TWI588164B - Radiation sensitive resin composition and polymer - Google Patents

Description

Sensitive radiation linear resin composition and polymer

The present invention relates to a radiation sensitive linear resin composition and a polymer.

The linear composition of the chemically amplified type sensitive radiation uses an ultraviolet light or an electron beam represented by a KrF excimer laser or an ArF excimer laser to generate an acid at the exposure site, and reacts with the acid as a catalyst. The composition of the photoresist pattern is formed on the substrate by making the difference between the exposure speed of the exposure portion and the unexposed portion.

A photoresist material having a finely processed ArF excimer laser (193 nm) as a light source is known as a polymer having an alicyclic hydrocarbon having a large absorption in a region of 193 nm and having high etching resistance. A sensitive radiation linear resin composition as a constituent component. A general positive-type radiation-sensitive linear resin composition contains an alkali-soluble resin by an action of an acid, and the resin is known to have an alicyclic hydrocarbon group as a unit (protecting group) which is desorbed by an action of an acid (refer to Kaiping No. 9-073173). Further, a technique of using a protective layer having a specific structure to improve the roughness of the line and the interval pattern (LWR) is also known (refer to Japanese Laid-Open Patent Publication No. 2008-308545 and JP-A-2008-308546). Further, a technique of combining a specific protecting group to improve the resolution and the coarseness is also known (refer to JP-A-2002-372784 and JP-A-2003-84438).

However, as the miniaturization of the photoresist pattern has progressed to the extent that the line width is 90 nm or less, not only the resolution improvement is required, but the basic characteristics of the LWR reduction are improved, and other properties are also required.

For example, immersion exposure, one of the miniaturization techniques, has progressed to practical use, and the photoresist material corresponding to the immersion exposure also requires MEEF (mask error enhancement coefficient) which can reduce the tolerance of the mask error tolerance. It is required to display the DOF (depth of focus) of the depth of focus.

[Previous Technical Literature]

[Patent Literature]

[Patent Document 1] JP-A-9-073173

[Patent Document 2] JP-A-2008-308545

[Patent Document 3] JP-A-2008-308546

[Patent Document 4] JP-A-2002-372784

[Patent Document 5] JP-A-2003-84438

The present invention is based on the above-described case, and the object of the invention is to provide a radiation sensitive linear resin composition which can form a photoresist pattern which can reduce LWR and MEEF and which is excellent in DOF.

The invention for solving the above problems is as follows: a sensitive radiation linear resin composition containing [A] having a structural unit (I) represented by the following formula (1) and a structural unit represented by the following formula (2) ( II) polymer (hereinafter also referred to as "[A] polymer"), and [B] sensitive radiation linear acid generator (hereinafter also referred to as "[B] acid generator")

(In the formula (1), R ¹ is a hydrogen atom or a methyl group, R ² is a carbon atom, R ³ is a linear or branched alkyl group having 1 to 4 carbon atoms, and Z is a carbon number formed together with R ² a divalent group derived from a cycloalkane of less than 10, but satisfying the condition that the number of carbon atoms in the group consisting of Z, R ² and R ³ is 8 or more in total, and the group consisting of Z and R ² When the carbon number is 5 or 6, R ³ is a linear or branched alkyl group having 2 to 4 carbon atoms, [Chemical 2]

(In the formula (2), R ⁴ is a hydrogen atom or a methyl group, R ⁵ is a carbon atom, R ⁶ is a linear or branched alkyl group having 2 to 4 carbon atoms, and X is a carbon number 10 together with R ⁵ The above divalent bridges the alicyclic hydrocarbon group).

The structural unit (I) is preferably at least one structural unit selected from the group consisting of a structural unit represented by the following formula (1-1) and a structural unit represented by the following formula (1-2), [Chemical 3]

(In the formulae (1-1) and (1-2), R ¹ has the same meaning as the above formula (1), and a is 1 or 2).

The above structural unit (II) is preferably a structural unit represented by the following formula (2-1), [Chemical 4]

(In the formula (2-1), R ⁴ and R ⁶ are synonymous with the above formula (2)).

In the present invention, it is also preferred to contain a polymer comprising a structural unit (I) represented by the following formula (1) and a structural unit (II) represented by the following formula (2), [Chem. 5]

(In the formula (1), R ¹ is a hydrogen atom or a methyl group, R ² is a carbon atom, R ³ is a linear or branched alkyl group having 1 to 4 carbon atoms, and Z is a carbon number formed together with R ² a divalent group derived from a cycloalkane of less than 10, but satisfying the condition that the number of carbon atoms in the group consisting of Z, R ² and R ³ is 8 or more in total, and is composed of Z and R ² When the carbon number is 5 or 6, R ³ is a linear or branched alkyl group having 2 to 4 carbon atoms, [Chemical 6]

(In the formula (2), R ⁴ is a hydrogen atom or a methyl group, R ⁵ is a carbon atom, R ⁶ is a linear or branched alkyl group having 2 to 4 carbon atoms, and X is a carbon number 10 together with R ⁵ The above divalent bridges the alicyclic hydrocarbon group).

The sensitive radiation linear resin composition of the present invention can form a photoresist pattern which can reduce LWR and MEEF and is excellent in DOF. Accordingly, the sensitive radiation linear resin composition can be suitably used as a photoresist material used in a lithography step using, for example, an ArF excimer laser or an electron beam as a light source.

<sensitive radiation linear resin composition>

The sensitive radiation linear resin composition of the present invention contains [A] a polymer and [B] an acid generator. Further, the radiation sensitive linear resin composition may contain a [C] acid diffusion controlling agent and a [D] solvent as preferred components. Further, the sensitive radiation linear resin composition may contain other optional components as long as the effects of the present invention are not impaired. The various ingredients are detailed below.

<[A] Polymer>

[A] The polymer has a property of being insoluble or insoluble as a base, and the acid produced by exposure is alkali-soluble. [A] The structural units (I) and (II) of the polymer have the property of being alkali-soluble by dissociation with an acid. Further, the structural units (I) and (II) are excellent in acid dissociation property at a lower temperature, and can suppress the diffusion of acid at a low temperature, so that LWR and MEEF are improved. Further, the combined structural units (I) and (II) can appropriately control the solubility and rigidity of the exposed portion and the unexposed portion after baking, and can greatly improve the performance of LWR, MEEF and DOF. Further, the [A] polymer may suitably contain a structural unit (III) having a lactone structure or a cyclic carbonate structure in addition to the structural units (I) and (II). By including these structural units, it is possible to exhibit an effect of exhibiting excellent LWR, MEEF, and adhesion to a substrate. Hereinafter, each structural unit will be described in detail. Further, the [A] polymer may contain two or more kinds of structural units.

[structural unit (I)]

The structural unit (I) is a structural unit represented by the above formula (I). In the above formula (I), R ¹ is a hydrogen atom or a methyl group. R ² is a carbon atom. R ³ is a linear or branched alkyl group having 1 to 4 carbon atoms. Z is a divalent group derived from R ² and derived from a cyclohexane having a carbon number of less than 10. However, the total number of carbon atoms in the group consisting of Z, R ² and R ³ is preferably 8 or more. Further, when the number of carbon atoms in the group consisting of Z and R ² is 5 or 6, R ³ is a linear or branched alkyl group having 2 to 4 carbon atoms.

The alkyl group having 1 to 4 carbon atoms represented by the above R ^{3 is} exemplified by a methyl group, an ethyl group, a n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group or the like. Among these, isopropyl and isobutyl groups are preferred. The divalent group having a carbon number of less than 10 formed by Z together with R ² is exemplified by a group obtained by removing two hydrogen atoms from a cycloalkane such as cyclopentane, cyclohexane, cycloheptane or cyclooctane. Among these, a group obtained by removing two hydrogen atoms from cyclopentane, cyclohexane or cyclooctane is preferred.

The structural unit (I) is preferably at least one structural unit selected from the group consisting of the structural unit represented by the above formula (1-1) and the structural unit represented by the formula (1-2). In the above formulae (1-1) and (1-2), R ¹ is synonymous with the above formula (1). a is 1 or 2.

The content ratio of the structural unit (I) is preferably from 10 mol% to 60 mol%, more preferably from 20 mol% to 50 mol%, based on all structural units in the [A] polymer. By setting the content ratio of the structural unit (I) within the above specific range, a photoresist pattern which can reduce LWR and MEEF and which is excellent in DOF can be formed.

[structural unit (II)]

The structural unit (II) is a structural unit represented by the above formula (2). In the above formula (2), R ⁴ is a hydrogen atom or a methyl group. R ⁵ is a carbon atom. R ⁶ is a linear or branched alkyl group having 2 to 4 carbon atoms. X is a group which forms a divalent bridged alicyclic hydrocarbon group having a carbon number of 10 or more together with R ⁵ .

on

The divalent alicyclic hydrocarbon group in which X and R ⁵ together form a carbon number of not more than 10 is exemplified by, for example, adamantane, bicyclo[2.2.1]heptane, tricyclo[4.3.01 ^2,5 ]nonane, A four-ring [4.4.0.1 ^2,5 .1 ^7,10 ] dodecane, such as a bridged alicyclic alicyclic skeleton, is formed by removing two hydrogen atoms. These are preferably those in which two hydrogen atoms are removed from the adamantane skeleton, that is, the structural unit (II) is preferably a structural unit represented by the above formula (2-1). In the above formula (2-1), R ⁴ and R ⁶ are synonymous with the above formula (2).

The content ratio of the structural unit (II) is preferably from 5 mol% to 55 mol%, more preferably from 5 mol% to 35 mol%, based on all structural units in the [A] polymer. By setting the content ratio of the structural unit (II) within the above specific range, it is possible to form a photoresist pattern which can reduce LWR and MEEF and is excellent in DOF.

[structural unit (III)]

The structural unit (III) is a structural unit having a lactone structure or a cyclic carbonate structure. [A] The polymer contains excellent structural unit (III), and can achieve excellent LWR, MEEF, and adhesion to the substrate.

The structural unit having a lactone structure is not particularly limited as long as it has a lactone structure, but is preferably a structural unit represented by the following formula (3).

【化7】

In the above formula (3), R ⁷ is a hydrogen atom or a methyl group. R ⁸ is a linear or branched alkyl group having 1 to 4 carbon atoms which may be substituted by a fluorine atom, a linear or branched alkoxy group having a carbon number of 1 to 4 or a cyano group. A is a single bond, a divalent hydrocarbon group having 1 to 4 carbon atoms, -A'-O-, -A'-COO- or -A'-OCO-. A' is a divalent hydrocarbon group having 1 to 4 carbon atoms. 1 is an integer of 0 or 1. n is an integer from 0 to 3. However, when R ⁸ is plural, a plurality of R ⁸ may be the same or different.

The linear or branched alkyl group having 1 to 4 carbon atoms represented by the above R ^{8 is} exemplified by a methyl group, an ethyl group, a n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group or the like. The linear or branched alkoxy group having 1 to 4 carbon atoms represented by the above R ⁸ is exemplified by a methoxy group, an ethoxy group or the like. R ^{8 is} preferably a methyl group, an ethyl group, a trifluoromethyl group or a methoxy group. The divalent hydrocarbon group having 1 to 4 carbon atoms represented by the above A and A' is preferably a linear hydrocarbon group such as a methyl group, an ethyl group, an exopropyl group or an exobutyl group. 1 is preferably 0. n is preferably 0 or 1.

The structural unit (III) is exemplified by a structural unit represented by the following formulas (3-1) to (3-8).

【化8】

In the above formulae (3-1) to (3-8), the R ⁷ system is synonymous with the above formula (3). Among these, it is preferably a structural unit represented by (3-1).

Other structural units having a lactone structure are, for example, structural units represented by the following formulas (3-9) to (3-17).

【化9】

In the above formulae (3-9) to (3-17), R ⁷ is synonymous with the above formula (3).

The structural unit having a cyclic carbonate structure is, for example, a structural unit represented by the following formulas (3-18) to (3-38).

【化10】

In the above formulae (3-18) to (3-38), R ⁷ is synonymous with the above formula (3). Among these, the structural unit represented by the above formula (3-18) is preferred.

The content ratio of the structural unit (III) is usually 70 mol% or less, more preferably 20 mol% to 65 mol%, more preferably 30 mol%, based on all structural units in the [A] polymer. 60% by mole. By setting the content ratio of the structural unit (III) within the above specific range, excellent LWR, MEEF, and adhesion to the substrate can be achieved.

[Other construction units]

[A] The polymer may also contain other structural units different from the structural units (I) to (3). As for the other structural units, it is exemplified by, for example, adamantyl-1-(meth)acrylate, 3-methyladamantan-1-yl (meth)acrylate, and 3-ethyl-gold (meth)acrylate. Alkan-1-yl ester, 3-hydroxyadamantan-1-yl (meth)acrylate, 3,5-dihydroxyadamantan-1-yl (meth)acrylate, 3-cyano(meth)acrylate Fundane-1-yl ester, 3-carboxyadamantan-1-yl (meth)acrylate, 3,5-dicarboxyadamantan-1-yl (meth)acrylate, (meth)acrylic acid 3 a structural unit obtained from a monomer such as carboxy-5-hydroxyadamantan-1-yl ester or 3-methoxycarbonyl-5-hydroxyadamantan-1-yl (meth)acrylate.

The content ratio of other structural units is preferably from 0 mol% to 20 mol% with respect to all structural units in the [A] polymer.

<[A] Synthesis Method of Polymer>

[A] The polymer can be synthesized according to a conventional method such as radical polymerization, and for example, a reaction solution containing each monomer and a radical initiator is added dropwise to a reaction solution containing a reaction solvent or a monomer to carry out polymerization. In the method, a reaction solution containing each monomer and a reaction solution containing a radical initiator are respectively added dropwise to a reaction solution containing a reaction solvent or a monomer to carry out a polymerization reaction, and a reaction solution prepared by separately modulating each monomer A method in which a reaction solution containing a radical initiator is added dropwise to a reaction solution containing a reaction solvent or a monomer to carry out a polymerization reaction, and the like.

The reaction temperature of each of the above reactions can be appropriately set depending on the type of the initiator, but it is usually from 30 ° C to 180 ° C, preferably from 40 ° C to 160 ° C, more preferably from 50 ° C to 140 ° C. The dropwise addition may be appropriately set depending on the reaction temperature, the type of the initiator, and the monomer to be reacted, but is preferably from 30 minutes to 8 hours, more preferably from 45 minutes to 6 hours, and most preferably one hour. ~5 hours. Further, the total reaction time including the dropping time can be appropriately set, but is preferably from 30 minutes to 8 hours, more preferably from 45 minutes to 7 hours, and most preferably from 1 to 6 hours. When added dropwise to the solution containing the monomer, the monomer content ratio in the dropwise addition solution is preferably 30 mol% or more, more preferably 50 mol% or more, more preferably 50 mol% or more, more preferably 70% or more.

The radical initiator used for the polymerization may be exemplified by 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile) and 2,2'-azobis(2-ring). Propylpropionitrile, 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis ( 2-methylbutyronitrile), 1,1'-azobis(cyclohexane-1-carbonitrile), 2,2'-azobis(2-methyl-N-phenylpropanthene) diphosphate Acid salt, 2,2'-azobis(2-methyl-N-2-propenylpropionamidine) dihydrochloride, 2,2'-azobis[2-(5-methyl-2- Imidazolin-2-yl)propane]dihydrochloride, 2,2'-azobis{2-methyl-N-[1,1-bis(hydroxymethyl)2-hydroxyethyl]propanamide }, dimethyl-2,2'-azobis(2-methylpropionate), 4,4'-azobis(4-cyanovaleric acid), 2,2'-azobis ( 2-(hydroxymethyl)propionitrile) and the like. These initiators may be used singly or in combination of two or more.

The solvent used for the polymerization can be used as long as it can dissolve the monomer to be used and does not interfere with the polymerization (for example, nitrobenzene or thiol compound). For example, it is exemplified by alcohols, ethers, ketones, guanamines, esters, lactones, nitriles, mixed liquids thereof and the like.

The alcohols are exemplified by, for example, methanol, ethanol, propanol, isopropanol, butanol, ethylene glycol, propylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, 1-methoxy-2-propane. Alcohol, etc. The ethers are exemplified by, for example, propyl ether, diisopropyl ether, butyl methyl ether, tetrahydrofuran, 1,4-dioxane, 1,3-dioxolane, 1,3-dioxane, and the like. The ketones are exemplified by acetone, methyl ethyl ketone, diethyl ketone, methyl isopropyl ketone, methyl isobutyl ketone and the like. The guanamines are exemplified by, for example, N,N-dimethylformamide, N,N-dimethylacetamide, and the like. The esters are exemplified by, for example, ethyl acetate, methyl acetate, isobutyl acetate, and the like. The lactones are exemplified by, for example, γ-butyrolactone. The nitriles are exemplified by, for example, acetonitrile, propionitrile, butyronitrile, and the like. Further, these solvents may be used singly or in combination of two or more.

After the completion of the polymerization, it is preferred to introduce the reaction liquid into a reprecipitation solvent to recover the target polymer as a powder. The reprecipitation solvent is exemplified by, for example, water, alcohols, ethers, ketones, guanamines, esters, lactones, nitriles, and the like. The alcohols are exemplified by, for example, methanol, ethanol, propanol, isopropanol, butanol, ethylene glycol, propylene glycol, 1-methoxy-2-propanol and the like. The ethers are exemplified by, for example, propyl ether, diisopropyl ether, butyl methyl ether, tetrahydrofuran, 1,4-dioxane, 1,3-dioxolane, 1,3-dioxane, and the like. The ketones are exemplified by acetone, methyl ethyl ketone, diethyl ketone, methyl isopropyl ketone, methyl isobutyl ketone and the like. The guanamines are exemplified by, for example, N,N-dimethylformamide, N,N-dimethylacetamide, and the like. The esters are exemplified by, for example, ethyl acetate, methyl acetate, isobutyl acetate, and the like. The lactones are exemplified by, for example, γ-butyrolactone. The nitriles are exemplified by, for example, acetonitrile, propionitrile, butyronitrile, and the like.

The weight average molecular weight (Mw) of the [A] polymer as measured by gel permeation chromatography (GPC) is preferably from 1,000 to 100,000, more preferably from 1,500 to 80,000, most preferably from 2,000 to 50,000. [A] When the Mw of the polymer is less than 1,000, the heat resistance of the photoresist film is lowered. On the other hand, when it exceeds 100,000, the developing property of a photoresist film may fall. Further, the ratio (Mw/Mn) of the Mw of the [A] polymer to the number average molecular weight (Mn) is preferably from 1 to 5, more preferably from 1 to 3.

Further, the less the impurities such as a halogen or a metal of the polymerization reaction liquid obtained by the above polymerization, the better. When the content of the impurity is small, the sensitivity, the resolution, the process stability, the pattern shape, and the like when the photoresist film is formed can be further improved. The purification method of the polymerization reaction liquid is exemplified by a chemical purification method such as water washing or liquid-liquid extraction, or a combination of the chemical purification method, a physical purification method such as ultrafiltration or centrifugation, and the like. Further, in the present invention, the [A] polymer may be used alone or in combination of two or more.

<[B]acid generator>

As the [B] acid generator, for example, an onium salt such as a phosphonium salt or a phosphonium salt; an organic halogen compound; an anthracene compound such as a dioxane or a diazomethane or the like can be given.

The [B] acid generator is preferably a phosphonium salt, and is preferably a compound represented by the following formula (4) from the viewpoint of the absorption efficiency of the radiation.

【化11】

In the above formula (4), R ⁹ is a hydrogen atom, a hydroxyl group, a linear or branched alkyl group having 1 to 10 carbon atoms, a linear or branched alkoxy group having 1 to 10 carbon atoms or a carbon number of 2~ a linear or branched alkoxycarbonyl group of 11. R ¹⁰ is a linear or branched alkyl group having 1 to 10 carbon atoms. R ¹¹ and R ^{12 are} each independently a linear or branched alkyl group having 1 to 10 carbon atoms, a substituted phenyl group or a substituted naphthyl group. However, R ¹¹ and R ¹² may be bonded to each other to form a divalent group having 2 to 10 carbon atoms which may be substituted. Y ^- is an anion represented by R ¹³ C _p F _2p sO ₃ ^- . R ¹³ is a fluorine atom or a hydrocarbon group having 1 to 12 carbon atoms which may be substituted. p is an integer from 1 to 10. k is an integer from 0 to 2. m is an integer from 0 to 10. However, when R ¹⁰ is plural, a plurality of R ^{10 's} may be the same or different.

The linear or branched alkyl group having 1 to 10 carbon atoms in R ⁹ , R ¹⁰ , R ¹¹ and R ¹² is exemplified by, for example, a methyl group, an ethyl group, a n-propyl group, an isopropyl group, an n-butyl group or an isobutyl group. Base, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-decyl, n-decyl and the like. The linear or branched alkoxy group having 1 to 10 carbon atoms represented by R ^{9 is} exemplified by, for example, a methoxy group, an ethoxy group, a n-propoxy group, an isopropoxy group, a n-butoxy group or an isobutoxy group. , n-pentyloxy, n-hexyloxy and the like. The linear or branched alkoxycarbonyl group having 2 to 11 carbon atoms represented by R ^{9 is} exemplified by, for example, a methoxycarbonyl group, an ethoxycarbonyl group, a n-propoxycarbonyl group, an isopropoxycarbonyl group, or a n-butoxy group. A carbonyl group, an isobutoxycarbonyl group, a n-pentyloxycarbonyl group, a n-hexyloxycarbonyl group or the like.

k is preferably 0 or 1. X ^- R as shown in the ¹³ C _p F _2p SO ₃ ^- in the R ¹³ is preferably a fluorine atom, or a substituted hydrocarbon group having 1 to 12 carbon atoms of the other, preferably from 1 to P 4.

The phosphonium cation in the above formula (4) is preferably a phosphonium cation represented by the following formula (4-1) or (4-2) from the viewpoint of improving the absorption efficiency of the radiation.

【化12】

In the above formula (4-1), R ¹⁸ , R ¹⁹ and R ^{20 are} each independently a hydroxyl group, a substituted linear or branched alkyl group having 1 to 12 carbon atoms or a carbon number 6 to 12 which may be substituted. The aryl group. Q1, q2, and q3 are each an integer of 0-5. However, when R ¹⁸ , R ¹⁹ and R ²⁰ are plural, a plurality of R ¹⁸ , R ¹⁹ and R ²⁰ may be the same or different.

In the above formula (4-2), R ²¹ is a hydrogen atom, a linear or branched alkyl group having 1 to 8 carbon atoms which may be substituted, or an optionally substituted aryl group having 6 to 8 carbon atoms. R ²² is a hydrogen atom, a linear or branched alkyl group having 1 to 7 carbon atoms which may be substituted, or an aryl group having 6 to 7 carbon atoms which may be substituted. Q4 is an integer from 0 to 7. Q5 is an integer from 0 to 6. Q6 is an integer from 0 to 3. However, when R ²¹ and R ²² are plural, a plurality of R ²¹ and R ²² may be the same or different. Further, a plurality of R ²² may be bonded to each other to form a ring structure.

The phosphonium cation in the above formula (4) is, for example, a phosphonium cation represented by the following formulas (i-1) to (i-63).

【化13】

【化14】

【化15】

【化16】

Among these, it is preferred to use the formula (i-1), the formula (i-2), the formula (i-6), the formula (i-8), the formula (i-13), the formula (i-19), a cation represented by the formula (i-25), the formula (i-27), the formula (i-29), the formula (i-33), the formula (i-51), and the formula (i-54).

[B] The acid generator may be used singly or in combination of two or more. The amount of the [B] acid generator to be used is preferably from 1 part by mass to 50 parts by mass, more preferably from 2 parts by mass to 30 parts by mass, per 100 parts by mass of the [A] polymer. In addition, the amount of the [B] acid generator represented by the above formula (4) is preferably from 1 part by mass to 50 parts by mass, more preferably from 2 parts by mass to 30% by mass based on 100 parts by mass of the [A] polymer. Share.

<[C] Acid Diffusion Control Agent>

The sensitive radiation linear resin composition may also contain a [C] acid diffusion controlling agent as an appropriate component. The acid diffusion controlling agent is a component that controls the diffusion of an acid generated by the acid generator in the photoresist film and suppresses an inappropriate chemical reaction in the unexposed region. By formulating the [C] acid diffusion controlling agent, the storage stability of the obtained radiation sensitive linear resin composition can be improved, and the resolution as the photoresist film can be further improved while suppressing the standing time from the self-exposure to the heat treatment. By changing the line width variation of the resulting photoresist pattern, a sensitive radiation linear resin composition excellent in process stability can be obtained.

The [C] acid diffusion controlling agent is exemplified by, for example, N-tert-butoxycarbonyldi-n-octylamine, N-tert-butoxycarbonyldi-n-decylamine, N-tert-butoxycarbonyldi-n-decyl Amine, N-tert-butoxycarbonyldicyclohexylamine, N-tert-butoxycarbonyl-1-adamantylamine, N-tert-butoxycarbonyl-2-adamantylamine, N- Tributoxycarbonyl-N-methyl-1-adamantylamine, (S)-(-)-1-(t-butoxycarbonyl)-2-pyrrolidinemethanol, (R)-(+) -1-(t-butoxycarbonyl)-2-pyrrolidinemethanol, N-tert-butoxycarbonyl-4-hydroxypiperidine, N-t-butoxycarbonylpyrrolidine, N,N'-di Third butoxycarbonylpiperidine, N,N-di-t-butoxycarbonyl-1-adamantylamine, N,N-di-t-butoxycarbonyl-N-methyl-1-adamantyl Amine, N-tert-butoxycarbonyl-4,4'-diaminodiphenylmethane, N,N'-di-t-butoxycarbonylhexamethylenediamine, N,N,N', N'-tetra-t-butoxycarbonylhexamethyldiamine, N,N'-di-t-butoxycarbonyl-1,7-diaminoheptane, N,N'-di-butadiene Alkylcarbonyl-1,8-diaminooctane, N,N'-di-t-butoxycarbonyl-1,9-diaminodecane , N,N'-di-t-butoxycarbonyl-1,10-diaminodecane, N,N'-di-t-butoxycarbonyl-1,12-diaminododecane, N , N'-di-t-butoxycarbonyl-4,4'-diaminodiphenylmethane, N-tert-butoxycarbonylbenzimidazole, N-tert-butoxycarbonyl-2-methyl An amino group-containing compound containing N-tert-butoxycarbonyl group, such as benzimidazole or N-t-butoxycarbonyl-2-phenylbenzimidazole.

The acid diffusion controlling agent other than the above [C] acid diffusion controlling agent is exemplified by, for example, a tertiary amine compound, a quaternary ammonium hydroxide compound, a nitrogen-containing heterocyclic compound, and the like.

The tertiary amine compound may, for example, be exemplified by triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n-octylamine, cyclohexyl Tri(cyclo)alkylamines such as dimethylamine, dicyclohexylmethylamine, tricyclohexylamine; aniline, N-methylaniline, N,N-dimethylaniline, 2-methylaniline, 3 Aromatic amines such as methylaniline, 4-methylaniline, 4-nitroaniline, 2,6-dimethylaniline, 2,6-diisopropylaniline; triethanolamine, N,N-di ( Alkanolamines such as hydroxyethyl)aniline; N,N,N',N'-tetramethylethylenediamine, N,N,N',N'-indole (2-hydroxypropyl)ethylenediamine, 1,3-bis[1-(4-aminophenyl)-1-methylethyl]benzenetetramethylamine, bis(2-dimethylaminoethyl)ether, bis(2-di Ethylaminoethyl ether and the like.

The fourth-order ammonium hydroxide compound may, for example, be tetra-n-propylammonium hydroxide or tetra-n-butylammonium hydroxide.

The nitrogen-containing heterocyclic compound is exemplified by, for example, pyridine, 2-methylpyridine, 4-methylpyridine, 2-ethylpyridine, 4-ethylpyridine, 2-phenylpyridine, 4-phenylpyridine, 2-methyl. Pyridines such as 4-phenylpyridine, nicotine, nicotinic acid, nicotinic acid decylamine, quinoline, 4-hydroxyquinoline, 8-oxoquinoline, acridine; piperazine, 1-(2- Piperazines such as hydroxyethyl)piperazine, and pyrazine, pyrazole, acridine, quinoxaline, porphyrin, pyrrolidine, piperidine, 3-piperidinyl-1,2-propanediol, morpholine, 4 -methylmorpholine, 1,4-dimethylpiperazine, 1,4-diazabicyclo[2.2.2]octane, imidazole, 4-methylimidazole, 1-benzyl-2-methylimidazole , 4-methyl-2-phenylimidazole, benzimidazole, 2-phenylbenzimidazole, and the like.

The [C] acid diffusion controlling agent may be used singly or in combination of two or more. The amount of the use of the diffusion controlling agent is preferably 10 parts by mass or less, more preferably 0.001 part by mass to 5 parts by mass based on 100 parts by mass of the [A] polymer. Parts by mass. When the amount used is more than 10 parts by mass, the sensitivity of the photoresist film is remarkably lowered. Further, when the amount of the [C] acid diffusion controlling agent used is not more than 0.001 part by mass, an improvement effect may not be obtained.

<[D] Solvent>

The radiation sensitive linear resin composition usually contains a solvent. The solvent [D] is exemplified by, for example, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol mono-n-propyl ether acetate, ethylene glycol mono-n-butyl ether Ethylene glycol monoalkyl ether acetate such as acid ester; propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-n-propyl ether, propylene glycol mono-n-butyl ether and other propylene glycol monoalkyl ether; propylene glycol Propylene glycol dialkyl ethers such as propyl ether, propylene glycol diethyl ether, propylene glycol di-n-propyl ether, propylene glycol di-n-butyl ether; propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol Propylene glycol monoalkyl ether acetate such as n-propyl ether acetate or propylene glycol mono-n-butyl ether acetate; lactate such as methyl lactate, ethyl lactate, n-propyl lactate or isopropyl lactate; formic acid Formates such as n-amyl ester and isoamyl formate; ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, n-amyl acetate, isoamyl acetate, acetic acid 3- Acetate such as methoxybutyl ester or 3-methyl-3-methoxybutyl acetate; isopropyl propionate, n-butyl propionate , propionate such as isobutyl propionate, 3-methyl-3-methoxybutyl propionate; ethyl hydroxyacetate, ethyl 2-hydroxy-2-methylpropionate, 2-hydroxy- Methyl 3-methylbutyrate, ethyl methoxyacetate, ethyl ethoxyacetate, methyl 3-methoxypropionate, ethyl 3-methylpropionate, 3-ethoxypropionic acid Ester, ethyl 3-ethoxypropionate, 3-methyl-3-methoxybutyl butyrate, methyl acetoxyacetate, ethyl acetoxyacetate, methyl pyruvate, pyruvate Other esters such as esters; aromatic hydrocarbons such as toluene and xylene; methyl ethyl ketone, 2-pentanone, 2-hexanone, 2-heptanone, 3-heptanone, 4-heptanone, cyclohexanone Ketones; N-methylformamide, N,N-dimethylformamide, N-methylacetamide, N,N-dimethylacetamide, N-methylpyrrolidone, etc. Classes; lactones such as γ-butyrolactone. These [D] solvents may be used singly or in combination of two or more.

<Other optional ingredients>

The radiation sensitive linear resin composition may contain an alicyclic additive having an acid dissociable group, a surfactant, a sensitizer, a halo preventing agent, a storage stabilizer, an antifoaming agent, and the like. Further, these other optional components may be used singly or in combination of two or more.

[alicyclic additive]

The alicyclic additive having an acid dissociable group is a component having an effect of improving dry etching resistance, pattern shape, adhesion to a substrate, and the like. The alicyclic additive is exemplified by, for example, a 1-butylantanecarboxylic acid tert-butyl ester, a 1-adamantanecarboxylic acid tert-butoxycarbonylmethyl ester, a 1,3-adamantane dicarboxylic acid di-t-butyl ester, and 1- Adamantane derivatives such as adamantane acetic acid tert-butyl ester, 1-adamantane acetic acid tert-butoxycarbonyl methyl ester, 1,3-adamantane diacetate di-t-butyl ester; deoxycholic acid tert-butyl ester, Deoxycholic acid, third butoxycarbonyl methyl ester, deoxycholic acid 2-ethoxyethyl ester, deoxycholic acid 2-cyclohexyloxyethyl ester, deoxycholic acid 3-oxocyclohexyl ester, deoxycholic acid Deoxycholate esters such as hydropyranyl ester and deoxycholate, such as tert-butyl choate, third butoxycarbonyl methyl lithate, 2-ethoxy B, lithocholic acid Ester, stearyl cholate 2-cyclohexyloxyethyl ester, lithocholic acid 3-oxocyclohexyl ester, lithochalic acid tetrahydropyranyl ester, lithocholic acid mevalonolactone, etc. .

[Surfactant]

The surfactant is a component having an effect of improving coatability, streaking property, and developing property. The surfactants are exemplified by, for example, polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene n-octyl phenyl ether, polyoxyethylene n-decyl phenyl ether, polyethyl b. A nonionic surfactant such as diol dilaurate or polyethylene glycol distearate.

Commercially available products are, for example, trade name KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.), POLYFLOW No. 75, POLYFLOW No. 95 (manufactured by Kyoeisha Chemical Co., Ltd.), EF TOP EF301, EF TOP EF303, EF TOP EF352 (above TORKEMU) Manufactured by PRODUCT, MEGAFAC F171, MEGAFAC F173 (above manufactured by Dainippon Ink Chemical Industry Co., Ltd.), FLORARD FC430, FLORARD FC431 (above manufactured by Sumitomo 3M), ASAHIGUARD AG710, SURFLON S-382, SURFLON SC-101, SURFLON SC-102, SURFLON SC-103, SURFLON SC-104, SURFLON SC-105, SURFLON SC-106 (above, manufactured by Asahi Glass Co., Ltd.).

<Modulation method of sensitive radiation linear resin composition>

The sensitive radiation linear resin composition is such that the total solid content concentration is 3% by mass to 50% by mass (preferably 5% by mass to 25% by mass), for example, [A] polymer, [B] acid generator The [C] acid diffusion controlling agent and other optional components are dissolved in the [D] solvent and then filtered by, for example, a filter having a pore size of 5 nm. The material of the filter is not particularly limited and is exemplified by, for example, nylon 6,6 or nylon 6, polyethylene or a combination thereof.

<Formation method of photoresist pattern>

The photoresist pattern using the sensitized radiation linear resin composition is formed by forming a photoresist film composed of the sensitized radiation linear resin composition on a substrate. Subsequently, the formed photoresist film is exposed. Here, the acid dissociable group in the [A] polymer is dissociated by the action of a sulfonic acid generated from the [B] acid generator by exposure to produce a carboxyl group. When a carboxyl group is produced, the solubility of the exposed portion of the photoresist film to the alkali developing solution is improved. Subsequently, the photoresist film is developed, and the exposed portion is dissolved and removed by the alkali developing solution to form a positive resist pattern.

The method for forming the photoresist film is to apply the prepared sensitive radiation linear resin composition to, for example, a germanium wafer and an aluminum-coated crystal by a suitable coating means such as spin coating, cast coating, or roll coating. On a substrate such as a circle. The heat treatment (SB) may also be performed in advance as appropriate.

Next, the photoresist film is exposed in such a manner as to form a specific photoresist pattern. Further, the radiation used for the exposure is exemplified by visible light, ultraviolet light, far ultraviolet light, X-rays, charged particle beam, or the like. It is preferably a far ultraviolet ray represented by an ArF excimer laser (wavelength 193 nm) or a KrF excimer laser (wavelength 248 nm), more preferably an ArF excimer laser.

Further, it is preferred to carry out heat treatment (PEB) after exposure. The dissociation reaction of the acid dissociable group in the photoresist film proceeds smoothly by PEB. The heating condition of the PEB varies depending on the composition of the sensitive radiation linear resin composition, but is preferably from 30 ° C to 200 ° C, more preferably from 50 ° C to 170 ° C. A means for satisfying the required characteristics of the present application is a method of performing PEB at a temperature of 105 ° C or lower to suppress acid diffusion generated in the exposed portion. Even in the case where the photolithography performance can be sufficiently exerted under such conditions, the structural units (I) and (II) can be preferably used under such conditions even when the acid dissociation property of the low temperature protecting group is required to be excellent. . In addition, by combining the structural units (I) and (II), the solubility and rigidity of the exposed portion and the unexposed portion after baking can be appropriately controlled, and the LWR, MEEF, and DOF can be greatly improved. Performance.

Further, since the sensitive radiation linear resin composition can maximize the potential of the substrate, an organic or inorganic antireflection can be formed on the substrate to be used, as disclosed in, for example, Japanese Patent Publication No. 6-12452. membrane. In addition, in order to prevent the influence of the alkaline impurities and the like contained in the environmental atmosphere, a protective film may be provided on the photoresist film as disclosed in, for example, JP-A-5-188598. Moreover, these techniques can also be employed.

Next, a specific photoresist pattern can be obtained by developing the exposed photoresist film. The developing solution used for development is preferably such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium citrate, sodium metasilicate, aqueous ammonia, ethylamine, n-propylamine, diethylamine, and N-propylamine, triethylamine, methyldiethylamine, ethyldimethylamine, triethanolamine, tetramethylammonium hydroxide, pyrrole, piperidine, choline, 1,8-diazabicyclo- [5.4.0] An alkaline aqueous solution obtained by dissolving at least one of a basic compound such as 7-undecene and 1,5-diazabicyclo-[4.3.0]-5-decene. The concentration of the above alkaline aqueous solution is preferably 10% by mass or less. When the concentration of the alkaline aqueous solution exceeds 10% by mass, the unexposed portion is also dissolved in the developing solution.

For example, an organic solvent may be added to the above developing solution. The organic solvent is exemplified by a ketone such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, 3-methylcyclopentanone or 2,6-dimethylcyclohexanone; Alcohols such as methanol, ethanol, n-propanol, isopropanol, n-butanol, tert-butanol, cyclopentanol, cyclohexanol, 1,4-hexanediol, 1,4-hexanedimethanol; tetrahydrofuran Ethers such as dioxane; esters such as ethyl acetate, n-butyl acetate, isoamyl acetate; aromatic hydrocarbons such as toluene and xylene; phenol, etidylacetone, dimethylformamide, and the like. Further, these organic solvents may be used singly or in combination of two or more.

The amount of the organic solvent used is preferably 100% by volume or less based on the above aqueous alkaline solution. When the amount of the organic solvent used exceeds 100% by volume, the development property is lowered, and the image retention of the exposed portion is increased. Further, a surfactant may be added in an appropriate amount to the above developing solution. Further, after development with the above developing solution, it is preferably washed with water and dried.

[Examples]

Hereinafter, the present invention will be specifically described by way of examples and comparative examples, but the present invention is not limited by the examples.

[Mw and Mn]

For Mw and Mn, a GPC column (2 G2000HXL, 1 G3000HXL, 1 G4000HXL) manufactured by TOSOH Co., Ltd. was used, and the solvent was dissolved at a concentration of 1.0 ml/min to dissolve the solvent in tetrahydrofuran at a column temperature of 40 ° C to form a monodisperse polymerization. Styrene was measured as a standard by gel permeation chromatography (GPC). Further, the degree of dispersion (Mw/Mn) was calculated from the above measurement results.

[ ¹³ C-NMR analysis]

The ¹³ C-NMR analysis for specifying the content of the structural unit of each polymer was carried out using a nuclear magnetic resonance apparatus (JNM-ECX400, manufactured by JEOL Ltd.).

The monomers used in the synthesis of [A] polymer and the synthesis of polymers other than [A] polymers are shown below. Further, the compound obtained by the structural unit (I) is a compound represented by the following (M-1), (M-7), (M-8), (M-10) and (M-11), and a structural unit is obtained ( The compound of the above II) is a compound represented by the following (M-2) or (M-3), and the compound obtained as another structural unit is a compound represented by the following (M-6).

M-1: 1-isopropylcyclopentyl methacrylate

M-2: 1-ethyladamantyl methacrylate

M-3: 1-isopropyl hydroxymethyl methacrylate

M-4: 2-hydroxyethyl methacrylate

M-5: 4-oxa-5-oxo-tricyclo[0.4.1.0 ^3,7 ]decan-2-yl methacrylate

M-6: 1-methyladamantyl methacrylate

M-7: 1-methylcyclopentyl methacrylate

M-8: 1-ethylcyclooctyl methacrylate

M-9: 1-ethylcarbonyl-1,1-difluoro-2-butyl methacrylate

M-10: 1-ethylcyclohexyl methacrylate

M-11: 1-ethylcyclooctyl methacrylate

<[A] Synthesis of Polymers>

[Synthesis Example 1]

11.51 g (40 mol%) of monomer (M-1), 1.91 g (10 mol%) of monomer (M-4), and 14.66 g (45 mol%) of monomer (M-5) were dissolved in In 60 g of 2-butanone, 2.41 g (10 mol%) of AIBN was added as a starter to prepare a monomer solution. Next, 30 g of 2-butanone and monomer (M-3) 1.92 g (5 mol%) were placed in a 500 mL three-necked flask equipped with a thermometer and a dropping funnel, dissolved, and nitrogen purged for 30 minutes. After blowing with nitrogen, the inside of the flask was stirred with a magnet stirrer and heated to 80 °C. The previously prepared monomer solution was added dropwise over 3 hours using a dropping funnel. The polymerization reaction was carried out for 6 hours at the start of the dropwise addition as the polymerization initiation time. After the completion of the polymerization, the polymerization solution was cooled to 30 ° C or lower with water cooling. After cooling, the mixture was poured into a liquid mixture of 480 g of methanol and 120 g of water, and the precipitated white powder was filtered. The filtered white powder was washed twice with 120 g of methanol. After filtration, it was dried at 60 ° C for 17 hours to obtain a white powder copolymer (A-1) (22 g, yield 72%). The copolymer (A-1) had Mw of 4,000 and Mw/Mn of 1.28. ^{The result of 13} C-NMR analysis, the structural unit derived from the compound (M-1): the structural unit derived from the compound (M-3): the structural unit derived from the compound (M-4): derived from the compound (M- 5) The content of the structural unit is 38.0:4.1:8.9:45.4 (% by mole).

[Synthesis Example 2]

11.51 g (40 mol%) of monomer (M-1), 1.91 g (10 mol%) of monomer (M-4), and 14.71 g (45 mol%) of monomer (M-5) were dissolved in In 60 g of 2-butanone, 2.42 g (10 mol%) of AIBN was charged as a starter to prepare a monomer solution. Next, 30 g of 2-butanone and monomer (M-2) 1.91 g (5 mol%) were placed in a 500 mL three-necked flask equipped with a thermometer and a dropping funnel, dissolved, and nitrogen purged for 30 minutes. After blowing with nitrogen, the inside of the flask was stirred with a magnet stirrer and heated to 80 °C. The previously prepared monomer solution was added dropwise over 3 hours using a dropping funnel. The polymerization reaction was carried out for 6 hours at the start of the dropwise addition as the polymerization initiation time. After the completion of the polymerization, the polymerization solution was cooled to 30 ° C or lower with water cooling. After cooling, the mixture was poured into a liquid mixture of 480 g of methanol and 120 g of water, and the precipitated white powder was filtered. The filtered white powder was washed twice with 120 g of methanol. Subsequently, it was filtered and dried at 60 ° C for 17 hours to obtain a white powder copolymer (A-2) (20 g, yield 68%). The copolymer (A-2) had a Mw of 4,100 and a Mw/Mn of 1.30. ^{The result of 13} C-NMR analysis, the structural unit derived from the compound (M-1): the structural unit derived from the compound (M-2): the structural unit derived from the compound (M-4): derived from the compound (M- 5) The content of the structural unit is 39.8:4.5:10.5:45.2 (% by mole).

[Synthesis Example 3]

12.47 g (45 mol%) of monomer (M-1) and 15.68 g (50 mol%) of monomer (M-5) were dissolved in 60 g of 2-butanone, and 2.32 g (10 mol%) of AIBN was charged. As a starter, and dissolved to prepare a monomer solution. Next, 30 g of 2-butanone and 1.85 g (5 mol%) of the monomer (M-3) were placed in a 500 mL three-necked flask equipped with a thermometer and a dropping funnel, dissolved, and nitrogen purged for 30 minutes. After blowing with nitrogen, the inside of the flask was stirred with a magnet stirrer and heated to 80 °C. The previously prepared monomer solution was added dropwise over 3 hours using a dropping funnel. The polymerization reaction was carried out for 6 hours at the start of the dropwise addition as the polymerization initiation time. After the completion of the polymerization, the polymerization solution was cooled to 30 ° C or lower with water cooling. After cooling, the mixture was poured into a liquid mixture of 480 g of methanol and 120 g of water, and the precipitated white powder was filtered. The filtered white powder was washed twice with 120 g of methanol. Subsequently, it was filtered and dried at 60 ° C for 17 hours to obtain a white powder copolymer (A-3) (23 g, yield: 75%). The copolymer (A-3) had a Mw of 4,050 and a Mw/Mn of 1.29. ^{The result of 13} C-NMR analysis, the structural unit derived from the compound (M-1): the structural unit derived from the compound (M-3): the content of the structural unit derived from the compound (M-5) was 44.8:4.9 : 50.3 (% by mole).

[Synthesis Example 4]

12.51 g (45 mol%) of monomer (M-1) and 15.73 g (50 mol%) of monomer (M-5) were dissolved in 60 g of 2-butanone, and 2.33 g (10 mol%) of AIBN was charged. As a starter, and dissolved to prepare a monomer solution. Next, 30 g of 2-butanone and 1.85 g (5 mol%) of the monomer (M-2) were placed in a 500 mL three-necked flask equipped with a thermometer and a dropping funnel, dissolved, and purged with nitrogen for 30 minutes. After blowing with nitrogen, the inside of the flask was stirred with a magnet stirrer and heated to 80 °C. The previously prepared monomer solution was added dropwise over 3 hours using a dropping funnel. The polymerization reaction was carried out for 6 hours at the start of the dropwise addition as the polymerization initiation time. After the completion of the polymerization, the polymerization solution was cooled to 30 ° C or lower with water cooling. After cooling, the mixture was poured into a liquid mixture of 480 g of methanol and 120 g of water, and the precipitated white powder was filtered. The filtered white powder was washed twice with 120 g of methanol. Subsequently, it was filtered and dried at 60 ° C for 17 hours to obtain a white powder copolymer (A-4) (23 g, yield: 75%). The copolymer (A-4) had a Mw of 4,100 and an Mw/Mn of 1.30. ^{The result of 13} C-NMR analysis, the structural unit derived from the compound (M-1): the structural unit derived from the compound (M-2): the content of the structural unit derived from the compound (M-5) was 44.7:4.9 : 50.4 (% by mole).

<[A] Synthesis of polymers other than polymers>

[Synthesis Example 5]

2.46 g (10 mol%) of monomer (M-1), 14.05 g (45 mol%) of monomer (M-6), and 13.33 g (45 mol%) of monomer (M-5) were dissolved in In 60 g of 2-butanone, 2.19 g (10 mol%) of AIBN was charged as a starter, and a monomer solution was prepared by dissolving. Next, 30 g of 2-butanone was placed in a 500 mL three-necked flask equipped with a thermometer and a dropping funnel, and nitrogen was blown for 30 minutes. After blowing with nitrogen, the inside of the flask was stirred with a magnet stirrer and heated to 80 °C. The previously prepared monomer solution was added dropwise over 3 hours using a dropping funnel. The polymerization reaction was carried out for 6 hours at the start of the dropwise addition as the polymerization initiation time. After the completion of the polymerization, the polymerization solution was cooled to 30 ° C or lower with water cooling. After cooling, the mixture was poured into a liquid mixture of 480 g of methanol and 120 g of water, and the precipitated white powder was filtered. The filtered white powder was washed twice with 120 g of methanol. Subsequently, it was filtered and dried at 60 ° C for 17 hours to obtain a white powder copolymer (CA-1) (24 g, yield 80%). The copolymer (CA-1) had a Mw of 4,300 and an Mw/Mn of 1.32. ^{The result of 13} C-NMR analysis, the structural unit derived from the compound (M-1): the structural unit derived from the compound (M-6): the content of the structural unit derived from the compound (M-5): 9.9: 45.0 : 45.1 (% by mole).

[Synthesis Example 6]

11.40 g (45 mol%) of monomer (M-7), 1.87 g (5 mol%) of monomer (M-2), and 16.73 g (50 mol%) of monomer (M-5) were dissolved in In 60 g of 2-butanone, 2.47 g (10 mol%) of AIBN was charged as a starter, and a monomer solution was prepared by dissolving. Next, 30 g of 2-butanone was placed in a 500 mL three-necked flask equipped with a thermometer and a dropping funnel, and nitrogen was blown for 30 minutes. After blowing with nitrogen, the inside of the flask was stirred with a magnet stirrer and heated to 80 °C. The previously prepared monomer solution was added dropwise over 3 hours using a dropping funnel. The polymerization reaction was carried out for 6 hours at the start of the dropwise addition as the polymerization initiation time. After the completion of the polymerization, the polymerization solution was cooled to 30 ° C or lower with water cooling. After cooling, the mixture was poured into a liquid mixture of 480 g of methanol and 120 g of water, and the precipitated white powder was filtered. The filtered white powder was washed twice with 120 g of methanol. Subsequently, it was filtered and dried at 60 ° C for 17 hours to obtain a white powder copolymer (CA-2) (20 g, yield 67%). The copolymer (CA-2) had a Mw of 3,900 and a Mw/Mn of 1.28. ^{The result of 13} C-NMR analysis, the structural unit derived from the compound (M-7): the structural unit derived from the compound (M-2): the content of the structural unit derived from the compound (M-5): 45.3: 4.4 : 50.3 (% by mole).

[Synthesis Example 7]

37.41 g (40 mol%) of monomer (M-8) and 62.59 g (60 mol%) of monomer (M-9) were dissolved in 133 g of 2-butanone, and 4.75 g (7 mol%) of AIBN was charged. As a starter, and dissolved to prepare a monomer solution. Next, 67 g of 2-butanone was placed in a 500 mL three-necked flask equipped with a thermometer and a dropping funnel, and nitrogen was blown for 30 minutes. After blowing with nitrogen, the inside of the flask was stirred with a magnet stirrer and heated to 80 °C. The previously prepared monomer solution was added dropwise over 3 hours using a dropping funnel. The polymerization reaction was carried out for 6 hours at the start of the dropwise addition as the polymerization initiation time. After the completion of the polymerization, the polymerization solution was cooled to 30 ° C or lower with water cooling. After cooling, the contents of the flask were concentrated to 150 g, and a precipitated liquid was collected by adding 760 g of methanol and 40 g of water. Repeat this operation twice. Subsequent solvent replacement with propylene glycol monomethyl ether acetate gave 20% propylene glycol monomethyl ether acetate solution (200 g, yield 40%). The copolymer (CA-3) contained in the solution had a Mw of 3,700 and a Mw/Mn of 1.30. As a result of ¹³ C-NMR analysis, the structural unit derived from the compound (M-8): the content of the structural unit derived from the compound (M-9) was 36.8:43.2 (mol%).

[Synthesis Example 8]

14.07 g (50 mol%) of monomer (M-10) and 15.93 g (50 mol%) of monomer (M-5) were dissolved in 60 g of 2-butanone, and 2.35 g (10 mol%) of AIBN was charged. As a starter, and dissolved to prepare a monomer solution. Next, 30 g of 2-butanone was poured into a 500 mL three-necked flask equipped with a thermometer and a dropping funnel, and nitrogen was blown for 30 minutes. After blowing with nitrogen, the inside of the flask was stirred with a magnet stirrer and heated to 80 °C. The previously prepared monomer solution was added dropwise over 3 hours using a dropping funnel. The polymerization reaction was carried out for 6 hours at the start of the dropwise addition as the polymerization initiation time. After the completion of the polymerization, the polymerization solution was cooled to 30 ° C or lower with water cooling. After cooling, the mixture was poured into a liquid mixture of 480 g of methanol and 120 g of water, and the precipitated white powder was filtered. The filtered white powder was washed twice with 120 g of methanol. Subsequently, it was filtered and dried at 60 ° C for 17 hours to obtain a white powder copolymer (CA-4) (20 g, yield 80%). The copolymer (CA-4) had a Mw of 4,300 and a Mw/Mn of 1.30. As a result of ¹³ C-NMR analysis, the structural unit derived from the compound (M-10): the content of the structural unit derived from the compound (M-5) was 48.3:51.7 (mol%).

[Synthesis Example 9]

14.14 g (45 mol%) of monomer (M-11), 1.82 g (10 mol%) of monomer (M-4), and 14.02 g (45 mol%) of monomer (M-5) were dissolved in In 60 g of 2-butanone, 2.30 g (10 mol%) of AIBN was charged as a starter, and a monomer solution was prepared by dissolving. Next, 30 g of 2-butanone was poured into a 500 mL three-necked flask equipped with a thermometer and a dropping funnel, and nitrogen was blown for 30 minutes. After blowing with nitrogen, the inside of the flask was stirred with a magnet stirrer and heated to 80 °C. The previously prepared monomer solution was added dropwise over 3 hours using a dropping funnel. The polymerization reaction was carried out for 6 hours at the start of the dropwise addition as the polymerization initiation time. After the completion of the polymerization, the polymerization solution was cooled to 30 ° C or lower with water cooling. After cooling, the mixture was poured into a liquid mixture of 480 g of methanol and 120 g of water, and the precipitated white powder was filtered. The filtered white powder was washed twice with 120 g of methanol. Subsequently, it was filtered and dried at 60 ° C for 17 hours to obtain a white powder copolymer (CA-5) (20 g, yield 80%). The copolymer (CA-5) had a Mw of 4,200 and a Mw/Mn of 1.29. ^{The result of 13} C-NMR analysis, the structural unit derived from the compound (M-11): the structural unit derived from the compound (M-4): the content of the structural unit derived from the compound (M-5): 43.5: 9.8 : 46.7 (% by mole).

<Modulation of Sensitive Radiation Linear Resin Composition>

The [B] acid generator and [C] acid diffusion controlling agent and [D] solvent used in the preparation of the sensitive radiation linear resin composition are shown below.

[B]acid generator

B-1: a compound represented by the following formula

B-1: triphenylsulfonium salicylate

【化17】

[C] acid diffusion control agent

C-1: tert-butyl-4-hydroxy-1-piperidine carboxylate

C-2: 2-phenylbenzimidazole

[D] solvent

D-1: propylene glycol monomethyl ether acetate

D-2: cyclohexanone

D-3: γ-butyrolactone

[Example 1]

100 parts by mass of the copolymer (A-1) as the component [A] and 3 parts by mass of (CA-3), and (B-1) 11 parts by mass and (B-2) as the [B] acid generator 7.5 parts by mass, and (D-1) 2,600 parts by mass, (D-2) 1,100 parts by mass, and (D-3) 200 parts by mass of [D] solvent are added to the mixture, and the mixture is dissolved to prepare a mixed solution. The resulting mixed solution was filtered through a filter having a pore size of 0.20 μm to prepare a radiation sensitive linear resin composition.

[Embodiment 2]

100 parts by mass of the copolymer (A-2) as the component [A] and 3 parts by mass of (CA-3), and (B-1) 11 parts by mass and (B-2) as the [B] acid generator 7.5 parts by mass, (D-1) 2,600 parts by mass, (D-2) 1,100 parts by mass, and (D-3) 200 parts by mass of [D] solvent were added to the mixture, and the mixture was dissolved to prepare a mixed solution. The resulting mixed solution was filtered through a filter having a pore size of 0.20 μm to prepare a radiation sensitive linear resin composition.

[Example 3]

100 parts by mass of the copolymer (A-3) as the component [A] and 3 parts by mass of (CA-3), and (B-1) 11 parts by mass and (B-2) as the [B] acid generator 7.5 parts by mass, (D-1) 2,600 parts by mass, (D-2) 1,100 parts by mass, and (D-3) 200 parts by mass of [D] solvent were added to the mixture, and the mixture was dissolved to prepare a mixed solution. The resulting mixed solution was filtered through a filter having a pore size of 0.20 μm to prepare a radiation sensitive linear resin composition.

[Example 4]

100 parts by mass of the copolymer (A-4) as the component [A] and 3 parts by mass of (CA-3), (B-1) 18 parts by mass of the [B] acid generator, and [C] acid 1 part by mass of (C-1) and 1 part by mass of (C-2) of the diffusion controlling agent, (D-1) 2,600 parts by mass, (D-2) 1,100 parts by mass as a [D] solvent are added to the mixture. And (D-3) 200 parts by mass, the above mixture was dissolved to prepare a mixed solution, and the resulting mixed solution was filtered through a filter having a pore size of 0.20 μm to prepare a radiation sensitive linear resin composition.

[Comparative Example 1]

100 parts by mass of the copolymer (CA-1) as the component [A] and 3 parts by mass of (CA-3), and (B-1) 11 parts by mass and (B-2) as the [B] acid generator 7.5 parts by mass, (D-1) 2,600 parts by mass, (D-2) 1,100 parts by mass, and (D-3) 200 parts by mass of [D] solvent were added to the mixture, and the mixture was dissolved to prepare a mixed solution. The resulting mixed solution was filtered through a filter having a pore size of 0.20 μm to prepare a radiation sensitive linear resin composition.

[Comparative Example 2]

100 parts by mass of the copolymer (CA-2) as the component [A] and 3 parts by mass of (CA-3), (B-1) 18 parts by mass of the [B] acid generator, and [C] acid 1 part by mass of (C-1) and 1 part by mass of (C-2) of the diffusion controlling agent, (D-1) 2,600 parts by mass, (D-2) 1,100 parts by mass as a [D] solvent are added to the mixture. And (D-3) 200 parts by mass, the above mixture was dissolved to prepare a mixed solution, and the resulting mixed solution was filtered through a filter having a pore size of 0.20 μm to prepare a radiation sensitive linear resin composition.

[Comparative Example 3]

100 parts by mass of the copolymer (CA-4) as the component [A] and 3 parts by mass of (CA-3), and (B-1) 11 parts by mass and (B-2) as the [B] acid generator 7.5 parts by mass, (D-1) 2,600 parts by mass, (D-2) 1,100 parts by mass, and (D-3) 200 parts by mass of [D] solvent were added to the mixture, and the mixture was dissolved to prepare a mixed solution. The resulting mixed solution was filtered through a filter having a pore size of 0.20 μm to prepare a radiation sensitive linear resin composition.

[Comparative Example 4]

100 parts by mass of the copolymer (CA-5) as the component [A] and 3 parts by mass of (CA-3), and (B-1) 11 parts by mass and (B-2) as the [B] acid generator 7.5 parts by mass, (D-1) 2,600 parts by mass, (D-2) 1,100 parts by mass, and (D-3) 200 parts by mass of [D] solvent were added to the mixture, and the mixture was dissolved to prepare a mixed solution. The resulting mixed solution was filtered through a filter having a pore size of 0.20 μm to prepare a radiation sensitive linear resin composition.

<Evaluation>

The following physical properties were evaluated using the sensitive radiation linear resin composition prepared as described above. The results are shown in Table 1.

[sensitivity (mJ/cm ² )]

The sensitive radiation linear resin composition was applied onto a 12-inch wafer on which a lower anti-reflection film (ARC66, manufactured by Nissan Chemical Co., Ltd.) was formed to form a coating film having a film thickness of 75 nm, and soft baked at 120 ° C for 60 seconds. Next, an ArF excimer laser immersion exposure apparatus (NSR S610C, manufactured by NIKON) was used, and exposure was performed through a mask pattern under the conditions of NA = 1.3, ratio = 0.800, and Annular. After the exposure, the temperature was measured at the temperature shown in Table 1 for 60 seconds and then baked (PEB). Subsequently, it was developed with a 2.38 mass% aqueous solution of tetramethylammonium hydroxide, washed with water, and dried to form a positive resist pattern. At this time, the exposure amount of the 1:1 line and the interval of the line width of 50 nm formed by the mask was formed by the pattern of the interval of 100 nm passing through the 50 nm line as the optimum exposure amount, and the optimum exposure amount was used as the sensitivity (mJ/cm ² ). Further, the length measuring system was a scanning electron microscope (CG-4000, manufactured by Hitachi High-Technologies).

[MEEF]

According to the evaluation of the above sensitivity, the LS pattern is formed by a mask pattern for forming a pattern of 48 nm line, 100 nm interval, 49 nm line 100 nm interval, 50 nm line 100 nm interval, 51 nm line 100 nm interval, and 52 nm line 100 nm interval, respectively. type. At this time, the line size (nm) of the pattern design size is calculated as the horizontal axis, and the line slope when the corresponding line width (nm) is formed as the vertical axis is calculated as the MEEF. MEEF (Linear Slope) determines that the reproducibility of the mask is better with the value closer to 1.

[LWR(nm)]

Using the scanning electron microscope described above, a pattern of 50 nm 1 L/1 S which was imaged at an optimum exposure amount was observed from the upper portion of the pattern, and the line width was measured at any 10 points. The 3σ value (deviation) of the measured value of the line width was taken as LWR (nm). The smaller the value of LWR, the better the shape of the pattern formed.

[DOF(nm)]

Using the above-described scanning electron microscope, a pattern of 50 nmL/140 nmP which was imaged at an optimum exposure amount was observed from the upper portion, and a focal length range in which CD was converged to a line of 45 nm line to 55 nm line when the focal length was shifted was taken as a line DOF (nm). Further, the pattern of the 50 nm interval/140 nm pitch which is resolved by the optimum exposure amount is observed from the upper portion, and the focal length range in which the CD converges to the range of 45 nm line to 55 nm line when the focal length is shifted is defined as the groove DOF (nm). The value of the narrower of the line DOF and the groove DOF is taken as the DOF. The larger the DOF value, the more difficult it is to be judged to be good by the influence of the difference in focus at the time of exposure.

The evaluation results in Table 1 clearly show that the sensitive radiation linear resin composition can form a photoresist pattern which can reduce LWR and MEEF and is excellent in DOF.

[Industry possible use]

The sensitive radiation linear resin composition of the present invention can form a photoresist pattern which can reduce LWR and MEEF and is excellent in DOF. Accordingly, the sensitive radiation linear resin composition is suitable as a photoresist material used in a lithography step using, for example, an ArF excimer laser or an electron beam as a light source.

Claims (4)

A sensitive radiation linear resin composition containing [A] a structural unit (I) represented by the following formula (1), a structural unit (II) represented by the following formula (2), and a formula (3) a polymer represented by the structural unit (III), and [B] a linear radiation acid generator represented by the following formula (4), a structural unit (I): relative to all structural units in the [A] polymer 20 mol%% to 50 mol%, structural unit (II): 5 mol% to 35 mol% relative to all structural units in the [A] polymer, (In the formula (1), R ¹ is a hydrogen atom or a methyl group, R ² is a carbon atom, R ³ is a linear or branched alkyl group having 1 to 4 carbon atoms, and Z is a carbon number formed together with R ² a group of divalent groups derived from less than 10 cyclohexanes, but satisfying the condition that the number of carbon atoms in the group consisting of Z, R ² and R ³ is 8 or more in total, and the group consisting of Z and R ² When the carbon number is 5 or 6, R ³ is a linear or branched alkyl group having 2 to 4 carbon atoms, (In the formula (2), R ⁴ is a hydrogen atom or a methyl group, R ⁵ is a carbon atom, R ⁶ is a linear or branched alkyl group having 2 to 4 carbon atoms, and X is a carbon number 10 together with R ⁵ The above divalent bridges the alicyclic hydrocarbon group), (In the formula (3), R ⁷ is a hydrogen atom or a methyl group, and R ⁸ is a linear or branched alkyl group having 1 to 4 carbon atoms which may be substituted by a fluorine atom, a linear chain having a carbon number of 1 to 4 or Branched alkoxy or cyano group, A is a divalent hydrocarbon group having 1 to 4 carbon atoms, -A'-O-, -A'-COO- or -A'-OCO-, and A' is a carbon number of 1 to 4. a divalent hydrocarbon group, wherein l is an integer of 0 or 1, and n is an integer of 0 to 3, but when R ⁸ is plural, plural R ⁸ may be the same or different) (In the formula (4), R ⁹ is a hydrogen atom, a hydroxyl group, a linear or branched alkyl group having 1 to 10 carbon atoms, a linear or branched alkoxy group having 1 to 10 carbon atoms, or a carbon number of 2~ a straight or branched alkoxycarbonyl group of 11; R ¹⁰ is a linear or branched alkyl group having 1 to 10 carbon atoms; and R ¹¹ and R ^{12 are} each independently a linear or branched carbon number of 1 to 10. An alkyl group, a substituted phenyl group or a substituted naphthyl group, but R ¹¹ and R ¹² may be bonded to each other to form a divalent group having 2 to 10 carbon atoms which may be substituted, and Y ^- is R ¹³ C _p F _2p SO ₃ ^- represents an anion, R ¹³ is a fluorine atom or a substituted hydrocarbon group having 1 to 12 carbon atoms, p is an integer of 1 to 10, k is an integer of 1 to 2, and m is 0 to 10 An integer, but when R ¹⁰ is plural, a plurality of R ^{10 's} may be the same or different). The sensitive radiation linear resin composition of the first aspect of the invention, wherein the structural unit (I) is a structural unit represented by the following formula (1-1) and a structural unit represented by the following formula (1-2) Forming at least one structural unit selected by the group, (In the formulae (1-1) and (1-2), R ¹ has the same meaning as the above formula (1), and a is 1 or 2). The sensitive radiation linear resin composition of claim 1, wherein the structural unit (II) is a structural unit represented by the following formula (2-1), (In the formula (2-1), R ⁴ and R ⁶ are synonymous with the above formula (2)). A polymer comprising a structural unit (I) represented by the following formula (1), a structural unit (II) represented by the following formula (2), and a structural unit (III) represented by the following formula (3), a structural unit (I): 20 mol% to 50 mol% relative to all structural units in the [A] polymer, tectonic unit (II): 5 mol relative to all structural units in the [A] polymer Ear %~35 mol%, (In the formula (1), R ¹ is a hydrogen atom or a methyl group, R ² is a carbon atom, R ³ is a linear or branched alkyl group having 1 to 4 carbon atoms, and Z is a carbon number formed together with R ² a group of divalent groups derived from less than 10 cyclohexanes, but satisfying the condition that the number of carbon atoms in the group consisting of Z, R ² and R ³ is 8 or more in total, and is composed of Z and R ² When the carbon number in the group is 5 or 6, R ³ is a linear or branched alkyl group having 2 to 4 carbon atoms), (In the formula (2), R ⁴ is a hydrogen atom or a methyl group, R ⁵ is a carbon atom, R ⁶ is a linear or branched alkyl group having 2 to 4 carbon atoms, and X is a carbon number 10 together with R ⁵ The above divalent bridges the alicyclic hydrocarbon group), (In the formula (3), R ⁷ is a hydrogen atom or a methyl group, and R ⁸ is a linear or branched alkyl group having 1 to 4 carbon atoms which may be substituted by a fluorine atom, a linear chain having a carbon number of 1 to 4 or Branched alkoxy or cyano group, A is a divalent hydrocarbon group having 1 to 4 carbon atoms, -A'-O-, -A'-COO- or -A'-OCO-, and A' is a carbon number of 1 to 4. The divalent hydrocarbon group, l is an integer of 0 or 1, and n is an integer of 0 to 3. However, when R ⁸ is plural, a plurality of R ⁸ may be the same or different.