JP2008127462A - Method for producing resin, resin produced by the method, positive type photosensitive composition containing the resin and method for forming pattern by using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a resin by removing a low molecular eight component giving bad effects to its resist performance effectively and simply, the resin and further a positive type photosensitive composition improved with resist performance [light exposure latitude, LER (line edge roughness), development defects and preservation stability], and a method for forming a pattern by using the same. <P>SOLUTION: This method for producing the resin increasing dissolving rate to an alkaline developing liquid by an action of an acid is provided by comprising a process of adding a solvent (b) containing a poor solvent to a solution (a) containing the resin of which dissolving rate to the alkaline development liquid is increased by the action of the acid to prepare a solution (c), and a process of precipitating the resin of which dissolving rate to the alkaline development liquid is increased by the action of the acid by adding the solution (c) to a solvent (d) containing the poor solvent. The resin produced by such the method of production, the positive type photosensitive composition containing the above resin and the method for forming the pattern by using the same are also provided. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for producing a resin used in a positive photosensitive composition used in a semiconductor production process such as an IC, a circuit board such as a liquid crystal or a thermal head, and other photofabrication processes, and its production. The present invention relates to a resin produced by the method, a positive photosensitive composition containing the resin, and a pattern forming method using the same. More specifically, a method for producing a resin used in a positive photosensitive composition suitable for use as an exposure light source such as far ultraviolet rays of 250 nm or less, preferably 220 nm or less, and an irradiation source using an electron beam, and a method for producing the same Relates to a positive photosensitive composition containing the resin and a pattern forming method using the same.

  The chemically amplified photosensitive composition generates an acid in the exposed area by irradiation with radiation such as far ultraviolet light, and the acid-catalyzed reaction causes the solubility of the active radiation irradiated area and non-irradiated area in the developer. This is a pattern forming material for changing the pattern to form a pattern on the substrate.

  When a KrF excimer laser is used as an exposure light source, a resin having a basic skeleton of poly (hydroxystyrene) having a small absorption mainly in the 248 nm region is used as a main component. A pattern is formed, which is a better system than the conventional naphthoquinone diazide / novolak resin system.

On the other hand, when a further short wavelength light source, for example, an ArF excimer laser (193 nm) is used as an exposure light source, the compound having an aromatic group exhibits a large absorption in the 193 nm region. It wasn't.
For this reason, resists for ArF excimer lasers containing a resin having an alicyclic hydrocarbon structure have been developed (see, for example, Patent Documents 1 and 2). When these resists contain a low molecular weight component, there is a problem that development defects on the resist pattern and storage stability are lowered. Methods for removing low molecular components include a method of refining using a solvent (reprecipitation), for example, a method using a hydrophobic solvent (for example, Patent Document 3), a method using a hydrophilic solvent (for example, Patent Document 4), a method of washing a resin obtained by reprecipitation twice or more with a solvent (for example, see Patent Document 5), a method of dissolving a resin obtained by reprecipitation with a solvent, and then washing and purifying the resin. (For example, refer to Patent Document 6). However, the methods of Patent Document 3 and Patent Document 4 have a low effect of removing low molecular weight components, and satisfactory resist performance cannot be obtained. Further, Patent Document 5 and Patent Document 6 have a high effect of removing low molecular weight components, but there is a problem that the manufacturing cost increases because the operation is complicated and the number of steps is long.

JP-A-9-73173 US Pat. No. 6,388,101 JP 2002-201232 A JP 2002-229220 A JP 2003-270788 A JP 2004-250672 A

The present invention has been made with respect to such problems of the prior art, and provides a resin production method and a resin in which low molecular weight components that adversely affect resist performance are effectively and simply removed.
It is another object of the present invention to provide a positive photosensitive composition having improved resist performance (exposure latitude, LER (line edge roughness), development defect, storage stability) and a pattern forming method using the same.

  The present inventor has intensively studied to achieve the above object, and devised a method for adding a solvent during purification so that the low molecular component is less likely to be contained in the precipitated resin, thereby removing the low molecular component. Has been found to increase dramatically, and the present invention has been completed. Furthermore, it has been found that the exposure latitude, LER (line edge roughness), development defect, and storage stability of the positive photosensitive composition can be improved by using the resin produced in the present invention, and the present invention has been achieved.

  The present invention has the following configuration.

  (1) In a method for producing a resin in which the dissolution rate in an alkaline developer is increased by the action of an acid, the solvent containing a poor solvent in the solution (a) containing a resin in which the dissolution rate in an alkaline developer is increased by the action of an acid (B) is added to prepare a solution (c), and the solution (c) is added to a solvent (d) containing a poor solvent to precipitate a resin whose dissolution rate in an alkaline developer is increased by the action of an acid. A process for producing a resin, wherein the dissolution rate in an alkaline developer is increased by the action of an acid, which comprises the step of

  (2) X is the concentration of the resin whose dissolution rate in the alkaline developer is increased by the action of the acid of the solution (c), and X is the saturated solubility of the resin whose dissolution rate is increased in the alkali developer by the action of the acid of the solution (c). Solvent (b) is added so that it may be set to Y <Y, The manufacturing method of resin with which the melt | dissolution rate with respect to an alkali developing solution increases by the effect | action of the acid as described in (1) characterized by the above-mentioned.

  (3) The poor solvent is an aliphatic hydrocarbon solvent, an aromatic hydrocarbon solvent, an alcohol solvent, water, an ester solvent, a ketone solvent or an ether solvent (1) or ( A method for producing a resin, wherein the dissolution rate in an alkaline developer is increased by the action of an acid as described in 2).

  (4) The poor solvent is an alkane having 5 to 15 carbon atoms, a cycloalkane having 5 to 15 carbon atoms, an alcohol having 1 to 5 carbon atoms, or water, described in (1) or (2) A method for producing a resin, wherein the dissolution rate in an alkaline developer is increased by the action of an acid.

  (5) The action of the acid according to any one of (1) to (4), wherein the resin whose dissolution rate in an alkaline developer is increased by the action of an acid has a repeating unit having an acid-decomposable group. A method for producing a resin in which the dissolution rate in an alkaline developer increases.

  (6) The resin according to any one of (1) to (5), wherein the resin whose dissolution rate in an alkali developer is increased by the action of an acid has a repeating unit having a group having a lactone structure. A method for producing a resin, which increases the dissolution rate in an alkaline developer by action.

  (7) The resin whose dissolution rate in an alkali developer increases by the action of an acid has a repeating unit having a polar group, and is alkali by the action of an acid according to any one of (1) to (6) A method for producing a resin, which increases the dissolution rate in a developer.

  (8) Resin which increases the dissolution rate in an alkaline developer by the action of an acid, which is produced by the method according to any one of (1) to (7).

(9) It contains (A) a compound capable of generating an acid upon irradiation with actinic rays or radiation, and (B) a resin whose dissolution rate in an alkali developer is increased by the action of the acid described in (8). Positive photosensitive composition.

  (10) A pattern forming method comprising a step of forming a film with the positive photosensitive composition according to (9), and exposing and developing the film.

  INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a resin production method and resin from which low molecular weight components that adversely affect resist performance are effectively and easily removed, and resist performance (exposure latitude, LER (line edge roughness)). A positive photosensitive composition having improved development defects and storage stability) and a pattern forming method using the same can be provided.

Hereinafter, the best mode for carrying out the present invention will be described.
In addition, in the description of the group (atomic group) in this specification, the description which does not describe substitution and non-substitution includes what does not have a substituent and what has a substituent. . For example, the “alkyl group” includes not only an alkyl group having no substituent (unsubstituted alkyl group) but also an alkyl group having a substituent (substituted alkyl group).

  The present invention includes a step of preparing a solution (c) by adding a solvent (b) containing a poor solvent to a solution (a) containing a resin whose dissolution rate in an alkaline developer is increased by the action of an acid, and a solution (c) ) Is added to the solvent (d) containing a poor solvent to precipitate the resin. By this method, low molecular weight components can be removed more effectively than the usual purification method (reprecipitation). The reason for this is an estimate, but is considered as follows. That is, in a normal purification method, the resin (a) containing the resin is added to the poor solvent (d) to precipitate the resin. In this case, since the resin solubility difference between the resin solution (solution (a)) and the reprecipitation solvent (solvent (d)) is large, the resin particles grow locally and rapidly in the solvent (d), Easy to incorporate low molecular weight components. On the other hand, in the present invention, the resin solubility difference between the resin solution (solution (c)) and the reprecipitation solvent (solvent (d)) is reduced by diluting with a solvent (b) containing a poor solvent in advance. It grows slowly and uniformly and precipitates without incorporating low molecular weight components. It is thought that the removal effect of low molecular weight components has been greatly improved by the difference in the growth mechanism of the resin particles. The present invention is particularly effective when the solvent (b) is added so that X <Y, where X is the concentration of the resin in the solution (c) and Y is the saturated solubility of the resin in the solution (c). . However, the solvent (b) may be added so that X ≧ Y. Here, the saturation solubility means the maximum solubility of the polymer in the solvent at the temperature at which the production method of the present invention is carried out. Although the temperature which implements the manufacturing method of this invention does not have a restriction | limiting in particular, 0-150 degreeC is preferable and 10-100 degreeC is especially preferable.

  In the present invention, the resin-containing solution (a) is a solution obtained by dissolving a resin in a solvent, or a polymerization solution obtained by polymerizing monomers, but a polymerization solution obtained by polymerizing monomers. It is preferable in production. In the case of obtaining a solution (a) by polymerizing monomers, examples of the polymerization method include addition polymerization such as radical polymerization, cationic polymerization, and ionic polymerization, polycondensation, and the like, and radical polymerization is particularly preferable. As a method of radical polymerization, a batch polymerization method in which a monomer species and an initiator are dissolved in a solvent and polymerization is performed by heating, and a solution of the monomer species and the initiator is added dropwise to the heating solvent over 1 to 10 hours. Although the dropping polymerization method etc. are mentioned, the dropping polymerization method is preferable. Examples of the reaction solvent include ether solvents such as tetrahydrofuran, 1,4-dioxane, diisopropyl ether, ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, ester solvents such as ethyl acetate, dimethylformamide, dimethylacetamide. Examples thereof include amide solvents such as propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, and cyclohexanone described below. These solvents may be used alone or in combination. More preferably, the polymerization is performed using the same solvent as the solvent used in the positive photosensitive composition of the present invention. Thereby, generation | occurrence | production of the particle at the time of a preservation | save can be suppressed.

  The polymerization reaction is preferably performed in an inert gas atmosphere such as nitrogen or argon. As a polymerization initiator, a commercially available radical initiator (azo initiator, peroxide, etc.) is used to initiate the polymerization. As the radical initiator, an azo initiator is preferable, and an azo initiator having an ester group, a cyano group, or a carboxyl group is preferable. Preferred initiators include azobisisobutyronitrile, azobisdimethylvaleronitrile, dimethyl 2,2′-azobis (2-methylpropionate) and the like. The polymerization may be performed by adding a chain transfer agent. As the chain transfer agent, a compound containing sulfur is preferable, and a thiol having 1 to 10 carbon atoms and a disulfide having 2 to 20 carbon atoms are most preferable. Examples of the thiol include 1-butanethiol, 1-pentanethiol, cyclohexanethiol, 1-octanethiol and the like. Examples of the disulfide include dibutyl disulfide, dioctyl disulfide, dicyclohexyl disulfide and the like. The addition amount of these chain transfer agents depends on the molecular weight of the target polymer and cannot be determined uniquely, but is generally 0.01 to 10 mol% with respect to the total number of monomer moles. The total monomer concentration in the polymerization reaction is 5 to 50% by mass, preferably 10 to 30% by mass. The reaction temperature is usually 10 ° C to 150 ° C, preferably 30 ° C to 120 ° C, more preferably 60 ° C to 100 ° C.

  The solvent (b) will be described. The solvent (b) is a solvent containing a poor solvent. The poor solvent here refers to a solvent or mixed solvent in which the saturation solubility of the resin is 0.010 g-resin / 1.0 mL-poor solvent (10 ° C.) or less. Examples of poor solvents include aliphatic hydrocarbon solvents (eg, pentane, hexane, cyclohexane, etc.), aromatic hydrocarbon solvents (eg, toluene, xylene, mesitylene, etc.), alcohol solvents (eg, methanol, ethanol, Isopropanol, n-butanol, 3-methylbutanol, propylene glycol monomethyl ether, etc.), water, ester solvents (eg, ethyl acetate, butyl acetate, ethyl propionate, propylene glycol monomethyl ether acetate, etc.), ketone solvents (eg, Acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, etc.) and ether solvents (for example, diethyl ether, dibutyl ether, tetrahydrofuran, etc.), and in particular, alkanes having 5 to 15 carbon atoms and silanes having 5 to 15 carbon atoms. Roarukan, preferably alcohols and water of 1 to 5 carbon atoms. These may be used as a mixture. The solvent (b) may be a poor solvent alone or may further contain another solvent in addition to the poor solvent. Other solvents that may be further contained in the solvent (b) include sulfoxide solvents (for example, dimethyl sulfoxide), nitrile solvents (for example, acetonitrile, propiononitrile), amide solvents (for example, N, N-dimethylformamide). N, N-dimethylacetamide, N-methylpyrrolidone, etc.), carboxylic acid solvents (eg, acetic acid, propionic acid, etc.), halogen solvents (eg, chloroform, 1,2-dichloroethane, etc.), System solvents and amide solvents are preferred. The ratio of the poor solvent contained in the solvent (b) is not particularly limited, but is preferably 20 to 100% by volume, and more preferably 40 to 100% by volume.

The solution (c) is prepared by adding the solvent (b) to the solution (a). When preparing the solution (c), the concentration of the resin whose dissolution rate in the alkaline developer is increased by the action of the acid in the solution (c) is X, and the dissolution rate in the alkaline developer is increased by the action of the acid in the solution (c). When the saturated solubility of the resin to be used is Y, the solvent (b) is added so that X <Y. The amount of the solvent (b) added is not particularly limited. However, if the amount is too large (that is, when X ≧ Y), the resin is not preferable because it precipitates. If the amount is too small, the effect of removing low molecular components of the present invention is low. The solvent (b) is preferably added so that 0.010Y ≦ X <Y, and the solvent (b) is particularly preferably added so that 0.10Y ≦ X <Y. By adding the solvent (b) within this range, the low molecular components can be removed to the maximum extent.

  The solvent (d) is a solvent containing a poor solvent. Examples of the poor solvent included in the solvent (d) include the poor solvent included in the solvent (b). The solvent (d) may further contain another solvent in addition to the poor solvent. Examples of the other solvent in the solvent (d) include the same solvents as those in the solvent (b). The solvent (d) preferably has a poor solvent of 30 to 100% by volume, particularly preferably 50 to 100% by volume. The amount of the solvent (d) to be used cannot be uniquely determined because it depends on the type of resin, production equipment, etc., but it is preferably 1.0 to 50 times the volume of the solution (c), and 2.0 It is particularly preferable to use ~ 20 times.

  The temperature (internal temperature) at which the purification step of the present invention is carried out can be carried out at -10 to 200 ° C, preferably 0 to 150 ° C, particularly preferably 10 to 100 ° C.

  The resin obtained in the present invention can be used for resist applications. When used as a resist application, a positive type containing (A) a compound that generates an acid upon irradiation with actinic rays or radiation, and (B) a resin that increases the dissolution rate in an alkaline developer obtained by the production method of the present invention. Used as a photosensitive composition. Hereinafter, (A) a compound that generates an acid upon irradiation with actinic rays or radiation, and (B) a resin that increases the dissolution rate in an alkali developer will be described.

(A) Compound that generates acid upon irradiation with actinic ray or radiation The positive photosensitive composition of the present invention is a compound that generates acid upon irradiation with actinic ray or radiation (hereinafter, also referred to as “photoacid generator”). Containing.
Examples of such photoacid generators include photoinitiators for photocationic polymerization, photoinitiators for photoradical polymerization, photodecolorants for dyes, photochromic agents, actinic rays used in microresists, etc. Known compounds that generate an acid upon irradiation with radiation and mixtures thereof can be appropriately selected and used.

  Examples thereof include diazonium salts, phosphonium salts, sulfonium salts, iodonium salts, imide sulfonates, oxime sulfonates, diazodisulfones, disulfones, and o-nitrobenzyl sulfonates.

  Further, a group that generates an acid upon irradiation with these actinic rays or radiation, or a compound in which a compound is introduced into the main chain or side chain of the polymer, for example, US Pat. No. 3,849,137, German Patent No. 3914407. JP, 63-26653, JP, 55-164824, JP, 62-69263, JP, 63-146038, JP, 63-163452, JP, 62-153853, The compounds described in JP-A 63-146029 can be used.

  Furthermore, compounds capable of generating an acid by light described in US Pat. No. 3,779,778, European Patent 126,712 and the like can also be used.

  Among the compounds that generate an acid upon irradiation with actinic rays or radiation, compounds represented by the following general formula (ZI), (ZII) or (ZIII) can be exemplified.

In general formula (ZI):
R ₂₀₁ , R ₂₀₂ and R ₂₀₃ each independently represents an organic group.
X ⁻ represents a non-nucleophilic anion, preferably sulfonate anion, carboxylate anion, bis (alkylsulfonyl) amide anion, tris (alkylsulfonyl) methide anion, BF ₄ ⁻ , PF ₆ ⁻ , SbF ₆ ^{— and the} like. An organic anion having a carbon atom is preferable.

  Preferred organic anions include organic anions represented by the following general formulas (AN1) to (AN4).

In general formulas (AN1) and (AN2):
Rc ₁ represents an organic group.

Formula (AN1) ~ (AN2), examples of the organic group in Rc _1, include those having 1 to 30 carbon atoms, preferably an alkyl group which may be substituted, cycloalkyl group, aryl group, or a mixture, A group in which a plurality of them are linked by a linking group such as a single bond, —O—, —CO ₂ —, —S—, —SO ₃ —, —SO ₂ N (Rd ₁ ) — can be exemplified. Rd ₁ represents a hydrogen atom or an alkyl group, and may form a ring structure with a bonded alkyl group, cycloalkyl group, or aryl group.
More preferred as the organic group for Rc ₁ is an alkyl group substituted at the 1-position with a fluorine atom or a fluoroalkyl group, or a phenyl group substituted with a fluorine atom or a fluoroalkyl group. By having a fluorine atom or a fluoroalkyl group, the acidity of the acid generated by light irradiation is increased and the sensitivity is improved. When Rc ₁ has 5 or more carbon atoms, it is preferable that at least one carbon atom has a hydrogen atom, not all hydrogen atoms are substituted with fluorine atoms, and the number of hydrogen atoms is fluorine. More preferably than atoms. By not having a perfluoroalkyl group having 5 or more carbon atoms, ecotoxicity is reduced.

As a particularly preferred embodiment of Rc ₁ , groups represented by the following general formula can be exemplified.

In the above general formula,
Rc ₆ is substituted with a perfluoroalkylene group having 4 or less carbon atoms, more preferably 2 to 4 carbon atoms, more preferably 2 to 3 carbon atoms, 1 to 4 fluorine atoms and / or 1 to 3 fluoroalkyl groups. Represents a phenylene group.
Ax represents a single bond or a divalent linking group (preferably —O—, —CO ₂ —, —S—, —SO ₃ —, —SO ₂ N (Rd ₁ ) —). Rd ₁ represents a hydrogen atom or an alkyl group, and may combine with Rc ₇ to form a ring structure.
Rc ₇ represents a hydrogen atom, a fluorine atom, may be substituted, represents a linear or branched alkyl group, a monocyclic or polycyclic cycloalkyl group or an aryl group. The optionally substituted alkyl group, cycloalkyl group and aryl group preferably do not have a fluorine atom as a substituent.

In the general formulas (AN3) and (AN4),
Rc ₃ , Rc ₄ and Rc ₅ each independently represents an organic group.
Rc ₃ and Rc ₄ may combine to form a ring.

In the general formulas (AN3) and (AN4), the organic groups represented by Rc ₃ , Rc ₄ and Rc ₅ are preferably the same as the preferred organic groups in Rc ₁ .
When Rc ₃ and Rc ₄ are combined to form a ring, examples of the group formed by combining Rc ₃ and Rc ₄ include an alkylene group and an arylene group. A perfluoroalkylene group having 2 to 4 carbon atoms is preferred. By combining Rc ₃ and Rc ₄ to form a ring, the acidity of the acid generated by light irradiation is increased, and the sensitivity is improved, which is preferable.

In the general formula (ZI), the organic group as R ₂₀₁ , R ₂₀₂ and R ₂₀₃ generally has 1 to 30 carbon atoms, preferably 1 to 20 carbon atoms.
Two members out of R _{201 to} R ₂₀₃ may combine to form a ring structure, and the ring may contain an oxygen atom, a sulfur atom, an ester bond, an amide bond, or a carbonyl group. The two of the group formed by bonding of the R ₂₀₁ to R _203, there can be mentioned an alkylene group (e.g., butylene, pentylene).

Specific examples of the organic group as R ₂₀₁ , R ₂₀₂ and R ₂₀₃ include corresponding groups in the compounds (ZI-1), (ZI-2) and (ZI-3) described later.

In addition, the compound which has two or more structures represented by general formula (Z1) may be sufficient. For example, the general formula at least one of R ₂₀₁ to R ₂₀₃ of a compound represented by (ZI) is, at least one bond with structure of R ₂₀₁ to R ₂₀₃ of another compound represented by formula (ZI) It may be a compound.

  Further preferred examples of the component (Z1) include compounds (ZI-1), (ZI-2) and (ZI-3) described below.

The compound (ZI-1) is at least one of the aryl groups R ₂₀₁ to R ₂₀₃ in formula (ZI), arylsulfonium compound, i.e., a compound having arylsulfonium as a cation.
In the arylsulfonium compound, all of R _{201 to} R ₂₀₃ may be an aryl group, or a part of R _{201 to} R ₂₀₃ may be an aryl group, and the rest may be an alkyl group or a cycloalkyl group.
Examples of the arylsulfonium compound include triarylsulfonium compounds, diarylalkylsulfonium compounds, aryldialkylsulfonium compounds, diarylcycloalkylsulfonium compounds, aryldicycloalkylsulfonium compounds, and the like.
The aryl group of the arylsulfonium compound is preferably an aryl group such as a phenyl group or a naphthyl group, or a heteroaryl group such as an indole residue or a pyrrole residue, more preferably a phenyl group or an indole residue. When the arylsulfonium compound has two or more aryl groups, the two or more aryl groups may be the same or different.
The alkyl group that the arylsulfonium compound has as necessary is preferably a linear or branched alkyl group having 1 to 15 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, sec- Examples thereof include a butyl group and a t-butyl group.
The cycloalkyl group that the arylsulfonium compound has as necessary is preferably a cycloalkyl group having 3 to 15 carbon atoms, and examples thereof include a cyclopropyl group, a cyclobutyl group, and a cyclohexyl group.
Aryl group, alkyl group of R ₂₀₁ to R _203, cycloalkyl group, an alkyl group (for example, 1 to 15 carbon atoms), a cycloalkyl group (for example, 3 to 15 carbon atoms), an aryl group (for example, 6 to 14 carbon atoms) , An alkoxy group (for example, having 1 to 15 carbon atoms), a halogen atom, a hydroxyl group, or a phenylthio group may be substituted. Preferred substituents are linear or branched alkyl groups having 1 to 12 carbon atoms, cycloalkyl groups having 3 to 12 carbon atoms, and linear, branched or cyclic alkoxy groups having 1 to 12 carbon atoms, and more preferably , An alkyl group having 1 to 4 carbon atoms, and an alkoxy group having 1 to 4 carbon atoms. The substituent may be substituted with any one of the three R _{201 to} R ₂₀₃ , or may be substituted with all three. When R _{201 to} R ₂₀₃ are an aryl group, the substituent is preferably substituted at the p-position of the aryl group.

Next, the compound (ZI-2) will be described.
The compound (ZI-2) is, R ₂₀₁ to R ₂₀₃ in formula (ZI) each independently is a compound when it represents an organic group having no aromatic ring. Here, the aromatic ring includes an aromatic ring having a hetero atom.
The aromatic ring-free organic group as R ₂₀₁ to R ₂₀₃ generally has 1 to 30 carbon atoms, preferably 1 to 20 carbon atoms.
R _{201 to} R ₂₀₃ are each independently preferably an alkyl group, a cycloalkyl group, an allyl group, or a vinyl group, more preferably a linear, branched, cyclic 2-oxoalkyl group, an alkoxycarbonylmethyl group, particularly A linear or branched 2-oxoalkyl group is preferred.

The alkyl group as R ₂₀₁ to R ₂₀₃ may be linear, may be either branched, preferably a straight-chain or branched alkyl group (e.g., methyl group having 1 to 10 carbon atoms, an ethyl group, a propyl group, Butyl group, pentyl group). The alkyl group as R ₂₀₁ to R ₂₀₃ is a straight-chain or branched 2-oxoalkyl group, more preferably an alkoxymethyl group.
The cycloalkyl group as R ₂₀₁ to R ₂₀₃ is preferably, and a cycloalkyl group having 3 to 10 carbon atoms (e.g., cyclopentyl, cyclohexyl, norbornyl). The cycloalkyl group as R ₂₀₁ to R ₂₀₃ is more preferably a cyclic 2-oxoalkyl group.
The 2-oxoalkyl group as R _{201 to} R ₂₀₃ may be linear, branched or cyclic, and preferably a group having> C═O at the 2-position of the above alkyl group or cycloalkyl group Can be mentioned.
The alkoxy group in the alkoxycarbonylmethyl group as R ₂₀₁ to R _203, preferably may be mentioned alkoxy groups having 1 to 5 carbon atoms (a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentoxy group).
R _{201 to} R ₂₀₃ may be further substituted with a halogen atom, an alkoxy group (eg, having 1 to 5 carbon atoms), a hydroxyl group, a cyano group, or a nitro group.

  The compound (ZI-3) is a compound represented by the following general formula (ZI-3), and is a compound having a phenacylsulfonium salt structure.

In general formula (ZI-3),
R ₁ c to R ₅ c each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, or a halogen atom.
R ₆ c and R ₇ c each independently represents a hydrogen atom, an alkyl group or a cycloalkyl group.
Rx and Ry each independently represents an alkyl group, a cycloalkyl group, an allyl group, or a vinyl group.
R ₁ c to R ₇ Any two or more of c, and Rx and Ry may combine with each other to form a ring structure, the ring structure may contain an oxygen atom, a sulfur atom, an ester bond, an amide bond May be included. R ₁ c to R ₇ Any two or more of c, and as the group Rx and Ry are formed by combined include a butylene group and a pentylene group.
X ^- represents a non-nucleophilic anion, in formula (ZI) in, X ^- are those same as the.

The alkyl group as R ₁ c to R ₇ c may be either linear or branched, for example, an alkyl group having 1 to 20 carbon atoms, preferably a linear chain having 1 to 12 carbon atoms and A branched alkyl group (for example, a methyl group, an ethyl group, a linear or branched propyl group, a linear or branched butyl group, a linear or branched pentyl group) can be exemplified.
Preferable examples of the cycloalkyl group as R ₁ c to R ₇ c include a cycloalkyl group having 3 to 8 carbon atoms (for example, a cyclopentyl group and a cyclohexyl group).
The alkoxy group as R ₁ c to R ₅ c may be linear, branched or cyclic, for example, an alkoxy group having 1 to 10 carbon atoms, preferably a linear or branched chain having 1 to 5 carbon atoms. Alkoxy groups (for example, methoxy group, ethoxy group, linear or branched propoxy group, linear or branched butoxy group, linear or branched pentoxy group), cyclic alkoxy groups having 3 to 8 carbon atoms (for example, cyclopentyloxy group, cyclohexyl) Oxy group).
Preferably any of R ₁ c to R ₅ c is a linear or branched alkyl group, a cycloalkyl group or a linear, branched or cyclic alkoxy group, more preferably the R ₁ c to R ₅ c atoms The sum of the numbers is 2-15. Thereby, solvent solubility improves more and generation | occurrence | production of a particle is suppressed at the time of a preservation | save.

The alkyl group as Rx and Ry, there can be mentioned the same alkyl groups as R ₁ c~R ₇ c. The alkyl group as Rx and Ry is more preferably a linear or branched 2-oxoalkyl group or an alkoxymethyl group.
The cycloalkyl group as Rx and Ry may be the same as the cycloalkyl group of R ₁ c~R ₇ c. The cycloalkyl group as Rx and Ry is more preferably a cyclic 2-oxoalkyl group.
Examples of the linear, branched, or cyclic 2-oxoalkyl group include a group having> C═O at the 2-position of the alkyl group or cycloalkyl group as R ₁ c to R ₇ c.
The alkoxy group in the alkoxycarbonylmethyl group may be the same as the alkoxy group as R ₁ c~R ₅ c.
Rx and Ry are preferably alkyl groups having 4 or more carbon atoms, more preferably 6 or more, and still more preferably 8 or more.

In the general formulas (ZII) and (ZIII),
R ₂₀₄ to R ₂₀₇ each independently represents an aryl group, an alkyl group or a cycloalkyl group.
The aryl group of R ₂₀₄ to R _207, a phenyl group, a naphthyl group, more preferably a phenyl group.
The alkyl group as R ₂₀₄ to R ₂₀₇ may be linear, it may be either branched, preferably a straight-chain or branched alkyl group (e.g., methyl group having 1 to 10 carbon atoms, an ethyl group, a propyl Group, butyl group, pentyl group).
The cycloalkyl group as R ₂₀₄ to R ₂₀₇ is preferably, and a cycloalkyl group having 3 to 10 carbon atoms (e.g., cyclopentyl, cyclohexyl, norbornyl).
R ₂₀₄ to R ₂₀₇ may have a substituent. The R ₂₀₄ to R ₂₀₇ are substituents which may have, for example, an alkyl group (for example, 1 to 15 carbon atoms), a cycloalkyl group (for example, 3 to 15 carbon atoms), an aryl group (e.g., 6 carbon atoms 15), alkoxy groups (for example, having 1 to 15 carbon atoms), halogen atoms, hydroxyl groups, phenylthio groups and the like.
X ⁻ represents a non-nucleophilic anion, and examples thereof include the same non-nucleophilic anion as X ^{− in} formula (ZI).

  Among the compounds that generate an acid upon irradiation with actinic rays or radiation, compounds represented by the following general formulas (ZIV), (ZV), and (ZVI) can be further exemplified.

In general formulas (ZIV) to (ZVI),
Ar ₃ and Ar ₄ each independently represents an aryl group.
R ₂₀₆ represents an alkyl group, a cycloalkyl group or an aryl group.
R ₂₀₇ and R ₂₀₈ each independently represents an alkyl group, a cycloalkyl group, an aryl group, or an electron-withdrawing group. R ₂₀₇ is preferably an aryl group. R ₂₀₈ is preferably an electron-withdrawing group, and more preferably a cyano group or a fluoroalkyl group.
A represents an alkylene group, a cycloalkylene group, an alkenylene group or an arylene group.

Among the compounds that generate an acid upon irradiation with actinic rays or radiation, more preferred are compounds represented by the general formulas (ZI) to (ZIII), and still more preferred are compounds represented by (ZI). Even more preferred are compounds represented by (ZI-1) to (ZI-3).
Furthermore, the compound which generate | occur | produces the acid represented by the following general formula (AC1)-(AC3) by irradiation of actinic light or a radiation is preferable.

That is, as a particularly preferred embodiment of the photoacid generator, in the structure represented by the general formula (ZI), X ⁻ is an anion selected from the general formulas (AN1), (AN3), and (AN4). A compound can be mentioned.

  Among the compounds that decompose upon irradiation with actinic rays or radiation to generate an acid, examples of particularly preferable compounds are listed below.

  A photo-acid generator can be used individually by 1 type or in combination of 2 or more types. When two or more types are used in combination, it is preferable to combine two types of compounds that generate two types of organic acids that differ in the total number of atoms excluding hydrogen atoms by two or more.

The content of the photoacid generator in the composition is preferably 0.1 to 20% by mass, more preferably 0.5 to 10% by mass, and still more preferably, based on the total solid content of the positive photosensitive composition. 1 to 7% by mass.

(B) Resin whose dissolution rate in an alkaline developer is increased by the action of an acid The resin used in the positive photosensitive composition of the present invention is a resin whose dissolution rate in an alkaline developer is increased by the action of an acid. Resin having a group (hereinafter also referred to as “acid-decomposable group”) that decomposes by the action of an acid to generate an alkali-soluble group (hereinafter also referred to as “acid-decomposable group”) in the main chain or side chain of Or “resin (B)”).
Alkali-soluble groups include phenolic hydroxyl groups, carboxylic acid groups, fluorinated alcohol groups, sulfonic acid groups, sulfonamido groups, sulfonylimide groups, (alkylsulfonyl) (alkylcarbonyl) methylene groups, (alkylsulfonyl) (alkylcarbonyl) Imido group, bis (alkylcarbonyl) methylene group, bis (alkylcarbonyl) imide group, bis (alkylsulfonyl) methylene group, bis (alkylsulfonyl) imide group, tris (alkylcarbonyl) methylene group, tris (alkylsulfonyl) methylene group A group having
Preferred alkali-soluble groups include carboxylic acid groups, fluorinated alcohol groups (preferably hexafluoroisopropanol), and sulfonic acid groups.
A preferable group as the acid-decomposable group is a group in which the hydrogen atom of these alkali-soluble groups is substituted with a group capable of leaving with an acid.
Examples of the group leaving with an acid include -C (R ₃₆ ) (R ₃₇ ) (R ₃₈ ), -C (R ₃₆ ) (R ₃₇ ) (OR ₃₉ ), -C (R ₀₁ ) (R ₀₂ ). ) (OR ₃₉ ) and the like.
In the formula, R _{36 to} R ₃₉ each independently represents an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, or an alkenyl group. R ₃₆ and R ₃₇ may be bonded to each other to form a ring.
R _{01 and} R ₀₂ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group or an alkenyl group.
The acid-decomposable group is preferably a cumyl ester group, an enol ester group, an acetal ester group, a tertiary alkyl ester group or the like. More preferably, it is a tertiary alkyl ester group.

  The resin (B) of the present invention preferably has a repeating unit having an acid-decomposable group. The repeating unit having an acid-decomposable group is preferably a repeating unit represented by the following general formula (AI).

In general formula (AI),
Xa ₁ represents a hydrogen atom, a methyl group, a trifluoromethyl group or a hydroxymethyl group.
Rx _{1 to} Rx ₃ each independently represents an alkyl group (straight or branched) or a cycloalkyl group (monocyclic or polycyclic).
At least two of Rx _{1 to} Rx ₃ may combine to form a cycloalkyl group (monocyclic or polycyclic).

Rx _{1 to} Rx ₃ are preferably alkyl groups having 1 to 4 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, and t-butyl.
Examples of the cycloalkyl group represented by Rx _{1 to} Rx ₃ include monocyclic cyclic alkyl groups such as cyclopentyl group and cyclohexyl group, and polycyclic cyclic alkyl groups such as norbornyl group, tetracyclodecanyl group, tetracyclododecanyl group, and adamantyl group. preferable.
Examples of the cycloalkyl group formed by combining at least two of Rx _{1 to} Rx ₃ include a monocyclic cyclic alkyl group such as a cyclopentyl group and a cyclohexyl group, a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, and an adamantyl group A polycyclic cyclic alkyl group such as
It is preferable that Rx ₁ is a methyl group or an ethyl group, and Rx ₂ and Rx ₃ are bonded to bond the above-described cycloalkyl group.

  As for content of the repeating unit which has an acid-decomposable group, 20-50 mol% is preferable with respect to all the repeating units in a polymer, More preferably, it is 25-45 mol%.

  Although the specific example of the repeating unit which has a preferable acid-decomposable group is shown below, this invention is not limited to this.

  The acid-decomposable resin preferably has a repeating unit having a group having a lactone structure. As the group having a lactone structure, any group having a lactone structure can be used, but a group having a 5- to 7-membered ring lactone structure is preferable. A structure in which another ring structure is condensed to form a structure or a spiro structure is preferable. It is more preferable to have a repeating unit having a group having a lactone structure represented by any of the following general formulas (LC1-1) to (LC1-16). Further, a group having a lactone structure may be directly bonded to the main chain. Preferred lactone structures are (LC1-1), (LC1-4), (LC1-5), (LC1-6), (LC1-13), (LC1-14), and a specific lactone structure is used. This improves line edge roughness and development defects.

The lactone structure moiety may or may not have a substituent (Rb ₂ ). Preferred substituents (Rb ₂ ) include an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 4 to 7 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an alkoxycarbonyl group having 1 to 8 carbon atoms, and a carboxyl group. , A halogen atom, a hydroxyl group, a cyano group, an acid-decomposable group, and the like, more preferably an alkyl group having 1 to 4 carbon atoms, a cyano group, and an acid-decomposable group. n2 represents an integer of 0 to 4. When n2 is 2 or more, a plurality of (Rb ₂ ) may be the same or different, and a plurality of (Rb ₂ ) may be bonded to form a ring.

  Examples of the repeating unit having a group having a lactone structure represented by any of the general formulas (LC1-1) to (LC1-16) include a repeating unit represented by the following general formula (AII).

In general formula (AII),
Rb ₀ represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms. Preferable substituents that the alkyl group of Rb ₀ may have include a hydroxyl group and a halogen atom. Examples of the halogen atom for Rb ₀ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Rb ₀ is preferably a hydrogen atom or a methyl group.
Ab represents a single bond, an alkylene group, a divalent linking group having a monocyclic or polycyclic alicyclic hydrocarbon structure, an ether group, an ester group, a carbonyl group, a carboxyl group, or a divalent group obtained by combining these. To express. A linking group represented by a single bond or —Ab ₁ —CO ₂ — is preferable. Ab ₁ represents a linear or branched alkylene group or a monocyclic or polycyclic cycloalkylene group, preferably a methylene group, an ethylene group, a cyclohexyl group, an adamantyl group, or a norbornyl group.
V represents a group having a structure represented by any one of the general formulas (LC1-1) to (LC1-16).

  The repeating unit having a group having a lactone structure usually has an optical isomer, but any optical isomer may be used. One optical isomer may be used alone, or a plurality of optical isomers may be mixed and used. When one kind of optical isomer is mainly used, the optical purity (ee) thereof is preferably 90 or more, more preferably 95 or more.

  The content of the repeating unit having a group having a lactone structure is preferably from 15 to 60 mol%, more preferably from 20 to 50 mol%, still more preferably from 30 to 50 mol%, based on all repeating units in the polymer.

  Specific examples of the repeating unit having a group having a lactone structure are given below, but the present invention is not limited thereto.

  Examples of the repeating unit having a group having a particularly preferable lactone structure include the following repeating units. By selecting the optimum lactone structure, the pattern profile and the density dependence become good.

  The acid-decomposable resin preferably has a repeating unit having a polar group. Examples of the polar group include a hydroxyl group, a cyano group, an amide group, a sulfonamide group, a carbonyl group, an ester group, and a sulfo group, and a hydroxyl group and a cyano group are more preferable. This improves the substrate adhesion and developer compatibility. The repeating unit having a polar group is preferably a repeating unit having an alicyclic hydrocarbon structure substituted with a polar group. The alicyclic hydrocarbon structure of the alicyclic hydrocarbon structure substituted with a polar group is preferably an adamantyl group, a diamantyl group, or a norbornane group. As the alicyclic hydrocarbon structure substituted with a preferable polar group, partial structures represented by the following general formulas (VIIa) to (VIId) are preferable.

In general formulas (VIIa) to (VIIc),
R ₂ c to R ₄ c each independently represents a hydrogen atom, a hydroxyl group or a cyano group. However, at least one of R ₂ c to R ₄ c represents a hydroxyl group or a cyano group. Preferably, one or two of R ₂ c to R ₄ c are a hydroxyl group and the rest are hydrogen atoms. In general formula (VIIa), it is more preferable that _two of R ₂ c to R ₄ c are a hydroxyl group and the remaining is a hydrogen atom.

  Examples of the repeating unit having a partial structure represented by general formulas (VIIa) to (VIId) include the repeating units represented by the following general formulas (AIIa) to (AIId).

In general formulas (AIIa) to (AIId),
R ₁ c represents a hydrogen atom, a methyl group, a trifluoromethyl group or a hydroxymethyl group.
R ₂ c to R ₄ c each independently represents a hydrogen atom, a hydroxyl group or a cyano group. However, at least one of R ₂ c to R ₄ c represents a hydroxyl group or a cyano group. R ₂ c to R ₄ c is a general formula (VIIa) ~ same meanings as in R ₂ c to R ₄ c to (VIIc).

  The content of the repeating unit having an alicyclic hydrocarbon structure substituted with a polar group is preferably 5 to 40 mol%, more preferably 5 to 30 mol%, still more preferably 10 to 25 mol based on all repeating units in the polymer. %.

  Specific examples of the repeating unit having a structure represented by the general formulas (AIIa) to (AIIb) are given below, but the present invention is not limited thereto.

The acid-decomposable resin preferably has a repeating unit having an alkali-soluble group. Examples of the alkali-soluble group include a carboxyl group, a sulfonamide group, a sulfonylimide group, a bisulsulfonylimide group, an aliphatic alcohol in which the α-position is substituted with an electron-withdrawing group, and has a repeating unit having a carboxyl group. More preferred. By having a repeating unit having an alkali-soluble group, the resolution in contact hole applications is increased. The repeating unit having an alkali-soluble group includes a repeating unit in which an alkali-soluble group is directly bonded to the main chain of the resin, such as a repeating unit of acrylic acid or methacrylic acid, or an alkali in the main chain of the resin through a linking group. Either a repeating unit to which a soluble group is bonded, or a polymerization initiator or chain transfer agent having an alkali-soluble group is used at the time of polymerization and introduced at the end of the polymer chain, and the linking group is monocyclic or polycyclic. It may have a cyclic hydrocarbon structure. Particularly preferred are repeating units of acrylic acid or methacrylic acid.

  As for content of the repeating unit which has an alkali-soluble group, 1-20 mol% is preferable with respect to all the repeating units in a polymer, More preferably, it is 3-15 mol%, More preferably, it is 5-10 mol%.

  Specific examples of the repeating unit having an alkali-soluble group are shown below, but the present invention is not limited thereto.

  In addition to the above repeating structural units, acid-decomposable resins adjust dry etching resistance, standard developer suitability, substrate adhesion, resist profile, and general required properties of resist, such as resolution, heat resistance, and sensitivity. For this purpose, various repeating structural units can be included.

  Examples of such repeating structural units include, but are not limited to, repeating structural units corresponding to the following monomers.

Thereby, the performance required for the acid-decomposable resin, in particular,
(1) Solubility in coating solvent,
(2) Film formability (glass transition point),
(3) Alkali developability,
(4) Membrane slip (hydrophobic, alkali-soluble group selection),
(5) Adhesion of unexposed part to substrate,
(6) Dry etching resistance,
Etc. can be finely adjusted.

  As such a monomer, for example, a compound having one addition polymerizable unsaturated bond selected from acrylic acid esters, methacrylic acid esters, acrylamides, methacrylamides, allyl compounds, vinyl ethers, vinyl esters, etc. Etc.

  In addition, any addition-polymerizable unsaturated compound that can be copolymerized with monomers corresponding to the above various repeating structural units may be copolymerized.

  In acid-decomposable resins, the molar ratio of each repeating structural unit is the resist dry etch resistance, standard developer suitability, substrate adhesion, resist profile, and general resist performance required for resolving power, heat resistance, and sensitivity. It is set appropriately in order to adjust etc.

  When the composition of the present invention is for ArF exposure, the resin preferably has no aromatic group from the viewpoint of transparency to ArF light.

  The acid-decomposable resin is preferably one in which all of the repeating units are composed of (meth) acrylate-based repeating units. In this case, all of the repeating units may be methacrylate repeating units, all of the repeating units may be acrylate repeating units, or a mixture of methacrylate repeating units / acrylate repeating units, but all of the acrylate repeating units may be used. It is preferable that it is 50 mol% or less of a repeating unit.

  More preferably, the acid-decomposable resin is 20 to 50 mol% of a (meth) acrylate-based repeating unit having an acid-decomposable group represented by the general formula (AI), and a (meth) acrylate-based repeating unit 20 to 20 mol% having a lactone structure. Copolymer having 5 to 30 mol% of (meth) acrylate-based repeating unit having an alicyclic hydrocarbon structure substituted with a polar group, 50 mol%, or further having 0 to 20 mol% of other repeating units It is.

  The resin (B) used in the present invention can be synthesized according to a conventional method (for example, radical polymerization). For example, as a general synthesis method, a monomer polymerization method in which a monomer species and an initiator are dissolved in a solvent and the polymerization is performed by heating, and a solution of the monomer species and the initiator is dropped into the heating solvent over 1 to 10 hours. The dropping polymerization method is added, and the dropping polymerization method is preferable. Examples of the reaction solvent include ethers such as tetrahydrofuran, 1,4-dioxane, diisopropyl ether, ketones such as methyl ethyl ketone and methyl isobutyl ketone, ester solvents such as ethyl acetate, amide solvents such as dimethylformamide and dimethylacetamide, Furthermore, the solvent which melt | dissolves the composition of this invention like the below-mentioned propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, and cyclohexanone is mentioned. More preferably, the polymerization is performed using the same solvent as the solvent used in the positive photosensitive composition of the present invention. Thereby, generation | occurrence | production of the particle at the time of a preservation | save can be suppressed.

  The polymerization reaction is preferably performed in an inert gas atmosphere such as nitrogen or argon. As a polymerization initiator, a commercially available radical initiator (azo initiator, peroxide, etc.) is used to initiate the polymerization. As the radical initiator, an azo initiator is preferable, and an azo initiator having an ester group, a cyano group, or a carboxyl group is preferable. Preferred initiators include azobisisobutyronitrile, azobisdimethylvaleronitrile, dimethyl 2,2′-azobis (2-methylpropionate) and the like. If desired, an initiator is added or added in portions, and after completion of the reaction, it is put into a solvent and a desired polymer is recovered by a method such as powder or solid recovery. The concentration of the reaction is 5 to 50% by mass, preferably 10 to 30% by mass. The reaction temperature is usually 10 ° C to 150 ° C, preferably 30 ° C to 120 ° C, more preferably 60 ° C to 100 ° C.

  The weight average molecular weight of the resin according to the present invention is preferably 1,000 to 200,000, more preferably 3,000 to 20,000, and most preferably 5,000 to 15 in terms of polystyrene by GPC method. , 000. By setting the weight average molecular weight to 1,000 to 200,000, deterioration of heat resistance and dry etching resistance can be prevented, developability is deteriorated, and viscosity is increased, resulting in deterioration of film forming property. Can be prevented. The molecular weight distribution is usually 1 to 5, preferably 1 to 3, more preferably 1 to 2. The smaller the molecular weight distribution, the better the resolution and the resist shape, and the smoother the side wall of the resist pattern, the better the roughness.

In the positive photosensitive composition of the present invention, the blending amount of all the acid-decomposable resins according to the present invention in the entire composition is preferably from 50 to 99.99% by mass, more preferably from 60 to It is 99.0 mass%.
In the present invention, the acid-decomposable resin may be used alone or in combination.

Resin having no group decomposable by the action of an acid The positive photosensitive composition of the present invention may contain a resin having no group decomposable by the action of an acid.
“No acid-decomposable group” means that there is no or very little decomposability due to the action of an acid in an image forming process in which the positive photosensitive composition of the present invention is usually used. It has no group that contributes to image formation by decomposition. Examples of such a resin include a resin having an alkali-soluble group and a resin having a group that decomposes by the action of an alkali and improves the solubility in an alkali developer.
As the resin having no group capable of decomposing by the action of an acid, a resin having at least one repeating unit derived from a (meth) acrylic acid derivative and / or an alicyclic olefin derivative is preferable.
Alkali-soluble groups contained in a resin that does not have a group decomposable by the action of an acid include a carboxyl group, a phenolic hydroxyl group, an aliphatic hydroxyl group substituted at the 1- or 2-position with an electron-withdrawing group, and electron-withdrawing properties. An amino group substituted with a group (for example, a sulfonamide group, a sulfonimide group, a bissulfonylimide group), a methylene group substituted with an electron-withdrawing group, or a methine group (for example, a ketone group or an ester group). A substituted methylene group and methine group) are preferred.
The group that decomposes by the action of an alkali contained in a resin that does not have a group that decomposes by the action of an acid and increases the solubility in an alkali developer is preferably a lactone group or an acid anhydride group, more preferably Lactone group.
The resin that does not have a group capable of decomposing by the action of an acid may have a repeating unit having a functional group other than the above. As the repeating unit having another functional group, an appropriate functional group can be introduced in consideration of dry etching resistance, hydrophilicity / hydrophobicity, interaction property and the like. Other repeating units include structural units having a polar functional group such as a hydroxyl group, a cyano group, a carbonyl group, and an ester group, a repeating unit having a monocyclic or polycyclic hydrocarbon structure, a silicon atom, a halogen atom, and a fluoroalkyl. A repeating unit having a group or a repeating unit having a plurality of these functional groups.

  Although the specific example of resin which does not have the group decomposed | disassembled by the effect | action of a preferable acid is shown below, this invention is not limited to this.

  The addition amount of the resin having no group capable of decomposing by the action of an acid is 0 to 30% by mass, preferably 0 to 20% by mass, and more preferably 0 to 15% by mass with respect to the acid-decomposable resin.

Dissolution control compound having a molecular weight of 3000 or less, having at least one selected from an alkali-soluble group, a hydrophilic group, and an acid-decomposable group. A dissolution controlling compound having a molecular weight of 3000 or less (hereinafter also referred to as “solubility controlling compound”) having at least one selected from
Examples of the dissolution control compound include a carboxyl group, a sulfonylimide group, a compound having an alkali-soluble group such as a hydroxyl group substituted at the α-position with a fluoroalkyl group, a hydroxyl group, a lactone group, a cyano group, an amide group, a pyrrolidone group, a sulfone group. A compound having a hydrophilic group such as an amide group or a compound containing a group capable of decomposing by the action of an acid to release an alkali-soluble group or a hydrophilic group is preferable. The group capable of decomposing by the action of an acid to release an alkali-soluble group or a hydrophilic group is preferably a group in which a carboxyl group or a hydroxyl group is protected with an acid-decomposable group. In order not to lower the permeability of 220 nm or less as the dissolution control compound, it is preferable to use a compound that does not contain an aromatic ring, or to use a compound having an aromatic ring in an amount of 20 wt% or less based on the solid content of the composition.
Preferred dissolution control compounds include carboxylic acid compounds having an alicyclic hydrocarbon structure such as adamantane (di) carboxylic acid, norbornane carboxylic acid, and cholic acid, or compounds in which the carboxylic acid is protected with an acid-decomposable group, and polyols such as saccharides. Or a compound having its hydroxyl group protected with an acid-decomposable group is preferred.

  The molecular weight of the dissolution controlling compound in the present invention is 3000 or less, preferably 300 to 3000, and more preferably 500 to 2500.

  The addition amount of the dissolution control compound is preferably 3 to 40% by mass, more preferably 5 to 20% by mass, based on the solid content of the positive photosensitive composition.

  Specific examples of the dissolution control compound are shown below, but the present invention is not limited thereto.

Basic Compound The positive photosensitive composition of the present invention contains a basic compound in order to reduce the change in performance over time from exposure to heating or to control the diffusibility of the acid generated by exposure in the film. Is preferred.

  Examples of basic compounds include nitrogen-containing basic compounds and onium salt compounds. Preferable nitrogen-containing basic compound structures include compounds having partial structures represented by the following general formulas (A) to (E).

In general formula (A),
R ²⁵⁰ , R ²⁵¹ and R ²⁵² are each independently a hydrogen atom, an alkyl having 1 to 20 carbons, a cycloalkyl group having 3 to 20 carbons or an aryl group having 6 to 20 carbons, wherein R ²⁵⁰ And R ²⁵¹ may combine with each other to form a ring. These may have a substituent. Examples of the alkyl group and cycloalkyl group having a substituent include an aminoalkyl group having 1 to 20 carbon atoms, an aminocycloalkyl group having 3 to 20 carbon atoms, and 1 to 1 carbon atoms. A 20 hydroxyalkyl group or a C 3-20 hydroxycycloalkyl group is preferred. These may contain an oxygen atom, a sulfur atom, or a nitrogen atom in the alkyl chain.
In general formula (E),
R ²⁵³ , R ²⁵⁴ , R ²⁵⁵ and R ²⁵⁶ each independently represent an alkyl group having 1 to 6 carbon atoms or a cycloalkyl group having 3 to 6 carbon atoms.

  Preferable compounds include guanidine, aminopyrrolidine, pyrazole, pyrazoline, piperazine, aminomorpholine, aminoalkylmorpholine, and piperidine, and may have a substituent. More preferred compounds include compounds having an imidazole structure, diazabicyclo structure, onium hydroxide structure, onium carboxylate structure, trialkylamine structure, aniline structure or pyridine structure, alkylamine derivatives having a hydroxyl group and / or an ether bond, hydroxyl groups and / or Or the aniline derivative which has an ether bond etc. can be mentioned.

  Examples of the compound having an imidazole structure include imidazole, 2,4,5-triphenylimidazole, benzimidazole, and the like. Examples of the compound having a diazabicyclo structure include 1,4-diazabicyclo [2,2,2] octane, 1,5-diazabicyclo [4,3,0] non-5-ene, and 1,8-diazabicyclo [5,4,0. ] Undec-7-ene. Examples of the compound having an onium hydroxide structure include triarylsulfonium hydroxide, phenacylsulfonium hydroxide, sulfonium hydroxide having a 2-oxoalkyl group, specifically triphenylsulfonium hydroxide, tris (t-butylphenyl) sulfonium. Examples thereof include hydroxide, bis (t-butylphenyl) iodonium hydroxide, phenacylthiophenium hydroxide, and 2-oxopropylthiophenium hydroxide. The compound having an onium carboxylate structure is a compound having an onium hydroxide structure in which the anion moiety is converted to a carboxylate, and examples thereof include acetate, adamantane-1-carboxylate, and perfluoroalkylcarboxylate. Examples of the compound having a trialkylamine structure include tri (n-butyl) amine and tri (n-octyl) amine. Examples of aniline compounds include 2,6-diisopropylaniline and N, N-dimethylaniline. Examples of the alkylamine derivative having a hydroxyl group and / or an ether bond include ethanolamine, diethanolamine, triethanolamine, and tris (methoxyethoxyethyl) amine. Examples of aniline derivatives having a hydroxyl group and / or an ether bond include N, N-bis (hydroxyethyl) aniline.

  These basic compounds are used alone or in combination of two or more. The usage-amount of a basic compound is 0.001-10 mass% normally based on solid content of a positive photosensitive composition, Preferably it is 0.01-5 mass%. In order to obtain a sufficient addition effect, 0.001% by mass or more is preferable, and 10% by mass or less is preferable in terms of sensitivity and developability of the non-exposed area.

Fluorine and / or silicon-based surfactant The positive photosensitive composition of the present invention further comprises a fluorine-based and / or silicon-based surfactant (fluorine-based surfactant and silicon-based surfactant, fluorine atom and silicon atom It is preferable to contain any one of these, or two or more of them.

  When the positive photosensitive composition of the present invention contains fluorine and / or a silicon-based surfactant, adhesion and development defects are obtained with good sensitivity and resolution when using an exposure light source of 250 nm or less, particularly 220 nm or less. It is possible to provide a resist pattern with less.

  Examples of these fluorine and / or silicon surfactants include, for example, JP-A No. 62-36663, JP-A No. 61-226746, JP-A No. 61-226745, JP-A No. 62-170950, JP 63-34540 A, JP 7-230165 A, JP 8-62834 A, JP 9-54432 A, JP 9-5988 A, JP 2002-277862 A, US Patent Nos. 5,405,720, 5,360,692, 5,529,881, 5,296,330, 5,436,098, 5,576,143, 5,294,511, 5,824,451 Surfactant can be mentioned, The following commercially available surfactant can also be used as it is.

Examples of commercially available surfactants that can be used include F-top EF301, EF303 (manufactured by Shin-Akita Kasei Co., Ltd.), Florard FC430, 431 (manufactured by Sumitomo 3M Co., Ltd.), MegaFuck F171, F173, F176, F189, R08 (Dainippon Ink Chemical Co., Ltd.), Surflon S-382, SC101, 102, 103, 104, 105, 106 (Asahi Glass Co., Ltd.), Troisol S-366 (Troy Chemical Co., Ltd.), etc. Fluorine type surfactant or silicon type surfactant can be mentioned. Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) can also be used as a silicon-based surfactant.

  In addition to the known surfactants described above, surfactants are derived from fluoroaliphatic compounds produced by the telomerization method (also referred to as the telomer method) or the oligomerization method (also referred to as the oligomer method). A surfactant using a polymer having a fluoroaliphatic group can be used. The fluoroaliphatic compound can be synthesized by the method described in JP-A-2002-90991.

  As the polymer having a fluoroaliphatic group, a copolymer of a monomer having a fluoroaliphatic group and (poly (oxyalkylene)) acrylate and / or (poly (oxyalkylene)) methacrylate is preferable and distributed irregularly. It may be block copolymerized. Examples of the poly (oxyalkylene) group include a poly (oxyethylene) group, a poly (oxypropylene) group, a poly (oxybutylene) group, and the like, and a poly (oxyethylene, oxypropylene, and oxyethylene group). A unit having different chain lengths in the same chain length, such as a block link) or poly (block link of oxyethylene and oxypropylene) may be used. Furthermore, a copolymer of a monomer having a fluoroaliphatic group and (poly (oxyalkylene)) acrylate (or methacrylate) is not only a binary copolymer but also a monomer having two or more different fluoroaliphatic groups, Further, it may be a ternary or higher copolymer obtained by simultaneously copolymerizing two or more different (poly (oxyalkylene)) acrylates (or methacrylates).

Examples of commercially available surfactants include Megafac F178, F-470, F-473, F-475, F-476, and F-472 (Dainippon Ink Chemical Co., Ltd.). Further, a copolymer of an acrylate (or methacrylate) having a C ₆ F ₁₃ group and (poly (oxyalkylene)) acrylate (or methacrylate), an acrylate (or methacrylate) having a C ₆ F ₁₃ group and (poly (oxy) (Ethylene)) acrylate (or methacrylate) and (poly (oxypropylene)) acrylate (or methacrylate) copolymer, acrylate (or methacrylate) and (poly (oxyalkylene)) acrylate having C ₈ F ₁₇ groups (or Copolymer of acrylate (or methacrylate), (poly (oxyethylene)) acrylate (or methacrylate), and (poly (oxypropylene)) acrylate (or methacrylate) having a C ₈ F ₁₇ group Coalesce, etc. Can.

  The amount of fluorine and / or silicon-based surfactant used is preferably 0.0001 to 2% by mass, more preferably 0.001 to 1% by mass, based on the total amount of the positive photosensitive composition (excluding the solvent). %.

Organic Solvent The positive photosensitive composition of the present invention is used by dissolving the above components in a predetermined organic solvent.

  Examples of the organic solvent that can be used include ethylene dichloride, cyclohexanone, cyclopentanone, 2-heptanone, γ-butyrolactone, methyl ethyl ketone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, 2-methoxyethyl acetate, ethylene glycol monoethyl. Ether acetate, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, toluene, ethyl acetate, methyl lactate, ethyl lactate, methyl methoxypropionate, ethyl ethoxypropionate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, N, N -Dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone, tetrahydrofuran, etc.

In the present invention, the organic solvent may be used alone or in combination, but it is preferable to use a mixed solvent containing two or more solvents having different functional groups. As a result, the solubility of the material is increased, and not only the generation of particles over time can be suppressed, but also a good pattern profile can be obtained. Preferable functional groups contained in the solvent include ester groups, lactone groups, hydroxyl groups, ketone groups, and carbonate groups. As the mixed solvent having different functional groups, the following mixed solvents (S1) to (S5) are preferable.
(S1) a mixed solvent obtained by mixing a solvent containing a hydroxyl group and a solvent not containing a hydroxyl group,
(S2) a mixed solvent obtained by mixing a solvent having an ester structure and a solvent having a ketone structure;
(S3) a mixed solvent obtained by mixing a solvent having an ester structure and a solvent having a lactone structure;
(S4) a mixed solvent obtained by mixing a solvent having an ester structure, a solvent having a lactone structure, and a solvent containing a hydroxyl group;
(S5) A mixed solvent containing a solvent having an ester structure, a solvent having a carbonate structure, and a solvent having a hydroxyl group.
As a result, the generation of particles during storage of the resist solution can be reduced, and the generation of defects during application can be suppressed.

  Examples of the solvent containing a hydroxyl group include ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, ethyl lactate, and the like. And propylene glycol monomethyl ether and ethyl lactate are more preferred.

  Examples of the solvent not containing a hydroxyl group include propylene glycol monomethyl ether acetate, ethyl ethoxypropionate, 2-heptanone, γ-butyrolactone, cyclohexanone, butyl acetate, N-methylpyrrolidone, N, N-dimethylacetamide, dimethyl sulfoxide and the like. Among these, propylene glycol monomethyl ether acetate, ethyl ethoxypropionate, 2-heptanone, γ-butyrolactone, cyclohexanone, and butyl acetate are more preferable, and propylene glycol monomethyl ether acetate, ethyl ethoxypropionate. 2-heptanone and cyclohexanone are particularly preferred.

Examples of the solvent having a ketone structure include cyclohexanone and 2-heptanone, and cyclohexanone is preferable.
Examples of the solvent having an ester structure include propylene glycol monomethyl ether acetate, ethyl ethoxypropionate, and butyl acetate, and propylene glycol monomethyl ether acetate is preferable.
Examples of the solvent having a lactone structure include γ-butyrolactone.
Examples of the solvent having a carbonate structure include propylene carbonate and ethylene carbonate, with propylene carbonate being preferred.

The mixing ratio (mass) of the solvent containing a hydroxyl group and the solvent not containing a hydroxyl group is 1/99 to 99/1, preferably 10/90 to 90/10, more preferably 20/80 to 60/40. . A mixed solvent containing 50% by mass or more of a solvent not containing a hydroxyl group is particularly preferred from the viewpoint of coating uniformity.
The mixing ratio (mass) of the solvent having an ester structure and the solvent having a ketone structure is 1/99 to 99/1, preferably 10/90 to 90/10, and more preferably 40/60 to 80/20. . A mixed solvent containing 50% by mass or more of a solvent having an ester structure is particularly preferable from the viewpoint of coating uniformity.
The mixing ratio (mass) of the solvent having an ester structure and the solvent having a lactone structure is 70/30 to 99/1, preferably 80/20 to 99/1, and more preferably 90/10 to 99/1. . A mixed solvent containing 70% by mass or more of a solvent having an ester structure is particularly preferable from the viewpoint of stability over time.
When mixing a solvent having an ester structure, a solvent having a lactone structure, and a solvent containing a hydroxyl group, the solvent having an ester structure is 30 to 80% by mass, the solvent having a lactone structure is 1 to 20% by mass, and the hydroxyl group is contained. It is preferable to contain 10-60 mass% of solvent to do.
When mixing a solvent having an ester structure, a solvent having a carbonate structure, and a solvent containing a hydroxyl group, the solvent having an ester structure is 30 to 80% by mass, the solvent having a carbonate structure is 1 to 20% by mass, and the hydroxyl group is contained. It is preferable to contain 10-60 mass% of solvent to do.

A preferable embodiment of these solvents is a solvent containing an alkylene glycol monoalkyl ether carboxylate (preferably propylene glycol monomethyl ether acetate), more preferably a mixed solvent of an alkylene glycol monoalkyl ether carboxylate and another solvent, The other solvent is at least one selected from a functional group selected from a hydroxyl group, a ketone group, a lactone group, an ester group, an ether group and a carbonate group, or a solvent having a plurality of these functional groups. A particularly preferable mixed solvent is a mixed solvent of at least one selected from ethyl lactate, γ-butyrolactone, propylene glycol monomethyl ether, butyl acetate, and cyclohexanone and propylene glycol monomethyl ether acetate.
The development defect performance can be improved by selecting an optimum solvent.

<Other additives>
The positive photosensitive composition of the present invention has further solubility in a dye, a plasticizer, a surfactant other than the fluorine and / or silicon surfactant, a photosensitizer, and a developer as necessary. A compound to be promoted and the like can be contained.

  The dissolution accelerating compound for the developer that can be used in the present invention is a low molecular weight compound having a molecular weight of 1,000 or less and having two or more phenolic OH groups or one or more carboxy groups. When it has a carboxy group, an alicyclic or aliphatic compound is preferable.

  A preferable addition amount of these dissolution promoting compounds is 2 to 50% by mass, and more preferably 5 to 30% by mass with respect to the polymer compound. The amount is preferably 50% by mass or less from the viewpoint of suppressing development residue and preventing pattern deformation during development.

  Such phenolic compounds having a molecular weight of 1000 or less can be obtained by referring to methods described in, for example, JP-A-4-1222938, JP-A-2-28531, U.S. Pat. No. 4,916,210, European Patent 219294, and the like. Can be easily synthesized.

  Specific examples of alicyclic or aliphatic compounds having a carboxyl group include carboxylic acid derivatives having a steroid structure such as cholic acid, deoxycholic acid, lithocholic acid, adamantane carboxylic acid derivatives, adamantane dicarboxylic acid, cyclohexane carboxylic acid, cyclohexane Examples thereof include, but are not limited to, dicarboxylic acids.

  In the present invention, a surfactant other than the fluorine-based and / or silicon-based surfactant may be added. Specifically, nonionic interfaces such as polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl ethers, polyoxyethylene / polyoxypropylene block copolymers, sorbitan aliphatic esters, polyoxyethylene sorbitan aliphatic esters, etc. Mention may be made of activators.

  These surfactants may be added alone or in some combination.

(Pattern formation method)
The positive photosensitive composition of the present invention is used by dissolving the above components in a predetermined organic solvent, preferably the mixed solvent, filtering the solution, and then applying the solution on a predetermined support as follows. The filter used for filter filtration is preferably made of polytetrafluoroethylene, polyethylene, or nylon of 0.1 microns or less, more preferably 0.05 microns or less, and still more preferably 0.03 microns or less.

For example, a positive photosensitive composition is coated on a substrate (eg, silicon / silicon dioxide coating) used in the manufacture of precision integrated circuit elements by a suitable coating method such as a spinner or coater, dried, and photosensitive. A film is formed.
The photosensitive film is irradiated with actinic rays or radiation through a predetermined mask, preferably baked (heated), developed and rinsed. Thereby, a good pattern can be obtained.
Exposure (immersion exposure) may be performed by filling a liquid (immersion medium) having a higher refractive index than air between the photosensitive film and the lens during irradiation with actinic rays or radiation. Thereby, resolution can be improved. As the immersion medium to be used, any liquid can be used as long as it has a higher refractive index than air, but pure water is preferred. Further, an overcoat layer may be further provided on the photosensitive film so that the immersion medium and the photosensitive film do not come into direct contact with each other during the immersion exposure. Thereby, the elution of the composition from the photosensitive film to the immersion medium is suppressed, and development defects are reduced.

Before forming the photosensitive film, an antireflection film may be coated on the substrate in advance.
As the antireflection film, any of an inorganic film type such as titanium, titanium dioxide, titanium nitride, chromium oxide, carbon, and amorphous silicon, and an organic film type made of a light absorber and a polymer material can be used. In addition, as the organic antireflection film, commercially available organic antireflection films such as DUV30 series, DUV-40 series manufactured by Brewer Science, AR-2, AR-3, AR-5 manufactured by Shipley, etc. may be used. it can.

Examples of the actinic ray or radiation include infrared light, visible light, ultraviolet light, far ultraviolet light, X-ray, electron beam, etc., but preferably far ultraviolet light having a wavelength of 250 nm or less, more preferably 220 nm or less. Specifically, KrF excimer laser (248 nm), ArF excimer laser (193 nm), F ₂ excimer laser (157 nm), X-ray, electron beam, etc. ArF excimer laser, F ₂ excimer laser, EUV (13 nm) An electron beam is preferred.

In the development step, an alkaline developer is used as follows. Examples of the alkaline developer of the positive photosensitive composition include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia and other inorganic alkalis, ethylamine, n-propylamine and the like. Secondary amines such as amines, diethylamine and di-n-butylamine, tertiary amines such as triethylamine and methyldiethylamine, alcohol amines such as dimethylethanolamine and triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxy Alkaline aqueous solutions such as quaternary ammonium salts such as pyrrole and cyclic amines such as pyrrole and pihelidine can be used.
Furthermore, alcohols and surfactants can be added in appropriate amounts to the alkaline developer.
The alkali concentration of the alkali developer is usually from 0.1 to 20% by mass.
The pH of the alkali developer is usually from 10.0 to 15.0.

  Next, although an Example is given and this invention is demonstrated, this invention is not limited to this.

Synthesis Example 1 (Preparation of polymer solution 1)
Under a nitrogen stream, 9.7 g of cyclohexanone was placed in a three-necked flask and heated to 80 ° C. The following monomer (1-a) 8.89 g (40.0 mmol), monomer (1-b) 4.73 g (20.0 mmol), monomer (1-c) 10.5 g (40.0 mmol), polymerization A solution prepared by dissolving 1.31 g (8.0 mmol) of initiator V-60 (manufactured by Wako Pure Chemical Industries, Ltd.) in 87.5 g of cyclohexanone was added dropwise over 6 hours. After completion of the dropwise addition, the mixture was further reacted at 80 ° C. for 2 hours to obtain a polymer solution 1.

Synthesis Example 2 (Preparation of polymer solution 2)
Under a nitrogen stream, 9.3 g of cyclohexanone was placed in a three-necked flask and heated to 80 ° C. The following monomer (2-a) 12.4 g (50.0 mmol), monomer (2-b) 2.36 g (10.0 mmol), monomer (2-c) 8.40 g (40.0 mmol), polymerization A solution prepared by dissolving 1.31 g (8.0 mmol) of initiator V-60 (manufactured by Wako Pure Chemical Industries, Ltd.) in 83.9 g of cyclohexanone was added dropwise over 6 hours. After the completion of the dropwise addition, the mixture was further reacted at 80 ° C. for 2 hours to obtain a polymer solution 2.

Synthesis Example 3 (Preparation of polymer solution 3)
Under a nitrogen stream, 8.2 g of cyclohexanone was placed in a three-necked flask and heated to 80 ° C. The following monomer (3-a) 8.51 g (50.0 mmol), monomer (3-b) 4.73 g (20.0 mmol), monomer (3-c) 7.03 g (30.0 mmol), polymerization A solution prepared by dissolving 1.84 g (8.0 mmol) of initiator V-601 (manufactured by Wako Pure Chemical Industries, Ltd.) in 73.6 g of cyclohexanone was added dropwise over 6 hours. After completion of the dropwise addition, the mixture was further reacted at 80 ° C. for 2 hours to obtain a polymer solution 3.

Synthesis Example 4 (Preparation of polymer solution 4)
Under a nitrogen stream, 9.7 g of cyclohexanone was placed in a three-necked flask and heated to 80 ° C. The following monomer (4-a) 11.2 g (50.0 mmol), monomer (4-b) 4.73 g (20.0 mmol), monomer (4-c) 8.23 g (30.0 mmol), polymerization A solution prepared by dissolving 1.84 g (8.0 mmol) of initiator V-601 (manufactured by Wako Pure Chemical Industries, Ltd.) in 87.7 g of cyclohexanone was added dropwise over 6 hours. After the completion of the dropwise addition, the mixture was further reacted at 80 ° C. for 2 hours to obtain a polymer solution 4.

Synthesis Example 5 (Preparation of polymer solution 5)
Under a nitrogen stream, 9.0 g of cyclohexanone was placed in a three-necked flask and heated to 80 ° C. To this, 11.1 g (50.0 mmol) of the following monomer (5-a), 5.05 g (20.0 mmol) of monomer (5-b), 3.93 g (20.0 mmol) of monomer (5-c), monomer (5-d) A solution prepared by dissolving 2.34 g (10.0 mmol) of polymerization initiator V-601 (manufactured by Wako Pure Chemical Industries, Ltd.) in 80.7 g of cyclohexanone was added dropwise over 6 hours. did. After completion of the dropwise addition, the mixture was further reacted at 80 ° C. for 2 hours to obtain polymer solution 5.

Example 1 (Production of resin (1-1))
100 mL of methanol / water = 9/1 (volume ratio) was added to the total amount of the polymer solution 1 obtained in Synthesis Example 1 over 10 minutes. At this time, the solution remained a homogeneous solution and no polymer was precipitated. The obtained solution was added to 900 mL of methanol / water = 9/1 (volume ratio) at an internal temperature of 25 ° C. over 30 minutes. The precipitated resin was collected by filtration and dried under reduced pressure at 40 ° C. for 24 hours. As a result, the resin (1-1) was obtained in 20.5 g (yield 85%). The weight average molecular weight of the resin (1-1) was 9,350 in terms of polystyrene, and the degree of dispersion was 1.85. According to the measurement by high performance liquid chromatography (developing solvent tetrahydrofuran / water, measurement wavelength 220 nm), the monomer (1-a) is 0.01% by mass and the monomer (1-b) is 0.01% in the resin (1-1). It was found that 0.01% by mass or less of the monomer (1-c) was contained. Moreover, the low molecular component whose weight average molecular weight is 500 or less was 0.09% (area%, RI measurement) by GPC measurement.

Examples 2-16
Resin (1-2) to (1-8), (2-1) to (2-2), using the polymer solution, additive solvent, and reprecipitation solvent described in Table 1 below in the same manner as in Example 1. (3-1) to (3-2), (4-1) to (4-2), and (5-1) to (5-2) were obtained. The ratio of the solvent in the table is a volume ratio. Table 1 shows the presence or absence of polymer precipitation when the additive solvent is added, and the obtained resins (1-2) to (1-8), (2-1) to (2-2), and (3-1) to (3). -2), (4-1) to (4-2) and (5-1) to (5-2) show the weight average molecular weight, dispersity, and yield, and are shown in Tables 2 and 3 below. Resins (1-2) to (1-8), (2-1) to (2-2), (3-1) to (3-2), (4-1) to (4-2) and ( The content of the low molecular weight component in (5-1) to (5-2) is shown.

Comparative Example 1 (Production of resin (1-9))
The total amount of the polymer solution 1 obtained in Synthesis Example 1 was added to 1000 mL of methanol / water = 9/1 (volume ratio) at an internal temperature of 25 ° C. over 30 minutes. The precipitated resin was collected by filtration and dried under reduced pressure at 40 ° C. for 24 hours to obtain 21.2 g (yield 88%) of the resin (1-9). The weight average molecular weight of the resin (1-9) was 9,450 in terms of polystyrene, and the degree of dispersion was 1.87. According to the measurement by high performance liquid chromatography (developing solvent tetrahydrofuran / water, measuring wavelength 220 nm), the monomer (1-a) is 0.12% by mass and the monomer (1-b) is 0.13 in the resin (1-1). It was found that 0.15 mass% of the monomer (1-c) was contained by mass%. Moreover, the low molecular component whose weight average molecular weight is 500 or less was 0.62% (area%, RI measurement) by GPC measurement.

Comparative Examples 2-10
Resins (1-10), (2-3) to (2-4), (3-3) to (3-4) were used in the same manner as in Comparative Example 1 using the polymer solution and reprecipitation solvent described in Table 1. ), (4-3) to (4-4) and (5-3) to (5-5). Resins (1-10), (2-3) to (2-4), (3-3) to (3-4), (4-3) to (4-4) and ( 5-3) to (5-5) showing the weight average molecular weight, dispersity, and yield, and resins (1-10) and (2-3) to (2-4) obtained in Tables 2 and 3 , (3-3) to (3-4), (4-3) to (4-4) and (5-3) to (5-5).

  From Tables 1 to 3, it is apparent that the production method of the present invention can produce a resin from which low molecular weight components are effectively and simply removed.

Examples 17-32 and Comparative Examples 11-20
<Resist preparation>
The components shown in Table 4 below were dissolved in a solvent to prepare a solution having a solid content concentration of 8% by mass, and this was filtered through a 0.03 m polyethylene filter to prepare a positive resist solution. The prepared positive resist solution was evaluated by the following method, and the results are shown in Table 5 below.

<Resist evaluation>
An anti-reflective coating DUV-42 manufactured by Brewer Science Co., Ltd. was uniformly applied to 600 angstroms on a silicon substrate subjected to hexamethyldisilazane treatment with a spin coater, dried on a hot plate at 100 ° C. for 90 seconds, and then at 190 ° C. Heat drying was performed for 240 seconds. Thereafter, each positive resist solution was applied by a spin coater and dried at 120 ° C. for 60 seconds to form a 150 nm resist film.
This resist film was exposed with an ArF excimer laser stepper (NAML = 0.75, 2/3 ring zone) through a mask, and heated on a hot plate at 120 ° C. for 60 seconds immediately after the exposure. Further, the resist film was developed with an aqueous 2.38 mass% tetramethylammonium hydroxide solution at 23 ° C. for 60 seconds, rinsed with pure water for 30 seconds, and then dried to obtain a line pattern.
<Sensitivity>
The exposure amount for reproducing the 80 nm line and space 1/1 mask pattern was determined as the optimum exposure amount (Eopt). The smaller this value, the higher the sensitivity.
<Exposure latitude (EL)>
The exposure amount that reproduces a 130-nm line-and-space mask pattern is set as the optimal exposure amount, and when the exposure amount is changed, an exposure amount width that allows a pattern size of 130 nm ± 10% is obtained. Divided by the amount and expressed as a percentage. The larger the value, the smaller the change in performance due to the change in exposure amount, and the better the exposure latitude (EL).
<Line edge roughness>
The line edge roughness (LER) is measured by using a length-measuring scanning electron microscope (SEM) to observe an isolated pattern of 120 nm and from the reference line where the edge in the longitudinal direction of the line pattern should be 5 μm. The distance was measured by 50 points with a length measuring SEM (Hitachi, Ltd. S-8840), the standard deviation was obtained, and 3σ was calculated. A smaller value indicates better performance.
<Development defect evaluation>
The entire surface of the 8-inch wafer was exposed with an exposure amount that a mask pattern of 130 nm line and space 1: 1 was reproduced to obtain a resist pattern. This was measured for development defects on the entire wafer surface using an intelligent line monitor 2360 manufactured by KLA Tencor.
<Particle evaluation>
About the prepared positive resist solution, the number of particles in the solution immediately after preparation (particle initial value) and the number of particles in the solution after standing for 1 week at 4 ° C. Counted. Along with the particle initial value, the number of particles increased calculated by (number of particles after time) − (particle initial value) was calculated. Here, particles having a particle diameter of 0.25 μm or more contained in 1 mL of the solution were counted.

  The abbreviations in Table 4 are shown below.

  [Photoacid generator]

[Basic compounds]
TPSA: triphenylsulfonium acetate DIA: 2,6-diisopropylaniline TEA: triethanolamine DBA: N, N-dibutylaniline PBI: 2-phenylbenzimidazole TMEA: tris (methoxyethoxyethyl) amine PEA: N-phenyldiethanolamine [ Surfactant]
W-1: MegaFuck F176 (Dainippon Ink Chemical Co., Ltd.) (Fluorine)
W-2: Megafuck R08 (Dainippon Ink Chemical Co., Ltd.) (fluorine and silicon)
W-3: Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) (silicon-based) W-4: Troysol S-366 (manufactured by Troy Chemical Co., Ltd.)
〔solvent〕
S1: Propylene glycol methyl ether acetate S2: 2-heptanone S3: Cyclohexanone S4: γ-butyrolactone S5: Propylene glycol methyl ether S6: Ethyl lactate S7: Propylene carbonate

  From Table 5, it is clear that the positive photosensitive composition of the present invention has good sensitivity and is excellent in exposure latitude, line edge roughness, development defect, and storage stability.

Claims (10)

  In the method for producing a resin in which the dissolution rate in an alkaline developer is increased by the action of an acid, the solvent (b) containing a poor solvent in the solution (a) containing the resin in which the dissolution rate in an alkaline developer is increased by the action of an acid. And adding a solution (c) to a solvent (d) containing a poor solvent to precipitate a resin whose dissolution rate in an alkaline developer is increased by the action of an acid. A process for producing a resin, wherein the dissolution rate in an alkaline developer is increased by the action of an acid.   If the concentration of the resin whose dissolution rate in the alkaline developer is increased by the action of the acid in the solution (c) is X, and the saturated solubility of the resin whose dissolution rate in the alkali developer is increased by the action of the acid in the solution (c) is Y. The method for producing a resin, wherein the solvent (b) is added so that X <Y, wherein the dissolution rate in an alkali developer is increased by the action of an acid according to claim 1.   The poor solvent is an aliphatic hydrocarbon solvent, an aromatic hydrocarbon solvent, an alcohol solvent, water, an ester solvent, a ketone solvent, or an ether solvent, according to claim 1 or 2. A method for producing a resin, wherein the dissolution rate in an alkaline developer is increased by the action of an acid.   The poor solvent is an alkane having 5 to 15 carbon atoms, a cycloalkane having 5 to 15 carbon atoms, an alcohol having 1 to 5 carbon atoms, or water, and is alkalinized by the action of an acid according to claim 1 or 2. A method for producing a resin, which increases the dissolution rate in a developer.   The resin that increases the dissolution rate in an alkaline developer by the action of an acid has a repeating unit having an acid-decomposable group. A method for producing a resin with an increased dissolution rate.   6. The alkaline developer by the action of an acid according to claim 1, wherein the resin whose rate of dissolution in an alkaline developer is increased by the action of an acid has a repeating unit having a group having a lactone structure. For producing a resin in which the dissolution rate with respect to the resin increases.   The resin whose rate of dissolution in an alkaline developer is increased by the action of an acid, has a repeating unit having a polar group, and is dissolved in an alkali developer by the action of an acid according to claim 1. Process for increasing the resin.   A resin produced by the method according to any one of claims 1 to 7 and having an increased dissolution rate in an alkaline developer by the action of an acid. (A) A positive photosensitive material comprising a compound capable of generating an acid upon irradiation with actinic rays or radiation, and (B) a resin whose dissolution rate in an alkali developer is increased by the action of the acid according to claim 8. Sex composition.   A pattern forming method comprising a step of forming a film with the positive photosensitive composition according to claim 9, and exposing and developing the film.