Composition for forming resist underlayer film

Abstract

To provide a composition for an underlayer film.SOLUTION: A resist underlayer film-forming composition containing a polymer having a repeating unit (1) represented by the following Formula (1) and a repeating unit (2) other than the repeating unit (1), and a solvent, wherein an average particle size of the polymer in a polymer solution containing the polymer is 50 nm or less. (In Formula (1), R1 represents a hydrogen atom, a methyl group, or a halogen atom.)SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a composition for forming a resist underlayer film, a resist underlayer film, a substrate for semiconductor processing, a method for manufacturing a semiconductor element, and a method for forming a pattern. [Background technology]

[0002] Conventionally, in the manufacture of semiconductor devices, microfabrication by lithography using a photoresist composition has been carried out. This microfabrication is a processing method in which a thin film of the photoresist composition is formed on a silicon wafer, and the thin film is irradiated with active energy rays such as ultraviolet light through a mask pattern on which a semiconductor device pattern is drawn, and then developed, and the silicon wafer is etched using the resulting resist pattern as a protective film.

[0003] However, in recent years, as semiconductor devices have become more highly integrated, the wavelength of the active energy rays used has tended to become shorter, from KrF excimer lasers (248 nm) to ArF excimer lasers (193 nm). This has led to major problems with the diffuse reflection of the active energy rays from the substrate and the effects of standing waves. Therefore, methods such as providing a bottom anti-reflective coating (BARC), which is a resist underlayer film, between the photoresist and the substrate, have come under widespread investigation.

[0004] For example, the present applicant has proposed an anti-reflective coating-forming composition that has a high anti-reflective light effect, does not cause intermixing with a resist layer, provides an excellent resist pattern and a wide focus depth margin, and can provide an anti-reflective coating for lithography that has a higher dry etching rate than a resist (see Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2003 / 017002 Pamphlet Summary of the Invention [Problem to be solved by the invention]

[0006] The present inventors have found that, when using the composition described in International Publication No. 2003 / 017002 as a composition for forming a resist underlayer film, etching a resist underlayer film obtained from the composition for forming a resist underlayer film may result in the generation of minute particulate etching residues, which may reduce the yield of semiconductor devices.

[0007] An object of the present invention is to provide a composition for forming a resist underlayer film, a resist underlayer film, a substrate for semiconductor processing, a method for manufacturing a semiconductor element, and a method for pattern formation, which are capable of suppressing the generation of minute particulate etching residues. [Means for solving the problem]

[0008] The present inventors have conducted extensive research to solve the above problems, and as a result have found that the above problems can be solved, and have completed the present invention having the following gist. That is, the present invention includes the following. [1] A polymer having a repeating unit (1) represented by the following formula (1) and a repeating unit (2) other than the repeating unit (1), and a solvent: The average particle size of the polymer in the polymer solution containing the polymer is 50 nm or less. A composition for forming a resist underlayer film. [ka] (In formula (1), R 1 represents a hydrogen atom, a methyl group, or a halogen atom; R 2 represents a trivalent hydrocarbon group having 3 to 6 carbon atoms, provided that R 2 The lactone structure containing is a 5-membered or 6-membered ring. [2] The composition for forming a resist underlayer film according to [1], wherein the repeating unit (2) includes a repeating unit (2A) represented by the following formula (2A): [ka] (In formula (2A), R 11 represents a hydrogen atom, a methyl group, or a halogen atom; Q 1 represents a single bond or a divalent linking group, R 12 represents a hydrogen atom or a monovalent organic group. [3] The composition for forming a resist underlayer film according to [1] or [2], wherein the repeating unit (2) includes a repeating unit (2A-1) represented by the following formula (2A-1) and a repeating unit (2A-2) represented by the following formula (2A-2): [ka] (In formula (2A-1), X 21 represents -O- or -N(-R)- (wherein R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms). 21 represents a hydrogen atom, a methyl group, or a halogen atom; R 22 represents a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms. In formula (2A-2), X 31 represents -O- or -N(-R)- (wherein R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms). 31 represents a hydrogen atom, a methyl group, or a halogen atom; R 32 represents a substituted or unsubstituted aralkyl group, a substituted or unsubstituted carbocyclic aromatic group, or a substituted or unsubstituted heterocyclic aromatic group. [4] In the polymer, the weight ratio of the repeating unit (1) to all repeating units is 1 to 75% by weight, In the polymer, the total weight ratio of the repeating unit (2A-1) and the repeating unit (2A-2) to all repeating units is 25 to 99% by weight. The composition for forming a resist underlayer film according to [3]. [5] The composition for forming a resist underlayer film according to any one of [1] to [4], wherein the polymer has a weight average molecular weight of 50,000 or less. [6] The composition for forming a resist underlayer film according to any one of [1] to [5], further comprising a crosslinking agent. [7] The composition for forming a resist underlayer film according to any one of [1] to [6], further comprising a curing catalyst. [8] A resist underlayer film, which is a cured product of the composition for forming a resist underlayer film according to any one of [1] to [7]. [9] a semiconductor substrate; [8] The resist underlayer film according to [8], A semiconductor processing substrate comprising:

[10] A step of forming a resist underlayer film on a semiconductor substrate using the composition for forming a resist underlayer film according to any one of [1] to [7]; forming a resist film on the resist underlayer film; A method for manufacturing a semiconductor device, comprising:

[11] A step of forming a resist underlayer film on a semiconductor substrate using the composition for forming a resist underlayer film according to any one of [1] to [7]; forming a resist film on the resist underlayer film; irradiating the resist film with light or an electron beam, and then developing the resist film to obtain a resist pattern; etching the resist underlayer film using the resist pattern as a mask; A pattern forming method comprising: [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a composition for forming a resist underlayer film, a resist underlayer film, a substrate for semiconductor processing, a method for manufacturing a semiconductor element, and a method for forming a pattern, which are capable of suppressing the generation of fine particulate etching residues. [Brief explanation of the drawings]

[0010] [Figure 1A] FIG. 1A shows the particle size distribution of Sample 1 of the polymer solution of Synthesis Example 1. [Figure 1B] FIG. 1B shows the particle size distribution of Sample 2 of the polymer solution of Synthesis Example 1. [Figure 1C] FIG. 1C shows the particle size distribution of Sample 3 of the polymer solution of Synthesis Example 1. [Figure 2A] FIG. 2A shows the particle size distribution of Sample 1 of the polymer solution of Synthesis Example 2. [Figure 2B] FIG. 2B shows the particle size distribution of Sample 2 of the polymer solution of Synthesis Example 2. [Figure 2C] FIG. 2C shows the particle size distribution of Sample 3 of the polymer solution of Synthesis Example 2. DETAILED DESCRIPTION OF THE INVENTION

[0011] (Composition for forming resist underlayer film) The composition for forming a resist underlayer film of the present invention contains a polymer and a solvent. The composition for forming a resist underlayer film may contain other components. The average particle size of the polymer in the polymer solution is 50 nm or less.

[0012] The present inventors have found that, when using the composition described in International Publication No. 2003 / 017002 as a composition for forming a resist underlayer film, etching a resist underlayer film obtained from the composition for forming a resist underlayer film may result in the generation of minute particulate etching residues, which may reduce the yield of semiconductor devices. The etching residue may be caused by, for example, metal impurities in the composition. However, as a result of investigations by the present inventors, the minute particulate etching residue was not caused by metal impurities. As a result of further investigations, the present inventors have found that the polymer contained in the composition for forming a resist underlayer film affects the formation of minute particulate etching residues. They have found that there are parts in the polymer that are difficult to etch, and these parts cause the formation of etching residues. The present inventors have focused on a monomer that constitutes a polymer and has a lactone structure and a polymerizable unsaturated bond (hereinafter, this may be referred to as a "lactone structure-containing monomer"). Generally, in multi-component polymers synthesized by radical polymerization using two or more monomers, the copolymerization reactivity ratios between the monomers differ, so the copolymerization composition ratios of the polymers produced in the early and late stages of polymerization differ, and the final polymer obtained has a composition distribution. Compared with other monomers, lactone structure-containing monomers have a faster polymerization rate in copolymerization. Therefore, as described in the Examples (e.g., Synthesis Examples 1 to 5) of International Publication No. 2003 / 017002, when two or more monomers are mixed together and polymerized in accordance with the composition ratio in the final polymer, a relatively large amount of lactone structure-containing monomer is consumed in the early stages of polymerization, which is thought to result in uneven distribution of repeating units derived from lactone structure-containing monomers in the polymer chains produced in the early stages of polymerization. The uneven distribution of repeating units derived from lactone structure-containing monomers in the polymer chains leads to increased entanglement of the polymer chains. This is thought to result in a decrease in the solubility of the polymer and an increase in the average particle size of the polymer in the polymer solution. As a result of further investigations, the present inventors have found that the generation of minute particulate etching residues can be suppressed by using a polymer having a small average particle size in a polymer solution as the polymer contained in a composition for forming a resist underlayer film, and have thus completed the present invention.

[0013] In the present invention, the average particle size of the polymer in the polymer solution containing the polymer is 50 nm or less, preferably 40 nm or less, more preferably 30 nm or less, and particularly preferably 20 nm or less. The lower limit of the average particle size of the polymer is not particularly limited, but may be 1 nm or more, 2 nm or more, or 5 nm or more. The average particle size of the polymer in the polymer solution can be determined by dynamic light scattering measurement. Dynamic light scattering measurements are performed using, for example, a dynamic light scattering photometer DLS-8000Ar (manufactured by Otsuka Electronics Co., Ltd.). A He-Ne laser (wavelength 633 nm) is used as the incident light, and measurements are performed at a scattering angle of 90° to determine the autocorrelation function. The obtained autocorrelation function can be analyzed by the cumulant method using an analysis program provided with the measuring instrument to determine the average particle size and polydispersity index. Particle size distribution analysis can be performed using the Contin method. The polydispersity index of the present invention is, for example, 0.25 or less, 0.24 or less, 0.23 or less, 0.22 or less, 0.21 or less, 0.20 or less, 0.18 or less, or 0.15 or less.

[0014] The number of minute particulate etching residues (Cone defect number) exhibited by the composition of the present invention is, for example, 2500 or less, 2300 or less, 2000 or less, 1500 or less, 1000 or less, 800 or less, 700 or less, 600 or less, 500 or less, 400 or less, 300 or less, 200 or less, 100 or less, 80 or less, 70 or less, 50 or less, 30 or less, 20 or less, or 10 or less, as determined by the etching defect evaluation method shown in the examples.

[0015] The solvent in the polymer solution is preferably the solvent used for polymerizing the polymer. Therefore, it is preferable to use the polymer solution obtained by polymerizing a monomer in a solvent as the polymer solution for measuring the average particle size. Examples of the solvent used for polymer polymerization include polyhydric alcohol derivatives. Examples of the polyhydric alcohol derivatives include ethylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, and propylene glycol monomethyl ether acetate.

[0016] From the viewpoint of measurement reliability, the polymer concentration in the polymer solution is preferably 10 to 30 mass %. With a polymer solution of such a concentration, entanglement of polymer chains occurs to some extent in the polymer solution, making it easier to obtain results that correlate with the generation of minute particulate etching residues. Typically, the amount of polymer in a composition for forming a resist underlayer film is small, so even if an attempt is made to measure the average particle size of the polymer using the composition for forming a resist underlayer film, it is difficult to obtain results that correlate with the occurrence of fine particulate etching residues. This is thought to be because when the polymer concentration is low, entanglement of polymer chains is less likely to occur. Furthermore, a composition for forming a resist underlayer film as a finished product may also contain components other than the polymer (e.g., crosslinking agents, curing catalysts, and other components). When dynamic light scattering measurement is performed on the composition for forming a resist underlayer film, the particle size distribution obtained is a mixture of the particle size distribution of the polymer and the particle size distribution of components other than the polymer, making it difficult to obtain results that correlate with the occurrence of fine particulate etching residues. From this viewpoint, when measuring the average particle size in the present invention, it is suitable to use a polymer solution, and more suitable to use a polymer solution having a polymer concentration of 10 to 30 mass %.Furthermore, it is suitable to use a polymer solution in which only the polymer is dissolved in a solvent, without containing a crosslinking agent, a curing catalyst, etc.

[0017] <Polymer> The polymer has a repeating unit (1) represented by the following formula (1): The polymer also has a repeating unit (2) other than the repeating unit (1). In this respect, the polymer can be said to be a copolymer. [ka] (In formula (1), R 1 represents a hydrogen atom, a methyl group, or a halogen atom; R 2 represents a trivalent hydrocarbon group having 3 to 6 carbon atoms, provided that R 2 The lactone structure containing is a 5-membered or 6-membered ring.

[0018] In this specification, halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms.

[0019] Examples of the repeating unit (1) represented by formula (1) include repeating units represented by the following formulae (1-1) to (1-3). [ka] (In formulas (1-1) to (1-3), R 1 represents a hydrogen atom, a methyl group, or a halogen atom.

[0020] R in formula (1) and formulas (1-1) to (1-3) 1 As the alkyl group, a methyl group is preferred.

[0021] The repeating unit (2) is not particularly limited as long as it is a repeating unit other than the repeating unit (1) represented by formula (1), but it is preferable that it contains a repeating unit (2A) represented by the following formula (2A). [ka] (In formula (2A), R 11 represents a hydrogen atom, a methyl group, or a halogen atom; Q 1 represents a single bond or a divalent linking group, R 12 represents a hydrogen atom or a monovalent organic group.

[0022] Q 1 The divalent linking group in is not particularly limited, and examples include -C(=O)O-, -O-, -C(=O)-N(-R)- (R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms), -NHC(=O)NH- (urea bond), -NHC(=O)O- (urethane bond), -C(=O)-, -S-, -SO-, and -NH-.

[0023] R 12 The monovalent organic group in is not particularly limited, but examples thereof include monovalent organic groups having 1 to 30 carbon atoms. R12 Examples of the monovalent organic group in the formula (I) include a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted carbocyclic aromatic group, and a substituted or unsubstituted heterocyclic aromatic group. Examples of the substituents include halogen atoms, hydroxy groups, carboxy groups, alkoxy groups, cyano groups, nitro groups, amino groups, etc. Examples of the alkoxy groups include alkoxy groups having 1 to 6 carbon atoms. It should be noted that the "1 to 10 carbon atoms" in the "substituted or unsubstituted alkyl group having 1 to 10 carbon atoms" does not include the number of carbon atoms of the substituent.

[0024] Examples of the alkyl group in the substituted or unsubstituted alkyl group having 1 to 10 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, a cyclopropyl group, an n-butyl group, an i-butyl group, an s-butyl group, a t-butyl group, a cyclobutyl group, a 1-methyl-cyclopropyl group, a 2-methyl-cyclopropyl group, an n-pentyl group, a 1-methyl-n-butyl group, a 2-methyl-n-butyl group, a 3-methyl-n-butyl group, a 1,1-dimethyl-n-propyl group, a 1,2-dimethyl-n-propyl group, a 2,2-dimethyl-n-propyl group, a butyl, 1-ethyl-n-propyl, cyclopentyl, 1-methyl-n-cyclobutyl, 2-methyl-cyclobutyl, 3-methyl-cyclobutyl, 1,2-dimethyl-cyclopropyl, 2,3-dimethyl-cyclopropyl, 1-ethyl-n-cyclopropyl, 2-ethyl-cyclopropyl, n-hexyl, 1-methyl-n-pentyl, 2-methyl-n-pentyl, 3-methyl-n-pentyl, 4-methyl-n-pentyl, 1,1-dimethyl-n-butyl, 1,2-dimethyl-n-butyl, 1,3-dimethyl -n-butyl, 2,2-dimethyl-n-butyl, 2,3-dimethyl-n-butyl, 3,3-dimethyl-n-butyl, 1-ethyl-n-butyl, 2-ethyl-n-butyl, 1,1,2-trimethyl-n-propyl, 1,2,2-trimethyl-n-propyl, 1-ethyl-1-methyl-n-propyl, 1-ethyl-2-methyl-n-propyl, cyclohexyl, 1-methyl-cyclopentyl, 2-methyl-cyclopentyl, 3-methyl-cyclopentyl, 1-ethyl-cyclobutyl, 2-ethyl-cyclo butyl, 3-ethylcyclobutyl, 1,2-dimethylcyclobutyl, 1,3-dimethylcyclobutyl, 2,2-dimethylcyclobutyl, 2,3-dimethylcyclobutyl, 2,4-dimethylcyclobutyl, 3,3-dimethylcyclobutyl, 1-n-propylcyclopropyl, 2-n-propylcyclopropyl, 1-i-propylcyclopropyl, 2-i-propylcyclopropyl, 1,2,2-trimethylcyclopropyl, 1,2,3-trimethylcyclopropyl, 2,2,Examples of the alkyl group include 3-trimethyl-cyclopropyl group, 1-ethyl-2-methyl-cyclopropyl group, 2-ethyl-1-methyl-cyclopropyl group, 2-ethyl-2-methyl-cyclopropyl group, 2-ethyl-3-methyl-cyclopropyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, and icodecyl group.

[0025] Examples of the aralkyl group in the substituted or unsubstituted aralkyl group include a benzyl group, a phenethyl group, a naphthylmethyl group, and an anthrylmethyl group.

[0026] Examples of the carbocyclic aromatic group in the substituted or unsubstituted carbocyclic aromatic group include a phenyl group, a naphthyl group, an anthryl group, and a phenanthryl group. The substituted or unsubstituted carbocyclic aromatic group may have 6 to 30 carbon atoms, for example. Examples of substituted or unsubstituted carbocyclic aromatic groups include phenyl, o-methylphenyl, m-methylphenyl, p-methylphenyl, o-chlorophenyl, m-chlorophenyl, p-chlorophenyl, o-fluorophenyl, p-fluorophenyl, o-methoxyphenyl, p-methoxyphenyl, p-nitrophenyl, p-cyanophenyl, α-naphthyl, β-naphthyl, o-biphenylyl, m-biphenylyl, p-biphenylyl, 1-anthryl, 2-anthryl, 9-anthryl, 1-phenanthryl, 2-phenanthryl, 3-phenanthryl, 4-phenanthryl, and 9-phenanthryl groups.

[0027] Examples of the heterocyclic aromatic group in the substituted or unsubstituted heterocyclic aromatic group include a pyridyl group, a quinolinyl group, and a quinoxalinyl group.

[0028] The repeating unit (2) preferably contains a repeating unit (2A-1) represented by the following formula (2A-1) and a repeating unit (2A-2) represented by the following formula (2A-2). [ka] (In formula (2A-1), X 21 represents -O- or -N(-R)- (wherein R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms). 21 represents a hydrogen atom, a methyl group, or a halogen atom; R 22 represents a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms. In formula (2A-2), X 31 represents -O- or -N(-R)- (wherein R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms). 31 represents a hydrogen atom, a methyl group, or a halogen atom; R 32 represents a substituted or unsubstituted aralkyl group, a substituted or unsubstituted carbocyclic aromatic group, or a substituted or unsubstituted heterocyclic aromatic group.

[0029] R 22 Specific examples of the substituted or unsubstituted alkyl group having 1 to 10 carbon atoms in the formula include, for example, R 12 Specific examples of the substituted or unsubstituted alkyl group having 1 to 10 carbon atoms in the description of the above are given. R 32 Specific examples of the substituted or unsubstituted aralkyl group, the substituted or unsubstituted carbocyclic aromatic group, and the substituted or unsubstituted heterocyclic aromatic group in 12 Specific examples of the substituted or unsubstituted aralkyl group, the substituted or unsubstituted carbocyclic aromatic group, and the substituted or unsubstituted heterocyclic aromatic group in the description of the above are given below.

[0030] R in formula (2A) 11 , R in formula (2A-1) 21 and R in formula (2A-2) 31 As the alkyl group, a methyl group is preferred.

[0031] The proportion of the repeating unit (1) in the polymer is not particularly limited. The weight proportion of the repeating unit (1) relative to all repeating units in the polymer is preferably from 1 to 75% by weight, more preferably from 5 to 60% by weight, and particularly preferably from 10 to 45% by weight. The weight proportion of the repeating unit (2) relative to all repeating units in the polymer is not particularly limited, but is preferably from 25 to 99% by weight, more preferably from 40 to 95% by weight, and particularly preferably from 55 to 90% by weight. The total weight proportion of the repeating units (2A-1) and (2A-2) to all repeating units in the polymer is not particularly limited, but is preferably 25 to 99% by weight, more preferably 40 to 95% by weight, and particularly preferably 55 to 90% by weight.

[0032] The molecular weight of the polymer is not particularly limited. The weight average molecular weight of the polymer measured by gel permeation chromatography is not particularly limited, but is preferably 100,000 or less, more preferably 50,000 or less, and particularly preferably 30,000 or less. The lower limit of the weight average molecular weight of the polymer is not particularly limited, but the weight average molecular weight is preferably 5,000 or more.

[0033] <<Polymer manufacturing method>> The polymer is obtained by radical polymerization of two or more monomers. One of the two or more monomers is a monomer represented by the following formula (1'). The polymer production method is a production method that reduces the average particle size of the polymer in the polymer solution. Examples of such production methods include the polymer production method described in WO 2012 / 053434. Specific examples include polymerization methods (Z1) and (Z2) described in paragraphs

[0062] to

[0066] of WO 2012 / 053434. The contents of WO 2012 / 053434 are incorporated herein by reference in their entirety. Specific examples of polymer production methods include those described in Reference Example B-3 and Example B-3 of WO 2012 / 053434. Herein, the monomer represented by the following formula (1') corresponds to the monomer m-1 represented by formula (m-1) in Reference Example B-3 of WO 2012 / 053434. The monomer represented by the following formula (2A'-1) in this specification corresponds to the monomer m-7 represented by formula (m-7) in Reference Example B-3 of WO 2012 / 053434. The monomer represented by the following formula (2A'-2) in this specification corresponds to the monomer m-6 represented by formula (m-6) in Reference Example B-3 of WO 2012 / 053434. In Reference Example B-3 of WO 2012 / 053434, the following polymerization is carried out to design the composition of a solution Uc to be used in a subsequent step. During the polymerization, a solution containing a monomer mixture, solvent, and polymerization initiator was added dropwise to the flask from a dropping funnel at a constant rate over a period of 4 hours, and the temperature was maintained at 80°C for another 3 hours. Seven hours after the start of the addition of the solution, the mixture was cooled to room temperature to terminate the reaction. In Reference Example B-3, 0.5 g of the polymerization reaction solution in the flask was sampled 0.5, 1, 2, 3, 4, 5, 6, and 7 hours after the start of dropping the dropping solution, and the amounts of the monomers m-1, m-6, and m-7 were determined, respectively. This allowed the mass of each monomer remaining in the flask to be determined. In Reference Example B-3, the content ratio of the monomer units (polymer composition) in the polymer produced during each reaction time period was determined. In Reference Example B-3, the composition of Uc is determined as x0:y0:z0. Based on the results of Reference Example B-3, Example B-3 includes a post-step of adding Uc dropwise after the main step of supplying Sa into the reactor in advance and adding Tb and a polymerization initiator solution dropwise. In Example B-3, in the first composition of Sa previously fed into the reaction vessel, the composition ratio of the monomer m-1 having a fast polymerization rate is smaller than the composition ratio of the monomer m-1 in the target composition. By doing so, in Example B-3, it is possible to prevent the monomer m-1 from being ubiquitous in the polymer chains produced in the early stages of polymerization in an amount greater than the composition ratio in the target composition. This reduces entanglement of the polymer chains, resulting in a polymer with a small average particle size in the polymer solution.

[0034] The monomer that gives the repeating unit (1) represented by formula (1) to the polymer is a monomer represented by the following formula (1'). [ka] (In formula (1'), R 1 , and R 2 are R in Equation (1), respectively. 1 , and R 2 is equivalent to

[0035] The monomer that gives the polymer the repeating unit represented by formula (1-1) is a monomer represented by the following formula (1'-1). The monomer that gives the polymer the repeating unit represented by formula (1-2) is a monomer represented by the following formula (1'-2). The monomer that gives the repeating unit represented by formula (1-3) to the polymer is a monomer represented by the following formula (1'-3). [ka] (In formula (1'-1), R 1 is R in formula (1-1) 1 is equivalent to (In formula (1'-2), R 1 is R in formula (1-2) 1 is equivalent to (In formula (1'-3), R 1 is R in formula (1-3) 1 is equivalent to

[0036] The monomer that provides the repeating unit (2A) represented by formula (2A) in the polymer is a monomer represented by the following formula (2A'). The monomer that provides the repeating unit (2A-1) represented by formula (2A-1) in the polymer is a monomer represented by the following formula (2A'-1). The monomer that provides the repeating unit (2A-2) represented by formula (2A-2) in the polymer is a monomer represented by the following formula (2A'-2). [ka] (In formula (2A'), R 11 , R 12 , and Q 1 are R in formula (2A), respectively. 11 , R 12 , and Q 1 is synonymous with. In formula (2A'-1), R 21 , R 22 , and X 21 are R in formula (2A-1), respectively. 21 , R 22 , and X 21 is synonymous with. In formula (2A'-2), R 31 , R 32 , and X 31 are R in formula (2A-2), respectively. 31 , R 32 , and X 31 is equivalent to

[0037] Examples of the monomer represented by formula (2A') include acrylic acid esters, methacrylic acid esters, acrylamides, methacrylamides, allyl compounds, vinyl ethers, vinyl esters, and styrenes. Examples of acrylic acid esters include substituted or unsubstituted alkyl acrylates in which the alkyl group has 1 to 10 carbon atoms, aralkyl esters of acrylic acid, and aryl esters of acrylic acid. Examples of methacrylic acid esters include substituted or unsubstituted alkyl methacrylates in which the alkyl group has 1 to 10 carbon atoms, aralkyl esters of methacrylic acid, and aryl esters of methacrylic acid. Examples of acrylamides include N-alkylacrylamide, N-arylacrylamide, N,N-dialkylacrylamide, N,N-diarylacrylamide, N-methyl-N-phenylacrylamide, and N-2-acetamidoethyl-N-acetylacrylamide. Examples of methacrylamides include N-alkylmethacrylamides, N-arylmethacrylamides, N,N-dialkylmethacrylamides, N,N-diarylmethacrylamides, N-methyl-N-phenylmethacrylamide, and N-ethyl-N-phenylmethacrylamide. Examples of vinyl ethers include alkyl vinyl ethers and vinyl aryl ethers. Examples of vinyl esters include vinyl butyrate, vinyl isobutyrate, and vinyl trimethyl acetate. Examples of styrenes include styrene, alkylstyrene, alkoxystyrene, halogenated styrene, and carboxystyrene.

[0038] <<<Polymerization initiator>>> As the polymerization initiator used in the polymerization, an organic peroxide or a diazo compound can be used.

[0039] Examples of organic peroxides include diacyl peroxides, peroxydicarbonates, peroxyesters, and peroxysulfonates. Examples of diacyl peroxides include diacetyl peroxide, diisobutyl peroxide, didecanoyl peroxide, benzoyl peroxide, and succinic acid peroxide. Examples of peroxydicarbonates include diisopropyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, and diallyl peroxydicarbonate. Examples of peroxyesters include tert-butyl peroxyisobutyrate, tert-butyl neodecanoate, and cumene peroxy neodecanoate. Examples of peroxide sulfonates include acetylcyclohexylsulfonyl peroxide.

[0040] Examples of diazo compounds include 2,2'-azobisisobutyronitrile, 4,4'-azobis(4-cyanovaleric acid), 2,2'-azobis(4-methoxy-2,4-dimethoxyvaleronitrile), and 2,2'-azobis(2-cyclopropylpropionitrile).

[0041] When it is desired to complete the polymerization in a short time, it is preferable to use a polymerization initiator having a decomposition half-life of 10 hours or less at 80° C. As such a polymerization initiator, benzoyl peroxide and 2,2′-azobisisobutyronitrile are preferred, and 2,2′-azobisisobutyronitrile is more preferred.

[0042] The amount of the polymerization initiator used is, for example, 0.0001 to 0.2 equivalents, and preferably 0.0005 to 0.1 equivalents, based on the total amount of the monomers used.

[0043] <<<Solvent>>> The solvent used in the polymerization is not particularly limited as long as it is a solvent that is not involved in the polymerization reaction and is compatible with the resulting polymer, and examples thereof 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 the 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. The sulfoxides include, for example, dimethyl sulfoxide. Examples of alcohols include methanol and ethanol. Examples of polyhydric alcohol derivatives include ethylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, and propylene glycol monomethyl ether acetate. These may be used alone or in combination of two or more.

[0044] The polymerization temperature is not particularly limited as long as it is within a temperature range in which side reactions such as transfer reactions and termination reactions do not occur, the monomers are consumed, and the polymerization is completed. However, it is preferable to carry out the polymerization within a temperature range of -100°C or higher and the boiling point of the solvent or lower. The concentration of the monomer relative to the solvent is not particularly limited, but is usually 1 to 40% by mass, and preferably 10 to 30% by weight. The time for the polymerization reaction can be appropriately selected, but is usually in the range of 2 to 50 hours.

[0045] The content of the polymer in the composition for forming a resist underlayer film is not particularly limited, but is preferably 30% by mass to 95% by mass, more preferably 50% by mass to 90% by mass, and particularly preferably 60% by mass to 85% by mass, based on the film constituent components. The film-constituting components are components remaining after excluding volatile components (solvent) from the composition for forming a resist film.

[0046] <Crosslinking agent> The composition for forming a resist underlayer film preferably contains a crosslinking agent. The crosslinking agent contained as an optional component in the composition for forming a resist underlayer film has, for example, a functional group that reacts by itself. Examples of crosslinking agents include hexamethoxymethylmelamine, tetramethoxymethylbenzoguanamine, 1,3,4,6-tetrakis(methoxymethyl)glycoluril (tetramethoxymethylglycoluril) (POWDERLINK (registered trademark) 1174), 1,3,4,6-tetrakis(butoxymethyl)glycoluril, 1,3,4,6-tetrakis(hydroxymethyl)glycoluril, 1,3-bis(hydroxymethyl)urea, 1,1,3,3-tetrakis(butoxymethyl)urea, and 1,1,3,3-tetrakis(methoxymethyl)urea.

[0047] The crosslinking agent may also be a nitrogen-containing compound having 2 to 6 substituents bonded to nitrogen atoms and represented by the following formula (1d) per molecule, as described in WO 2017 / 187969.

[0048] [ka] (In formula (1d), R1 represents a methyl group or an ethyl group. * represents a bond bonded to the nitrogen atom.)

[0049] The nitrogen-containing compound having 2 to 6 substituents represented by the formula (1d) in one molecule may be a glycoluril derivative represented by the following formula (1E).

[0050] [ka] (In formula (1E), four R1s each independently represent a methyl group or an ethyl group, and R2 and R3 each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a phenyl group.)

[0051] Examples of the glycoluril derivative represented by the formula (1E) include compounds represented by the following formulae (1E-1) to (1E-6).

[0052] [ka]

[0053] The nitrogen-containing compound having 2 to 6 substituents represented by the formula (1d) in one molecule can be obtained by reacting a nitrogen-containing compound having 2 to 6 substituents bonded to a nitrogen atom in one molecule represented by the following formula (2d) with at least one compound represented by the following formula (3d):

[0054] [ka] (In formula (2d) and formula (3d), R1 represents a methyl group or an ethyl group, and R4 represents an alkyl group having 1 to 4 carbon atoms. * represents a bond bonded to the nitrogen atom.)

[0055] The glycoluril derivative represented by the formula (1E) can be obtained by reacting a glycoluril derivative represented by the following formula (2E) with at least one compound represented by the formula (3d).

[0056] The nitrogen-containing compound having 2 to 6 substituents represented by the formula (2d) in one molecule is, for example, a glycoluril derivative represented by the following formula (2E).

[0057] [ka] (In formula (2E), R2 and R3 each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a phenyl group, and R4 each independently represent an alkyl group having 1 to 4 carbon atoms.)

[0058] Examples of glycoluril derivatives represented by the formula (2E) include compounds represented by the following formulae (2E-1) to (2E-4): Furthermore, examples of compounds represented by the formula (3d) include compounds represented by the following formulae (3d-1) and (3d-2):

[0059] [ka] [ka]

[0060] The entire disclosure of WO2017 / 187969 is incorporated herein by reference for the content relating to the nitrogen-containing compound having 2 to 6 substituents represented by formula (1d) bonded to the nitrogen atom per molecule.

[0061] The crosslinking agent may be a crosslinkable compound represented by the following formula (G-1) or (G-2), which is described in WO 2014 / 208542.

[0062] [ka] (In the formula, Q 1 represents a single bond or a monovalent organic group, and R 1 and R 4 each represents an alkyl group having 2 to 10 carbon atoms or an alkyl group having 2 to 10 carbon atoms and an alkoxy group having 1 to 10 carbon atoms; R 2 and R 5 each represents a hydrogen atom or a methyl group, and R 3 and R 6 represents an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 40 carbon atoms. n1 is an integer satisfying 1≦n1≦3, n2 is an integer satisfying 2≦n2≦5, n3 is an integer satisfying 0≦n3≦3, n4 is an integer satisfying 0≦n4≦3, and 3≦(n1+n2+n3+n4)≦6. n5 is an integer in the range of 1≦n5≦3, n6 is an integer in the range of 1≦n6≦4, n7 is an integer in the range of 0≦n7≦3, n8 is an integer in the range of 0≦n8≦3, and 2≦(n5+n6+n7+n8)≦5. m1 represents an integer of 2 to 10.

[0063] The crosslinkable compound represented by the above formula (G-1) or formula (G-2) may be obtained by reacting a compound represented by the following formula (G-3) or formula (G-4) with a hydroxyl group-containing ether compound or an alcohol having 2 to 10 carbon atoms.

[0064] [ka] (In the formula, Q 2 represents a single bond or a divalent organic group. 8 , R 9 , R 11 and R 12 each represents a hydrogen atom or a methyl group, and R 7 and R 10 represents an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 40 carbon atoms. n9 is an integer in the range of 1≦n9≦3, n10 is an integer in the range of 2≦n10≦5, n11 is an integer in the range of 0≦n11≦3, n12 is an integer in the range of 0≦n12≦3, and 3≦(n9+n10+n11+n12)≦6. n13 is an integer satisfying 1≦n13≦3, n14 is an integer satisfying 1≦n14≦4, n15 is an integer satisfying 0≦n15≦3, n16 is an integer satisfying 0≦n16≦3, and 2≦(n13+n14+n15+n16)≦5. m2 represents an integer from 2 to 10.

[0065] Examples of the compounds represented by the above formula (G-1) and formula (G-2) include the following.

[0066] [ka]

[0067] [ka]

[0068] [ka]

[0069] [ka]

[0070] [ka]

[0071] Examples of the compounds represented by formula (G-3) and formula (G-4) include the following.

[0072] [ka]

[0073] [ka] In the formula, Me represents a methyl group.

[0074] The entire disclosure of WO 2014 / 208542 is incorporated herein by reference.

[0075] When the crosslinking agent is used, the content of the crosslinking agent in the composition for forming a resist underlayer film is, for example, 1% by mass to 50% by mass, and preferably 5% by mass to 40% by mass, relative to the polymer.

[0076] <Curing catalyst> The curing catalyst contained as an optional component in the composition for forming a resist underlayer film may be either a thermal acid generator or a photoacid generator, but it is preferable to use a thermal acid generator.

[0077] Examples of the thermal acid generator 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 p-phenolsulfonate salt), 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, and hydroxybenzoic acid.

[0078] Examples of the photoacid generator include an onium salt compound, a sulfonimide compound, and a disulfonyldiazomethane compound.

[0079] Examples of the onium salt compound include iodonium salt compounds such as diphenyliodonium hexafluorophosphate, diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoro-normal butanesulfonate, diphenyliodonium perfluoro-normal 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 nonafluoro-normal butanesulfonate, triphenylsulfonium camphorsulfonate, and triphenylsulfonium trifluoromethanesulfonate.

[0080] Examples of the sulfonimide compound include N-(trifluoromethanesulfonyloxy)succinimide, N-(nonafluoronormalbutanesulfonyloxy)succinimide, N-(camphorsulfonyloxy)succinimide, and N-(trifluoromethanesulfonyloxy)naphthalimide.

[0081] Examples of disulfonyldiazomethane compounds include bis(trifluoromethylsulfonyl)diazomethane, bis(cyclohexylsulfonyl)diazomethane, bis(phenylsulfonyl)diazomethane, bis(p-toluenesulfonyl)diazomethane, bis(2,4-dimethylbenzenesulfonyl)diazomethane, and methylsulfonyl-p-toluenesulfonyldiazomethane.

[0082] The curing catalyst may be used alone or in combination of two or more.

[0083] When a curing catalyst is used, the content of the curing catalyst is, for example, 0.1% by mass to 50% by mass, and preferably 1% by mass to 30% by mass, relative to the crosslinking agent.

[0084] <Solvent> The solvent is preferably an organic solvent generally used in chemical solutions for semiconductor lithography processes, specifically 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 monoethyl ether, propylene glycol monomethyl ether acetate, propylene glycol propyl ether acetate, toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, cyclohexane, cyclohexane-1, cyclohexane-2, cyclohexane-3, cyclohexane-4, cyclohexane-5, cyclohexane-6, cyclohexane-7, cyclohexane-8, cyclohexane-9, cyclohexane-10, cyclohexane-11, cyclohexane-12, cyclohexane-13, cyclohexane-14, cyclohexane-15, cyclohexane-16, cyclohexane-17, cyclohexane-18, cyclohexane-19, cyclohexane-20, cyclohexane-21, cyclohexane-22, cyclohexane-23, cyclohexane-24, cyclohexane-25, cyclohexane-26, cyclohexane-27, cyclohexane-28, cyclohexane-29, cyclohexane-30, cyclohexane-31, cyclohexane-32, cyclohexane-33, cyclohexane-34, cyclohexane-35, cyclohexane-36, cyclohexane-37, cyclohexane-38, cyclohexane-39, cyclohexane-40, cyclohexane-41, cyclohexane-42, cyclohexane-43, cyclohexane-44, cyclohexane-45, cyclohexane-45, cyclohexane-46, cyclohexane-47, cyclohexane-48, cyclohexane-49, cyclohexane-51, cyclohexane-52, cyclohexane-53, cyclohexane-54 Examples of suitable solvents include heptanone, 4-methyl-2-pentanol, methyl 2-hydroxyisobutyrate, ethyl 2-hydroxyisobutyrate, ethyl ethoxyacetate, 2-hydroxyethyl acetate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl 3-ethoxypropionate, methyl pyruvate, ethyl pyruvate, ethyl acetate, butyl acetate, ethyl lactate, butyl lactate, 2-heptanone, methoxycyclopentane, anisole, γ-butyrolactone, N-methylpyrrolidone, N,N-dimethylformamide, and N,N-dimethylacetamide. These solvents may be used alone or in combination of two or more.

[0085] Among these solvents, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, ethyl lactate, butyl lactate, and cyclohexanone are preferred, with propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate being particularly preferred.

[0086] <Other ingredients> A surfactant may be further added to the composition for forming a resist underlayer film in order to prevent pinholes, striations, etc., and to further improve coating properties for preventing surface irregularities.

[0087] Examples of surfactants include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, and polyoxyethylene oleyl ether; polyoxyethylene alkyl aryl ethers such as polyoxyethylene octylphenol ether and polyoxyethylene nonylphenol ether; polyoxyethylene-polyoxypropylene block copolymers; sorbitan fatty acid esters such as sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, sorbitan trioleate, and sorbitan tristearate; polyoxyethylene sorbitan monolaurate; polyoxyethylene sorbitan monopalmitate; nonionic surfactants such as polyoxyethylene sorbitan fatty acid esters, such as polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, and polyoxyethylene sorbitan tristearate; fluorine-based surfactants such as F-TOP EF301, EF303, and EF352 (trade names, manufactured by Tochem Products Co., Ltd.), Megafac F171, F173, and R-30 (trade names, manufactured by DIC Corporation), Fluorad FC430 and FC431 (trade names, manufactured by Sumitomo 3M Limited), Asahiguard AG710, Surflon S-382, SC101, SC102, SC103, SC104, SC105, and SC106 (trade names, manufactured by Asahi Glass Co., Ltd.); and organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.). The amount of these surfactants to be added is not particularly limited, but is usually 2.0% by mass or less, and preferably 1.0% by mass or less, based on the total solid content of the composition for forming a resist underlayer film. These surfactants may be added alone or in combination of two or more.

[0088] The film-constituting components contained in the composition for forming a resist underlayer film, ie, the components excluding the solvent, are, for example, 0.01% by mass to 10% by mass of the composition for forming a resist underlayer film.

[0089] (resist underlayer film) The resist underlayer film of the present invention is a cured product of the above-mentioned composition for forming a resist underlayer film. The resist underlayer film can be produced, for example, by applying the above-described composition for forming a resist underlayer film onto a semiconductor substrate and baking it.

[0090] Examples of semiconductor substrates onto which the resist underlayer film-forming composition can be applied include silicon wafers, germanium wafers, and wafers of compound semiconductors such as gallium arsenide, indium phosphide, gallium nitride, indium nitride, and aluminum nitride.

[0091] When a semiconductor substrate having an inorganic film formed on its surface is used, the inorganic film can be formed by, for example, ALD (atomic layer deposition), CVD (chemical vapor deposition), reactive sputtering, ion plating, vacuum deposition, or spin-coating (spin-on-glass: SOG). Examples of the inorganic film include polysilicon film, silicon oxide film, silicon nitride film, BPSG (Boro-Phospho Silicate Glass) film, titanium nitride film, titanium nitride oxide film, tungsten film, gallium nitride film, and gallium arsenide film. The inorganic film may be a single layer or a multilayer structure consisting of two or more layers. In the case of a multilayer structure, each layer may be the same type of inorganic film or different types of inorganic film. The thickness of the inorganic film is not particularly limited.

[0092] The resist underlayer film-forming composition of the present invention is applied onto such a semiconductor substrate using an appropriate application method such as a spinner or coater. The composition is then baked using a heating means such as a hot plate to form a resist underlayer film. Baking conditions are appropriately selected from a baking temperature of 100°C to 400°C and a baking time of 0.3 to 60 minutes. A baking temperature of 120°C to 350°C and a baking time of 0.5 to 30 minutes are preferred, and a baking temperature of 150°C to 300°C and a baking time of 0.8 to 10 minutes are more preferred.

[0093] The lower limit of the film thickness of the resist underlayer film is, for example, 1 nm, 2 nm, 3 nm, 5 nm, 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 70 nm, 80 nm, 90 nm, or 100 nm, and the upper limit is, for example, 10 μm, 8 μm, 5 μm, 3 μm, 2 μm, 1 μm, 900 nm, 800 nm, 700 nm, 600 nm, 500 nm, 400 nm, 300 nm, or 200 nm.

[0094] In this specification, the method for measuring the film thickness of the resist underlayer film is as follows. Measurement equipment name: Ellipsometric film thickness measurement equipment RE-3100 (SCREEN Co., Ltd.) SWE (Single Wavelength Ellipsometer) mode Arithmetic mean of 8 points (e.g., 8 points measured at 1cm intervals in the X direction of the wafer)

[0095] (Substrates for semiconductor processing) The substrate for semiconductor processing of the present invention comprises a semiconductor substrate and the resist underlayer film of the present invention. The semiconductor substrate may be, for example, the semiconductor substrate described above. The resist underlayer film is disposed on, for example, a semiconductor substrate.

[0096] (Semiconductor device manufacturing method, pattern formation method) The method for manufacturing a semiconductor device of the present invention includes at least the following steps. forming a resist underlayer film on a semiconductor substrate using the composition for forming a resist underlayer film of the present invention; and A process of forming a resist film on top of the resist underlayer film

[0097] The pattern forming method of the present invention includes at least the following steps. forming a resist underlayer film on a semiconductor substrate using the composition for forming a resist underlayer film of the present invention; A process of forming a resist film on top of the resist underlayer film A step of irradiating the resist film with light or an electron beam and then developing the resist film to obtain a resist pattern; and A process of etching the resist underlayer film using the resist pattern as a mask.

[0098] Usually, a resist film is formed on a resist underlayer film. The thickness of the resist film is preferably 200 nm or less, more preferably 150 nm or less, even more preferably 100 nm or less, and particularly preferably 80 nm or less, and is preferably 10 nm or more, more preferably 20 nm or more, and particularly preferably 30 nm or more.

[0099] The resist formed on the resist underlayer film by coating and baking using a known method is not particularly limited as long as it responds to light or electron beams (EB) used for irradiation. Either a negative photoresist or a positive photoresist can be used. The light or electron beam is not particularly limited, but examples thereof include i-line (365 nm), KrF excimer laser (248 nm), ArF excimer laser (193 nm), EUV (extreme ultraviolet; 13.5 nm), and EB (electron beam). In this specification, a resist that responds to EB is also referred to as a photoresist. Examples of photoresists include positive photoresists made of novolac resin and 1,2-naphthoquinone diazide sulfonic acid ester, chemically amplified photoresists made of a binder having a group that decomposes in the presence of acid to increase the alkaline dissolution rate and a photoacid generator, chemically amplified photoresists made of a low-molecular-weight compound that decomposes in the presence of acid to increase the alkaline dissolution rate of the photoresist, an alkali-soluble binder, and a photoacid generator, and chemically amplified photoresists made of a binder having a group that decomposes in the presence of acid to increase the alkaline dissolution rate of the photoresist, a low-molecular-weight compound that decomposes in the presence of acid to increase the alkaline dissolution rate of the photoresist, and a photoacid generator, and resists containing metal elements. Examples include V146G (trade name) manufactured by JSR Corporation, APEX-E (trade name) manufactured by Shipley Chemical Co., Ltd., PAR710 (trade name) manufactured by Sumitomo Chemical Co., Ltd., and AR2772 and SEPR430 (trade names) manufactured by Shin-Etsu Chemical Co., Ltd. Further examples include fluorine-containing polymer photoresists such as those described in Proc. SPIE, Vol. 3999, 330-334 (2000), Proc. SPIE, Vol. 3999, 357-364 (2000), and Proc. SPIE, Vol. 3999, 365-374 (2000).

[0100] Also, WO2019 / 188595, WO2019 / 187881, WO2019 / 187803, WO2019 / 167737, WO2019 / 167725, WO2019 / 187445, WO2019 / 167419, WO2019 / 123842, WO2019 / 054282, WO2019 / 058945, WO2019 / 058890, WO2019 / 039290, WO2019 / 044259, WO2019 / 044231, WO2019 / 026549, WO2018 / 193954, WO2019 / 123842 9 / 172054, WO2019 / 021975, WO2018 / 230334, WO2018 / 194123, JP 2018-180525, WO2018 / 190088, JP 2018-070596, JP 2018-028090, JP 2016-153409, JP 2016-130240, JP 2016-108325, JP 2016-047920, JP 2016-035570, JP 2016-035567, JP 2016-035565, JP 2019-101417, JP 2019-117373, JP 2019-052294, JP 2019-008280, JP 2019-008279, JP 2019-003176, JP 2019-003175, JP 2018-197853, JP 2019-191298, JP 2019-061217, JP 2018-045152, JP 2018-022039, JP 2016-090441, JP 2015-10878, JP 2012-168279, JP 2012-022261, JP 2012-022258, JP 2011-043749, JP 2010-18 1857, JP 2010-128369, WO2018 / 031896, JP 2019-113855, WO2017 / 156388, WO2017 / 066319, JP 2018-41099, WO2016 / 065120, WO2015 / 026482, JP 2016-29498, JP 2011-253185, etc., radiation-sensitive resin compositions, so-called resist compositions such as high-resolution patterning compositions based on organometallic solutions, and metal-containing resist compositions can be used, but are not limited to these.

[0101] Examples of the resist composition include the following compositions.

[0102] An actinic ray-sensitive or radiation-sensitive resin composition comprising: resin A having a repeating unit having an acid-decomposable group in which a polar group is protected with a protecting group that is cleaved by the action of an acid; and a compound represented by the following general formula (21):

[0103] [ka] In the general formula (21), m represents an integer of 1 to 6. R1 and R2 each independently represent a fluorine atom or a perfluoroalkyl group. L1 represents -O-, -S-, -COO-, -SO2-, or -SO3-. L2 represents an alkylene group which may have a substituent or a single bond. W1 represents a cyclic organic group which may have a substituent. M + represents a cation.

[0104] A metal-containing film-forming composition for extreme ultraviolet or electron beam lithography, comprising a compound having a metal-oxygen covalent bond and a solvent, wherein the metal element constituting the compound belongs to Periods 3 to 7 of Groups 3 to 15 of the periodic table.

[0105] A radiation-sensitive resin composition comprising a polymer having a first structural unit represented by the following formula (31) and a second structural unit represented by the following formula (32) containing an acid-dissociable group, and an acid generator.

[0106] [ka] In formula (31), Ar is a group obtained by removing (n+1) hydrogen atoms from an arene having 6 to 20 carbon atoms. 1 is a hydroxy group, a sulfanyl group, or a monovalent organic group having 1 to 20 carbon atoms. n is an integer of 0 to 11. When n is 2 or more, multiple R 1 are the same or different. R 2is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. 3 is a monovalent group having 1 to 20 carbon atoms containing the above acid-dissociable group. Z is a single bond, an oxygen atom, or a sulfur atom. R 4 is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0107] A resist composition comprising: a resin (A1) containing a structural unit having a cyclic carbonate structure, a structural unit represented by the following formula, and a structural unit having an acid labile group; and an acid generator.

[0108] [ka] [In the formula, R 2 represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom; X 1 is a single bond, -CO-O-* or -CO-NR 4 -*, * represents a bond to -Ar, R 4 represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and Ar represents an aromatic hydrocarbon group having 6 to 20 carbon atoms which may have one or more groups selected from the group consisting of a hydroxy group and a carboxyl group.]

[0109] Examples of the resist film include the following.

[0110] A resist film comprising a base resin containing a repeating unit represented by the following formula (a1) and / or a repeating unit represented by the following formula (a2), and a repeating unit that generates an acid bonded to the polymer main chain upon exposure:

[0111] [ka] (In formula (a1) and formula (a2), R A are each independently a hydrogen atom or a methyl group. 1 and R 2are each independently a tertiary alkyl group having 4 to 6 carbon atoms. 3 are each independently a fluorine atom or a methyl group, and m is an integer of 0 to 4. X 1 X is a single bond, a phenylene group, or a naphthylene group, or a linking group having 1 to 12 carbon atoms and containing at least one selected from an ester bond, a lactone ring, a phenylene group, and a naphthylene group. 2 is a single bond, an ester bond, or an amide bond.

[0112] Examples of resist materials include the following:

[0113] A resist material comprising a polymer having a repeating unit represented by the following formula (b1) or (b2):

[0114] [ka] (In formula (b1) and formula (b2), R A is a hydrogen atom or a methyl group. 1 is a single bond or an ester group. 2 is a linear, branched or cyclic alkylene group having 1 to 12 carbon atoms or an arylene group having 6 to 10 carbon atoms, and some of the methylene groups constituting the alkylene group may be substituted with an ether group, an ester group or a lactone ring-containing group; and X 2 At least one hydrogen atom in X is substituted with a bromine atom. 3 Rf is a single bond, an ether group, an ester group, or a linear, branched, or cyclic alkylene group having 1 to 12 carbon atoms, and some of the methylene groups constituting the alkylene group may be substituted with an ether group or an ester group. 1 ~Rf 4 are each independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group, but at least one is a fluorine atom or a trifluoromethyl group. 1 and Rf 2 may combine to form a carbonyl group. 1 ~R 5are each independently a linear, branched, or cyclic alkyl group having 1 to 12 carbon atoms, a linear, branched, or cyclic alkenyl group having 2 to 12 carbon atoms, an alkynyl group having 2 to 12 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, or an aryloxyalkyl group having 7 to 12 carbon atoms, in which some or all of the hydrogen atoms may be substituted with a hydroxy group, a carboxy group, a halogen atom, an oxo group, a cyano group, an amido group, a nitro group, a sultone group, a sulfone group, or a sulfonium salt-containing group, and in which some of the methylene groups constituting these groups may be substituted with an ether group, an ester group, a carbonyl group, a carbonate group, or a sulfonate ester group. 1 and R 2 may be bonded to form a ring together with the sulfur atom to which they are attached.

[0115] A resist material comprising a base resin containing a polymer containing a repeating unit represented by the following formula (a):

[0116] [ka] (In formula (a), R A is a hydrogen atom or a methyl group. 1 is a hydrogen atom or an acid labile group. 2 is a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms, or a halogen atom other than bromine. 1 X is a single bond, a phenylene group, or a linear, branched, or cyclic alkylene group having 1 to 12 carbon atoms which may contain an ester group or a lactone ring. 2 is -O-, -O-CH2-, or -NH-. m is an integer of 1 to 4. u is an integer of 0 to 3, provided that m+u is an integer of 1 to 4.

[0117] A resist composition that generates an acid upon exposure and whose solubility in a developer changes due to the action of the acid, The composition contains a base component (A) whose solubility in a developer changes under the action of an acid, and a fluorine additive component (F) that is decomposable in an alkaline developer, The fluorine additive component (F) comprises a fluorine resin component (F1) having a structural unit (f1) containing a base dissociable group and a structural unit (f2) containing a group represented by the following general formula (f2-r-1):

[0118] [ka] [In formula (f2-r-1), Rf 21 are each independently a hydrogen atom, an alkyl group, an alkoxy group, a hydroxyl group, a hydroxyalkyl group, or a cyano group. n" is an integer of 0 to 2. * is a bond.

[0119] The structural unit (f1) includes a structural unit represented by the following general formula (f1-1) or a structural unit represented by the following general formula (f1-2).

[0120] [ka] [In formulas (f1-1) and (f1-2), each R is independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. X is a divalent linking group that does not have an acid-dissociable site. A aryl X is a divalent aromatic cyclic group which may have a substituent. 01 R is a single bond or a divalent linking group. 2 are each independently an organic group having a fluorine atom.

[0121] Coatings, coating solutions, and coating compositions include, for example:

[0122] A coating comprising a metal oxo-hydroxo network having organic ligands via metal carbon bonds and / or metal carboxylate bonds.

[0123] Inorganic oxo / hydroxyl-based composition.

[0124] A coating solution comprising an organic solvent; a first organometallic composition represented by the formula R z SnO (2-(z / 2)-(x / 2)) (OH) x (where 0 < z ≦ 2 and 0 < (z + x) ≦ 4), the formula R’ n SnX 4-n (where n = 1 or 2), or a mixture thereof, where R and R’ are independently hydrocarbyl groups having 1 to 31 carbon atoms, and X is a ligand having a hydrolyzable bond to Sn or a combination thereof; and a hydrolyzable metal compound represented by the formula MX’ v (where M is a metal selected from Groups 2 to 16 of the Periodic Table of the Elements, v is a number from 2 to 6, and X’ is a ligand having a hydrolyzable M-X bond or a combination thereof), a coating solution containing a hydrolyzable metal compound.

[0125] A coating solution comprising an organic solvent and a first organometallic compound represented by the formula RSnO (3 / 2-x / 2) (OH) x (where 0 < x < 3), wherein the solution contains about 0.0025 M to about 1.5 M of tin, and R is an alkyl group or cycloalkyl group having 3 to 31 carbon atoms, and the alkyl group or cycloalkyl group is bonded to tin at a secondary or tertiary carbon atom.

[0126] An inorganic pattern-forming precursor aqueous solution comprising a mixture of water, metal oxide cations, polyatomic inorganic anions, and a radiation-sensitive ligand containing peroxide groups.

[0127] Irradiation with light or an electron beam is performed, for example, through a mask (reticle) for forming a predetermined pattern. The exposure dose and the irradiation energy of the electron beam are not particularly limited.

[0128] After the irradiation with light or electron beams and before development, baking (PEB: Post Exposure Bake) may be performed. The baking temperature is not particularly limited, but is preferably 60°C to 150°C, more preferably 70°C to 120°C, and particularly preferably 75°C to 110°C. The baking time is not particularly limited, but is preferably from 1 second to 10 minutes, more preferably from 10 seconds to 5 minutes, and particularly preferably from 30 seconds to 3 minutes.

[0129] For development, for example, an alkaline developer is used. The development temperature is, for example, 5°C to 50°C. The development time may be, for example, 10 seconds to 300 seconds. Examples of alkaline developers include aqueous solutions of inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia; primary amines such as ethylamine and n-propylamine; secondary amines such as diethylamine and di-n-butylamine; tertiary amines such as triethylamine and methyldiethylamine; alcohol amines such as dimethylethanolamine and triethanolamine; quaternary ammonium salts such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, and choline; and cyclic amines such as pyrrole and piperidine. Furthermore, aqueous solutions of the above-mentioned alkalis can be used by adding an appropriate amount of alcohols such as isopropyl alcohol or a nonionic surfactant. Among these, preferred developers are aqueous solutions of quaternary ammonium salts, more preferably aqueous solutions of tetramethylammonium hydroxide and choline. Furthermore, surfactants can also be added to these developers. Instead of an alkaline developer, a method can also be used in which development is performed with an organic solvent such as butyl acetate to develop portions of the photoresist where the alkaline dissolution rate is not improved.

[0130] Next, the resist underlayer film is etched using the formed resist pattern as a mask. The etching may be dry etching or wet etching, but dry etching is preferred. Examples of etching gases used in dry etching include fluorine-based gases such as CHF3, CF4, C2F6, C3F8, and SF6; chlorine-based gases such as Cl2 and BCl3; oxygen-based gases such as O2, O3, and H2O; reducing gases such as H2, NH3, CO, CO2, CH4, C2H2, C2H4, C2H6, C3H4, C3H6, C3H8, HF, HI, HBr, HCl, NO, NH3, and BCl3; and inert gases such as He, N2, and Ar. These gases may be used alone or in combination of two or more. For example, Japanese Patent Application Laid-Open No. 11-135476 proposes a technique for etching an organic anti-reflection film using a mixed gas of O2 (oxygen) gas and a halogen-based gas. When the inorganic film is formed on the surface of the semiconductor substrate used, the surface of the inorganic film is exposed, and when the inorganic film is not formed on the surface of the semiconductor substrate used, the surface of the semiconductor substrate is exposed. Thereafter, the semiconductor substrate is processed by a known method (dry etching method, etc.), whereby a semiconductor device can be manufactured. [Example]

[0131] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples in any way.

[0132] <Molecular weight measurement> The weight-average molecular weights of the polymers shown in the synthesis examples below in this specification are the results of measurements by gel permeation chromatography (hereinafter abbreviated as GPC). Measurements were performed using a GPC device manufactured by Tosoh Corporation under the following conditions: GPC column: Shodex KF803L, Shodex KF802, Shodex KF801 (registered trademark) (Showa Denko K.K.) Column temperature: 40℃ Solvent: dimethylformamide (DMF) ·Flow rate: 1.0ml / min Standard sample: Polystyrene (manufactured by Tosoh Corporation)

[0133] <Explanation of abbreviations> The abbreviations of the compounds have the following meanings. BzMA: benzyl methacrylate (structure below) [ka]

[0134] HPMA: 2-hydroxypropyl methacrylate (structure below) [ka]

[0135] GBLMA: γ-butyrolactone methacrylate (structure below) [ka]

[0136] PGME: Propylene glycol monomethyl ether

[0137] <Synthesis example 1: BzMA / HPMA / GBLMA=25 / 47 / 28(wt%)> In a reaction vessel, 0.68 kg of benzyl methacrylate, 0.66 kg of 2-hydroxypropyl methacrylate, and 0.66 kg of γ-butyrolactone methacrylate were dissolved in 7.0 kg of PGME, and the temperature was raised to 80°C while heating and stirring. 0.02 kg of azobisisobutyronitrile dissolved in 1.0 kg of PGME was added dropwise to the reaction vessel under nitrogen pressure over 1 hour, and the reaction was allowed to proceed for 24 hours. After the reaction, the mixture was cooled to obtain a polymer solution with a solids content of 20% by mass. The composition ratio of the obtained polymer was BzMA / HPMA / GBLMA=25 / 47 / 28 (wt %). The weight average molecular weight of the resulting polymer was 89,000 and the number average molecular weight was 30,000.

[0138] <Synthesis Example 2: BzMA / HPMA / GBLMA = 25 / 47 / 28 (wt%)> Using BzMA, HPMA, and GBLMA as monomers, polymerization was carried out referring to Reference Example B-3 and Example B-3 of WO 2012 / 053434 pamphlet to obtain a polymer solution with a solid content of 20% by mass. The composition ratio of the obtained polymer is BzMA / HPMA / GBLMA = 25 / 47 / 28 (wt%). The weight average molecular weight of the obtained polymer solution was 10,500, and the number average molecular weight was 5,300.

[0139] <Comparative Example 1> To 38.0 kg of a solution containing 7.7 kg of the polymer obtained in Synthesis Example 1, 1.885 kg of tetramethoxymethyl glycoluril (Nippon Cytec Industries Co., Ltd., trade name: POWDERLINK® 1174) and 0.118 kg of pyridinium-p-toluenesulfonate were mixed. The obtained mixture was dissolved in 440.67 kg of propylene glycol monomethyl ether and 52.83 kg of propylene glycol monomethyl ether acetate to form a solution, and a composition for forming a resist underlayer film was prepared.

[0140] <Example 1> To 15.2 kg of a solution containing 3.0 kg of the polymer obtained in Synthesis Example 2, 0.729 kg of tetramethoxymethyl glycoluril (Nippon Cytec Industries Co., Ltd., trade name: POWDERLINK® 1174) and 0.0455 kg of pyridinium-p-toluenesulfonate were mixed. The obtained mixture was dissolved in 188.25 kg of propylene glycol monomethyl ether and 22.05 kg of propylene glycol monomethyl ether acetate to form a solution, and a composition for forming a resist underlayer film was prepared.

[0141] <DLS Evaluation> Dynamic light scattering measurement was performed on each polymer solution obtained in Synthesis Example 1 and Synthesis Example 2. Dynamic light scattering measurement was performed using a dynamic light scattering photometer DLS-8000Ar (manufactured by Otsuka Electronics Co., Ltd.). Using a He-Ne laser (light wavelength 633 nm) as the incident light, measurement was carried out at a scattering angle of 90°, and the autocorrelation function was obtained. For the obtained autocorrelation function, the average particle size and the polydispersity index were determined by cumulant method analysis using the analysis program attached to the above measurement device. The particle size distribution analysis was performed by the Contin method. The results are shown in Table 1.

[0142] As shown in Table 1, when the polymer solution obtained in Synthesis Example 2 was used, it was confirmed that the average particle size and the polydispersity index were smaller compared to the case of Synthesis Example 1. In FIGS. 1A to 1C, the particle size distributions of Samples 1st, 2nd, and 3rd of Synthesis Example 1 are shown respectively. In FIGS. 2A to 2C, the particle size distributions of Samples 1st, 2nd, and 3rd of Synthesis Example 2 are shown respectively. Note that "f(ls)%" in FIGS. 1A to 1C and FIGS. 2A to 2C represents the scattering intensity distribution. The vertical axis on the right side (the second axis) represents the integrated value of the scattering intensity distribution. As shown in FIGS. 1A to 1C and FIGS. 2A to 2C, it was confirmed that the distribution of larger particle sizes in Synthesis Example 2 was significantly less even when comparing the particle size distributions.

[0143]

Table 1

[0144] <Etching defect evaluation> ]Etching defect evaluation was carried out as follows. Each resist underlayer film-forming composition obtained in Comparative Example 1 and Example 1 was applied onto an Etching defect evaluation substrate (Poly Si: 150 nm / SiO2: 80 nm / Si) by a spinner respectively. It was heated at 205 °C for 1 minute on a hot plate to form a resist underlayer film (film thickness 55 nm). This film was etched using a chlorine-based mixed gas in a Lam etching device. After that, the number of defects after etching (110 nm up: 81 cm) was counted using a defect inspection device (KLA-Tencor: product name SP1-DLS). 2 The results are shown in Table 2.

[0145] As shown in Table 2, it was confirmed that the sample of Example 1 had a smaller number of cone defects (the number of minute granular etching residues) than the sample of Comparative Example 1.

[0146] [Table 2]

Claims

1. The polymer includes a repeating unit (1) represented by the following formula (1) and a repeating unit (2) other than the repeating unit (1), and a solvent: The average particle size of the polymer in the polymer solution containing the polymer is 20 nm or less. The repeating unit (2) includes a repeating unit (2A-1) represented by the following formula (2A-1) and a repeating unit (2A-2) represented by the following formula (2A-2): A composition for forming a resist underlayer film. 【Chemical 1】 (In formula (1), R １ represents a hydrogen atom, a methyl group, or a halogen atom; R ２ represents a trivalent hydrocarbon group having 3 to 6 carbon atoms. ２ is a 5- or 6-membered ring. 【Chemistry 2】 (In formula (2A-1), X ２１ represents -O- or -N(-R)- (wherein R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms). ２１ represents a hydrogen atom, a methyl group, or a halogen atom; R ２２ represents an alkyl group having 1 to 10 carbon atoms substituted with a hydroxy group. In formula (2A-2), X ３１ represents -O- or -N(-R)- (wherein R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms). ３１ represents a hydrogen atom, a methyl group, or a halogen atom; R ３２ represents a substituted or unsubstituted aralkyl group, a substituted or unsubstituted carbocyclic aromatic group, or a substituted or unsubstituted heterocyclic aromatic group.

2. 2. The composition for forming a resist underlayer film according to claim 1, wherein the number of etching residues is 2,500 or less when measured by the following Etching Defect Evaluation Method. [Etching defect evaluation method] The resist underlayer film-forming composition was applied to an etching defect evaluation substrate (Poly Si: 150 nm / SiO ２ : 80 nm / Si). The coating is heated on a hot plate at 205° C. for 1 minute to form a resist underlayer film (film thickness: 55 nm). Etching is performed using a chlorine-based mixed gas in an etching device. After that, a defect inspection device is used to measure the number of defects after etching (110 nm up: 81 cm ２ Check the result.

3. In the polymer, the weight ratio of the repeating unit (1) to all repeating units is 1 to 75% by weight, In the polymer, the total weight ratio of the repeating unit (2A-1) and the repeating unit (2A-2) to all repeating units is 25 to 99% by weight. The composition for forming a resist underlayer film according to claim 1 .

4. 2. The composition for forming a resist underlayer film according to claim 1, wherein the polymer has a weight average molecular weight of 50,000 or less.

5. The composition for forming a resist underlayer film according to claim 1 , further comprising a crosslinking agent.

6. The composition for forming a resist underlayer film according to claim 1 , further comprising a curing catalyst.

7. A resist underlayer film, which is a cured product of the composition for forming a resist underlayer film according to any one of claims 1 to 6.

8. a semiconductor substrate; The resist underlayer film according to claim 6 ; A semiconductor processing substrate comprising:

9. forming a resist underlayer film on a semiconductor substrate using the composition for forming a resist underlayer film according to any one of claims 1 to 6; forming a resist film on the resist underlayer film; A method for manufacturing a semiconductor device, comprising:

10. forming a resist underlayer film on a semiconductor substrate using the composition for forming a resist underlayer film according to any one of claims 1 to 6; forming a resist film on the resist underlayer film; irradiating the resist film with light or an electron beam, and then developing the resist film to obtain a resist pattern; etching the resist underlayer film using the resist pattern as a mask; A pattern forming method comprising:

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