazole, thiouracil, mercaptoimidazole, and mercaptopyrimidine; and ureas such as 1,1-dimethylurea and 1,3-dimethylurea, or thiourea compounds. These adhesive aids are usually added in a proportion of less than 10% by mass, preferably less than 5% by mass, per the total gap fill material forming composition.

[0132] The gap-fill material forming composition of the present invention does not produce pinholes or striations, and surfactants can be added to further improve the coatability against surface unevenness. Examples of surfactants include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, and polyoxyethylene oleyl ether; polyoxyethylene alkyl allyl ethers such as polyoxyethylene octyl phenol ether and polyoxyethylene nonyl phenol ether; polyoxyethylene / polyoxypropylene block copolymers; sorbitan fatty acid esters such as sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, sorbitan trioleate, and sorbitan tristearate; and polyoxyethylene sorbitan monolaurate and polyoxyethylene sorbitan monopalmitate. Examples include nonionic surfactants such as polyoxyethylene sorbitan fatty acid esters like polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, and polyoxyethylene sorbitan tristearate; fluorine-based surfactants such as F-Top EF301, EF303, EF352 (manufactured by Tochem Products Co., Ltd.), Megafac F171, F173, R-08, R-30 (manufactured by Dainippon Ink, Inc.), Florard FC430, FC431 (manufactured by Sumitomo 3M Co., Ltd.), Asahi Guard AG710, Surflon S-382, SC101, SC102, SC103, SC104, SC105, SC106 (manufactured by Asahi Glass Co., Ltd.); and organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.). The amount of these surfactants added is typically 0.2% by mass or less, preferably 0.1% by mass or less, per gap fill material forming composition of the present invention. These surfactants may be added individually or in combination of two or more types.

[0133] <Solvent> The gap fill material forming composition of the present invention is preferably used in solution form, and therefore various solvents can be used.

[0134] As solvents for dissolving the polymer, crosslinking agent, etc., in the gap fill material forming composition, the following can be used: ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, methyl cellosolve acetate, ethyl cellosolve acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol propyl ether acetate, toluene, xylene, methyl ethyl ketone, cyclopentanone, cyclohexanone, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxyethyl acetate, ethyl hydroxyethyl acetate, methyl 2-hydroxy-3-methylbutanoate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl 3-ethoxypropionate, methyl pyruvate, ethyl pyruvate, ethyl acetate, ethyl lactate, butyl lactate, etc. These organic solvents can be used alone or in combination of two or more. Furthermore, high-boiling point solvents such as propylene glycol monobutyl ether and propylene glycol monobutyl ether acetate can be mixed and used.

[0135] The proportion of solids in the gap fill material forming composition is not particularly limited as long as each component is uniformly dissolved, but is for example 0.5 to 50% by mass, or for example 1 to 30% by mass. Here, solids refer to the total components of the gap fill material forming composition excluding the solvent components.

[0136] A gap fill material layer formed from the gap fill material forming composition of the present invention is coated with an anti-reflective coating composition or a photoresist composition in a subsequent lithography process. At this time, the gap fill material layer is coated with an organic solvent commonly used in anti-reflective coatings or photoresist compositions, such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, methyl cellosolve acetate, ethyl cellosolve acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol propyl ether acetate, toluene, xylene, methyl ethyl ketone, cyclopentanone, cyclohexanone, 2-H If the gap fill material is soluble in ethyl hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxyacetate, ethyl hydroxyacetate, methyl 2-hydroxy-3-methylbutanoate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl 3-ethoxypropionate, methyl pyruvate, ethyl pyruvate, ethyl acetate, ethyl lactate, butyl lactate, etc., intermixing occurs between the gap fill material layer and the anti-reflective film or photoresist layer, leading to adverse effects such as a decrease in resolution in the subsequent lithography process. In the gap fill material forming composition of the present invention, the aforementioned crosslinking reaction can prevent intermixing that causes such adverse effects.

[0137] (Gap fill material layer) The gap fill material layer of the present invention is formed from the gap fill material forming composition of the present invention.

[0138] The gap-fill material forming composition of the present invention is used in semiconductor device manufacturing processes, particularly lithography processes, using substrates having holes with an aspect ratio of 1 or more, indicated by height / diameter. The process using the gap-fill material forming composition of the present invention is described below (Figure 1).

[0139] A gap fill material forming composition of the present invention is applied to a substrate having holes with an aspect ratio of 1 or more, indicated by height / diameter (for example, a silicon / silicon dioxide coated substrate, a silicon nitride substrate, a glass substrate, an ITO substrate, etc.) using an appropriate coating method such as a spinner or coater, and then fired to form a gap fill material layer (step (1) in Figure 1).

[0140] The firing conditions are appropriately selected from a firing temperature of 60°C to 220°C and a firing time of 0.3 to 120 minutes. During coating, an excess amount of gap fill material forming composition is used to ensure that the gap fill material forming composition fills the holes, resulting in a thick gap fill material layer (0.01 to 5 μm as the film thickness on the top of the substrate). In addition, in substrates with areas where holes are densely and areas where they are sparsely arranged, a difference in film thickness may occur on the substrate due to the density of the holes. To minimize this difference, an excess amount of gap fill material forming composition may be used to coat the substrate as a thick film.

[0141] Performing subsequent lithography processes using a thick gap fill layer presents problems in terms of resolution, etc., therefore, the excess gap fill layer is removed by etching, i.e., etch-back. Since the gap fill layer of the present invention is soluble in alkaline aqueous solutions, etch-back is performed using an alkaline aqueous solution (step (2) in Figure 1). In this etch-back step with an alkaline aqueous solution, the gap fill layer can be adjusted to a desired thickness by selecting the type and concentration of the alkaline aqueous solution used or the etch-back time. Furthermore, etch-back can also improve the flatness of the surface of the gap fill layer. After etch-back, a firing step can be added under conditions appropriately selected from a firing temperature of 100°C to 220°C and a firing time of 0.3 to 120 minutes. Note that etch-back may also be performed using a neutral solution other than an alkaline aqueous solution, a weakly acidic aqueous solution, or an acidic aqueous solution.

[0142] Examples of neutral solutions include propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, ethyl 2-hydroxypropionate, methyl 2-hydroxyisobutyrate, gamma butyrolactone, ethyl acetate, butyl acetate, toluene, xylene, methyl ethyl ketone, cyclopentanone, and cyclohexanone.

[0143] Examples of weakly acidic aqueous solutions include aqueous solutions containing acetic acid or a chelating agent. Examples of chelating agents include organic acids, salts of organic acids, amino acids, and derivatives of amino acids.

[0144] Examples of acidic aqueous solutions include sulfuric acid, nitric acid, hydrochloric acid, phosphoric acid, and hydrofluoric acid.

[0145] Next, an anti-reflective film layer is formed on the gap fill material layer after etch-back (step (3) in Figure 1), followed by the formation of a photoresist layer (step (4) in Figure 1). After that, substrate processing such as exposure, development, and dry etching is carried out.

[0146] In the steps (1) to (4) of Figure 1 using the gap fill material forming composition of the present invention, the etch-back of the gap fill material layer can be performed with an alkaline aqueous solution (step (2)), so the series of steps (1) to (4) can be performed using a commonly used coat and developer device (coating and developing device).

[0147] Conventionally, since it was not possible to etch back the gap fill material layer with an alkaline aqueous solution, etch-back was performed by dry etching. Therefore, it was necessary to move the substrate. Specifically, the process required moving the substrate from the coat and developer equipment to the dry etching equipment (step (A) in Figure 1), etch-back by dry etching (step (2') in Figure 1), and then moving the substrate from the dry etching equipment back to the coat and developer equipment (step (A') in Figure 1), thus requiring the movement of the substrate between equipment. In contrast, the process using the gap fill material forming composition of the present invention allows a series of steps to be performed in a single device, making it possible to improve production efficiency compared to conventional processes.

[0148] There are no particular restrictions on the alkaline aqueous solution used for etch-back, but alkaline aqueous solutions used as developers for positive-type photoresists can be used. For example, aqueous solutions of inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and ammonia; aqueous solutions of organic amines such as ethylamine, n-propylamine, diethylamine, triethylamine, dimethylethanolamine, and triethanolamine; aqueous solutions of quaternary ammonium salts such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, and choline; and aqueous solutions of cyclic amines such as pyrrole and piperidine can be used. In addition, alkaline aqueous solutions to which alcohols such as isopropyl alcohol or anionic surfactants have been added in appropriate amounts can also be used. Furthermore, the concentration of the alkaline aqueous solution used can be appropriately selected from, for example, concentrations of 0.1% to 20%. In addition, NMD-3 (manufactured by Tokyo Ohka Kogyo Co., Ltd.) can also be used.

[0149] The etch-back time can be appropriately selected from 10 to 300 seconds, depending on the type and concentration of the alkaline aqueous solution used, the desired film thickness and condition of the gap fill material layer, etc.

[0150] Furthermore, when etching back the gap fill material layer with an alkaline aqueous solution, the dissolution rate in the alkaline aqueous solution is preferably 3 to 500 nm per second, more preferably 5 to 400 nm per second, and more preferably 10 to 300 nm per second as the rate of reduction in film thickness. If the dissolution rate is faster than this, it becomes difficult to control the amount of gap fill material layer removed by etch-back, i.e., the amount of film thickness reduced. If the dissolution rate is slower than this, the time required for etch-back increases, leading to a decrease in productivity.

[0151] The dissolution rate of the gap fill material layer in an alkaline aqueous solution can be adjusted by changing the type and content of polymer contained in the gap fill material forming composition used (hereinafter also simply referred to as "composition"), the type and amount of crosslinking agent added to the composition, the type and amount of curing catalyst added to the composition, the type and amount of alkaline dissolution rate modifier added to the composition, and the firing conditions (firing temperature, firing time). Ultimately, the dissolution rate of the gap fill material layer in an alkaline aqueous solution is determined by the combination of the type of gap fill material forming composition, the type and concentration of the alkaline aqueous solution, and the firing conditions.

[0152] Furthermore, by appropriately selecting the conditions for etch-back of the gap fill material layer with an alkaline aqueous solution (type of gap fill material forming composition, type and concentration of alkaline aqueous solution, and time), the state of the gap fill material layer formed on the substrate can be controlled. In other words, the etch-back conditions allow for the selection of a state in which the gap fill material layer is also present on the upper surface of the substrate (Figure 2A (S1)), a state in which only the inside of the holes in the substrate is filled with the gap fill material layer (Figure 2B (S2)), or a partial-fill state in which only a part of the holes in the substrate is filled with the gap fill material layer (Figure 2C (S3)).

[0153] The gap fill material layer formed from the gap fill material forming composition of the present invention is ultimately completely removed in the semiconductor device manufacturing process after exposure and development of photoresist and processing of the substrate, and this removal is usually performed by dry etching. It is generally known that the rate of removal by dry etching decreases as the proportion of aromatic ring structures in the layer being removed increases. Therefore, in the gap fill material layer of the present invention, if the rate of removal by dry etching is to be increased, the amount of aromatic ring structures contained in the gap fill material forming composition used should be reduced, and in particular, the amount of aromatic ring structures contained in the polymer component should be reduced. Thus, when a gap fill material layer with a high rate of removal by dry etching is required, a polymer that does not have aromatic ring structures in its structure is preferably used.

[0154] Examples of such polymers include polymers produced solely from monomers selected from acrylic acid, methacrylic acid, 2-hydroxyethyl methacrylate, and vinyl alcohol. Furthermore, polymers produced by copolymerizing these monomers with monomers selected from alkyl acrylates or alkyl methacrylates such as methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, and hexyl methacrylate, alkyl vinyl ethers such as ethyl vinyl ether and ethyl butyl ether, alkyl carboxylate vinyl esters such as vinyl acetate and vinyl butyrate, N-alkyl maleimides such as N-methyl maleimide and N-cyclohexyl maleimide, maleic anhydride, and acrylonitrile are also examples.

[0155] Examples include polymethacrylic acid, poly(2-hydroxyethyl) methacrylate, polyvinyl alcohol, copolymers of acrylic acid and ethyl methacrylate, copolymers of vinyl alcohol and butyl vinyl ether, copolymers of ethyl methacrylate and 2-hydroxyethyl vinyl ether, copolymers of 2-hydroxypropyl methacrylate, propyl acrylate and acrylonitrile, copolymers of methacrylic acid, 2-hydroxyethyl methacrylate and ethyl methacrylate, copolymers of 2-hydroxyethyl methacrylate, ethyl methacrylate and maleic anhydride, and copolymers of methacrylic acid, 2-hydroxyethyl methacrylate, methyl methacrylate and N-cyclohexylmaleimide.

[0156] In the present invention, both negative and positive type photoresists can be used as the photoresist applied to the upper layer of the gap fill material layer. Examples include a positive type photoresist consisting of novolac resin and 1,2-naphthoquinone diazide sulfonic acid ester, a chemically amplified photoresist consisting of a binder having a group that decomposes with acid to increase the alkali dissolution rate and a photoacid generator, a chemically amplified photoresist consisting of a low molecular weight compound that decomposes with acid to increase the alkali dissolution rate of the photoresist, an alkali-soluble binder and a photoacid generator, and a chemically amplified photoresist consisting of a binder having a group that decomposes with acid to increase the alkali dissolution rate and a low molecular weight compound that decomposes with acid to increase the alkali dissolution rate of the photoresist and a photoacid generator. Examples include APEX-E from Rohm & Haas and SEPR430 from Shin-Etsu Chemical Co., Ltd. After forming the photoresist, a photoresist pattern can be obtained by exposure through a predetermined mask, development, rinsing and drying. Post-exposure baking (PEB) can also be performed if necessary.

[0157] In the present invention, an anti-reflective coating layer may be applied and formed on top of the gap fill material layer before the photoresist is applied and formed. There are no particular restrictions on the anti-reflective coating composition used, and any composition can be arbitrarily selected from those conventionally used in lithography processes. Furthermore, the anti-reflective coating can be formed by conventional methods, such as application and firing using a spinner or coater. Examples of anti-reflective coating compositions include those mainly composed of an absorbent compound, resin and solvent; those mainly composed of a resin having absorbent groups linked by chemical bonds, a crosslinking agent and solvent; those mainly composed of an absorbent compound, a crosslinking agent and solvent; and those mainly composed of an absorbent polymer crosslinking agent and solvent. These anti-reflective coating compositions may also optionally contain an acid component, an acid generator component, a rheology modifier, etc.

[0158] As for the light-absorbing compound, any compound that has high absorption capacity for light in the photosensitive wavelength range of the photosensitive component in the photoresist provided on the anti-reflective film can be used. Examples include benzophenone compounds, benzotriazole compounds, azo compounds, naphthalene compounds, anthracene compounds, anthraquinone compounds, and triazine compounds. Examples of resins include polyester, polyimide, polystyrene, novolac resin, polyacetal resin, and (meth)acrylic resin. Examples of resins having light-absorbing groups linked by chemical bonds include resins having light-absorbing aromatic ring structures such as anthracene rings, naphthalene rings, benzene rings, quinoline rings, quinoxaline rings, and thiazole rings.

[0159] (Substrate) The substrates to which the gap fill material forming composition of the present invention is applied are mainly substrates commonly used in the manufacture of semiconductor devices having holes with an aspect ratio of 1 or more, indicated by height / diameter (e.g., silicon / silicon dioxide coated substrates, silicon nitride substrates, glass substrates, ITO substrates, etc.). However, it can also be used to flatten the surface of substrates having holes with an aspect ratio less than 1 or substrates with steps. It can also be used on substrates without steps or other irregularities. These substrates may have an inorganic anti-reflective film formed by CVD or the like on their surface layer, and the gap fill material forming composition of the present invention can be applied on top of them.

[0160] The gap fill material layer formed from the gap fill material forming composition of the present invention may also have absorption properties for certain wavelengths of light used in the lithography process, and in such cases, it can function as a layer that prevents reflected light from the substrate. Furthermore, the gap fill material layer of the present invention can also be used as a layer for preventing interaction between the substrate and the photoresist, a layer that prevents adverse effects on the substrate by materials used in the photoresist or substances generated during exposure to the photoresist, and a layer that prevents the diffusion and adverse effects of substances generated from the substrate to the upper photoresist during heating and firing.

[0161] Next, the contents of the present invention will be specifically explained with reference to synthesis examples and embodiments, but the present invention is not limited to these.

[0162] The weight-average molecular weights of the polymers shown in Synthesis Examples 1 to 15 below were obtained by gel permeation chromatography (hereinafter abbreviated as GPC). A GPC instrument manufactured by Tosoh Corporation was used for the measurement, and the measurement conditions were as follows: Column temperature: 40°C Flow rate: 0.35 ml / min Eluent: Tetrahydrofuran (THF) Standard sample: Polystyrene (Tosoh Corporation)

[0163] <Synthesis Example 1> A solution of 5.00 g of 1-butoxyethyl methacrylate, 1.59 g of 4-hydroxyphenyl methacrylate (manufactured by Resonaq Corporation), 0.13 g of 2,2'-azobis(isobutyrate)dimethyl (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), and 21.52 g of methyl ethyl ketone was added to a dropping funnel and added dropwise to a reaction flask containing 5.38 g of methyl ethyl ketone. The mixture was heated and stirred at 80°C under a nitrogen atmosphere for 16 hours. Subsequently, the solution of the reaction product was added dropwise to a hexane solution, and the resulting precipitate was separated by filtration and dried at 40°C under vacuum. The resulting reaction product corresponds to formula (x-1), and the weight-average molecular weight Mw, measured in polystyrene equivalent by GPC, was 23000. The values ​​in formula (x-1) represent the molar ratio of each structural unit.

[0164] <Synthesis Example 2> A solution of 5.00 g of 1-butoxyethyl methacrylate, 1.59 g of hydroxymethyl acrylamide, 0.33 g of 2,2'-azobis(isobutyrate)dimethyl (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), and 22.13 g of propylene glycol monomethyl ether was added to a dropping funnel and added dropwise to a reaction flask containing 5.53 g of propylene glycol monomethyl ether. The mixture was heated and stirred at 100°C under a nitrogen atmosphere for 14 hours. Subsequently, the solution of the reaction product was added dropwise to a hexane solution, and the resulting precipitate was separated by filtration and dried under vacuum at 40°C. The obtained reaction product corresponds to formula (x-2), and the weight-average molecular weight Mw, measured in polystyrene equivalent by GPC, was 18000. The values ​​in formula (x-2) represent the molar ratio of each structural unit.

[0165] <Synthesis Example 3> A solution of 5.00 g of 1-butoxyethyl methacrylate, 0.90 g of methyl methacrylate (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.12 g of 2,2'-azobis(isobutyrate)dimethyl (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), and 19.24 g of methyl ethyl ketone was added to a dropping funnel and added dropwise to a reaction flask containing 4.81 g of methyl ethyl ketone. The mixture was heated and stirred at 80°C under a nitrogen atmosphere for 17 hours. Subsequently, the solution of the reaction product was added dropwise to a methanol solution, and the resulting precipitate was separated by filtration and dried at 40°C under vacuum. The resulting reaction product corresponds to formula (x-3), and the weight-average molecular weight Mw, measured in polystyrene equivalent by GPC, was 32000. The numerical values ​​in formula (x-3) represent the molar ratio of each structural unit.

[0166] <Synthesis Example 4> A solution of 4.00 g of 1-butoxyethyl methacrylate, 1.77 g of 4-hydroxyphenyl methacrylate (manufactured by Resonaq Corporation), 0.23 g of glycidyl methacrylate (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.30 g of 2,2'-azobis(isobutyrate)dimethyl (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), and 20.16 g of methyl ethyl ketone was added to a dropping funnel and added dropwise to a reaction flask containing 5.04 g of methyl ethyl ketone. The mixture was heated and stirred at 80°C under a nitrogen atmosphere for 20 hours. Subsequently, the solution of the reaction product was added dropwise to a hexane solution, and the resulting precipitate was separated by filtration and dried under vacuum at 40°C. The resulting reaction product corresponds to formula (x-4), and the weight-average molecular weight Mw, measured in polystyrene equivalent by GPC, was 16500. The values ​​in formula (x-4) represent the molar ratio of each structural unit.

[0167] <Synthesis Example 5> A solution of 3.00 g of 1-butoxyethyl methacrylate, 2.87 g of 4-hydroxyphenyl methacrylate (manufactured by Resonaq Corporation), 0.29 g of 2,2'-azobis(isobutyrate)dimethyl (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), and 19.72 g of methyl ethyl ketone was added to a dropping funnel and added dropwise to a reaction flask containing 4.93 g of methyl ethyl ketone. The mixture was heated and stirred at 80°C under a nitrogen atmosphere for 16 hours. Subsequently, the solution of the reaction product was added dropwise to a hexane solution, and the resulting precipitate was separated by filtration and dried at 40°C under vacuum. The resulting reaction product corresponds to formula (x-5), and the weight-average molecular weight Mw, measured in polystyrene equivalent by GPC, was 11000. The values ​​in formula (x-5) represent the molar ratio of each structural unit.

[0168] <Synthesis Example 6> A solution of 4.00 g of 1-butoxyethyl methacrylate, 0.75 g of styrene (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.09 g of 2,2'-azobis(isobutyrate)dimethyl (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), and 15.49 g of methyl ethyl ketone was added to a dropping funnel and added dropwise to a reaction flask containing 3.87 g of methyl ethyl ketone. The mixture was heated and stirred at 80°C under a nitrogen atmosphere for 16 hours. The reaction product solution was then added dropwise to a methanol solution, and the resulting precipitate was separated by filtration and dried at 40°C under vacuum. The resulting reaction product corresponds to formula (x-6), and the weight-average molecular weight Mw, measured in polystyrene equivalent by GPC, was 18000. The values ​​in formula (x-6) represent the molar ratio of each structural unit.

[0169] <Synthesis Example 7> A solution of 4.00 g of 1-butoxyethyl methacrylate, 1.26 g of benzyl methacrylate (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.11 g of 2,2'-azobis(isobutyrate)dimethyl (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), and 17.17 g of methyl ethyl ketone was added to a dropping funnel and added dropwise to a reaction flask containing 4.29 g of methyl ethyl ketone. The mixture was heated and stirred at 80°C under a nitrogen atmosphere for 16 hours. The reaction product solution was then added dropwise to a methanol solution, and the resulting precipitate was separated by filtration and dried under vacuum at 40°C. The resulting reaction product corresponds to formula (x-7), and the weight-average molecular weight Mw, measured in polystyrene equivalent by GPC, was 20000. The values ​​in formula (x-7) represent the molar ratio of each structural unit.

[0170] <Synthesis Example 8> 3.00 g of EX-201 (resorcinol diglycidyl ether, manufactured by Nagase ChemteX Corporation), 2.02 g of tartaric acid (manufactured by Tokyo Chemical Industry Co., Ltd.), and 0.16 g of tetrabutylphosphonium bromide (manufactured by Hokko Chemical Co., Ltd.) were added to a reaction flask, to which 20.74 g of propylene glycol monomethyl ether was added. The resulting mixture was heated and stirred in the reaction flask under a nitrogen atmosphere at 120°C for 16 hours. The resulting reaction product corresponds to formula (x-8), and the weight-average molecular weight Mw, measured in polystyrene equivalent by GPC, was 2070.

[0171] <Synthesis Example 9> 3.50 g of EX-721 (manufactured by Nagase ChemteX Corporation), 1.72 g of tartaric acid (manufactured by Tokyo Chemical Industry Co., Ltd.), and 0.09 g of tetrabutylphosphonium bromide (manufactured by Hokko Chemical Co., Ltd.) were added to a reaction flask, to which 21.26 g of propylene glycol monomethyl ether was added. The resulting mixture was heated and stirred in the reaction flask under a nitrogen atmosphere at 120°C for 16 hours. The resulting reaction product corresponds to formula (x-9), and the weight-average molecular weight Mw, measured in polystyrene equivalent by GPC, was 1070.

[0172] <Synthesis Example 10> 5.00 g of EX-711 (manufactured by Nagase ChemteX Corporation), 2.70 g of tartaric acid (manufactured by Tokyo Chemical Industry Co., Ltd.), and 0.21 g of tetrabutylphosphonium bromide (manufactured by Hokko Chemical Co., Ltd.) were added to a reaction flask, to which 18.49 g of propylene glycol monomethyl ether was added. The resulting mixture was heated and stirred in the reaction flask under a nitrogen atmosphere at 120°C for 16 hours. The resulting reaction product corresponds to formula (x-10), and the weight-average molecular weight Mw, measured in polystyrene equivalent by GPC, was 2480.

[0173] <Synthesis Example 11> 7.00 g of monoallyl diglycidyl isocyanuric acid (product name: MA-DGIC, manufactured by Shikoku Chemicals, Inc.), 3.93 g of tartaric acid (manufactured by Tokyo Chemical Industry Co., Ltd.), and 0.21 g of tetrabutylphosphonium bromide (manufactured by Hokko Chemical Co., Ltd.) were added to a reaction flask, to which 44.58 g of propylene glycol monomethyl ether was added. The resulting mixture was heated and stirred in the reaction flask under a nitrogen atmosphere at 120°C for 20 hours. The resulting reaction product corresponds to formula (x-11), and the weight-average molecular weight Mw, measured in polystyrene equivalent by GPC, was 2200.

[0174] <Synthesis Example 12> 10.00 g of a propylene glycol monomethyl ether solution of monomethyl diglycidyl isocyanuric acid (product name: Me-DGIC, manufactured by Shikoku Chemicals, Ltd., solids content: 30% by mass), 1.87 g of tartaric acid (manufactured by Tokyo Chemical Industries, Ltd.), and 0.15 g of tetrabutylphosphonium bromide (manufactured by Hokko Chemical Co., Ltd.) were added to a reaction flask, to which 13.06 g of propylene glycol monomethyl ether was added. The resulting mixture was heated and stirred in the reaction flask under a nitrogen atmosphere at 120°C for 14 hours. The resulting reaction product corresponds to formula (x-12), and the weight-average molecular weight Mw, measured in polystyrene equivalent by GPC, was 950.

[0175] <Synthesis Example 13> 10.00 g of a propylene glycol monomethyl ether solution of 1,3-diglycidyl-5,5-dimethylhydantoin (solid content: 30% by mass), 1.99 g of tartaric acid (manufactured by Tokyo Chemical Industry Co., Ltd.), and 0.13 g of tetrabutylphosphonium bromide (manufactured by Hokko Chemical Co., Ltd.) were added to a reaction flask, to which 13.66 g of propylene glycol monomethyl ether was added. The resulting mixture was heated and stirred in the reaction flask under a nitrogen atmosphere at 120°C for 15 hours. The resulting reaction product corresponds to formula (x-13), and the weight-average molecular weight Mw, measured in polystyrene equivalent by GPC, was 1100.

[0176] <Synthesis Example 14> 3.00 g of HP-4032D (manufactured by DIC Corporation), 1.69 g of tartaric acid (manufactured by Tokyo Chemical Industry Co., Ltd.), and 0.14 g of tetrabutylphosphonium bromide (manufactured by Hokko Chemical Co., Ltd.) were added to a reaction flask, to which 27.36 g of propylene glycol monomethyl ether was added. The resulting mixture was heated and stirred in the reaction flask under a nitrogen atmosphere at 105°C for 16 hours. The resulting reaction product corresponds to formula (x-14), and the weight-average molecular weight Mw, measured in polystyrene equivalent by GPC, was 1600.

[0177] <Synthesis Example 15> 5.00 g of RE-303S-L (manufactured by Nippon Kayaku Co., Ltd.), 2.68 g of succinic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), and 0.19 g of tetrabutylphosphonium bromide (manufactured by Hokko Chemical Co., Ltd.) were added to a reaction flask, to which 18.38 g of propylene glycol monomethyl ether was added. The resulting mixture was heated and stirred in the reaction flask under a nitrogen atmosphere at 105°C for 15 hours. The resulting reaction product corresponds to formula (x-15), and the weight-average molecular weight Mw, measured in polystyrene equivalent by GPC, was 3080.

[0178] <Example 1> 85.30 g of a propylene glycol monomethyl ether solution (solid content 20% by mass) of the reaction product obtained in Synthesis Example 10 was mixed with 0.85 g of tetramethoxymethyl glycoluryl, 0.09 g of pyridinium p-phenolsulfonic acid, 5.53 g of propylene glycol monomethyl ether, and 8.20 g of propylene glycol monomethyl ether acetate. The mixture was then filtered using a PTFE syringe filter with a pore size of 0.20 μm to prepare a gap fill material forming composition (solution).

[0179] The obtained solution was applied onto a silicon wafer using a spinner. It was heated on a hot plate at 200°C for 1 minute to form a lithography gap fill material layer (thickness 1.0 μm). This gap fill material layer was immersed in a 2.38% tetramethylammonium hydroxide aqueous solution for a predetermined time, and the alkali dissolution rate was measured. Based on the immersion time and the decrease in thickness, the alkali dissolution rate of the gap fill material layer was determined to be 200 nm per second.

[0180] The obtained solution was applied onto a silicon wafer using a spinner. A gap fill material layer (thickness 1.0 μm) was formed by baking on a hot plate at 120°C for 1 minute, followed by 205°C for 1 minute. This gap fill material layer was immersed in solvents used in photoresists, such as ethyl lactate and propylene glycol monomethyl ether, and its insolubility in these solvents was confirmed.

[0181] A gap fill material forming composition (solution) was applied to a silicon substrate (hole substrate) with holes of 0.5 μm in diameter, 5.0 μm in depth, and 0.5 μm in spacing using a spin coater. The substrate was then heated on a hot plate at 200°C for 1 minute to form a gap fill material layer with a thickness of approximately 1.0 μm. The embedding ability was evaluated by observing the cross-sectional shape of the hole substrate coated with the gap fill material forming composition (solution) obtained in Example 1 (Figure 3) using a scanning electron microscope (SEM). In the case of the gap fill material forming composition of Example 1, it can be seen that the composition is embedded in the hole substrate (Figure 4). Next, to confirm the alkali solubility of the gap fill material layer, the hole substrate after coating was immersed in a 2.38% tetramethylammonium hydroxide aqueous solution (NMD-3, manufactured by Tokyo Ohka Kogyo Co., Ltd.) for 120 seconds. The cross-sectional shape of the hole substrate after solvent immersion (Figure 5) was observed using a scanning electron microscope (SEM). The results confirmed that the gap fill material forming composition of Example 1 in the hole substrate was soluble in an alkaline solvent.

[0182] a... Substrate. b... Gap fill material layer before etch-back with alkaline aqueous solution. c... Gap fill material layer after etch-back with alkaline aqueous solution. d... Anti-reflective coating layer. e... Photoresist layer.

Claims

1. A method for manufacturing a semiconductor device, which is used in the production of a semiconductor device by a method of coating a substrate having a hole with an aspect ratio of 1 or more, expressed by height / diameter, with a photoresist and transferring an image onto the substrate using a lithography process. A gap filling material forming composition coated on the substrate before coating the photoresist, the gap filling material forming composition containing one or more selected from a polymer, a crosslinking agent, and a curing catalyst, the polymer including at least one polymer selected from a polymer having a partial structure represented by the following formula (A), a polymer having a structural unit represented by the following formula (B), and a polyamic acid. [In formula (A), R １１ represents a single bond or a divalent group having 1 to 4 carbon atoms. R １２ and R １３ each independently represent a hydrogen atom, a hydroxy group, or a methyl group. * represents a bond. ] [In formula (B), R １ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R ２ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, R ３ represents an optionally substituted alkyl group having 1 to 10 carbon atoms, R ２ and R ３ together with the carbon atom and the oxygen atom between R ２ and R ３ may form a ring, and the ring may contain a hetero atom other than the oxygen atom. ] 2. The gap fill material forming composition according to claim 1, wherein the weight-average molecular weight of the polymer is 500 to 30,000.

3. The gap fill material forming composition according to claim 1, wherein the polymer having the substructure represented by formula (A) has the substructure represented by formula (A) in its main chain.

4. The gap fill material forming composition according to claim 1, wherein the polymer having the substructure represented by formula (A) has the substructure represented by formula (A) in its side chains.

5. The gap fill material forming composition according to claim 1, wherein the polymer does not have an aromatic ring structure in its structure.

6. The gap fill material forming composition according to claim 1, wherein the crosslinking agent or curing catalyst has at least two crosslinking functional groups.

7. The gap fill material forming composition according to claim 1, further comprising an alkaline dissolution rate modifier.

8. A method for forming a gap fill material layer for use in the manufacture of a semiconductor device, comprising applying the gap fill material forming composition according to any one of claims 1 to 7 onto a substrate and firing it.

9. A gap fill material layer obtained by coating a semiconductor substrate with the gap fill material forming composition according to any one of claims 1 to 7 and firing it, wherein the dissolution rate in an alkaline aqueous solution with a concentration of 0.1% to 20% is 3 to 500 nm per second.

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