JP2008038118A - Method for producing resin for photosensitive composition, resin for resist produced by the same production method, resist composition containing the same resin for resist and method for forming pattern by using the same resist composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a resin for photosensitive composition, from which high molecular weight component is removed, by a simple method and to provide a resin for resist produced by the method and a resist composition in which development defect and pattern collapse are improved by using the resin for resist and to provide a pattern-forming method using the resin for resist. <P>SOLUTION: The method for producing the resin for photosensitive composition comprises a step for depositing a high-molecular weight component of the resin by bringing a resin solution in which the resin is dissolved in a solvent into contact with a solvent having low ability to dissolve the resin and removing the high-molecular weight component to provide the resin solution from which the high-molecular weight component is removed. The resin for resist is produced by the above method. The resist composition improved in development defect and pattern collapse is obtained by using the resin for resist produced by the method. The pattern-forming method is obtained by using the resist composition. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention is for a photosensitive composition that can be suitably used for a photosensitive composition used in a semiconductor manufacturing process such as an IC, a circuit board such as a liquid crystal and a thermal head, and other photofabrication processes. The present invention relates to a resin production method, a resist resin produced by the production method, a resist composition containing the resist resin, and a pattern formation method using the resist composition. More specifically, a method for producing a resin for a 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 by an electron beam, for a resist produced by this production method The present invention relates to a resin, a resist composition containing the resist resin, and a pattern forming method using the resist composition.

  The chemically amplified resist 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. It is a pattern forming material that changes and forms a pattern on a 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, ArF excimer laser (193 nm) is used as the exposure light source, the compound having an aromatic group exhibits a large absorption in the 193 nm region. ArF excimer laser resists containing a resin having been developed have been developed.
The resist composition usually contains a resin that changes its alkali solubility in response to the acid generated in the exposed area. For example, a positive chemically amplified resist composition contains a resin that decomposes by the action of an acid to increase alkali solubility, and a negative resist composition contains a resin that reacts with an acid crosslinking agent to reduce alkali solubility.
Resins used in these resist compositions can be produced by various polymerization methods, but radical polymerization using an azo compound as a polymerization initiator is advantageous because of cost and ease of reaction control. Resins obtained by general radical polymerization have a wide molecular weight distribution and include unreacted residual monomers and oligomer components to components having a very high molecular weight. In the conventional production method, as shown in JP-A-2004-231834 (Patent Document 1), a so-called reprecipitation in which a resin solution obtained by polymerization is poured into a solvent having a low ability to dissolve the resin. A method has been used in which a resin is deposited by a process, and the deposited resin is collected to remove unreacted residual monomers and oligomer components.
However, the high molecular weight component contained in the resin is very poor in solvent solubility or developer solubility, and it is desired to efficiently remove the high molecular weight component from the viewpoint of development defects and pattern collapse. Living polymerization is known as a method for suppressing the formation of polymer components, as disclosed in JP 2002-3533 (Patent Document 2) and JP 2004-220009 (Patent Document 3). However, the substrate used for the reaction is limited, post-treatment after the reaction is complicated, and the obtained resin has a large absorption or a problem in stability.

JP 2004-231834 A JP 2002-3533 A Japanese Patent Laid-Open No. 2004-220009

  An object of the present invention is to use a method for producing a photosensitive composition resin from which a high molecular weight component has been removed by a simple method, a resist resin produced by this method, and a resist resin produced by this method. An object of the present invention is to provide a resist composition with improved development defects and pattern collapse and a pattern forming method using the same.

  The present invention is as follows.

  (1) The resin solution (ps1) in which the resin (p1) is dissolved in the solvent (s1) is brought into contact with a solvent (s2) having a low ability to dissolve the resin, whereby the high molecular weight component of the resin is changed. A method for producing a resin for a photosensitive composition, comprising the step (X) of depositing and removing the high molecular weight component to obtain a resin solution (ps2) from which the high molecular weight component has been removed.

  (2) A resist resin obtained by the production method according to (1).

  (3) A resist composition comprising the resist resin according to (2).

(4) A positive resist composition containing (A1) an acid-decomposable resin and (B) an acid generator,
A positive resist composition, wherein the component (A1) is a resin obtained by the production method according to (1).

(5) A negative resist composition containing (A2) an alkali-soluble resin, (B) an acid generator, and (C) an acid crosslinking agent,
A negative resist composition, wherein the component (A2) is a resin obtained by the production method according to (1).

  (6) A pattern forming method comprising a step of forming a resist film from the resist composition according to any one of (3) to (5), and exposing and developing the resist film.

  The preferred embodiments of the present invention will be further described below.

  (7) The resist resin as described in (2), wherein the resin has a monocyclic or polycyclic alicyclic hydrocarbon structure.

  (8) The resist resin as described in (2), wherein the resin has at least one selected from a lactone group, an acid anhydride group, a cyano group, a hydroxyl group, and an alkali-soluble group.

  (9) The resist resin as described in (2), wherein the resin does not have an aromatic group.

  (10) The resist resin as described in (2), wherein the resin has a hydroxystyrene-based repeating unit.

  (11) The resist resin as described in (2), wherein the resin has a silicon atom.

  (12) The solvent (S2) having a low ability to dissolve the resin has at least one kind selected from water, an alcohol solvent and a hydrocarbon solvent having no polar group, or water, an alcohol solvent and a polar group. The method for producing a resist resin as described in (1), which is a mixed solvent of at least one selected from non-hydrocarbon solvents and another solvent.

  (13) In the resin solution (ps1), the solvent (s1) in which the resin (p1) is dissolved is selected from at least one selected from ether solvents and ketone solvents, or from ether solvents and ketone solvents. (1) The method for producing a resist resin according to (1), wherein the solvent is a mixed solvent of at least one kind and another solvent.

  (14) The component (B) is a compound that generates an acid having a fluoroalkyl chain having 2 to 4 carbon atoms or a benzenesulfonic acid having a fluorine atom upon irradiation with an actinic ray or radiation (4 ) Or (5).

  (15) Furthermore, the resin solution (ps2) obtained through the step (X) is contacted with a solvent having a low ability to dissolve the resin, thereby precipitating the powder resin and collecting the resin ( The manufacturing method of resin for photosensitive compositions as described in 1).

  According to the present invention, a method for producing a photosensitive composition resin from which a high molecular weight component has been removed by a simple method, a resist resin produced by this method, and development using a resist resin produced by this method It is possible to provide a resist composition with improved defects and pattern collapse and a pattern forming method using the same.

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).

In the method for producing a resin for a photosensitive composition of the present invention, a solvent (poor solvent) having a low ability to dissolve a resin (ps1) in which the resin (p1) is dissolved in the solvent (s1) (poor solvent) ( a step (X) of depositing a high molecular weight component of the resin by contacting s2) and removing the high molecular weight component to obtain a resin solution (ps2) from which the high molecular weight component has been removed. And
A photosensitive composition using a resin from which a high molecular weight component has been removed has improved development defects and further pattern collapse compared to a resin produced by a conventional method.
Here, the high molecular weight component refers to a resin having a weight average molecular weight higher than that of the original resin (p1).
Resins obtained by radical polymerization generally have a degree of dispersion of about 2.0 and a broad molecular weight distribution from oligomer components to very high molecular weight components. For example, a resin having a weight average molecular weight of 10,000 and a dispersity of 2.0 synthesized by radical polymerization using a normal azo-based initiator is obtained from an oligomer component having a molecular weight of several hundred to several thousand, and a high molecular weight polymer having a molecular weight of tens of thousands or more contains.
As a conventionally used method, it is common to use a so-called reprecipitation step in which a resin solution obtained by a polymerization reaction or the like is poured into a poor solvent to precipitate and recover a resin component. In the conventional method, the unreacted residual monomer and oligomer components can be removed by the reprecipitation step, and a resin having a narrow degree of dispersion can be obtained. On the other hand, the high molecular weight component is preferential because it has low solubility in a solvent. It is difficult to remove it in the reprecipitation process.
In the production method of the present invention, a high molecular weight component having low solubility in a solvent is contacted with a resin solution having a low ability to dissolve the resin to selectively precipitate the high molecular weight component. By introducing the step (X) to be removed, a resin solution from which the high molecular weight component has been removed can be obtained.

  By contacting the resin solution (ps1) in which the resin (p1) is dissolved in the solvent (s1), which is a feature of the present invention, with a solvent (poor solvent) (s2) having a low ability to dissolve the resin. The resin solution (ps1) used in the step (X) of precipitating the high molecular weight component of the resin and removing the high molecular weight component to obtain a resin solution (ps2) from which the high molecular weight component has been removed is the resin Any solution may be used as long as (p1) is dissolved in the solvent (s1). For example, a reaction solution obtained by a polymerization reaction may be used as it is, or a resin solution obtained by another method, for example, a resin solution obtained by recovering a resin from a reaction solution and dissolving the resin in a solvent again. Also good. As a density | concentration of a resin solution (ps1), 1-50 mass% is preferable, More preferably, it is 5-30 mass%, More preferably, it is 10-25 mass%. In the resin solution (ps1), as the solvent (s1) dissolving the resin, any solvent can be used as long as it is a solvent capable of dissolving the resin, but preferably an ether solvent (more preferably propylene glycol methyl). Ether, tetrahydrofuran), ketone solvents (more preferably methyl ethyl ketone, cyclohexanone, cyclopentanone, acetone, methyl isobutyl ketone), ester solvents (more preferably ethyl acetate, butyl acetate, ethyl lactate, propylene glycol methyl ether acetate) Can be mentioned. In the resin solution (ps1), as the solvent (s1) dissolving the resin (p1), a single solvent of these solvents or a mixed solvent of two or more kinds can be used, and these solvents and other solvents can be used. And a mixed solvent can be used.

As the solvent (poor solvent) (s2) having a low ability to dissolve the resin, any solvent having a low ability to dissolve the resin can be used. Preferred examples of the poor solvent (s2) include a hydrocarbon solvent having no polar group (more preferably hexane, heptane, octane, toluene), water, and an alcohol solvent (more preferably methanol, ethanol, isopropanol). Can do. As the poor solvent (s2), the poor solvent (s2) may be used singly or as a mixture of two or more kinds, but a mixture in which a solvent having a low ability to dissolve a resin and a solvent having a high ability to dissolve a resin are mixed. Solvents are preferred. By using a mixed solvent of a solvent having a low ability to dissolve the resin and a solvent having a high ability to dissolve the resin, the solubility of the resin can be adjusted, and a desired component can be removed. Preferred poor solvents (s2) include water, methanol, water / methanol mixed solvent, isopropanol, water / isopropanol mixed solvent, hexane, ethyl acetate, hexane / ethyl acetate mixed solvent, heptane, heptane / ethyl acetate mixed solvent, heptane / An isopropanol mixed solvent can be mentioned.
As solubility of resin (p1) with respect to a poor solvent (s2), 10 mass% or less is preferable, More preferably, it is 5 mass% or less, More preferably, it is 3 mass% or less.

  The production method of the present invention utilizes the low solvent solubility of the polymer component of the resin, but the solubility of the resin varies depending on various factors such as the constituent monomer species, polymer terminal species, and molecular weight. Therefore, as the solvent (s1), (s2) or reprecipitation solvent to be used, an optimum solvent is selected for each resin.

  The ratio of the preferable resin solution (ps1) and the poor solvent (s2) to be contacted is preferably 1: 0.01 to 1:10, more preferably 1 in terms of the mass ratio of the resin solution (ps1): the poor solvent (s2). : 0.1 to 1: 5, even more preferably 1: 0.5 to 1: 3.

As a method of bringing the poor solvent (s2) into contact with the resin solution (ps1), it is preferable to add the poor solvent (s2) to the stirred resin solution (ps1) over 0.1 to 10 hours. The temperature at which the poor solvent (s2) is added to the resin solution (ps1) is preferably 0 ° C to 100 ° C, more preferably 10 ° C to 50 ° C.
It is preferable to further stir for 0.5 to 5 hours after adding the poor solvent (s2). A heating and / or cooling step may be added when adding the poor solvent (s2) or stirring.

  After bringing the poor solvent (s2) into contact with the resin solution (ps1), the deposited high molecular weight component is removed. As a removal method, filtration or decantation is preferable. The amount of the resin to be removed is preferably 1 to 40% by mass, more preferably 3 to 30% by mass, and still more preferably 5 to 20% by mass with respect to the total resin. By adjusting the amount of the component to be removed, the performance of the photosensitive composition using the resin can be improved without reducing the yield.

  The solution (ps2) from which the high molecular weight component has been deposited and removed may be used as it is in the photosensitive composition, but it may be subjected to a so-called reprecipitation step in which the resin is precipitated by bringing it into contact with a poor solvent again to recover the resin. preferable. By performing the reprecipitation step, the low molecular weight component and the remaining oligomer are further removed, and the resolution of the photosensitive composition is improved. As the poor solvent used in the reprecipitation step, the same solvent as the poor solvent (s2) used in step (X) can be preferably used.

The resin used in the method for producing the resin of 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 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 examples of the initiator include azobisisobutyronitrile, azobisdimethylvaleronitrile, dimethyl 2,2′-azobis (2-methylpropionate) and the like. If desired, an initiator is added or added in portions to carry out the reaction. 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 60-100 ° C.
The obtained reaction solution may be used as it is or after further adding a solvent (s1) to form a resin solution (ps1), which may be used in the step (X) of the present invention, or the reaction solution is added to a solvent and powdered. The resin (p1) recovered by a method such as body recovery or solid recovery may be dissolved in the solvent (s1) to obtain a resin solution (ps1), which may be used in the step (X) of the present invention.

  The resin (p1) contained in the resin solution (ps1) has a weight average molecular weight (Mw) obtained by radical polymerization of preferably 1000 to 200000, more preferably 3000 to 20000, particularly preferably 5000 to 20000, and molecular weight. Resins having a dispersity (Mw / Mn) of 1.4 to 2.5 are suitable. The resin produced by applying the production method of the present invention to this resin solution (ps1) has a weight average molecular weight (Mw) of 4500 to 18000 and a molecular weight dispersity (Mw / Mn) of 1.2 to 1.7. Preferably there is.

In the photosensitive composition using the resin obtained by the production method of the present invention,
A preferred first embodiment is (A1) a positive resist composition containing an acid-decomposable resin obtained by the production method of the present invention and (B) an acid generator.
As a preferred second embodiment, there can be mentioned a negative resist composition containing (A2) an alkali-soluble resin obtained by the production method of the present invention, (B) an acid generator and (C) an acid crosslinking agent.

Examples of the resin (p1) suitable for the production method of the present invention include a resin having a repeating unit having a phenolic hydroxyl group (preferably a hydroxystyrene structure) and a resin having a repeating unit having a monocyclic or polycyclic hydrocarbon structure. It is.
More preferably, it is a resin whose solubility in an alkaline developer is increased by the action of an acid, or an alkali-soluble resin, which undergoes a crosslinking reaction with an acid crosslinking agent by the action of an acid, thereby reducing its solubility in an alkaline developer. Resin.

(A1) Acid-decomposable resin The acid-decomposable resin has a repeating unit having a group (hereinafter, also referred to as “acid-decomposable group”) that is decomposed by the action of an acid to increase the solubility in an alkali developer.
Examples of the acid-decomposable group include a group in which a hydrogen atom of an alkali-soluble group such as a carboxyl group or a phenolic hydroxyl group is protected with a group capable of leaving by the action of an acid.
Group capable of leaving by the action of an acid The (hereinafter, also referred to as "acid-eliminable group"), for _{example, -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.
Examples of the acid-decomposable resin suitable for the production method of the present invention include a resin having a repeating unit having a hydroxystyrene structure, a resin having a repeating unit having a monocyclic or polycyclic hydrocarbon structure, and a resin having a silicon atom. Can be mentioned.

When the resin produced by the method of the present invention is used for a positive resist composition that irradiates a KrF excimer laser beam, an electron beam, an X-ray, a high energy beam (EUV, etc.) having a wavelength of 50 nm or less, It preferably has a hydroxystyrene-based repeating unit such as a repeating unit of hydroxystyrene. More preferably, it is a resin having a hydroxystyrene-based repeating unit and a repeating unit having an acid-decomposable group. The repeating unit having an acid-decomposable group is preferably a hydroxystyrene-based repeating unit protected with an acid-eliminable group or an acid-decomposable (meth) acrylic acid tertiary alkyl ester-based repeating unit.
The hydroxystyrene-based repeating unit protected with an acid leaving group is preferably a repeating unit of 1-alkoxyethoxystyrene, t-butylcarbonyloxystyrene or the like. Examples of the alkyl group in the acid-decomposable (meth) acrylic acid tertiary alkyl ester-based repeating unit include a linear or monocyclic or polycyclic alkyl group. The acid-decomposable (meth) acrylic acid tertiary alkyl ester-based repeating unit is preferably t-butyl (meth) acrylate, 2-alkyl-2-adamantyl (meth) acrylate, 2- (1-adamantyl) -2- Examples of the repeating unit include propyl (meth) acrylate, 1-alkyl-1-cyclohexyl (meth) acrylate, 1-alkyl-1-cyclopentyl (meth) acrylate, and the like.

Specific examples of the resin having a hydroxystyrene-based repeating unit and a repeating unit having an acid-decomposable group used in the present invention are shown below, but the present invention is not limited thereto.

  In the specific example, tBu represents a t-butyl group.

The content of the acid-decomposable group is expressed as B / (B + S) with the number of acid-decomposable groups in the resin (B) and the number of alkali-soluble groups not protected by an acid-eliminating group (S). Is done. The content is preferably 0.01 to 0.7, more preferably 0.05 to 0.50, still more preferably 0.0.
5 to 0.40.

  When the resin produced by the method of the present invention is used in a positive resist composition that is irradiated with ArF excimer laser light, the resin has a monocyclic or polycyclic alicyclic hydrocarbon structure, and is caused by the action of an acid. A resin that decomposes and increases the solubility in an alkaline developer is preferable. More preferably, the resin has a repeating unit having an aromatic structure of 15 mol% or less, more preferably a resin having no aromatic structure.

  A resin having a monocyclic or polycyclic alicyclic hydrocarbon structure, decomposed by the action of an acid, and increased in solubility in an alkali developer (hereinafter also referred to as “alicyclic hydrocarbon-based acid-decomposable resin”) The repeating unit having an acid-decomposable group preferably has a repeating unit represented by the following general formula (II).

In general formula (II):
Xa ₁ represents a hydrogen atom, an alkyl group, a cyano group, or a halogen atom. The alkyl group represented by Xa ₁ is preferably a linear or branched alkyl group having 1 to 4 carbon atoms, and may be substituted with a hydroxyl group or a halogen atom.
Xa ₁ is preferably a hydrogen atom or a methyl group.
Rx _{1 to} Rx ₃ each independently represents a linear or branched alkyl group or a monocyclic or polycyclic cycloalkyl group. At least two of Rx _{1 to} Rx ₃ may combine to form a monocyclic or polycyclic cycloalkyl group.
The linear or branched alkyl group of Rx _{1 to} Rx ₃ has 1 to 4 carbon atoms such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, and t-butyl group. Those are preferred.
Examples of the monocyclic or polycyclic cycloalkyl group represented by Rx _{1 to} Rx ₃ include a monocyclic cycloalkyl group such as a cyclopentyl group and a cyclohexyl group, a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, and an adamantyl group. The polycyclic cycloalkyl group is preferable.
The monocyclic or polycyclic cycloalkyl group formed by combining at least two of Rx _{1 to} Rx ₃ includes a monocyclic cycloalkyl group such as a cyclopentyl group and a cyclohexyl group, a norbornyl group, and a tetracyclodecanyl group. And a polycyclic cycloalkyl group such as a tetracyclododecanyl group and an adamantyl group are preferred.
It is preferable that Rx ₁ is a methyl group or an ethyl group, and Rx ₂ and Rx ₃ are bonded to each other to bond the above monocyclic or polycyclic 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 alicyclic hydrocarbon-based acid-decomposable resin preferably has a repeating unit having a lactone structure.
Any lactone structure can be used as long as it has a lactone structure, but a 5- to 7-membered lactone structure is preferable, and a bicyclo structure or a spiro structure is formed in the 5- to 7-membered ring lactone structure. The other ring structure is preferably condensed. It is more preferable to have a repeating unit having a lactone structure represented by any of the following general formulas (LC1-1) to (LC1-16). The 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. , Halogen atom, hydroxyl group, cyano group, acid-decomposable group and the like. More preferably, they are a C1-C4 alkyl group, 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 lactone structure represented by any one of the general formulas (LC1-1) to (LC1-16) include a repeating unit represented by the following general formula (AI).

In general formula (AI),
R _b0 represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 4 carbon atoms. Preferable substituents that the alkyl group for R _b0 may have include a hydroxyl group and a halogen atom.
Examples of the halogen atom for R _b0 include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
R _b0 is preferably a hydrogen atom or a methyl group.
A _b is 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 linking that is a combination thereof. Represents a group. Preferably a single bond, -Ab ₁ -CO ₂ - is a divalent linking group represented by. Ab ₁ is a linear, branched alkylene group, 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 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 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 lactone structure are given below, but the present invention is not limited thereto.

  Particularly preferred repeating units having a lactone structure include the following repeating units. By selecting the optimum lactone structure, the pattern profile and the density dependence become good.

  The alicyclic hydrocarbon-based acid-decomposable resin preferably has a repeating unit having a hydroxyl group or a cyano group. This improves the substrate adhesion and developer compatibility. The repeating unit having a hydroxyl group or a cyano group is preferably a repeating unit having an alicyclic hydrocarbon structure substituted with a hydroxyl group or a cyano group. The alicyclic hydrocarbon structure in the alicyclic hydrocarbon structure substituted with a hydroxyl group or a cyano group is preferably an adamantyl group, a diamantyl group, or a norbornane group. As the alicyclic hydrocarbon structure substituted with a preferred hydroxyl group or cyano group, partial structures represented by the following general formulas (VIIa) to (VIId) are preferred.

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 remaining is a hydrogen atom. In general formula (VIIa), more preferably, _two of R ₂ c to R ₄ c are hydroxyl groups and the remaining are hydrogen atoms.

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

In the general formulas (AIIa) to (AIIb),
R ₁ c represents a hydrogen atom, a methyl group, a trifluoromethyl group or a hydroxymethyl group.
R ₂ c to R ₄ c are in the general formula (VIIa) ~ (VIIc), same meanings as R ₂ c~R ₄ c.

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

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

The alicyclic hydrocarbon-based 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, and an aliphatic alcohol (for example, hexafluoroisopropanol group) substituted with an electron-attracting group at the α-position. It is more preferable to have a repeating unit. By containing the 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, the alicyclic hydrocarbon-based acid-decomposable resin has dry etching resistance, standard developer suitability, substrate adhesion, resist profile, and general required properties of resist, resolving power and heat resistance. In order to adjust sensitivity and the like, 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 component (A1), 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 alicyclic hydrocarbon-based acid-decomposable resins, the molar ratio of each repeating structural unit is the resist's dry etching resistance, standard developer suitability, substrate adhesion, resist profile, and resolution that is a general required performance of resists. In order to adjust heat resistance, sensitivity, etc., it is set appropriately.

  When the positive resist composition of the present invention is for ArF exposure, the alicyclic hydrocarbon-based acid-decomposable resin preferably has no aromatic group from the viewpoint of transparency to ArF light.

  The alicyclic hydrocarbon-based 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 are methacrylate repeating units, all of the repeating units are acrylate repeating units, or all of the repeating units are methacrylate repeating units and acrylate repeating units. Although it can be used, the acrylate-based repeating unit is preferably 50 mol% or less of the total repeating units. More preferably, the (meth) acrylate repeating unit having an acid-decomposable group is 20 to 50 mol%, the (meth) acrylate repeating unit having a lactone structure is 20 to 50 mol%, and the alicyclic ring is substituted with a hydroxyl group or a cyano group. It is a copolymer containing 5 to 30 mol% of a (meth) acrylate-based repeating unit having a hydrocarbon structure and further 0 to 20 mol% of another (meth) acrylate-based repeating unit.

  When the positive resist composition of the present invention is used for the upper resist of a multilayer resist, the resin has a silicon atom, decomposes by the action of an acid, and increases in solubility in an alkaline developer (hereinafter referred to as “silicon”). The acid-decomposable resin having an atom "is preferred.

As the acid-decomposable resin having a silicon atom, a resin having a silicon atom in at least one of a main chain and a side chain can be used. Examples of the resin having a siloxane structure in the side chain of the resin include, for example, an olefin monomer having a silicon atom in the side chain, maleic anhydride and a (meth) acrylic acid monomer having an acid-decomposable group in the side chain. Mention may be made of copolymers.
The acid-decomposable resin having a silicon atom is preferably a resin having a trialkylsilyl structure or a monocyclic or polycyclic siloxane structure, and has a structure represented by the following general formulas (SS-1) to (SS-4). More preferably, the resin has a (meth) acrylate-based repeating unit, a vinyl-based repeating unit, or an allyl-based repeating unit having a structure represented by General Formulas (SS-1) to (SS-4). A resin is more preferable.

  In general formulas (SS-1) to (SS-4), Rs represents an alkyl group having 1 to 5 carbon atoms, preferably a methyl group or an ethyl group.

  The acid-decomposable resin having a silicon atom preferably has a repeating unit having two or more different types of silicon atoms, more preferably (Sa) a repeating unit having 1 to 4 silicon atoms and (Sb) a silicon atom. It is a resin having both 5 to 10 repeating units, and even more preferably, at least one repeating unit having a structure represented by general formulas (SS-1) to (SS-3) and general formula (SS) -4) It is resin which has a repeating unit which has a structure represented.

In the positive resist composition of the present invention, the blending amount of the acid-decomposable resin in the whole composition is preferably 50 to 99% by mass, more preferably 60 to 98.0% by mass in the total solid content.
In the present invention, the acid-decomposable resin may be used alone or in combination.

(A2) Alkali-soluble resin The alkali-soluble resin preferably has an alkali dissolution rate of at least 20 kg / sec as measured with 0.261N tetramethylammonium hydroxide (TMAH) (23 ° C.). Particularly preferred is 200 Å / sec or more (Å is angstrom).

  Examples of the alkali-soluble resin used in the present invention include novolak resin, hydrogenated novolak resin, acetone-pyrogalol resin, o-polyhydroxystyrene, m-polyhydroxystyrene, p-polyhydroxystyrene, hydrogenated polyhydroxystyrene, and halogen. Alternatively, alkyl-substituted polyhydroxystyrene, hydroxystyrene-N-substituted maleimide copolymer, o / p- and m / p-hydroxystyrene copolymer, partially O-alkylated product of hydroxyl group of polyhydroxystyrene (for example, 5- 30 mol% O-methylated product, O- (1-methoxy) ethylated product, O- (1-ethoxy) ethylated product, O-2-tetrahydropyranylated product, O- (t-butoxycarbonyl) methylated product, etc.) Or O-acylated product (for example, 5 to 30 mol) O-acetylated product, O- (t-butoxy) carbonylated product, etc.), styrene-maleic anhydride copolymer, styrene-hydroxystyrene copolymer, α-methylstyrene-hydroxystyrene copolymer, carboxyl group-containing methacrylic acid Examples thereof include, but are not limited to, resins and derivatives thereof, and polyvinyl alcohol derivatives.

  Particularly preferred alkali-soluble resins are novolak resins and o-polyhydroxystyrene, m-polyhydroxystyrene, p-polyhydroxystyrene and copolymers thereof, alkyl-substituted polyhydroxystyrene, partially O-alkylated polyhydroxystyrene. Or an O-acylated product, a styrene-hydroxystyrene copolymer, and an α-methylstyrene-hydroxystyrene copolymer.

  The novolak resin is obtained by subjecting a predetermined monomer as a main component to addition condensation with an aldehyde in the presence of an acidic catalyst.

  Moreover, the weight average molecular weight of alkali-soluble resin is 2000 or more, Preferably it is 5000-200000, More preferably, it is 5000-100000.

  Here, the weight average molecular weight is defined as a polystyrene equivalent value of gel permeation chromatography.

  These alkali-soluble resins in the present invention may be used in combination of two or more.

  The usage-amount of alkali-soluble resin is 40-97 mass% with respect to solid content of the whole composition of a negative resist composition, Preferably it is 60-90 mass%.

(B) Acid generator The resist composition of this invention contains the compound (it is also called an "acid generator") which generate | occur | produces an acid by irradiation of actinic light or a radiation.
Examples of such an acid generator include a photoinitiator for photocationic polymerization, a photoinitiator for photoradical polymerization, a photodecolorant for dyes, a photochromic agent, or an actinic ray or radiation used for a microresist. A known compound that generates an acid by irradiation and a mixture 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.

  The compound that generates an acid upon irradiation with actinic rays or radiation is a compound that generates an acid having a fluoroalkyl chain having 2 to 4 carbon atoms or a benzenesulfonic acid having a fluorine atom upon irradiation with actinic rays or radiation. Is preferred.

  Among the compounds that generate an acid upon irradiation with actinic rays or radiation, compounds represented by the following general formulas (ZI), (ZII), and (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. Preferably, it is an organic anion containing a carbon atom.

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

In general formulas (AN1) to (AN2),
Rc ₁ represents an organic group.
Examples of the organic group for Rc ₁ include those having 1 to 30 carbon atoms, and preferably an alkyl group, an aryl group, or a plurality thereof, which may be substituted, is a single bond, —O—, —CO ₂ —. , —S—, —SO ₃ —, —SO ₂ N (Rd ₁ ) — and the like. Rd ₁ represents a hydrogen atom or an alkyl group, and may form a ring structure with the bonded alkyl group or aryl group.
The organic group of Rc ₁ is more preferably 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, 3 to 5 fluorine atoms and / or 1 to 3 fluoroalkyl groups. Represents a phenylene group.
Ax represents a linking group (preferably a single bond, —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, a linear or branched alkyl group, a monocyclic or polycyclic cycloalkyl group or an aryl group. The alkyl group, cycloalkyl group and aryl group may be substituted, but preferably have no fluorine atom as a substituent.

In the general formulas (AN3) to (AN4),
Rc ₃ , Rc ₄ and Rc ₅ each independently represents an organic group.
Preferred examples of the organic group for Rc ₃ , Rc ₄ and Rc ₅ include the same organic groups as those for Rc ₁ .
Rc ₃ and Rc ₄ may combine to form a ring. Examples of the group formed by combining Rc ₃ and Rc ₄ include an alkylene group and an arylene group. Preferably, it is a C2-C4 perfluoroalkylene group. 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 carbon number of the organic group as R ₂₀₁ , R ₂₀₂ and R ₂₀₃ is generally 1-30, preferably 1-20.
Two of R _{201 to} R ₂₀₃ may be bonded 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 (ZI) 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.

  More preferable (ZI) components 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, and aryldicycloalkylsulfonium compounds.
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.
The aryl group, alkyl group, and cycloalkyl group of R _{201 to} R ₂₀₃ are an alkyl group (for example, having 1 to 15 carbon atoms), a cycloalkyl group (for example, having 3 to 15 carbon atoms), an aryl group (for example, having 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 as a substituent. 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, particularly preferably. They are a C1-C4 alkyl group and a C1-C4 alkoxy group. 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.
(ZI-1) as preferably, triphenylsulfonium salts R ₂₀₁ to R ₂₀₃ is a phenyl group optionally substituted or one is an aryl group which may be substituted of R ₂₀₁ to R _203, R ₂₀₁ two of to R ₂₀₃ is a diarylcycloalkylsulfonium salt is an alkyl radical (the two alkyl groups may be ring formed by bonding).

Next, the compound (ZI-2) will be described.
Compound (ZI-2) is a compound in the case where R _{201 to} R ₂₀₃ in formula (ZI) each independently represents an organic group containing no aromatic ring. Here, the aromatic ring includes an aromatic ring containing a hetero atom.
The organic group having no aromatic ring 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, or an alkoxycarbonylmethyl group, particularly preferably Is a linear, branched 2-oxoalkyl group.

The alkyl group as R ₂₀₁ to R ₂₀₃ is preferably include a linear or branched alkyl group having 1 to 10 carbon atoms (e.g., methyl group, ethyl group, propyl group, butyl group, pentyl group) . The alkyl group as R ₂₀₁ to R ₂₀₃ may be linear, 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.
Linear as R ₂₀₁ to R _203, branched or cyclic 2-oxoalkyl group may preferably be a group having a 2-position> C = O in the above-described alkyl or cycloalkyl group.
The alkoxy group in the alkoxycarbonylmethyl group as R ₂₀₁ to R _203,
Preferable examples include an alkoxy group having 1 to 5 carbon atoms (methoxy group, ethoxy group, propoxy group, butoxy group, 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, a nitro group, or the like.

  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 _{1c to} R _5c each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group or a halogen atom.
R _6c and R _7c 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.
Any two or more of R _1c to R _7c, and R _x and R _y may be bonded to 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. Examples of the group formed by combining any two or more of R _{1c to} R _7c and R _x and R _y include a butylene group and a pentylene group.
X ⁻ represents a non-nucleophilic anion, and examples thereof include those similar to the non-nucleophilic anion of X ⁻ in formula (I).

The alkyl group as R _{1c to} R _7c is, for example, a linear or branched alkyl group having 1 to 20 carbon atoms, preferably a linear or branched alkyl group having 1 to 12 carbon atoms (for example, a methyl group). , Ethyl group, linear or branched propyl group, linear or branched butyl group, linear or branched pentyl group).
Preferable examples of the cycloalkyl group as R _{1c to} R _7c include a cycloalkyl group having 3 to 8 carbon atoms (for example, a cyclopentyl group and a cyclohexyl group).
The alkoxy group as R _{1c to} R _{5c may} be linear, branched or cyclic, for example, an alkoxy group having 1 to 10 carbon atoms, preferably a linear or branched alkoxy group having 1 to 5 carbon atoms. (For example, methoxy group, ethoxy group, linear or branched propoxy group, linear or branched butoxy group, linear or branched pentoxy group), C3-C8 cyclic alkoxy group (for example, cyclopentyloxy group, cyclohexyloxy group) ).
Preferably any one of R _{1c to} R _5c is a linear or branched alkyl group, a cycloalkyl group, or a linear, branched or cyclic alkoxy group, and more preferably the sum of the carbon number of R _{1c to} R _5c is 2-15. Thereby, solvent solubility improves more and generation | occurrence | production of a particle is suppressed at the time of a preservation | save.

_Examples of the alkyl group as R _x and R _y include the same alkyl groups as R _{1c to} R _7c . The alkyl group as R _x and R _y is more preferably a linear or branched 2-oxoalkyl group or an alkoxymethyl group.
The cycloalkyl group as R _x and R _y may be the same as the cycloalkyl group as R _1c to R _7c. The cycloalkyl group as R _x and R _y is more preferably a cyclic 2-oxoalkyl group.
Examples of the linear or branched alkyl group and the cyclic 2-oxoalkyl group include a group having> C═O at the 2-position of the alkyl group or cycloalkyl group as R _{1c to} R _7c .
Examples of the alkoxy group in the alkoxycarbonylmethyl group include the same alkoxy groups as R _{1c to} R _5c .
R _x and R _y are preferably an alkyl group 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 preferably be mentioned a linear or branched alkyl group having 1 to 10 carbon atoms (e.g., methyl group, ethyl group, 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 as the non-nucleophilic anion of X ^{− in} formula (I).

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

In the 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, more preferably a cyano group or a fluoroalkyl group.
A represents an alkylene group, an alkenylene group or an arylene group.

Of the compounds that generate an acid upon irradiation with actinic rays or radiation, more preferred are compounds represented by general formulas (ZI) to (ZIII), and even more preferred are compounds represented by general formula (ZI). And particularly preferred are compounds represented by the general formulas (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.

In formula (AC1) ~ (AC3), Rc 1, Rc 3 ~Rc 5 are in the general formula (AN1) ~ (AN4), and Rc _1, Rc ₃ ~Rc ₅ synonymous.

  A particularly preferred acid generator is a compound in which, in the structure of the general formula (ZI), X- is an anion selected from the above (AN1), (AN3), and (AN4).

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

An 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 acid generator in the composition is preferably 0.1 to 20% by mass, more preferably 0.5 to 10% by mass, and still more preferably 1 to 7% by mass, based on the total solid content of the resist composition. %.

(C) Acid crosslinking agent An acid crosslinking agent is used in the negative resist composition of the present invention.

Any acid crosslinking agent can be used as long as it is a compound that crosslinks an alkali-soluble resin by the action of an acid, but the following (1) to (3) are preferred.
(1) Hydroxymethyl, alkoxymethyl, and acyloxymethyl forms of phenol derivatives.
(2) A compound having an N-hydroxymethyl group, an N-alkoxymethyl group, or an N-acyloxymethyl group.
(3) A compound having an epoxy group.

  The alkoxymethyl group preferably has 6 or less carbon atoms, and the acyloxymethyl group preferably has 6 or less carbon atoms.

  Among these acid crosslinking agents, particularly preferred are listed below.

In the formula, L ^{1 to} L ⁸ may be the same or different and each represents a hydrogen atom, a hydroxymethyl group, a methoxymethyl group, an ethoxymethyl group, or an alkyl group having 1 to 6 carbon atoms.

  The acid crosslinking agent is used in an amount of usually 3 to 70% by mass, preferably 5 to 50% by mass, in the solid content of the negative resist composition.

A 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. The resist composition of the present invention is 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 may be added.
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 having an acid-decomposable group is preferred. The acid-decomposable group is preferably a group in which a carboxyl group or a hydroxyl group is protected with an acid-decomposable protecting 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 obtained by protecting the carboxylic acid with an acid-decomposable protecting group, such as saccharides. A polyol or a compound having its hydroxyl group protected with an acid-decomposable protecting group is preferred.

  The molecular weight of the dissolution controlling compound 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 resist composition.

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

Basic Compound The resist composition of the present invention preferably 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.

Examples of basic compounds include nitrogen-containing basic compounds and onium salt compounds.
Preferred examples of the structure of the nitrogen-containing basic compound 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 carbon atoms, a cycloalkyl group or an aryl group having 6 to 20 carbon atoms having 3 to 20 carbon atoms, R ²⁵⁰ and R ²⁵¹ may be bonded to 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 carbon atom. A -20 hydroxyalkyl group or a C3-C20 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, and benzimidazole. 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 and the like. 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) Examples thereof include sulfonium hydroxide, bis (t-butylphenyl) iodonium hydroxide, phenacylthiophenium hydroxide, and 2-oxopropylthiophenium hydroxide. Examples of the compound having an onium carboxylate structure are compounds in which the anion portion of the compound having an onium hydroxide structure is converted to a carboxylate, and examples thereof include acetate, adamantane-1-carboxylate, and perfluoroalkylcarboxylate. it can. 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 resist 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 surfactant The resist composition of the present invention further contains fluorine and / or silicon surfactant (fluorine surfactant, silicon surfactant and both fluorine atoms and silicon atoms). Or a combination of two or more surfactants.
When the resist composition of the present invention contains fluorine and / or a silicon-based surfactant, a resist having low adhesion and development defects with good sensitivity and resolution when using an exposure light source of 250 nm or less, particularly 220 nm or less. A pattern can be given.

  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 resist composition (excluding the solvent). .

Solvent The resist composition of the present invention is used by dissolving each component in a predetermined solvent.
Examples of solvents 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- Examples include organic solvents such as dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone, and tetrahydrofuran. Kill.

In the present invention, the solvent may be used alone or mixed, but it is preferable to use a mixed solvent containing two or more kinds of 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 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. Particularly preferred are propylene glycol monomethyl ether and ethyl lactate.
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 particularly preferred, 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. And the other solvent is at least one solvent selected from solvents having at least one functional group selected from a hydroxyl group, a ketone group, a lactone group, an ester group, an ether group, and a carbonate group. 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>
In the resist composition of the present invention, if necessary, a dye, a plasticizer, a surfactant other than the fluorine and / or silicon surfactant, a photosensitizer, and a compound that promotes solubility in a developer. Etc. 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 acid-decomposable resin. 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, other surfactants than fluorine and / or silicon surfactants can 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 resist composition of the present invention is used by dissolving each component in a predetermined solvent, preferably the above mixed solvent, filtering through a filter, and coating 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 photosensitive composition is formed by applying and drying a resist composition on a substrate (eg, silicon / silicon dioxide coating) used in the manufacture of precision integrated circuit elements by an appropriate application method such as a spinner or a coater. To do.
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. As an alkaline developer of the resist composition, inorganic hydroxides such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia, primary amines such as ethylamine and n-propylamine, Secondary amines such as diethylamine and di-n-butylamine, tertiary amines such as triethylamine and methyldiethylamine, alcohol amines such as dimethylethanolamine and triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide and the like Alkaline aqueous solutions such as quaternary ammonium salts, 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.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to this.

Synthesis example 1
Under a nitrogen stream, 48 g of methyl ethyl ketone was placed in a three-necked flask and heated to 80 ° C. To this, 41.6 g of norbornane lactone acrylate, 25.2 g of 3,5-dihydroxy-1-adamantyl methacrylate, 52.5 g of 2- (1-adamantyl) propyl-2-methacrylate, polymerization initiator V-601 (Wako Pure Chemical Industries, Ltd.) (Product) was added dropwise over 6 hours with a solution obtained by dissolving 8 mol% of the monomer in 430 g of methyl ethyl ketone. After completion of the dropwise addition, the reaction mixture was further reacted at 80 ° C. for 2 hours to obtain a reaction solution of resin (A) having the following structure. The weight average molecular weight of the resin (A) in the reaction solution was 9100 in terms of standard polystyrene, and the dispersity (Mw / Mn) was 1.90.

  The reaction solution was diluted to 10% by mass with methyl ethyl ketone to prepare a resin solution (A).

Method for Producing Resin (Aa), (A-b1), (A-b2) by Method of the Present Invention Using the prepared resin solution (A), resin (A A-a), (A-b1), and (A-b2) were produced.
(Method a) When 180 g of methanol was gradually added to 120 g of the resin solution (A), a viscous product was precipitated. The polymer solution from which the viscous material was removed was collected by decantation, and poured into 1200 ml of stirring distilled water to perform reprecipitation. The precipitated powder was collected by filtration, washed with water, and dried to obtain a resin (Aa).
The weight average molecular weight of the removed viscous substance component was 14600, the weight average molecular weight of the obtained resin (Aa) was 8640, and the degree of dispersion was 1.64.
(Method b1) When 180 g of methanol was gradually added to 120 g of the resin solution (A), a viscous product was precipitated. The polymer solution from which the viscous material was removed was collected by decantation, and the polymer solution was poured into 1200 ml of stirring hexane for reprecipitation. The precipitated powder was collected by filtration, washed with water, and dried to obtain a resin (A-b1).
The weight average molecular weight of the removed viscous product component was 14700, and the obtained resin (A-b1) had a weight average molecular weight of 8520 and a dispersity of 1.68.
(Method b2) Resin (A-b2) is obtained using the same method as Method b1, except that the solvent used for reprecipitation is changed from 1200 ml of hexane to 1200 ml of a mixed solvent of hexane / ethyl acetate = 50/50 (mass ratio). It was.
The weight average molecular weight of the removed viscous component was 14,500, and the obtained resin (A-b2) had a weight average molecular weight of 9560 and a dispersity of 1.36.

Production method of resin (Ac), (Ad), (Ae) by conventional method (comparative method)
Resin (Ac) and (Ad) were manufactured using the prepared resin solution (A) and the following methods c and d.
Moreover, resin (Ae) was manufactured using the following methods e.
(Procedure c) 120 g of the resin solution (A) was poured into 1200 ml of stirring distilled water to perform reprecipitation. The precipitated powder was collected by filtration, washed with water, and dried to obtain a resin (Ac).
(Method d) 120 g of the resin solution (A) was poured into 1200 ml of stirring hexane, and reprecipitation was performed. The precipitated powder was collected by filtration, washed with water, and dried to obtain a resin (Ad).
(Method e) A reaction solution was obtained in the same manner as in Synthesis Example 1 except that 12 mol% of the polymerization initiator V-601 was used with respect to the monomer. 120 g of the reaction solution was poured into 1200 ml of a mixed solvent of ethyl acetate / hexane = 5/5 (mass ratio) to perform reprecipitation. The precipitated powder was collected by filtration, washed with water, and dried to obtain a resin (Ae).

Production Method of Resin (Af) According to the Present Invention Using Resin (Ac) Obtained by Conventional Method Resin (Ac) Obtained by Method (Method f) (Method c) is Methyl Ethyl Ketone 120 g of a 10% by mass solution was prepared. When 180 g of methanol was gradually added thereto, a viscous product was precipitated. The polymer solution from which the viscous material was removed was collected by decantation, and poured into 1200 ml of stirring distilled water to perform reprecipitation. The precipitated powder was collected by filtration, washed with water, and dried to obtain a resin (Af). The weight average molecular weight of the removed viscous product component was 15000, the weight average molecular weight of the obtained resin (Af) was 8600, and the degree of dispersion was 1.60.

The weight average molecular weights and dispersities of the obtained resins (Aa) to (Af) are shown in Table 1 below.
Resins (Aa) and (A-b1) obtained by the methods a and b1 of the present invention have a weight average molecular weight of the removed component larger than the weight average molecular weight of the reaction solution of the resin (A), and Since the weight average molecular weight of the obtained resins (Aa) and (A-b1) is smaller than the weight average molecular weight of the reaction liquid of the resin (A) and the degree of dispersion is narrow, the polymer component is selective. It can be seen that it has been removed. Resin (A-b2) has a weight average molecular weight of the removed component larger than the weight average molecular weight of the reaction solution of resin (A), and the dispersity is extremely narrow compared to (A-b1). It can be seen that the high molecular weight component was removed by the method of the invention, and the low molecular component could be selectively removed by using a mixed solvent of ethyl acetate as the reprecipitation solvent.
The resins (Ac) and (Ad) obtained by the conventional methods c and d have a weight average molecular weight larger than the weight average molecular weight of the reaction solution of the resin (A), and the dispersity is narrow. From this, it can be seen that the low molecular components are selectively removed.
Resin (Ae) is obtained by using a conventional technique and selectively removing low molecular components using a mixed solvent of ethyl acetate as a reprecipitation solvent, so that the weight average molecular weight and the dispersity are resin (A-). It turns out that it became a thing comparable to a) and (A-b1).
Resin (Af) is obtained by dissolving the resin (Ac) obtained by the conventional method in a solvent again and applying the method of the present invention. The weight average molecular weight of the removed component is larger than the weight average molecular weight of the resin (Ac), and the weight average molecular weight of the obtained resin (Af) is smaller than the weight average molecular weight of the resin (Ac). From the fact that the degree of dispersion is narrow, it can be seen that the polymer component is selectively removed.

Synthesis example 2
Under a nitrogen stream, 16 g of propylene glycol methyl ether acetate and 11 g of propylene glycol methyl ether were placed in a three-necked flask and heated to 80 ° C. To this, 25.0 g of norbornane lactone acrylate, 15.1 g of 3,5-dihydroxy-1-adamantyl methacrylate, 23.1 g of 2- (1-adamantyl) propyl-2-methacrylate, 2.6 g of methacrylic acid, polymerization initiator V A solution prepared by dissolving -601 (manufactured by Wako Pure Chemical Industries, Ltd.) in 10 mol% of the monomer in 143 g of propylene glycol methyl ether acetate and 95.5 g of propylene glycol methyl ether was added dropwise over 6 hours. After completion of dropping, the reaction was further carried out at 80 ° C. for 2 hours. The reaction solution was poured into 2500 ml of a mixed solvent of hexane / ethyl acetate = 1/9 (mass ratio), and the powder was recovered to obtain a resin (B) having the following structure. The weight average molecular weight of the resin (B) was 6820 in terms of standard polystyrene, and the dispersity (Mw / Mn) was 1.79.

  The obtained resin (B) was dissolved in a mixed solvent of propylene glycol methyl ether acetate / propylene glycol methyl ether = 6/4 (mass ratio) to prepare a 20 mass% resin solution (B).

Manufacturing method of resin (Bf), (Bg), (Bh) by the method of the present invention The prepared resin solution (B) is used, and the resin is prepared using the following methods f, g, h. Manufactured.
(Method f) 60 ml of ethyl acetate was gradually added to 50 g of the stirred resin solution (B), and the precipitated powder was filtered off with a 0.2 micron polytetrafluoroethylene filter. The filtrate was poured into 500 ml of a mixture of hexane / ethyl acetate = 1/9 (mass ratio) to perform reprecipitation. The precipitated powder was collected to obtain a resin (Bf).
(Method g) Resin (Bf) was obtained using the same method as Method f except that 120 ml of ethyl acetate was added to 50 g of the resin solution (B) instead of 60 ml of ethyl acetate.
(Method h) Resin (Bh) was obtained using the same method as Method f except that 50 ml of the resin solution (B) was added with 80 ml of methanol instead of 60 ml of ethyl acetate.

The weight average molecular weights and dispersities of the obtained resins (Bf) to (Bh) are shown in Table 2 below.
It can be seen that the resins (Bf), (Bg), and (Bh) obtained by the methods f, g, and h of the present invention have high molecular weight components removed.

In the same manner as in Synthesis Example 1, reaction solutions (C) to (H) of resins (C) to (H) having the following structures were obtained.
In addition, when synthesizing the resins (C) to (H), as shown in Table 3 below, the amount of the polymerization initiator used was changed to adjust the weight average molecular weight of each resin.

  Reaction liquid (C)-(H) was diluted to 10 mass% with methyl ethyl ketone, and resin solution (C)-(H) was prepared.

Resins (Ci), (Di), (Ei), (Fi) by the method of the present invention using the prepared resin solutions (C) to (H) and using the following method i , (G-i) and (Hi) were produced.
(Method i) When 180 g of methanol was gradually added to 120 g of the resin solutions (C) to (H), a viscous product or powder precipitated. The polymer solution from which the viscous material was removed was collected by decantation, and poured into 1200 ml of stirring distilled water to perform reprecipitation. The precipitated powder is collected by filtration, washed with water, and dried. Resins (Ci), (Di), (Ei), (Fi), (Gi), and (Hi) Obtained.

Resins (Cj), (Dj), (Ej), (Fj) by the comparison method using the prepared resin solutions (C) to (H) and using the following method j, (Gj) and (Hj) were produced.
(Method j) 120 g of the resin solutions (C) to (H) were poured into 1200 ml of stirring distilled water to perform reprecipitation. The precipitated powder is collected by filtration, washed with water, and dried to obtain resins (Cj), (Dj), (Ej), (Fj), (Gj), and (Hj). Obtained.

The weight average molecular weights and dispersities of the obtained resins (Ci) to (Hj) are shown in Table 3 below.
Resins (Ci), (Di), (Ei), (Fi), (Gi), and (Hi) obtained by the technique i of the present invention are high molecular weight components. It can be seen that is removed.

Examples 1-13 and Comparative Examples 1-10
<Resist preparation>
The components shown in Table 4 below were dissolved in a solvent to prepare a solution having a solid content concentration of 6% by mass, and this was filtered through a 0.02 m polyethylene filter to prepare a positive resist solution.

<Pattern collapse 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 160 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 form a line pattern.
When the exposure amount that reproduces the mask pattern of 75nm line / 90nm space is set as the optimal exposure amount and the line width of the line pattern formed by further increasing the exposure amount from the optimal exposure amount is reduced, the pattern does not collapse It was defined as the line width that resolves to. The smaller the value, the finer pattern is resolved without falling, and the pattern collapse is less likely to occur and the resolution is higher.
The evaluation results are shown in Table 4.

<Development defect evaluation>
Each positive resist solution is uniformly coated on a 6-inch silicon substrate subjected to hexamethyldisilazane treatment by a spin coater, and heated and dried on a hot plate at 120 ° C. for 90 seconds to form a 150 nm resist film. did. This resist film was heated on a hot plate at 110 ° C. for 90 seconds without exposure. Further, the resist film was developed with an aqueous 2.38 wt% tetramethylammonium hydroxide solution at 23 ° C. for 60 seconds, rinsed with pure water for 30 seconds, and then dried. The number of development defects of the sample wafer thus obtained was measured with a KLA2112 machine (manufactured by KLA Tencor) (Threshold12, Pixcel Size = 0.39).
The evaluation results are shown in Table 4.

  Hereinafter, abbreviations in the table are shown.

[Basic compounds]
TPSA: Triphenylsulfonium acetate
DIA: 2,6-diisopropylaniline
TEA: Triethanolamine
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: Troisol S-366 (manufactured by Troy Chemical Co., Ltd.) (silicon-based)

〔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 4, the resist composition containing the resin produced by the production method of the present invention has improved development defects and pattern collapse compared to the resist composition containing the resin produced by the conventional production method. I understand that

(Immersion exposure)
<Preparation of positive resist solution>
The components listed in Table 4 were dissolved in a solvent to prepare a solution having a solid content concentration of 6% by mass, and this was filtered through a 0.03 μm polyethylene filter to prepare a positive resist solution, which was evaluated by the following method.

<Resolution evaluation>
An organic antireflection film ARC29A (manufactured by Nissan Chemical Industries, Ltd.) was applied on a silicon wafer and baked at 205 ° C. for 60 seconds to form a 78 nm antireflection film. A positive resist solution prepared thereon was applied and baked at 115 ° C. for 60 seconds to form a 140 nm resist film. The wafer thus obtained was subjected to two-beam interference exposure (wet exposure) using pure water as the immersion liquid. In the two-beam interference exposure (wet), as shown in FIG. 1, a laser 1, an aperture 2, a shutter 3, three reflecting mirrors 4, 5, 6 and a condenser lens 7 are used, a prism 8, a liquid The wafer 10 having an antireflection film and a resist film was exposed through an immersion liquid (pure water) 9. The wavelength of the laser 1 was 193 nm, and the prism 8 forming a 65 nm line and space pattern was used. Immediately after the exposure, the film was heated at 115 ° C. for 90 seconds, developed with a tetramethylammonium hydroxide aqueous solution (2.38%) for 60 seconds, rinsed with pure water, and spin-dried to obtain a scanning electron microscope ( Hitachi S-9260) was used for observation. When the positive resist solution of the example was used, the 65 nm line and space pattern was resolved without causing pattern collapse. When the positive resist solution of the comparative example was used, pattern collapse was observed in some patterns although the 65 nm line and space pattern was resolved.
It is apparent that the positive resist solution of the present invention has a good image forming ability even in an exposure method using an immersion liquid.

It is the schematic of a two-beam interference exposure experiment apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Laser 2 Aperture 3 Shutter 4, 5, 6 Reflection mirror 7 Condensing lens 8 Prism 9 Immersion liquid 10 Wafer having antireflection film and resist film 11 Wafer stage

Claims (6)

  By contacting the resin solution (ps1) in which the resin (p1) is dissolved in the solvent (s1) with a solvent (s2) having a low ability to dissolve the resin, the high molecular weight component of the resin is precipitated, A process for producing a resin for a photosensitive composition, comprising the step (X) of removing the high molecular weight component to obtain a resin solution (ps2) from which the high molecular weight component has been removed.   A resist resin obtained by the production method according to claim 1.   A resist composition comprising the resist resin according to claim 2. A positive resist composition containing (A1) an acid-decomposable resin and (B) an acid generator,
A positive resist composition, wherein the component (A1) is a resin obtained by the production method according to claim 1. (A2) a negative resist composition containing an alkali-soluble resin, (B) an acid generator, and (C) an acid crosslinking agent,
The negative resist composition, wherein the component (A2) is a resin obtained by the production method according to claim 1.   A pattern forming method comprising: forming a resist film from the resist composition according to claim 3; and exposing and developing the resist film.

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