Developer-resistant resist underlayer film composition and method for producing a resist pattern

Abstract

A developer-resistant resist underlayer film composition comprising a polymer (A), a crosslinking agent (B), a thermal acid generator (C), and a solvent (D), wherein the polymer (A) comprises at least a unit having a protecting group that is deprotected by an acid, and the hydrophilicity of a portion where the units deprotected after exposure are present changes.

Description

Technical Field

[0001] The present invention relates to a developer-resistant resist underlayer film composition. The present invention also relates to a method for manufacturing a resist pattern.

Background Art

[0002] In the manufacturing process of devices such as semiconductors, microfabrication by lithography technology using a photoresist is generally performed. The wavelength used for exposure is becoming shorter, and lithography technology using extreme ultraviolet light (EUV) with a wavelength of 13.5 nm is being studied. Under conventional exposure conditions with wavelengths of 248 nm and 193 nm, a chemically amplified resist composition is used as the resist material. When using EUV, various resist materials are being studied, and one of them is a metal-containing resist (for example, Patent Document 1).

[0003] In the lithography process, problems occur such that the dimensional accuracy of the photoresist pattern decreases due to the influence of standing waves caused by reflection of light from the substrate and the influence of irregular reflection of exposure light due to the step of the substrate. Therefore, in order to solve this problem, methods of providing a resist underlayer film are widely studied. A resist underlayer film that can be developed simultaneously with the resist film in an alkaline developer has also been proposed (for example, Patent Document 2).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] The inventors conceived that the physical properties of the film surface change before and after exposure for a film formed from a metal-containing resist composition. Specifically, in the exposed area, the hydrophilicity changes before and after exposure. The inventors considered that there were one or more problems still requiring improvement. For example, the following can be mentioned: Resist pattern collapse is likely to occur; the solvent resistance of the resist underlayer film is low; the resist underlayer film creeps due to the resist composition; the resist underlayer film dissolves in the developer; the hydrophilicity of the resist film changes, resulting in a decrease in the adhesion to the substrate. The present invention has been made based on the above technical background, and provides a resist underlayer film composition.

Means for Solving the Problems

[0006] The developer-resistant resist underlayer film composition according to the present invention comprises a polymer (A), a crosslinking agent (B), a thermal acid generator (C), and a solvent (D), and the polymer (A) comprises at least a unit having a protecting group that is deprotected by an acid, and the hydrophilicity of the portion where the deprotected unit exists after exposure changes.

[0007] The method for producing a resist pattern according to the present invention comprises the following steps: (1) Applying a resist underlayer film composition above a substrate, heating the resist underlayer film composition, and forming a resist underlayer film; (2) Applying a resist composition directly above the resist underlayer film, heating the resist composition, and forming a resist film; (3) Exposing the resist film; (4) Optionally, heating the resist film after exposure; and (5) Developing the resist film with a developer to form a resist pattern (however, the resist underlayer film is not developed with the developer) and comprises where the contact angle of the resist film before exposure is θ PrR and the contact angle of the resist film after exposure is θ PeR and the contact angle of the resist underlayer film before exposure is θ PrUand the contact angle θ of the resist underlayer film after exposure PeU When it is θ PeR / θ PrR < 1.0, θ PeU / θ PrU < 1.0, and θ PeR / θ PrR > 1.0, θ PeU / θ PrU > 1.0, and Here, the contact angle is measured using water.

[0008] The method for manufacturing a device according to the present invention comprises the method described above. [Advantages of the Invention]

[0009] According to the present invention, it is possible to obtain one or more of the following advantages. It is possible to suppress resist pattern collapse; the solvent resistance of the resist underlayer film is sufficient; it is possible to suppress film sagging of the resist underlayer film due to the resist composition; it is possible to suppress dissolution of the resist underlayer film by the developer; the acid generated from the thermal acid generator (C) promotes the crosslinking reaction between the polymer (A) and the crosslinking agent (B), imparting developer resistance to the resist underlayer film; the acid generated when the photoacid generating portion (E) receives light selectively deprotects the polymer (A), changing the hydrophilicity of the polymer (A); the acid generated from the photoacid generator present in the resist film migrates to the resist underlayer film, selectively deprotecting the polymer (A) and changing the hydrophilicity of the polymer (A); it is possible to match the change in the hydrophilicity of the resist underlayer film with the change in the hydrophilicity of the resist film; even if a part of the resist underlayer film has a reduced affinity with the substrate due to the physical connection between the exposed portion and the unexposed portion of the resist underlayer film after development, it is possible to maintain the adhesion of the entire resist underlayer film to the substrate. [Embodiments for Carrying Out the Invention]

[0010] [Definitions] In this specification, unless otherwise particularly limited, the definitions and examples described in this paragraph shall apply. The singular form includes the plural form, and "one" and "the" mean "at least one". The elements of a certain concept can be expressed by multiple types, and when the amount (e.g., mass %, molar %) is described, the amount means the sum of these multiple types. "And / or" includes all combinations of elements and also includes use alone. When indicating a numerical range using "~" or "-", these include both endpoints and the units are common. For example, 5~25 mol% means 5 mol% or more and 25 mol% or less. "C x-y ", "C x ~C y " and "C x " and other descriptions mean the number of carbons in the molecule or substituent. For example, C 1-6 alkyl means an alkyl chain having 1 to 6 carbons (such as methyl, ethyl, propyl, butyl, pentyl, hexyl, etc.). When a polymer has multiple types of repeating units, these repeating units copolymerize. These copolymerizations may be any of alternating copolymerization, random copolymerization, block copolymerization, graft copolymerization, or a mixture thereof. When showing the polymer or resin by a structural formula, n, m, etc. written in parentheses indicate the number of repetitions. The unit of temperature uses Celsius. For example, 20 degrees means 20 degrees Celsius. An additive refers to the compound itself having that function (for example, if it is a base generator, it is the compound itself that generates a base). There may also be a form in which the compound is dissolved or dispersed in a solvent and added to the composition. As one form of the present invention, such a solvent is preferably contained in the composition according to the present invention as solvent (D) or as another component.

[0011] Hereinafter, the embodiments of the present invention will be described in detail. <Developer-resistant resist underlayer film composition> The developer-resistant resist underlayer film composition according to the present invention (hereinafter sometimes referred to as the composition) comprises a polymer (A), a crosslinking agent (B), a thermal acid generator (C) and a solvent (D). The polymer (A) comprises at least a unit having a protecting group that is deprotected by an acid, and the hydrophilicity of the portion where the unit deprotected after exposure is present changes. In the present invention, the developer-resistant resist underlayer film composition is a composition that forms a resist underlayer film having resistance to a developer. The resist underlayer film is formed above the substrate and directly under the resist film. An intermediate layer may be formed between the resist underlayer film and the substrate. The resist underlayer film of the present invention is preferably a substrate adhesion enhancing film. The resist underlayer film of the present invention may have an antireflection performance for light used in exposure. That is, the resist underlayer film of the present invention may be an antireflection film. The developer preferably comprises an organic solvent, and more preferably consists of an organic solvent. Preferably, the developer develops the resist layer and does not develop the resist underlayer film. As a mode of the present invention, when the developer is paddled on the resist underlayer film for 30 seconds, the reduction amount of the thickness of the resist underlayer film is preferably 0 to 30% (more preferably 0 to 10%; still more preferably 0.1 to 10%; even more preferably 0.1 to 5%), and / or is preferably 5 nm or less (more preferably 0 to 5 nm; still more preferably 0.1 to 3 nm; even more preferably 0.1 to 2 nm).

[0012] Polymer (A) The composition according to the present invention comprises a polymer (A). The polymer (A) comprises at least a unit having a protecting group that is deprotected by an acid, and the hydrophilicity of the portion where the unit deprotected after exposure is present changes. Specifically, the polymer (A) is hydrophobic before exposure and becomes hydrophilic after exposure, or is hydrophilic before exposure and becomes hydrophobic after exposure. Preferably, it is hydrophobic before exposure and changes to hydrophilic after exposure. The change in hydrophobicity or hydrophilicity can be measured by the contact angle of water dropped on the film. This will be described later.

[0013] Polymer (A) preferably comprises unit (A1) represented by formula (a1). Unit (A1) preferably has a protecting group that is deprotected by an acid and is deprotected after exposure. [Chemical formula] Here, R 11 is each independently H or methyl (preferably H). L 15 is each independently a C 6-20 aromatic hydrocarbon group or a C 1-6 saturated hydrocarbon group (preferably a C 6-20 aromatic hydrocarbon group; more preferably cyclohexyl). In a form of the present invention, L 15 is each independently preferably phenyl or cyclohexyl. R 13 is each independently tert-butyl or C 5-10 alkyl (wherein the methylene in the alkyl may be replaced by oxy and / or carbonyl). In the present specification, tert-butyl may be described as t-Bu or tBu. R 13 is preferably t-Bu or -C(=O)-O-tBu (more preferably t-Bu). R 14 is each independently C 1-5 alkyl (preferably methyl, ethyl, i-propyl, or n-propyl; more preferably methyl). R 16 is each independently t-Bu or C 5-15 alkyl (preferably t-Bu, 1-methylcyclopentyl, 1-ethylcyclopentyl, 1-methyladamantyl, 1-ethyladamantyl, or 1-ethylcyclohexyl; more preferably t-Bu, 1-ethylcyclopentyl, 1-ethyladamantyl, or 1-ethylcyclohexyl; still more preferably t-Bu, or 1-ethylcyclopentyl; even more preferably t-Bu). C5-15 R which is alkyl 16 may form a saturated hydrocarbon group with or without being coiled. n12, n15 and n16 are each independently a number from 0 to 1 (preferably each independently 0 or 1). n12 is more preferably 1. In another form of the present invention, n12 is more preferably 0. n13 is each independently a number from 1 to 3 (preferably 1, 2 or 3; more preferably 1). n14 is each independently a number from 0 to 4 (preferably 1, 2 or 3; more preferably 1). However, when n15 = 0, n12 = n16 = 1, and when n15 = 1, n16 = 0. Preferably n15 = 0. n16 = 0 is also another preferred form of the present invention.

[0014] Specific examples of unit (A1) include, for example, the following.

Chemical formula

[0015] The following structure can be read as unit (A1). In formula (a1), when n12 = n16 = 1, n15 = 0, R 11 = H, R 16 = t-Bu, the following compound is obtained.

Chemical formula

[0016] The following structure can be read as unit (A1). In formula (a1), when n12 = n16 = 0, n15 = 1, R 11 = H, L 15 = phenyl, n14 = 0, n13 = 1, R 13 = t-Bu, the following compound is obtained.

Chemical formula

[0017] Polymer (A) more preferably further comprises at least one of unit (A2) represented by formula (a2), unit (A3) represented by formula (a3), unit (A4) represented by formula (a4), and unit (A5) represented by formula (a5). In a preferred embodiment, polymer (A) comprises unit (A1) represented by formula (a1) and unit (A2) represented by formula (a2). In a more preferred embodiment, in addition to the above, polymer (A) further comprises at least any one of unit (A3) represented by formula (a3), unit (A4) represented by formula (a4), and unit (A5) represented by formula (a5).

[0018] Formula (a2) is as follows.

Chemical formula

[0019] Specific examples of unit (A2) include, for example, the following.

Chemical formula

[0020] Formula (a3) is as follows. [Chemical Formula] Here, R 31 is, independently of each other, H or methyl (preferably H). L 33 is, independently of each other, C 1-10 alkylene (preferably methylene). Ar 34 is, independently of each other, C 6-20 aryl (preferably phenyl). R 35 is, independently of each other, -O-R 35a , -(C=O)-R 35b , -(C=O)-O-R 35a , -(C=O)-NR 35c R 35d , -O-(C=O)-R 35e , -NR 35f -(C=O)-R 35g , or -R 35j OH (preferably -O-R 35a ; more preferably methoxy). n32 and n33 are, independently of each other, numbers from 0 to 1 (preferably 0 or 1; more preferably 0). n35 is, independently of each other, a number from 0 to 3 (preferably 0 or 1; more preferably 1). R 35a is, independently of each other, C 1-4 alkyl (excluding t-Bu). R 35a is preferably methyl or ethyl (more preferably methyl). R 35b is, independently of each other, H or C 1-4 alkyl (preferably methyl, ethyl, n-propyl, or i-propyl; more preferably methyl). R 35c and R 35d are, independently of each other, H or C1-4 is alkyl (preferably H, methyl, ethyl, n-propyl, or i-propyl; more preferably H or methyl). R 35c and R 35d may combine to form a ring when both are alkyl. R 35e is each independently H, C 1-4 alkyl or C 1-4 alkoxy (excluding tert-butoxy) (preferably H, methyl, ethyl, n-propyl, i-propyl, or methoxy; more preferably H, methyl, or methoxy). R 35f is each independently H or C 1-4 alkyl (preferably H, methyl, ethyl, n-propyl, or i-propyl; more preferably H or methyl). R 35g is each independently H, C 1-4 alkyl or -NR 35h R 35r (preferably H, methyl, ethyl, n-propyl, i-propyl, or -NR 35h R 35r ; more preferably H, methyl, or -NR 35h R 35r ). R 35h and R 35r are each independently H or C 1-4 alkyl (preferably H, methyl, ethyl, n-propyl, or i-propyl; more preferably H or methyl). R 35f and R 35h may combine to form a ring when both are alkyl. R 35j is each independently C 1-4 alkylene (preferably methylene, or ethylene; more preferably methylene).

[0021] Specific examples of unit (A3) include, for example, the following.

Chemical formula

[0022] Formula (a4) is as follows.

Chemical formula

Chemical formula

[0023] Specific examples of unit (A4) include, for example, the following.

Chemical formula

[0024] Formula (a5) is as follows.

Chemical formula

[0025] Specific examples of unit (A5) include, for example, the following.

Chemical formula

[0026] Let the repetition numbers of unit (A1), unit (A2), unit (A3), unit (A4), and unit (A5) of polymer (A) be nA1, nA2, nA3, nA4, and nA5, respectively. nA1 / (nA1 + nA2 + nA3 + nA4 + nA5) is preferably 5 to 100% (more preferably 10 to 60%; even more preferably 20 to 50%; even more preferably 25 to 45%). nA2 / (nA1 + nA2 + nA3 + nA4 + nA5) is preferably 0 to 95% (more preferably 10 to 90%; even more preferably 30 to 80%; even more preferably 40 to 75%). nA3 / (nA1 + nA2 + nA3 + nA4 + nA5) is preferably 0 to 95% (more preferably 0 to 30%; even more preferably 0 to 20%; even more preferably 5 to 20%). The case where nA3 / (nA1 + nA2 + nA3 + nA4 + nA5) is 0% is also a preferred embodiment of the present invention. nA4 / (nA1 + nA2 + nA3 + nA4 + nA5) is preferably 0 to 95% (more preferably 0 to 30%; even more preferably 0 to 20%; still more preferably 5 to 20%). The case where nA4 / (nA1 + nA2 + nA3 + nA4 + nA5) is 0% is also a preferred form of the present invention. nA5 / (nA1 + nA2 + nA3 + nA4 + nA5) is preferably 0 to 95% (more preferably 0 to 30%; even more preferably 0 to 20%; still more preferably 1 to 10%). The case where nA5 / (nA1 + nA2 + nA3 + nA4 + nA5) is 0% is also a preferred form of the present invention. As a preferred form of the present invention, 5% ≤ nA1 / (nA1 + nA2 + nA3 + nA4 + nA5) ≤ 100%, 0% ≤ nA2 / (nA1 + nA2 + nA3 + nA4 + nA5) ≤ 95%, 0% ≤ nA3 / (nA1 + nA2 + nA3 + nA4 + nA5) ≤ 95%, 0% ≤ nA4 / (nA1 + nA2 + nA3 + nA4 + nA5) ≤ 95%, and 0% ≤ nA5 / (nA1 + nA2 + nA3 + nA4 + nA5) ≤ 95% Those satisfying the above are exemplified.

[0027] Let n be the total number of all repeating units contained in polymer (A). total Then. (nA1 + nA2 + nA3 + nA4 + nA5) / n total is preferably 80 to 100% (more preferably 90 to 100%; even more preferably 95 to 100%). (nA1 + nA2 + nA3 + nA4 + nA5) / n total The case where (nA1 + nA2 + nA3 + nA4 + nA5) / n = 100%, that is, the case where there are no repeating units other than unit (A1), unit (A2), unit (A3), unit (A4), and unit (A5), is also a preferred form of the present invention. When any one of nA3, nA4, and nA5 is greater than 0, the other two being 0 is a preferred form of the present invention.

[0028] The weight average molecular weight of polymer (A) (hereinafter sometimes referred to as Mw) is preferably 2,000 to 50,000 (more preferably 2,500 to 30,000; still more preferably 3,000 to 20,000). The polydispersity index Mw / Mn (PDI) of polymer (A) is preferably 1.0 to 2.0 (more preferably 1.4 to 1.9). In the present invention, Mw and Mn can be measured by gel permeation chromatography (GPC). In this measurement, it is a preferred example to use a GPC column at 40 degrees Celsius, an elution solvent tetrahydrofuran at 0.6 mL / min, and monodisperse polystyrene as a standard.

[0029] The content of polymer (A) is preferably 0.1 to 10% by mass (more preferably 0.1 to 2% by mass; still more preferably 0.1 to 1% by mass; even more preferably 0.2 to 0.5% by mass) based on the composition. The content of polymer (A) is preferably 40 to 90% by mass (more preferably 50 to 80% by mass; still more preferably 70 to 80% by mass) based on the sum of the other components excluding solvent (D).

[0030] The method for synthesizing polymer (A) is not particularly limited, but specific examples are described in the synthesis examples of the following examples. It is also possible to combine known synthesis methods in the synthesis examples.

[0031] Crosslinking agent (B) The composition according to the present invention comprises a crosslinking agent (B). Without being bound by theory, the crosslinking agent is considered useful for improving the film-forming property when forming a film of the composition, eliminating intermixing with the resist film formed on the upper layer, and eliminating diffusion of low molecular components into the upper layer film. Examples of the crosslinking agent (B) include melamine compounds, guanamine compounds, glycoluril compounds, or urea compounds substituted with at least one group selected from methylol groups, alkoxymethyl groups, and acyloxymethyl groups, epoxy compounds, thioepoxy compounds, isocyanate compounds, azide compounds, and compounds containing double bonds such as alkenyl ether groups. Further, compounds containing hydroxy groups are also used as crosslinking agents.

[0032] Examples of the epoxy compound include tris(2,3-epoxypropyl) isocyanurate, trimethylolmethane triglycidyl ether, trimethylolpropane triglycidyl ether, and triethanol ethane triglycidyl ether. Examples of the melamine compound include hexamethylol melamine, hexamethoxymethyl melamine, compounds in which 1 to 6 methylol groups of hexamethylol melamine are methoxymethylated and mixtures thereof, hexamethoxyethyl melamine, hexaacyloxymethyl melamine, compounds in which 1 to 6 methylol groups of hexamethylol melamine are acyloxymethylated, or mixtures thereof. Examples of the guanamine compound include tetramethylol guanamine, tetramethoxymethyl guanamine, compounds in which 1 to 4 methylol groups of tetramethylol guanamine are methoxymethylated and mixtures thereof, tetramethoxyethyl guanamine, tetraacyloxy guanamine, compounds in which 1 to 4 methylol groups of tetramethylol guanamine are acyloxymethylated, or mixtures thereof. Examples of the glycoluril compound include tetramethylol glycoluril, tetramethoxy glycoluril, tetramethoxymethyl glycoluril, compounds in which 1 to 4 methylol groups of tetramethylol glycoluril are methoxymethylated, or mixtures thereof, compounds in which 1 to 4 methylol groups of tetramethylol glycoluril are acyloxymethylated, or mixtures thereof. Examples of the urea compound include dimethoxymethylol dimethoxyethylene urea, tetramethylol urea, tetramethoxymethyl urea, a compound in which 1 to 4 methylol groups of tetramethylol urea are methoxymethylated or a mixture thereof, and tetramethoxyethyl urea. Examples of the compound containing an alkenyl ether group include ethylene glycol divinyl ether, triethylene glycol divinyl ether, 1,2-propanediol divinyl ether, 1,4-butanediol divinyl ether, tetramethylene glycol divinyl ether, neopentyl glycol divinyl ether, trimethylolpropane trivinyl ether, hexanediol divinyl ether, 1,4-cyclohexanediol divinyl ether, pentaerythritol trivinyl ether, pentaerythritol tetravinyl ether, sorbitol tetravinyl ether, sorbitol pentavinyl ether, and trimethylolpropane trivinyl ether.

[0033] In a preferred embodiment, the crosslinking agent (B) is represented by the formula (b1). [Chemical formula] Here, nb1 is 1, 2, 3, or 4 (preferably 1, 2, or 3; more preferably 1 or 2; still more preferably 1). nb2 is 0 when nc1 is 1, and is 1 when nc1 is 2 or more. nb3 is 0, 1, or 2 (preferably 2). nb4 is 1 or 2 (preferably 1). nb5 is 0 or 1 (preferably 1). L b is a single bond or a C 1-30 hydrocarbon group (preferably a single bond, C 1-20 alkylene, or C 6-30 arylene; more preferably a single bond). R b each independently represents a C 1-6Alkyl (wherein the methylene in the alkyl may be replaced by oxy), or C 6-10 is aryl (preferably methyl or phenyl). R’ is H or methyl (preferably methyl).

[0034] Examples of the crosslinking agent (B) include the following.

Chemical formula

[0035] The crosslinking agent (B) may be one or more (more preferably one). The content of the crosslinking agent (B) is preferably 5 to 100% by mass (more preferably 10 to 50% by mass; even more preferably 20 to 40% by mass) based on the polymer (A).

[0036] Thermal acid generator (C) The composition according to the present invention comprises a thermal acid generator (C). The thermal acid generator generates an acid by heat. Preferably, the acid derived from (C) promotes the crosslinking reaction between the polymer (A) and the crosslinking agent (B). The pKa (H2O) of the acid generated from the thermal acid generator (C) is preferably 1 to 8 (more preferably 2 to 6). In a preferred embodiment, the acid generated from the thermal acid generator (C) is a carboxylic acid. Without being bound by theory, it is considered that the acid derived from (C) promotes the crosslinking reaction between (A) and (B), and by not deprotecting the protecting group of the polymer (A), it is possible to control so that not all of the resist underlayer film is deprotected while having developability resistance.

[0037] Preferably, the thermal acid generator (C) is activated at a temperature exceeding 80°C. Examples of the thermal acid generator (C) include metal-free strong non-nucleophilic alkylammonium, dialkylammonium, and trialkylammonium.

[0038] In a preferred embodiment, the thermal acid generator (C) is represented by the formula (c1). [Chemical formula] Here, nc1 is 1 or 2 (preferably 2). L c1 When nc1 is 1, is H or C 1-6 alkyl (wherein the alkyl may be substituted with halogen or hydroxy) (preferably fluorine-substituted or unsubstituted C 1-6 alkyl; more preferably fluorine-substituted C 1-6 alkyl; even more preferably fluorine-substituted ethyl). L c1 When nc1 is 2, is C 1-4 alkylene (wherein the alkylene may be substituted with halogen or hydroxy, and the methylene in the alkylene may be replaced by carbonyl, oxy or amide) (preferably C 1-3 alkylene (wherein the methylene in the alkylene may be replaced by carbonyl); more preferably methylene). nc2 is 1 or 2 (preferably 1). L c2 When nc2 is 1, is C 1-6 alkyl (wherein the alkyl may be substituted with halogen or hydroxy) (preferably methyl or ethyl). L c2 When nc2 is 1, is C 1-4 alkylene (wherein the alkylene may be substituted with halogen or hydroxy, and the methylene in the alkylene may be replaced by carbonyl, oxy or amide) (preferably methylene or ethylene). R c1 R c2 and R c3 are each independently H or C 1-10 alkyl (wherein the alkyl may be substituted with halogen or hydroxy) (preferably H, methyl, or ethyl; more preferably methyl, or ethyl; even more preferably ethyl). x and y are 1 or 2, provided that nc1 × x = nc2 × y is satisfied. Preferably, x is 2 and y is 1.

[0039] Examples of the cation of formula (c1) include the following.

Chemical formula

[0040] Examples of the anion of formula (c1) include the following.

Chemical formula

[0041] The thermal acid generator (C) may be one or more (more preferably one). The content of the thermal acid generator (C) is preferably 0.5 to 30% by mass (more preferably 1 to 15% by mass; even more preferably 2 to 8% by mass) based on the polymer (A).

[0042] Solvent (D) The composition according to the present invention comprises a solvent (D). The solvent (D) is preferably water, a hydrocarbon solvent, an ether solvent, an ester solvent, an alcohol solvent, a ketone solvent, or a combination of any of these. (D) Specific examples of the solvent include, for example, water, n - pentane, i - pentane, n - hexane, i - hexane, n - heptane, i - heptane, 2,2,4 - trimethylpentane, n - octane, i - octane, cyclohexane, methylcyclohexane, benzene, toluene, xylene, ethylbenzene, trimethylbenzene, methylethylbenzene, n - propylbenzene, i - propylbenzene, diethylbenzene, i - butylbenzene, triethylbenzene, di - i - propylbenzene, n - amylnaphthalene, trimethylbenzene, methanol, ethanol, n - propanol, i - propanol, n - butanol, i - butanol, sec - butanol, t - butanol, n - pentanol, i - pentanol, 2 - methylbutanol, sec - pentanol, t - pentanol, 3 - methoxybutanol, n - hexanol, 2 - methylpentanol, sec - hexanol, 2 - ethylbutanol, sec - heptanol, heptanol - 3, n - octanol, 2 - ethylhexanol, sec - octanol, n - nonyl alcohol, 2,6 - dimethylheptanol - 4, n - decanol, sec - undecyl alcohol, trimethylnonyl alcohol, sec - tetradecyl alcohol, sec - heptadecyl alcohol, phenol, cyclohexanol, methylcyclohexanol, 3,3,5 - trimethylcyclohexanol, benzyl alcohol, phenylmethylcarbinol, diacetone alcohol, cresol, ethylene glycol, propylene glycol, 1,3 - butylene glycol, pentanediol - 2,4, 2 - methylpentanediol - 2,4, hexanediol - 2,5, heptanediol - 2,4, 2 - ethylhexanediol - 1,3, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol, glycerin, acetone, methyl ethyl ketone, methyl - n - propyl ketone, methyl - n - butyl ketone, diethyl ketone, methyl - i - butyl ketone, methyl - n - pentyl ketone, ethyl - n - butyl ketone, methyl - n - hexyl ketone, di - i - butyl ketone, trimethylnonanone, cyclohexanone, cyclopentanone, methylcyclohexanone, 2,4 - pentanedione, acetonylacetone, diacetone alcohol,Acetophenone, fenchone, ethyl ether, i-propyl ether, n-butyl ether, n-hexyl ether, 2-ethylhexyl ether, ethylene oxide, 1,2-propylene oxide, dioxolane, 4-methyldioxolane, dioxane, dimethyldioxane, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol diethyl ether, ethylene glycol mono-n-butyl ether, ethylene glycol mono-n-hexyl ether, ethylene glycol monophenyl ether, ethylene glycol mono-2-ethylbutyl ether, ethylene glycol dibutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol diethyl ether, diethylene glycol mono-n-butyl ether, diethylene glycol di-n-butyl ether, diethylene glycol mono-n-hexyl ether, ethoxytriethylene glycol, tetraethylene glycol di-n-butyl ether, propylene glycol monomethyl ether (PGME), propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monobutyl ether, tripropylene glycol monomethyl ether, tetrahydrofuran, 2-methyltetrahydrofuran, diethyl carbonate, methyl acetate, ethyl acetate, γ-butyrolactone, γ-valerolactone, n-propyl acetate, i-propyl acetate, n-butyl acetate, i-butyl acetate, sec-butyl acetate, n-pentyl acetate, sec-pentyl acetate, 3-methoxybutyl acetate, methylpentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, benzyl acetate, cyclohexyl acetate, methylcyclohexyl acetate, n-nonyl acetate, methyl acetoacetate, ethyl acetoacetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol mono-n-butyl ether acetate,Propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether acetate, dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether acetate, glycol diacetate, methoxytriglycol acetate, ethyl propionate, n-butyl propionate, i-amyl propionate, diethyl oxalate, di-n-butyl oxalate, methyl lactate, ethyl lactate (EL), γ-butyrolactone, n-butyl lactate, n-amyl lactate, diethyl malonate, dimethyl phthalate, diethyl phthalate, propylene glycol 1-monomethyl ether 2-acetate (PGMEA), propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate and other ester solvents; N-methylformamide, N,N-dimethylformamide, N,N-diethylformamide, acetamide, N-methylacetamide, N,N-dimethylacetamide, N-methylpropionamide, N-methylpyrrolidone, dimethyl sulfide, diethyl sulfide, thiophene, tetrahydrothiophene, dimethyl sulfoxide, sulfolane, and 1,3-propanesultone. These solvents can be used alone or in combination of two or more. (D) As the solvent, more preferably, it is PGMEA, PGME, EL or a mixture thereof (even more preferably, a mixture of PGMEA, PGME and EL).

[0043] In relation to other layers and films, one form is that the (D) solvent does not contain water. For example, the amount of water in the whole (D) solvent is preferably 0.1% by mass or less (more preferably 0.01% by mass or less; even more preferably 0.001% by mass or less). It is also a preferred form of the present invention that the (D) solvent does not contain any water (0.000% by mass).

[0044] (D) The content of the solvent is preferably 80 to 99.99% by mass (more preferably 90 to 99.9% by mass; even more preferably 95 to 99.9% by mass; still more preferably 99.0 to 99.8% by mass) based on the total mass of the composition.

[0045] Photoacid generator part (E) The composition according to the present invention may further contain a photoacid generator part (E). The photoacid generator part (E) is a part that generates an acid upon exposure. Preferably, the photoacid generator part (E) is a part of the polymer (A) or a component different from (A) to (D). More preferably, the photoacid generator part (E) is a part of the polymer (A), and (E) is incorporated into (A) as the unit (A5). In this specification, when (E) is incorporated into the unit (A5), it is calculated as the content of the polymer (A). That is, in this case, the content of (E) is 0% by mass. The composition according to the present invention may further contain a photoacid generator (F). The photoacid generator (F) is a component that generates an acid upon exposure. In a preferred form, the photoacid generator (F) is a component different from (A) to (D). As a preferred form, the photoacid generator part (E) is the photoacid generator (F). Without being bound by theory, it is considered that the photoacid generator part (E) generates an acid, acts on the polymer (A), and causes deprotection, thereby making it easier to change the hydrophilicity of the polymer (A). The pKa (H2O) of the acid generated from the photoacid generator part (E) is preferably -20 to 3 (more preferably -20 to 1). The pKa (H2O) of the acid generated from the thermal acid generator (C) is preferably greater than the pKa (H2O) of the acid generated from the photoacid generator part (E). Without being bound by theory, it is considered that the acid derived from (E) can selectively change the hydrophilicity of the exposed or unexposed part of the resist underlayer film by deprotecting the protecting group of the polymer (A).

[0046] The photoacid generator part (E) is preferably represented by the formula (E1). Anion 54m- Cation 54m+ (E1) However, when the photoacid generator part (E) is a part of the polymer (A), H or F in Anion 54 m- is substituted and bonded to another part of the polymer (A). Here,[[]] Anion 54m- is an anion selected from the group consisting of the anion represented by the formula (ea1) and the anion represented by the formula (ea2) (preferably the anion represented by the formula (ea1)). Anion 54m- is m-valent as a whole.[[]] Cation 54m+ is a cation selected from the group consisting of the cation represented by the formula (ec1), the cation represented by the formula (ec2), and the cation represented by the formula (ec3) (preferably the cation represented by the formula (ec1)). Cation 54m+ is m-valent as a whole.[[]]

[0047] The formula (ea1) is as follows.[[]]

Chemical formula

[0048] Specific examples of formula (ea1) include the following.

Chemical formula

[0049] Formula (ea2) is as follows.

Chemical formula

[0050] Specific examples of formula (ea2) include the following.

Chemical formula

[0051] Formula (ec1) is as follows.

Chemical formula

[0052] Formula (ec1) is preferably represented by the following formula (ec1-1).

Chemical formula

[0053] Specific examples of formula (ec1) include, for example, the following.

Chemical formula

[0054] Formula (ec2) is as follows.

Chemical formula

[0055] Formula (ec3) is as follows.

Chemical formula

[0056] Specific examples of formula (ec3) are as follows, for example. [Chemical formula]

[0057] When (E) is part of polymer (A), H or F in Anion 54m- is substituted and bonded to another part of polymer (A). For the sake of clarity, it will be explained using examples. The structure on the left below is the photoacid generator part (E) but is part of polymer (A) and can be read as unit (A5). Specifically, in formula (a5), R 51 = methyl, n52 = 1. Anion 54m- was a pentafluorosulfonic acid ion (the anion on the right below), but one F has been substituted and is bonded to polymer (A). Cation 54m+is a triphenylsulfonium ion. m = 1. [Chemical formula]

[0058] The photoacid generator (E) may be one or more (more preferably one). The content of the photoacid generator (E) is preferably 0.5 to 20% by mass (more preferably 1 to 15% by mass; still more preferably 2 to 10% by mass) based on the polymer (A). When the photoacid generator (E) is a part of the polymer (A), the content of the photoacid generator (E) in the composition is calculated as the content of the polymer (A). In this case, the content of the photoacid generator (E) is 0% by mass based on the polymer (A).

[0059] Photoacid generator (F) The composition according to the present invention can further contain a photoacid generator (F). As a preferred form, the photoacid generator (E) is a component different from (A) to (D) and is a photoacid generator (F). The photoacid generator (F) is preferably represented by the above formula (E1), and its preferred form is also the same as above. The photoacid generator (F) may be one or more (more preferably one). The content of the photoacid generator (F) is preferably 0.5 to 20% by mass (more preferably 1 to 15% by mass; still more preferably 2 to 10% by mass) based on the polymer (A).

[0060] Surfactant (G) The composition according to the present invention can further contain a surfactant (G). By further containing the surfactant (G), the coatability can be improved.

[0061] Examples of the surfactant (G) that can be used in the present invention include (I) anionic surfactants, (II) cationic surfactants, or (III) nonionic surfactants. More specifically, (I) alkyl sulfonates, alkylbenzene sulfonic acids, and alkylbenzene sulfonates, (II) lauryl pyridinium chloride and lauryl methyl ammonium chloride, and (III) polyoxyethylene octyl ether, polyoxyethylene lauryl ether, and polyoxyethylene acetylenic glycol ether are preferred.

[0062] The surfactant (G) may be one or more (more preferably one). The content of the surfactant (G) is preferably 0 to 10% by mass (more preferably 0.5 to 8% by mass; even more preferably 1 to 5% by mass) based on the polymer (A). It is also a preferred embodiment that the composition of the present invention does not contain the surfactant (G) (0.0% by mass).

[0063] Additive (H) The composition according to the present invention may further contain other additives (H) other than (A) to (G). Here, the additive (H) is a dye, a lower alcohol, a surface smoothing agent, an acid, a base, a substrate adhesion enhancer, an antifoaming agent, a preservative, or a combination thereof (preferably a dye, an acid, a base, a substrate adhesion enhancer, or a combination with any of these). When containing an acid or a base, it is also a preferred embodiment of the present invention to contain only one of them. The content of the additive (H) is preferably 0 to 10% by mass (more preferably 0 to 5% by mass; even more preferably 0.1 to 3% by mass) based on the polymer (A). It is also a preferred example of the composition according to the present invention not to contain the additive (H) (0.0% by mass).

[0064] <Method for manufacturing a resist pattern> The method for manufacturing a resist pattern according to the present invention comprises the following steps: (1) Applying a resist underlayer film composition above a substrate and heating the resist underlayer film composition to form a resist underlayer film; (2) Apply a resist composition directly above the resist underlayer film, heat the resist composition, and form a resist film; (3) Expose the resist film; (4) Optionally, heat the resist film after exposure; and (5) Develop the resist film using a developer to form a resist pattern (however, the resist underlayer film is not developed with the developer) It comprises. In this specification, unless otherwise specified, the numbers in () indicating steps mean the order.

[0065] Hereinafter, one embodiment of the manufacturing method according to the present invention will be described. Step (1) In step (1), a resist underlayer film composition is applied above the substrate, the resist underlayer film composition is heated, and a resist underlayer film is formed. Apply a resist underlayer film composition above the substrate (for example, a silicon / silicon dioxide coated substrate, a silicon nitride substrate, a silicon wafer substrate, a glass substrate, an ITO substrate, etc.) by an appropriate method. The contact angle θ of the surface of the substrate s is preferably less than 90° or greater than 90° (more preferably less than 90°; even more preferably less than 85°). The contact angle is measured by applying water in the same manner as described later. In order to make the surface of the substrate hydrophobic as described above, treatment may be performed (for example, HMDS treatment). In the present invention, above includes the case where it is formed directly above and the case where it is formed via other layers. For example, a planarization film may be formed directly above the substrate, and the composition according to the present invention may be applied directly above the planarization film. The application method is not particularly limited, and examples include methods such as spin coating and coating with a coater. After coating, a resist underlayer film is formed by heating. Preferably, in step (1), the resist underlayer film composition is applied directly above the substrate. The resist underlayer film composition is preferably the above-described developer-resistant resist underlayer film composition. (1) is heated, for example, by a hot plate. The heating temperature is preferably 100 to 250 °C (more preferably 125 to 225 °C; even more preferably 150 to 200 °C). The temperature here is the heating atmosphere temperature, for example, the heating surface temperature of the hot plate. The heating time is preferably 30 to 300 seconds (more preferably 45 to 180 seconds; even more preferably 60 to 120 seconds). The heating is preferably carried out in an atmosphere of air or nitrogen gas. By this heating, the cross-linking reaction proceeds in the composition. Therefore, the resist underlayer film does not easily dissolve in the subsequent steps. The film thickness of the resist underlayer film is preferably 2 to 50 nm (more preferably 3 to 30 nm; even more preferably 5 to 20 nm).

[0066] Step (2) In step (2), the resist composition is applied directly on top of the resist underlayer film, the resist composition is heated, and a resist film is formed. The method of applying the resist composition is not particularly limited, and it may be the same as the above application, or a vapor deposition method is also possible. A coating method is mentioned as a more preferred form. The resist composition is preferably a metal-containing resist, more preferably an organometallic oxide hydroxide-containing resist, and those described in JP 2021-73367 can be used. The resist composition is preferably an EUV resist, and in a preferred form, it is a negative resist. (2) The heating temperature is preferably 75 to 140 °C (more preferably 80 to 130 °C; even more preferably 90 to 120 °C). The heating time is preferably 30 to 240 seconds (more preferably 90 to 180 seconds). The heating is preferably carried out in an atmosphere of air or nitrogen gas. The film thickness of the resist film is preferably 20 to 70 nm (more preferably 25 to 50 nm). Without being bound by theory, it is more preferable that the resist underlayer film is not dissolved by the resist composition. It can be confirmed that it is not dissolved by checking whether there is film peeling before and after the application of the resist composition.

[0067] Step (3) In step (3), the resist film is exposed through a predetermined mask. The wavelength of the light used for exposure is not particularly limited, but it is preferable to perform exposure with light having a wavelength of 13.5 to 248 nm. Specifically, a KrF excimer laser (wavelength 248 nm), an ArF excimer laser (wavelength 193 nm), extreme ultraviolet light (wavelength 13.5 nm), etc. can be used, and extreme ultraviolet light is preferable. These wavelengths allow a range of ±1%. In a preferred embodiment of the present invention, the exposure light wavelength passes through the resist film and reaches the underlying resist film. When the underlying resist film composition contains a photoacid generator (E), it is a preferred embodiment of the present invention that an acid is generated from (E) by the exposure in step (3).

[0068] Step (4) After exposure, Post Exposure Bake (PEB) can be performed if necessary. The temperature of the PEB is preferably 100 to 200°C (more preferably 150 to 190°C), and the heating time is preferably 30 to 240 seconds (more preferably 90 to 180 seconds). Although not bound by theory, a form in which the acid generated from the photoacid generator present in the resist film moves to the underlying resist film and this acid deprotects the protecting group of the polymer (A) of the underlying resist film is also a preferred embodiment of the present invention. In this case, even if the underlying resist film composition of the present invention does not contain the photoacid generating part (E) (for example, (E) incorporated into (A) as the unit (A5)) and the photoacid generator (F), it is considered that the hydrophilicity of the exposed part of the underlying resist film can be changed.

[0069] Let the contact angle of the resist film before exposure be θ PrR and the contact angle of the resist film after exposure be θ PeR Let the contact angle of the underlying resist film before exposure be θ PrU and the contact angle of the underlying resist film after exposure be θ PeU Then,[[]] θ PeR / θ PrR When <1.0, θ PeU / θ PrU <1.0, and θ PeR / θ PrR When > 1.0, θ PeU / θ PrU > 1.0. For example, when the hydrophilicity of the resist film increases by exposure, the contact angle of the resist film decreases. In this case, since θ PrR from θ PeR changes to become smaller, θ PeR / θ PrR < 1.0. In the manufacturing method of the present invention, it is preferable that the hydrophilicity of the underlayer resist film changes in accordance with the hydrophilicity of the resist film. That is, when the hydrophilicity of the resist film increases (θ PrR from θ PeR changes to become smaller), it is preferable that the hydrophilicity of the underlayer resist film also increases (θ PrU from θ PeU changes to become smaller). Also, when the hydrophilicity of the resist film decreases (hydrophobicity increases) by exposure, it is preferable that the hydrophilicity of the underlayer resist film also decreases. Since the change in hydrophilicity is caused by the deprotection of the protecting group by an acid, it is preferable that the hydrophilicity in the exposed area changes. θ PeR / θ PrR < 1.0 and θ PeU / θ PrU < 1.0 is a more preferred embodiment of the present invention. Here, the contact angle is measured using water. Preferably, the contact angle is measured using a contact angle meter by dropping 2 μL of water onto the resist film or the underlayer resist film.

[0070] Step (5) The exposed resist film is developed using a developer to form a resist pattern. Examples of development include alkali development and organic solvent development, with organic solvent development being preferred. The developer contains an organic solvent and is more preferably composed of an organic solvent. In the case of organic solvent development, examples of the developer include hydrocarbon solvents, ether solvents, ester solvents, ketone solvents, and alcohol solvents, with ester solvents or ketone solvents being preferred. Specifically, examples of the developer include 2-heptanone, butyl acetate, PGMEA, etc. By using such a developer, the resist layer can be developed. On the other hand, the developer does not develop the underlying resist film. Without being bound by theory, it is considered that the underlying resist film is not developed because the crosslinking agent (B) and the polymer (A) are crosslinked. "Not developed" can be confirmed by the following operation. When the developer is paddled on the underlying resist film for 30 seconds, the reduction in the thickness of the underlying resist film is 0 to 30% and / or 5 nm or less. "Developer resistance" can also be confirmed by the above operation. Without being bound by theory, by having the underlying resist film of the present invention, it is considered possible to prevent the collapse of the resist pattern due to a decrease in the affinity with the substrate by changing the hydrophilicity of the underlying resist film in accordance with the change in the hydrophilicity of the resist film. Without being bound by theory, since the hydrophilicity of the underlying resist film in the exposed or unexposed area changes in accordance with the resist film, it is considered possible to maintain a state where the affinity between the resist pattern and the underlying resist film is sufficient. Without being bound by theory, even if a part of the underlying resist film has a decreased affinity with the substrate due to the physical connection between the exposed and unexposed areas of the underlying resist film after development, it is considered possible to maintain the adhesion between the entire underlying resist film and the substrate.

[0071] The method for manufacturing a resist pattern according to the present invention further includes the following step: (6) Washing the resist pattern with a cleaning liquid and removing the cleaning liquid between the patterns can be included. To remove local film residues, the resist pattern can be cleaned using a cleaning solution. Examples of the cleaning solution include water or an organic solvent (e.g., IPA, PGME, PGMEA, PGEE, nBA). In a preferred embodiment of the present invention, the cleaning solution is a rinse solution, and the developer is replaced with the rinse solution for cleaning. Examples of the rinse solution include JP2019-519804A and WO2021 / 204651A1.

[0072] The method for manufacturing a processed substrate according to the present invention comprises the following steps: Forming a resist pattern by the above method; and (7) Processing using the resist pattern as a mask and comprises. Preferably, step (7) processes the underlying resist film and / or the substrate. The substrate may be processed by etching the underlying resist film and the substrate at once, or may be processed step by step, such as etching the underlying resist film first and then using it as a mask to etch the substrate. More preferably, the underlying resist film and the substrate are etched at once. The etching may be either dry etching or wet etching. Thereby, a gap can be formed in the substrate or a layer on the substrate. After the formation of the gap, the resist pattern can be removed by contacting it with water, a mixture of a water-soluble organic solvent and water, or an aqueous alkali solution. It is also possible to process the substrate by a method other than etching.

[0073] Thereafter, if necessary, the substrate is further processed to form a device. These further processes can apply known methods. Preferably, it further comprises a step of forming wiring on the processed substrate. If necessary, the substrate is cut into chips, connected to a lead frame, and packaged with resin. In the present invention, this packaged product is referred to as a device. Preferably, the device is a semiconductor device.

[0074] [Examples] The present invention is described by way of examples as follows. Note that the forms of the present invention are not limited to only these examples.

[0075] In the following examples, the weight average molecular weight (Mw) is measured by gel permeation chromatography (GPC) based on polystyrene. GPC measurements are performed using an allianceTM e2695 type high-speed GPC system (Waters Japan) and an organic solvent-based GPC column Shodex KF-805L (Showa Denko). The measurements are carried out under the measurement conditions of a flow rate of 0.6 milliliters per minute and a column temperature of 40 °C, using monodisperse polystyrene as a standard sample and chloroform as an eluent solvent, and then Mw is calculated as the relative molecular weight to the standard sample.

[0076] <Synthesis of Polymer 2> 95.8 g of p-acetoxystyrene as a monomer that will become unit (A2) after deprotection later, 37.8 g of t-butyl acrylate as a monomer of unit (A1), 10.3 g of styrene as a monomer of unit (A3), and 6 g of azobisisobutyronitrile (AIBN) and 1 g of t-dodecyl mercaptan as polymerization initiators are dissolved in 230 g of PGME, and polymerized at 70 °C for 16 hours in a nitrogen atmosphere. After the polymerization is completed, the reaction solution is dropped into a large amount of hexane to solidify / purify the formed polymer. Next, 150 g of PGME is added to the polymer thus purified, and then 300 g of methanol, 80 g of triethylamine, and 15 g of water are further added, and a hydrolysis reaction is carried out under heating under reflux for 8 hours. After the reaction is completed, the solvent and triethylamine are distilled off under reduced pressure. Next, the obtained polymer is dissolved in acetone. This solution is dropped into a large amount of distilled water with stirring to solidify it. The generated white solid is filtered and then dried at 50 °C under reduced pressure overnight. The polymer 2 thus obtained is a random copolymer with a weight average molecular weight (Mw) = 12,000 and has a polydispersity index (PDI) = 1.6, and its 13 C-NMR analysis shows that the units derived from 4-vinylphenol, the units derived from t-butyl acrylate, and the units derived from styrene are in a molar ratio of 60:30:10.

[0077] <Synthesis of Polymer 6> 16.7 g of 4-vinylphenol as the monomer of unit (A2), 3.0 g of triphenylsulfonium 2,3,5,6-tetrafluoro-4-(methacryloyloxy)benzenesulfonate as the monomer of unit (A5), 27.9 g of 2-ethyl-2-adamantyl methacrylate as the monomer of unit (A1), and 2.1 g of AIBN as a polymerization initiator are dissolved in 76 g of anhydrous tetrahydrofuran and acetonitrile (volume ratio = 1:1), and polymerized at 65 °C for 24 hours in a sealed pressure vessel. After the polymerization is completed, the reaction solution is added dropwise to a large amount of diethyl ether with stirring to solidify the polymer. The generated white solid is filtered and then dried under reduced pressure at 50 °C overnight. Then, the dried white solid is dissolved in tetrahydrofuran, and the solution is added dropwise to a large amount of diethyl ether with stirring to solidify the polymer again and filtered. The obtained white solid is dissolved in tetrahydrofuran, and the solution is added dropwise to a large amount of diethyl ether with stirring to solidify the polymer again and filtered. The obtained solid is dried under reduced pressure at 50 °C overnight. The thus obtained Polymer 6 is a random copolymer with Mw = 4,000 and has a PDI = 1.6, and its 13 C-NMR analysis shows that the units derived from 4-vinylphenol, the units derived from 2-ethyl-2-adamantyl methacrylate, and the units derived from triphenylsulfonium 2,3,5,6-tetrafluoro-4-(methacryloyloxy)benzenesulfonate are in a molar ratio of 65:30:5.

[0078] <Synthesis of Polymers 1, 3 to 5 and 7> Polymers 1, 3 to 5 and 7 are synthesized in the same manner as the synthesis of Polymer 2 above, except that the monomers and the molar ratio are changed. The synthesized polymers are listed in Table 1.

Table 1

[0079] <Preparation of the Composition of Example 1> PGMEA, PGME, and EL are mixed so that the mass ratio is 30:40:30 to obtain Solvent 1. To Solvent 1, 100 parts by mass of the above Polymer 1, 30 parts by mass of Crosslinking Agent 1, 5 parts by mass of Thermal Acid Generator 1, and 5 parts by mass of Photoacid Generator 1 are added, and it is prepared so that the concentration of the solid content is 0.385% by mass. The components other than the solvent are the solid content. This is stirred at room temperature for 30 minutes. Visually confirm that the solid content is completely dissolved. Filter through a filter with a pore size of 0.2 μm. Thereby, the composition of Example 1 is obtained. Crosslinking Agent 1 is as follows. [Chemical formula] Thermal Acid Generator 1 is a mixture of malonic acid:triethylamine = 1:2. [Chemical formula] Photoacid Generator 1 is diphenyl-2,4,6-trimethylphenylsulfonium p-toluenesulfonate. [Chemical formula]

[0080] <Preparation of Compositions of Examples 2 to 6 and Comparative Example 1> The compositions of Examples 2 to 6 and Comparative Example 1 are prepared in the same manner as the preparation of the composition of Example 1, except that each component and its blending ratio are changed as shown in Table 2. The concentration of the solid content is 0.385% by mass, the same as in Example 1, for all compositions. [Table 2] In the table, Polymers 1 to 7, Crosslinking Agent 1, Thermal Acid Generator 1, Photoacid Generator 1, and Solvent 1 are as described above. Crosslinking Agent 2 is as follows. [Chemical formula] Crosslinking Agent 3 is as follows. [Chemical formula] The crosslinking agent 4 is as follows.

Chemical formula

Chemical formula

Chemical formula

[0081] <Evaluation of pattern collapse> Each composition prepared above is spin-coated on a silicon substrate. This is heated on a hot plate at 170°C for 90 seconds to cause a crosslinking reaction, and a resist lower layer film (thickness 10 nm) is obtained. Next, a 4-methyl-2-pentanol solution of the organometallic tin oxyhydroxide resist composition is spin-coated on the resist lower layer film and heated at 100°C for 2 minutes to form a Sn resist film (thickness 35 nm). This substrate is exposed using extreme ultraviolet light with a wavelength of 13.5 nm to form a pattern with a line of 16 nm and a space of 16 nm. This substrate is subjected to PEB at 170°C for 2 minutes in an air atmosphere using a hot plate. The resist film on the substrate is paddle-developed using 2-heptanone for 30 seconds. The wafer is rotated at high speed and dried. An SEM (0.5 μm × 0.5 μm) photograph of the resist pattern is taken. The space size of the resist pattern was 16 nm. The pattern collapse prevention performance is evaluated using CG4000 (Hitachi High-Technologies). The evaluation criteria are as described below. The obtained results are shown in Table 2. A: No pattern collapse is observed. B: Pattern collapse is observed. Although not bound by theory, since the polymer 7 of Comparative Example 1 does not have a unit having a protecting group that is deprotected by an acid, it is considered that even if an acid is generated from a photoacid generator, no change in hydrophilicity occurs.

[0082] <Evaluation of Solvent Resistance> Each of the compositions prepared above is spin-coated on a silicon substrate. It is heated on a hot plate at 170 °C for 90 seconds to cause a crosslinking reaction to obtain a resist underlayer film (thickness 10 nm). Whether this underlayer film is insoluble in 4-methyl-2-pentanol and 2-heptanone is confirmed by the following test. The resist underlayer film is filled with 4-methyl-2-pentanol and allowed to stand for 30 seconds. This is spin-dried and an SEM section is prepared. Film thickness measurement is performed using an ellipsometer. The same test is performed with the liquid changed from 4-methyl-2-pentanol to 2-heptanone. The evaluation criteria for solvent resistance are as follows. The results obtained are shown in Table 2. A: No film swelling of the resist underlayer film is confirmed or it is less than 1 nm with any of the liquids. B: Film swelling of 1 - 2 nm is confirmed with at least one of the liquids. C: Film swelling greater than 2 nm is confirmed with at least one of the liquids. Although not bound by theory, it is considered that by using the resist underlayer film of the present invention, it is possible to suppress film swelling caused by the resist composition and the developer.

Claims

1. A developer-resistant resist underlayer film composition comprising a polymer (A), a crosslinking agent (B), a thermal acid generator (C), and a solvent (D): Here, the polymer (A) comprises at least a unit having a protecting group that is deprotected by an acid, and the hydrophilicity of the portion where the unit deprotected after exposure is present changes.

2. The composition according to claim 1, wherein the polymer (A) comprises a unit (A1) represented by formula (a1). 【Chemical 1】 (Herein, R １１ each independently is H or methyl, L １５ is, independently of each other, C ６－２０ an aromatic hydrocarbon group or C １－６ a saturated hydrocarbon group, and R １３ is, independently of one another, tert-butyl or C ５－１０ alkyl (wherein the methylene in the alkyl may be replaced by oxy and / or carbonyl), R １４ is, independently of one another, C １－５ alkyl, and R １６ is, independently of each other, tert-butyl or C ５－１５ alkyl, and n12, n15, and n16 are each independently a number from 0 to 1, n13 is each independently a number from 1 to 3, n14 is each independently a number from 0 to 4, provided that when n15 = 0, n12 = n16 = 1, and when n15 = 1, n16 = 0)

3. The composition according to claim 1 or 2, wherein the polymer (A) further comprises at least one of a unit (A2) represented by formula (a2), a unit (A3) represented by formula (a3), a unit (A4) represented by formula (a4), and a unit (A5) represented by formula (a5). 【Chemical 2】 (Herein, In formula (a2), R ２１ is, independently of each other, H or methyl, L ２３ is, independently, C １－１０ alkylene, and Ar ２４ is, independently of each other, C ６－２０ aryl, and R ２６ is, independently of one another, C １－５ alkyl, and n22 and n23 are each independently a number from 0 to 1, n25 is each independently a number from 0 to 4, n26 is each independently a number from 1 to 3, In formula (a3), R ３１ is, independently of each other, H or methyl, L ３３ is, independently of each other, C １－１０ alkylene, and Ar ３４ is, independently of each other, C ６－２０ aryl, and R ３５ is, independently of each other, -O-R ３５ａ , -(C=O)-R ３５ｂ , -(C=O)-O-R ３５ａ , -(C=O)-NR ３５ｃ R ３５ｄ , -O-(C=O)-R ３５ｅ , -NR ３５ｆ -(C=O)-R ３５ｇ , or -R ３５ｊ OH, and n32 and n33 are each independently a number from 0 to 1, n35 is each independently a number from 0 to 3, R ３５ａ is, independently of each other, C １－４ alkyl (excluding tert-butyl), and R ３５ｂ is, independently of each other, H or C １－４ alkyl, R ３５ｃ and R ３５ｄ are each independently H or C １－４ alkyl, and R ３５ｃ and R ３５ｄ may combine to form a ring when both are alkyl, R ３５ｅ is, independently of each other, H, C １－４ alkyl or C １－４ alkoxy (except tert-butoxy), and R ３５ｆ is, independently of one another, H or C １－４ alkyl. R ３５ｇ is, independently of each other, H, C １－４ alkyl or -NR ３５ｈ R ３５ｒ and is R ３５ｈ and R ３５ｒ are each independently H or C １－４ alkyl, and R ３５ｈ and R ３５ｒ may combine to form a ring when both are alkyl, R ３５ｊ is, independently of one another, C １－４ alkylene, and In formula (a4), R ４１ is, independently of each other, H or methyl, L ４２ is an alkylene of C １－４ and n42 is a number from 0 to 1, R ４３ is an alkyl (excluding tBu) of C １－４ or the following group, [Chemical Formula 3] n43 is a number from 1 to 2, In formula (a5), R ５１ is, independently of each other, H or methyl, L ５３ is, independently of each other, C １－１０ alkylene, and n52 and n53 are each independently a number from 0 to 1, Anion ５４ｍ－ is an m-valent anion that binds upward in the formula, Cation ５４ｍ＋ is an m-valent cation that ionically bonds with ５４ｍ－ Anion m is a number from 1 to 2)

4. When the repeating numbers of the unit (A1), the unit (A2), the unit (A3), the unit (A4), and the unit (A5) are nA1, nA2, nA3, nA4, and nA5, respectively, 5% ≤ nA1 / (nA1 + nA2 + nA3 + nA4 + nA5) ≤ 100%, 0% ≤ nA2 / (nA1 + nA2 + nA3 + nA4 + nA5) ≤ 95%, 0% ≤ nA3 / (nA1 + nA2 + nA3 + nA4 + nA5) ≤ 95%, 0% ≤ nA4 / (nA1 + nA2 + nA3 + nA4 + nA5) ≤ 95%, and 0% ≤ nA5 / (nA1 + nA2 + nA3 + nA4 + nA5) ≤ 95% The composition according to at least any one of claims 1 to 3, which satisfies.

5. The composition according to at least any one of claims 2 to 4, wherein the unit (A1) has a protecting group that is deprotected by an acid and is deprotected after exposure.

6. The composition according to at least any one of claims 1 to 5, wherein the crosslinking agent (B) is represented by the formula (b1). [Chemical Formula 4] (Herein, nb1 is 1, 2, 3, or 4, nb2 is 0 when nc1 is 1, and 1 when nc1 is 2 or more, nb3 is 0, 1, or 2, nb4 is 1 or 2, nb5 is 0 or 1, L ｂ is a single bond or a C １－３０ hydrocarbon group, and R ｂ is, independently of one another, C １－６ alkyl (wherein the methylene in the alkyl may be replaced by oxy), or C ６－１０ aryl, R' is H or methyl)

7. The composition according to at least any one of claims 1 to 6, wherein the thermal acid generator (C) is represented by the formula (c1). 【Chemical Formula 5】 (Herein, nc1 is 1 or 2, L ｃ１ is H or C when nc1 is 1 １－６ alkyl (wherein the alkyl may be substituted with halogen or hydroxy), and is C when nc1 is 2 １－４ alkylene (wherein the alkylene may be substituted with halogen or hydroxy, and the methylene in the alkylene may be replaced by carbonyl, oxy or amide), nc2 is 1 or 2, L ｃ２ is C when nc2 is 1 １－６ alkyl (wherein the alkyl may be substituted with halogen or hydroxy), and is C when nc2 is 1 １－４ alkylene (wherein the alkylene may be substituted with halogen or hydroxy, and the methylene in the alkylene may be replaced by carbonyl, oxy or amide), and R ｃ１ 、 R ｃ２ and R ｃ３ are each independently H or C １－１０ alkyl (wherein the alkyl may be substituted with halogen or hydroxy), x and y are 1 or 2, provided that nc1 × x = nc2 × y is satisfied)

8. The composition according to at least any one of claims 1 to 7, wherein the solvent (D) is water, a hydrocarbon solvent, an ether solvent, an ester solvent, an alcohol solvent, a ketone solvent, or any combination thereof.

9. The composition according to at least any one of claims 1 to 8, comprising a photoacid generating part (E): Preferably, the photoacid generating part (E) is part of the polymer (A), or a component different from (A) to (D), or Preferably, the photoacid generating part (E) is a photoacid generator (F).

10. The pKa (H ２ O) of the acid generated from the thermal acid generator (C) is greater than the pKa (H ２ O) of the acid generated from the photoacid generating part (E). The composition according to at least any one of claims 1 to 9: Preferably, the pKa (H ２ O) of the acid generated from the thermal acid generator (C) is 1 to 8 (more preferably 2 to 6), or Preferably, the pKa (H2O) of the acid generated from the photoacid generating part (E) is -20 to 3 (more preferably -20 to 1).

11. The photoacid generating part (E) has the formula (E1): Anion ５４ｍ－ Cation ５４ｍ＋ (E1) represented by (however, when the photoacid generator part (E) is a part of the polymer (A), H or F in Anion ５４ｍ－ is substituted and bonded to another part of the polymer (A)), the composition according to at least any one of claims 1 to 10. (Herein, Anion ５４ ｍ－ is an anion selected from the group consisting of the anion represented by formula (ea1) and the anion represented by formula (ea2), is m-valent as a whole, Cation ５４ｍ＋ is a cation selected from the group consisting of the cation represented by formula (ec1), the cation represented by formula (ec2), and the cation represented by formula (ec3), has an overall valence of m, and 【Chemical Formula 6】 Herein, R ｅ１ is a C ４－３０ hydrocarbon group containing a ring structure having 5 or more ring atoms, at least one of the ring atoms may be nitrogen, and the hydrocarbon group is nitro, hydroxy, halogen, -OSO ２ -R ｅ４ , -SO ２ -R ｅ４ , -OR ｅ４ , -COOR ｅ４ , -O-CO-R ｅ４ , -O-R ｅ５ -COOR ｅ４ , -R ｅ５ -CO-R ｅ４ , or -S-R ｅ５ may be substituted by, and -CH ２ - in the hydrocarbon group may be replaced by carbonyl, ether, carbonyloxy, sulfide, thiocarbonyl, or sulfonyl, R ｅ２ and R ｅ３ are each independently H, fluorine, fluorine-substituted C １－５ alkyl, or C １－５ alkyl, and R ｅ４ is, independently of each other, C １－１０ hydrocarbon group, and R ｅ５ each independently represents a single bond or a C １－１０ hydrocarbon group, p1 is each independently a number from 0 to 10, 【Chemical Formula 7】 Herein, X is carbonyl or sulfonyl, R ｅ６ and R ｅ７ are each independently C １－６ fluorine-substituted alkyl, C １－６ fluorine-substituted alkoxy, C ６－１２ fluorine-substituted aryl, C ２－１２ fluorine-substituted acyl, or C ６－１２ fluorine-substituted alkoxyaryl, where R ｅ６ and R ｅ７ may be mutually bonded to form a fluorine-substituted heterocyclic structure. 【Chemical Formula 8】 Herein, R ｅ１１ and R ｅ１２ are each independently a C １－２０ hydrocarbon group, and the hydrocarbon group is -OSO ２ -R ｅ１４ , -SO ２ -R ｅ１４ , -OR ｅ１４ , -COOR ｅ１４ , -O-CO-R ｅ１４ , -O-R ｅ１５ -COOR ｅ１４ , -R ｅ１５ -CO-R ｅ１４ , or -S-R ｅ１４ and may be substituted by R ｅ１３ is, independently of each other, nitro, hydroxy, halogen, -OSO ２ -R ｅ１４ 、-SO ２ -R ｅ１４ 、-OR ｅ１４ 、-COOR ｅ１４ 、-O-CO-R ｅ１４ 、-O-R ｅ１５ -COOR ｅ１４ 、-R ｅ１５ -CO-R ｅ１４ 、-S-R ｅ１４ 、or C １－２０ is a hydrocarbon group, and the hydrocarbon group may be substituted by -OSO ２ -R ｅ１４ 、-SO ２ -R ｅ１４ 、-OR ｅ１４ 、-COOR ｅ１４ 、-O-CO-R ｅ１４ 、-O-R ｅ１５ -COOR ｅ１４ 、-R ｅ１５ -CO-R ｅ１４ 、or -S-R ｅ１４ and may be substituted by, R ｅ１４ is, independently of each other, C １－１０ hydrocarbon group, and R ｅ１５ is, independently of one another, a single bond or a C １－１０ hydrocarbon group, q11 is a number from 0 to 3, q13 is a number from 0 to 11, 【Chemical Formula 9】 Herein, R ｅ２１ and R ｅ２３ are each independently nitro, hydroxy, halogen, -OSO ２ -R ｅ２４ , -SO ２ -R ｅ２４ , -OR ｅ２４ , -COOR ｅ２４ , -O-CO-R ｅ２４ , -O-R ｅ２５ -COOR ｅ２４ , -R ｅ２５ -CO-R ｅ２４ , -S-R ｅ２４ , or C １－２０ is a hydrocarbon group, and the hydrocarbon group may be substituted by -OSO ２ -R ｅ２４ , -SO ２ -R ｅ２４ , -OR ｅ２４ , -COOR ｅ２４ , -O-CO-R ｅ２４ , -O-R ｅ２５ -COOR ｅ２４ , -R ｅ２５ -CO-R ｅ２４ , or -S-R ｅ２４ and may be substituted thereby, R ｅ２２ is a single bond or a C １－２０ hydrocarbon group, and the hydrocarbon group is -OSO ２ -R ｅ２４ -, -SO ２ -R ｅ２４ -, -OR ｅ２４ -, -COOR ｅ２４ -, -O-CO-R ｅ２４ -, -O-R ｅ２５ -COOR ｅ２４ -, -R ｅ２５ -CO-R ｅ２４ -, or -S-R ｅ２４ and may be substituted by R ｅ２４ is, independently, a C １－１０ hydrocarbon group, R ｅ２５ is, independently of one another, a single bond or a C １－１０ hydrocarbon group, q21 is a number from 0 to 9, q23 is a number from 0 to 10, q24 is a number from 0 to 2, q25 is a number from 0 to 3, 【Chemical Formula 10】 Herein, R ｅ３１ and R ｅ３２ are each independently nitro, hydroxy, halogen, -OSO ２ -R ｅ３３ , -SO ２ -R ｅ３３ , -OR ｅ３３ , -COOR ｅ３３ , -O-CO-R ｅ３３ , -O-R ｅ３４ -COOR ｅ３３ , -R ｅ３４ -CO-R ｅ３３ , -S-R ｅ３３ or C １－２０ is a hydrocarbon group, and the hydrocarbon group may be substituted by -OSO ２ -R ｅ３３ , -SO ２ -R ｅ３３ , -OR ｅ３３ , -COOR ｅ３３ , -O-CO-R ｅ３３ , -O-R ｅ３４ -COOR ｅ３３ , -R ｅ３４ -CO-R ｅ３３ or -S-R ｅ３３ and may be substituted by R ｅ３３ is, independently of each other, C １－１０ hydrocarbon group, and R ｅ３４ is, independently of one another, a single bond or a C １－１０ hydrocarbon group, q31 is a number from 0 to 5, q32 is a number from 0 to 5)

12. The composition according to at least any one of claims 1 to 11, further comprising a surfactant (G).

13. The composition according to at least any one of claims 1 to 12, further comprising other additives (H): Herein, the additives (H) are dyes, lower alcohols, surface smoothing agents, acids, bases, substrate adhesion enhancers, antifoaming agents, preservatives, or any combination thereof.

14. The content of the polymer (A) is 0.1 to 10% by mass based on the composition, The content of the crosslinking agent (B) is 5 to 100% by mass based on the polymer (A), the content of the thermal acid generator (C) is 0.5 to 30% by mass based on the polymer (A), or the content of the solvent (D) is 80 to 99.99% by mass based on the composition: the composition according to at least one of claims 1 to 13 Preferably, the content of the photoacid generating part (E) is 0.5 to 20% by mass based on the polymer (A), Preferably, the content of the photoacid generator (F) is 0.5 to 20% by mass based on the polymer (A), Preferably, the content of the surfactant (G) is 0 to 10% by mass based on the polymer (A), or Preferably, the content of the additive (H) is 0 to 10% by mass based on the polymer (A).

15. The composition according to at least one of claims 1 to 14, wherein the developer contains an organic solvent: Preferably, the developer develops the resist layer and does not develop the underlying resist film, Preferably, when the developer is paddled on the underlying resist film for 30 seconds, the reduction in the thickness of the underlying resist film is 0 to 30%, or Preferably, when the developer is paddled on the underlying resist film for 30 seconds, the reduction in the thickness of the underlying resist film is 5 nm or less.

16. The composition according to at least one of claims 1 to 15, wherein the resist is a metal-containing resist: Preferably, the resist is an organometallic oxide hydroxide-containing resist, Preferably, the resist is an EUV resist, or Preferably, the resist is a negative resist.

17. A method for manufacturing a resist pattern, comprising the following steps: (1) Applying a resist underlayer film composition above a substrate, heating the resist underlayer film composition to form a resist underlayer film; (2) Applying a resist composition directly above the resist underlayer film, heating the resist composition to form a resist film; (3) Exposing the resist film; (4) Optionally, heating the resist film after exposure; and (5) Developing the resist film with a developer to form a resist pattern (however, the resist underlayer film is not developed with the developer); Here, let the contact angle of the resist film before exposure be θ ＰｒＲ , the contact angle of the resist film after exposure be θ ＰｅＲ , the contact angle of the resist underlayer film before exposure be θ ＰｒＵ , and the contact angle θ of the resist underlayer film after exposure ＰｅＵ . Then θ ＰｅＲ / θ ＰｒＲ When < 1.0, θ ＰｅＵ / θ ＰｒＵ < 1.0, and θ ＰｅＲ / θ ＰｒＲ When > 1.0, θ ＰｅＵ / θ ＰｒＵ > 1.0 and Here, the contact angle is measured using water.

18. The method according to claim 17, wherein the resist underlayer film composition is the developer-resistant resist underlayer film composition according to at least one of claims 1 to 16.

19. The method according to claim 17 or 18, wherein the contact angle is measured using a contact angle meter by dropping 2 μL of water onto the resist film or the underlayer resist film.

20. The contact angle θ of the surface of the substrate ｓ The method according to at least any one of claims 17 to 19, wherein the contact angle θ is less than 90° or greater than 90°.

21. The acid generated in processes (3) and (4) moves to the resist underlayer film, causing a change from θ ＰｒＵ to θ ＰｅＵ The method according to at least one of claims 17 to 20, wherein the change occurs.

22. The method according to at least one of claims 17 to 21, further comprising step (6): (6) Cleaning the resist pattern with a cleaning liquid and removing the cleaning liquid from between the patterns.

23. A method for manufacturing a processed substrate, comprising the following steps: Forming a resist pattern by the method according to at least one of claims 17 to 22; (7) Processing using the resist pattern as a mask: Preferably, step (7) processes the underlayer resist film and / or the substrate.

24. A method for manufacturing a device, comprising the method according to at least one of claims 17 to 23: Preferably, the method further comprises a step of forming wiring on the processed substrate, or Preferably, the device is a semiconductor device.

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