JPWO2008087840A1 - Radiation-sensitive resin composition for immersion exposure and method for forming photoresist pattern - Google Patents

Abstract

The object of the present invention is that the pattern shape obtained is good, the depth of focus is excellent, the amount of eluate in the immersion medium such as water contacted during immersion exposure is small, and the occurrence of bubble defects is suppressed. It is to provide a radiation sensitive resin composition for immersion exposure and a method for forming a photoresist pattern using the same. The radiation-sensitive resin composition for immersion exposure according to the present invention comprises a polymer (A) containing a fluorinated alkyl group, having a fluorine content of 3 atom% or more and being alkali-soluble by the action of an acid, A resin composition comprising a resin (B) that becomes alkali-soluble by action and has a fluorine content of less than 3 atom%, and a radiation-sensitive acid generator (C), and the resin composition is placed on a substrate. The advancing contact angle with respect to water of the photoresist film formed by coating is 95 degrees or less.

Description

  The present invention relates to a radiation-sensitive resin composition for immersion exposure that can be suitably used for an immersion exposure method in which a photoresist film is exposed through an immersion medium such as water, and a photoresist pattern formation using the same. Regarding the method.

In the field of microfabrication represented by the manufacture of integrated circuit elements, in order to obtain a higher degree of integration, recently, a lithography technique capable of microfabrication at a level of 0.10 μm or less is required. However, in the conventional lithography process, near-ultraviolet rays such as i rays are generally used as radiation, and it is said that fine processing at the subquarter micron level is extremely difficult with this near-ultraviolet rays. Therefore, in order to enable fine processing at a level of 0.10 μm or less, use of radiation having a shorter wavelength is being studied. Examples of such short-wavelength radiation include an emission line spectrum of a mercury lamp, far-ultraviolet rays typified by an excimer laser, X-rays, electron beams, and the like. ) Or ArF excimer laser (wavelength 193 nm) has been attracting attention.
As a resist suitable for irradiation with such an excimer laser, a component having an acid-dissociable functional group and a component that generates acid upon irradiation with radiation (hereinafter referred to as “exposure”) (hereinafter referred to as “acid generator”) )) And a number of resists using the chemical amplification effect (hereinafter referred to as “chemically amplified resist”) have been proposed. As the chemically amplified resist, for example, a resist containing a resin having a t-butyl ester group of carboxylic acid or a t-butyl carbonate group of phenol and an acid generator has been proposed. In this resist, the t-butyl ester group or t-butyl carbonate group present in the resin is dissociated by the action of an acid generated by exposure, and the resin has an acidic group composed of a carboxyl group or a phenolic hydroxyl group. As a result, the phenomenon that the exposed region of the photoresist film becomes readily soluble in an alkali developer is utilized.

  In such a lithography process, further fine pattern formation (for example, a fine resist pattern having a line width of about 45 nm) will be required in the future. In order to achieve such fine pattern formation of less than 45 nm, it is conceivable to shorten the light source wavelength of the exposure apparatus and increase the numerical aperture (NA) of the lens as described above. However, a new expensive exposure apparatus is required to shorten the light source wavelength. Further, when the lens has a high NA, the resolution and the depth of focus are in a trade-off relationship. Therefore, there is a problem that the depth of focus decreases even if the resolution is increased.

  Recently, a liquid immersion lithography (liquid immersion lithography) method has been reported as a lithography technique that can solve such problems. In this method, at the time of exposure, a liquid refractive index medium (immersion medium) such as pure water or a fluorine-based inert liquid having a predetermined thickness is formed on at least the photoresist film between the lens and the photoresist film on the substrate. It is to intervene. In this method, a light source having the same exposure wavelength can be used by replacing the exposure optical path space, which has conventionally been an inert gas such as air or nitrogen, with a liquid having a higher refractive index (n), such as pure water. Similar to the case of using a light source with a shorter wavelength or the case of using a high NA lens, high resolution is achieved and there is no reduction in the depth of focus. If such immersion exposure is used, it is possible to realize the formation of a resist pattern that is low in cost, excellent in high resolution, and excellent in depth of focus, using a lens mounted on an existing apparatus. It is attracting a lot of attention.

However, in the above-described immersion exposure process, the photoresist film directly comes into contact with an immersion medium such as water at the time of exposure, so that the acid generator and the like are eluted from the photoresist film. When the amount of the eluted material is large, there are problems that the lens is damaged, a predetermined pattern shape cannot be obtained, and sufficient resolution cannot be obtained.
In addition, when water is used as the immersion medium, bubbles may be generated during exposure, and the bubbles serve as a lens and cannot be exposed at the initial predetermined refractive index. There is also a problem in that a bubble defect that a pattern having a predetermined shape cannot be formed in the periphery.

As resist resins used in the immersion exposure apparatus, for example, resins described in Patent Document 1 and Patent Document 2, additives described in Patent Document 3, and the like have been proposed.
However, even in a resist using these resins and additives, it cannot be said that the amount of the eluate in water such as an acid generator is sufficient, and bubble defects are likely to occur.

International Publication WO 2004/062422 JP 2005-173474 A JP 2006-48029 A

  The present invention has been made in view of the above circumstances, the pattern shape obtained is good, excellent in the depth of focus, the amount of eluate to the immersion medium such as water contacted during immersion exposure is small, And it aims at providing the radiation sensitive resin composition for immersion exposure which can suppress generation | occurrence | production of a bubble defect, and the photoresist pattern formation method using the same.

Means for achieving the above object are as follows.
[1] A polymer (A) containing a fluorinated alkyl group, having a fluorine content of 3 atom% or more and becoming alkali-soluble by the action of an acid, and alkali-soluble by the action of an acid and having a fluorine content of 3 atom% A radiation-sensitive resin composition for immersion exposure, comprising a resin (B) that is less than 1 and a radiation-sensitive acid generator (C), wherein the radiation-sensitive resin composition for immersion exposure is a substrate. A radiation-sensitive resin composition for immersion exposure, wherein the photoresist film formed on the substrate has a forward contact angle with water of 95 degrees or less.
[2] The radiation-sensitive material for immersion exposure according to [1], wherein the resin (B) includes a repeating unit containing a lactone structure and a repeating unit containing a skeleton that becomes alkali-soluble by the action of an acid. Resin composition.
[3] The above [1] or [2], wherein the polymer (A) includes a repeating unit represented by the following general formula (1) and a repeating unit containing a skeleton that becomes alkali-soluble by the action of an acid. ] The radiation sensitive resin composition for immersion exposure as described in any one of the above.
[In General Formula (1), R ¹ represents hydrogen, a methyl group or a trifluoromethyl group, A represents a single bond, a methylene group, an alkylene group having 2 to 6 carbon atoms, an oxygen atom, a sulfur atom, a carbonyloxy group, An oxycarbonyl group, an amide group, a sulfonylamide group or a urethane group is shown. R ² represents a linear or branched alkyl group having 1 to 6 carbon atoms, a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof containing at least one fluorine atom. Show. ]
[4] The monomer giving the repeating unit represented by the general formula (1) is 2,2,2-trifluoroethyl (meth) acrylate, 2- (1,1,1,3,3,3 -Hexafluoro) propyl (meth) acrylate, 1- (2,2,3,3,4,4,5,5-octafluoro) hexyl (meth) acrylate, 1- (2,2,3,3,4 , 4,4-heptafluoro) penta (meth) acrylate and perfluorocyclohexyl (meth) acrylate, the radiation-sensitive resin for immersion exposure according to any one of the above [1] to [3] Composition.
[5] The above [1] to [1] to the content of the polymer (A) is 0.1% by mass or more when the total of the polymer (A) and the resin (B) is 100% by mass. [4] The radiation-sensitive resin composition for immersion exposure according to any one of [4].
[6] (1) A step of forming a photoresist film on a substrate using the radiation-sensitive resin composition for immersion exposure according to any one of [1] to [5], and (2) A step of irradiating the photoresist film with radiation through an immersion medium and a mask having a predetermined pattern and exposing the photoresist film; and (3) a step of causing the exposed photoresist film to form a resist pattern. A method for forming a photoresist pattern, comprising:

  If the radiation-sensitive resin composition for immersion exposure of the present invention is used, the pattern shape obtained is good, the depth of focus is excellent, and the amount of eluate to the immersion medium such as water that has been contacted during immersion exposure can be reduced. Less. Furthermore, since the advancing contact angle between the photoresist film and the immersion medium is 95 degrees or less, the occurrence of bubble defects during immersion exposure can be suppressed.

It is a schematic diagram explaining the method of producing the sample for a measurement of the elution amount. It is a figure which shows the cross-sectional shape of a line and space pattern. It is a figure which shows a typical watermark defect. It is a figure which shows a typical bubble defect.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1; Silicon wafer, 21; HMDS, 2; Silicon rubber sheet, 3; Ultrapure water, 4; Silicon wafer, 41; Antireflection film, 42; Photoresist film, 5;

Hereinafter, the present invention will be described in detail.
The radiation-sensitive resin composition for immersion exposure of the present invention (hereinafter also simply referred to as “radiation-sensitive resin composition” or “resin composition”) contains a fluorinated alkyl group and has a fluorine content of 3 atom%. A polymer (A) that is alkali-soluble by the action of an acid, a resin (B) that is alkali-soluble by the action of an acid and has a fluorine content of less than 3 atom%, and a radiation-sensitive acid generator ( C), and a photoresist film formed by applying the resin composition on a substrate has a forward contact angle with water of 95 degrees or less.
This radiation-sensitive resin composition is a resist including immersion exposure in which radiation is irradiated between a lens and a photoresist film through an immersion medium (for example, water) having a refractive index higher than that of air at a wavelength of 193 nm. In the pattern forming method, it is used to form a photoresist film.

  Moreover, in the radiation sensitive resin composition of this invention, the advance contact angle with respect to the water of the photoresist film formed by apply | coating this resin composition on a board | substrate is 95 degrees or less. When the advancing contact angle is 95 degrees or less, it is possible to suppress bubble biting during high-speed scanning, and it is possible to suppress the occurrence of bubble defects. In the present specification, “advanced contact angle” means that 25 μL of water is dropped on a substrate on which a photoresist film made of the resin composition of the present invention is formed, and then water drops on the substrate are fed at a rate of 10 μL / min. This means the contact angle between the liquid surface and the substrate when injected in step (b). Specifically, as shown in the below-mentioned Example, it can measure using "DSA-10" by KRUS.

  In the radiation-sensitive resin composition of the present invention, the receding contact angle with respect to water of a photoresist film formed by applying this resin composition on a substrate is preferably 75 degrees or more, more preferably 80 degrees or more, more preferably 85 degrees or more. When the receding contact angle is 75 degrees or more, water drainage at the time of high-speed scan exposure becomes good, and the occurrence of watermark defects can be suppressed. In this specification, “retreat contact angle” means that 25 μL of water is dropped on a substrate on which a photoresist film is formed of the resin composition of the present invention, and then water droplets on the substrate are dropped at a rate of 10 μL / min. This means the contact angle between the liquid surface and the substrate when sucked in step (b). Specifically, as shown in the below-mentioned Example, it can measure using "DSA-10" by KRUS.

<Polymer (A)>
The polymer (A) containing a fluorinated alkyl group in the present invention, having a fluorine content of 3 atom% or more and becoming alkali-soluble by the action of an acid [hereinafter also referred to simply as “polymer (A)”. ] Is an alkali-insoluble or alkali-insoluble polymer that becomes alkali-soluble by the action of an acid. The term “alkali-insoluble or alkali-insoluble” as used herein refers to alkali development conditions employed when a resist pattern is formed from a photoresist film formed from a radiation-sensitive resin composition containing the polymer (A). Thus, when a film using only the polymer (A) instead of the photoresist film is developed, it means that 50% or more of the initial film thickness of the film remains after development.

Since this polymer (A) contains a fluorinated alkyl group in the structure, when added as a component of the resist composition, when the photoresist film is formed, the polymer (A) in the film is oil-repellent. Due to the feature, the distribution tends to be higher on the surface of the photoresist film, and elution of an acid generator, an acid diffusion controller, and the like into an immersion medium such as water during immersion exposure can be suppressed.
Further, due to the water-repellent characteristics of the polymer (A), the advancing contact angle between the photoresist film and the immersion medium falls within a predetermined range, and the occurrence of bubble defects can be suppressed. Furthermore, the receding contact angle between the photoresist film and the immersion medium is increased, and high-speed scanning exposure is possible without leaving water droplets. Moreover, by using together with the conventional upper layer film for immersion, elution is further reduced, and the resist has high water repellency, and the occurrence of defects derived from the immersion medium such as watermarks and bubble defects can be further suppressed.

Further, the fluorine content of the fluorinated alkyl group contained in the polymer (A) is 3 atom% or more, preferably 3 to 50 atom%, more preferably, when the whole polymer (A) is 100 atom%. 5 to 30 atom%.
This fluorine content can be measured by ¹³ C-NMR.

  The polymer (A) in the present invention is not particularly limited as long as it contains a fluorinated alkyl group and becomes alkali-soluble by the action of an acid. For example, a monomer containing a fluorinated alkyl group in the structure What contains the repeating unit derived from and the repeating unit containing the frame | skeleton which becomes alkali-soluble by the effect | action of an acid is preferable.

Monomers containing a fluorinated alkyl group in the structure include those containing a fluorinated alkyl group in the main chain, those containing a fluorinated alkyl group in the side chain, and those containing a fluorinated alkyl group in the main chain and the side chain. Is mentioned.
Examples of the monomer containing a fluorinated alkyl group in the main chain include an α-trifluoromethyl acrylate compound, a β-trifluoromethyl acrylate compound, an α, β-trifluoromethyl acrylate compound, and one or more kinds of vinyl moieties. And compounds in which hydrogen is substituted with a fluorinated alkyl group such as a trifluoromethyl group.

  Examples of the monomer containing a fluorinated alkyl group in the side chain include those in which the side chain of an alicyclic olefin compound such as norbornene is a fluorinated alkyl group or a derivative thereof, the side of acrylic acid or methacrylic acid. Examples thereof include ester compounds in which the chain is a fluorinated alkyl group or a derivative thereof, and one or more olefin side chains (parts not including a double bond) being a fluorinated alkyl group or a derivative thereof.

  Furthermore, examples of the monomer containing a fluorinated alkyl group in the main chain and the side chain include α-trifluoromethylacrylic acid, β-trifluoromethylacrylic acid, α, β-trifluoromethylacrylic acid, and the like. Ester compound whose chain is a fluorinated alkyl group or a derivative thereof. The side chain of a compound in which hydrogen of one or more vinyl sites is substituted with a fluorinated alkyl group such as a trifluoromethyl group is substituted with a fluorinated alkyl group or a derivative thereof. The hydrogen bonded to the double bond of one or more alicyclic olefin compounds is replaced with a fluorinated alkyl group such as a trifluoromethyl group, and the side chain is a fluorinated alkyl group or a derivative thereof. And the like. In addition, an alicyclic olefin compound here shows the compound in which a part of ring is a double bond.

  In the present invention, the repeating unit derived from a monomer containing a fluorinated alkyl group in the structure is not particularly limited as shown above, but the repeating unit represented by the following general formula (1) (Hereinafter referred to as “repeating unit (1)”).

[In General Formula (1), R ¹ represents hydrogen, a methyl group, or a trifluoromethyl group. A represents a single bond, a methylene group, an alkylene group having 2 to 6 carbon atoms, an oxygen atom, a sulfur atom, a carbonyloxy group, an oxycarbonyl group, an amide group, a sulfonylamide group, or a urethane group, and R ² represents at least one or more. Or a linear or branched alkyl group having 1 to 6 carbon atoms, a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms, or a derivative thereof. ]

Examples of the linear or branched alkyl group having 1 to 6 carbon atoms and containing at least one fluorine atom in R ² of the general formula (1) include, for example, a methyl group, an ethyl group, and a 1-propyl group. 2-propyl group, 1-butyl group, 2-butyl group, 2- (2-methylpropyl) group, 1-pentyl group, 2-pentyl group, 3-pentyl group, 1- (2-methylbutyl) group, 1- (3-methylbutyl) group, 2- (2-methylbutyl) group, 2- (3-methylbutyl) group, neopentyl group, 1-hexyl group, 2-hexyl group, 3-hexyl group, 1- (2- Methylpentyl) group, 1- (3-methylpentyl) group, 1- (4-methylpentyl) group, 2- (2-methylpentyl) group, 2- (3-methylpentyl) group, 2- (4- Methylpentyl) group, 3- (2-methylpene) A partially fluorinated or perfluoroalkyl group of a linear or branched alkyl group such as a (til) group and a 3- (3-methylpentyl) group.

In addition, as R ² in the general formula (1), a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms containing at least one fluorine atom or a derivative thereof includes a cyclopentyl group, a cyclopentylmethyl group, 1- (1-cyclopentylethyl) group, 1- (2-cyclopentylethyl) group, cyclohexyl group, cyclohexylmethyl group, 1- (1-cyclohexylethyl) group, 1- (2-cyclohexylethyl group), cycloheptyl group A partially fluorinated or perfluoroalkyl group of an alicyclic alkyl group such as a cycloheptylmethyl group, a 1- (1-cycloheptylethyl) group, a 1- (2-cycloheptylethyl) group, and a 2-norbornyl group. Can be mentioned.

Examples of the monomer that gives the repeating unit (1) include trifluoromethyl (meth) acrylate, 2,2,2-trifluoroethyl (meth) acrylate, perfluoroethyl (meth) acrylate, perfluoro n-propyl ( (Meth) acrylate, perfluoro i-propyl (meth) acrylate, perfluoro n-butyl (meth) acrylate, perfluoro i-butyl (meth) acrylate, perfluoro t-butyl (meth) acrylate, perfluorocyclohexyl (meth) Acrylate, 2- (1,1,1,3,3,3-hexafluoro) propyl (meth) acrylate, 1- (2,2,3,3,4,4,5,5-octafluoro) pentyl ( (Meth) acrylate, 1- (2,2,3,3,4,4,5,5-octafluoro) he Sil (meth) acrylate, perfluorocyclohexylmethyl (meth) acrylate, 1- (2,2,3,3,3-pentafluoro) propyl (meth) acrylate, 1- (2,2,3,3,4,4) 4,4-Heptafluoro) penta (meth) acrylate, 1- (3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10- Heptadecafluoro) decyl (meth) acrylate, 1- (5-trifluoromethyl-3,3,4,4,5,6,6,6-octafluoro) hexyl (meth) acrylate and the like.
Among these monomers, 2,2,2-trifluoroethyl (meth) acrylate, 2- (1,1,1,3,3,3-hexafluoro) propyl (meth) acrylate, 1- ( 2,2,3,3,4,4,5,5-octafluoro) hexyl (meth) acrylate, 1- (2,2,3,3,4,4,4-heptafluoro) penta (meth) acrylate And at least one selected from perfluorocyclohexyl (meth) acrylate.

  The said polymer (A) may contain only 1 type of this repeating unit (1), and may contain 2 or more types.

The repeating unit containing a skeleton that becomes alkali-soluble by the action of the acid is not particularly limited, but a repeating unit represented by the following general formula (2) (hereinafter referred to as “repeating unit (2)”) is preferable. . By containing this repeating unit (2), a predetermined advancing contact angle can be obtained at the time of exposure, and alkali solubility becomes possible at the time of development. That is, at the time of exposure, the structure of the general formula (2) is maintained, and it has a predetermined advancing contact angle without losing the effect of the repeating unit derived from the monomer containing the fluorinated alkyl group in the structure, Due to the action, the —C (R ⁴ ) ₃ moiety is eliminated from the structure of the general formula (2), so that it becomes alkali-soluble.

[In General Formula (2), R ³ represents hydrogen, a methyl group, or a trifluoromethyl group. Each R ⁴ independently represents a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof, or a linear or branched alkyl group having 1 to 4 carbon atoms. ]

Examples of the monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms in R ⁴ of the general formula (2) include norbornane, tricyclodecane, tetracyclododecane, adamantane, cyclobutane, cyclopentane, cyclohexane, Groups composed of alicyclic rings derived from cycloalkanes such as cycloheptane and cyclooctane; groups composed of these alicyclic rings include, for example, methyl group, ethyl group, n-propyl group, i-propyl group 1 or more or 1 or more of linear, branched or cyclic alkyl groups having 1 to 4 carbon atoms such as n-butyl group, 2-methylpropyl group, 1-methylpropyl group and t-butyl group. Examples include substituted groups. Further, any two R ⁴ may be bonded to each other to form a divalent alicyclic hydrocarbon group or a derivative thereof together with the carbon atom to which each R ⁴ is bonded.
Among these alicyclic hydrocarbon groups, a group consisting of an alicyclic ring derived from norbornane, tricyclodecane, tetracyclododecane, adamantane, cyclopentane or cyclohexane, or a group consisting of these alicyclic rings is described above. A group substituted with an alkyl group is preferred.

Examples of the linear or branched alkyl group having 1 to 4 carbon atoms in R ⁴ of the general formula (2) include, for example, methyl group, ethyl group, n-propyl group, i-propyl group, n- A butyl group, 2-methylpropyl group, 1-methylpropyl group, t-butyl group and the like can be mentioned.

In the general formula (2), preferred examples of —C (R ⁴ ) ₃ include t-butyl group, 1-n- (1-ethyl-1-methyl) propyl group, 1-n- (1,1- Dimethyl) propyl group, 1-n- (1,1-dimethyl) butyl group, 1-n- (1,1-dimethyl) pentyl group, 1- (1,1-diethyl) propyl group, 1-n- ( 1,1-diethyl) butyl group, 1-n- (1,1-diethyl) pentyl group, 1- (1-methyl) cyclopentyl group, 1- (1-ethyl) cyclopentyl group, 1- (1-n- Propyl) cyclopentyl group, 1- (1-i-propyl) cyclopentyl group, 1- (1-methyl) cyclohexyl group, 1- (1-ethyl) cyclohexyl group, 1- (1-n-propyl) cyclohexyl group, 1 -(1-i-propyl) cyclohexyl group, 1 {1-methyl-1- (2-norbornyl)} ethyl group, 1- {1-methyl-1- (2-tetracyclodecanyl)} ethyl group, 1- {1-methyl-1- (1-adamantyl) )} Ethyl group, 2- (2-methyl) norbornyl group, 2- (2-ethyl) norbornyl group, 2- (2-n-propyl) norbornyl group, 2- (2-i-propyl) norbornyl group, 2 -(2-methyl) tetracyclodecanyl group, 2- (2-ethyl) tetracyclodecanyl group, 2- (2-n-propyl) tetracyclodecanyl group, 2- (2-i-propyl) tetra Cyclodecanyl group, 1- (1-methyl) adamantyl group, 1- (1-ethyl) adamantyl group, 1- (1-n-propyl) adamantyl group, 1- (1-i-propyl) adamantyl group, A group consisting of these alicyclic rings is For example, straight chain having 1 to 4 carbon atoms such as methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, 2-methylpropyl group, 1-methylpropyl group, t-butyl group, etc. And groups substituted with one or more branched or cyclic alkyl groups.

Preferred monomers that give the repeating unit (2) include (meth) acrylic acid 2-methyladamantyl-2-yl ester, (meth) acrylic acid 2-methyl-3-hydroxyadamantyl-2-yl ester, (Meth) acrylic acid 2-ethyladamantyl-2-yl ester, (meth) acrylic acid 2-ethyl-3-hydroxyadamantyl-2-yl ester, (meth) acrylic acid 2-n-propyladamantyl-2-yl ester, (Meth) acrylic acid 2-isopropyladamantyl-2-yl ester, (meth) acrylic acid-2-methylbicyclo [2.2.1] hept-2-yl ester, (meth) acrylic acid-2-ethylbicyclo [ 2.2.1] Hept-2-yl ester, (meth) acrylic acid-8-methyltricyclo [5.2.1] 0 ^2,6] decan-8-yl ester, (meth) ethyl-8-acrylic acid tricyclo [5.2.1.0 ^2,6] decan-8-yl ester, (meth) acrylic acid-4- Methyltetracyclo [6.2.1 ^3,6 . 0 ^2,7 ] dodecan-4-yl ester, (meth) acrylic acid-4-ethyltetracyclo [6.2.1 ^3,6 . 0 ^2,7 ] dodecan-4-yl ester, (meth) acrylic acid 1- (bicyclo [2.2.1] hept-2-yl) -1-methylethyl ester, (meth) acrylic acid 1- (tricyclo [5.2.1.0 ^2,6 ] decan-8-yl) -1-methylethyl ester, (meth) acrylic acid 1- (tetracyclo [6.2.1 ^3,6.0 0.0 ^2,7 ] dodecane -4-yl) -1-methylethyl ester, (meth) acrylic acid 1- (adamantan-1-yl) -1-methylethyl ester, (meth) acrylic acid 1- (3-hydroxyadamantan-1-yl) -1-methyl ethyl ester, (meth) acrylic acid 1,1-dicyclohexylethyl ester, (meth) acrylic acid 1,1-di (bicyclo [2.2.1] hept-2-yl) ethyl ester, Meth) acrylic acid 1,1-di (tricyclo [5.2.1.0 ^2,6] decan-8-yl) ethyl ester, (meth) acrylic acid 1,1-di (tetracyclo [6.2.1 ^3,6 .0 ^2,7] dodecane-4-yl) ethyl ester, (meth) acrylic acid 1,1-di (adamantan-1-yl) ethyl ester, (meth) acrylic acid 1-methyl-1-cyclopentyl Examples include esters, (meth) acrylic acid 1-ethyl-1-cyclopentyl ester, (meth) acrylic acid 1-methyl-1-cyclohexyl ester, (meth) acrylic acid 1-ethyl-1-cyclohexyl ester, and the like.

  Among these monomers, (meth) acrylic acid 2-methyladamantyl-2-yl ester, (meth) acrylic acid 2-ethyladamantyl-2-yl ester, (meth) acrylic acid-2-methylbicyclo [ 2.2.1] Hept-2-yl ester, (meth) acrylic acid-2-ethylbicyclo [2.2.1] hept-2-yl ester, (meth) acrylic acid 1- (bicyclo [2.2 .1] Hept-2-yl) -1-methylethyl ester, (meth) acrylic acid 1- (adamantan-1-yl) -1-methylethyl ester, (meth) acrylic acid 1-methyl-1-cyclopentyl ester (Meth) acrylic acid 1-ethyl-1-cyclopentyl ester, (meth) acrylic acid 1-methyl-1-cyclohexyl ester, (meth) acrylic acid 1- Chill-1-cyclohexyl ester, and the like are particularly preferable.

  The said polymer (A) may contain only 1 type of this repeating unit (2), and may contain 2 or more types.

  In the polymer (A), in addition to the above-mentioned repeating unit containing a fluorinated alkyl group in the structure and the repeating unit (2), for example, a lactone structure, a hydroxyl group, a carboxyl group in order to improve alkali solubility Such as a repeating unit containing an alicyclic compound or a repeating unit derived from an aromatic compound to increase etching resistance, a repeating unit derived from an aromatic compound to suppress reflection from the substrate, etc. One or more kinds of “other repeating units” can be contained.

  Examples of the monomer that generates the repeating unit containing the lactone structure (hereinafter referred to as “repeating unit (3)”) include the following general formulas (3-1) to (3-6).

In formulas (3-1) to (3-6), R ⁵ represents a hydrogen atom or a methyl group, and R ⁶ represents a hydrogen atom or an alkyl which may have a substituent having 1 to 4 carbon atoms. Represents a group, and R ⁷ represents a hydrogen atom or a methoxy group. A represents a single bond or a methylene group, and B represents an oxygen atom or a methylene group. Further, l represents an integer of 1 to 3, and m is 0 or 1.
Examples of the alkyl group which may have a substituent having 1 to 4 carbon atoms in R ⁶ of the general formula (3-1) include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, Examples include n-butyl group, 2-methylpropyl group, 1-methylpropyl group, t-butyl group and the like.

Specific examples of a preferable monomer that gives the repeating unit (3) include (meth) acrylic acid-5-oxo-4-oxa-tricyclo [4.2.1.0 ^3,7 ] non-2-yl. Ester, (meth) acrylic acid-9-methoxycarbonyl-5-oxo-4-oxa-tricyclo [4.2.1.0 ^3,7 ] non-2-yl ester, (meth) acrylic acid-5-oxo -4-oxa-tricyclo [5.2.1.0 ^3,8 ] dec-2-yl ester, (meth) acrylic acid-10-methoxycarbonyl-5-oxo-4-oxa-tricyclo [5.2. 1.0 ^3,8 ] non-2-yl ester, (meth) acrylic acid-6-oxo-7-oxa-bicyclo [3.2.1] oct-2-yl ester, (meth) acrylic acid-4 -Methoxycarbonyl-6- Xo-7-oxa-bicyclo [3.2.1] oct-2-yl ester, (meth) acrylic acid-7-oxo-8-oxa-bicyclo [3.3.1] oct-2-yl ester, (Meth) acrylic acid-4-methoxycarbonyl-7-oxo-8-oxa-bicyclo [3.3.1] oct-2-yl ester, (meth) acrylic acid-2-oxotetrahydropyran-4-yl ester , (Meth) acrylic acid-4-methyl-2-oxotetrahydropyran-4-yl ester, (meth) acrylic acid-4-ethyl-2-oxotetrahydropyran-4-yl ester, (meth) acrylic acid-4 -Propyl-2-oxotetrahydropyran-4-yl ester, (meth) acrylic acid-5-oxotetrahydrofuran-3-yl ester, (meth) acrylic Luric acid-2,2-dimethyl-5-oxotetrahydrofuran-3-yl ester, (meth) acrylic acid-4,4-dimethyl-5-oxotetrahydrofuran-3-yl ester, (meth) acrylic acid-2-oxo Tetrahydrofuran-3-yl ester, (meth) acrylic acid-4,4-dimethyl-2-oxotetrahydrofuran-3-yl ester, (meth) acrylic acid-5,5-dimethyl-2-oxotetrahydrofuran-3-yl ester , (Meth) acrylic acid-2-oxotetrahydrofuran-3-yl ester, (meth) acrylic acid-5-oxotetrahydrofuran-2-ylmethyl ester, (meth) acrylic acid-3,3-dimethyl-5-oxotetrahydrofuran -2-ylmethyl ester, (meth) acrylic acid-4,4-dimethyl 5-oxo tetrahydrofuran-2-yl methyl ester.

  Examples of the repeating unit containing the alicyclic compound (hereinafter referred to as “repeating unit (4)”) include a repeating unit represented by the following general formula (4).

In [Formula (4), R ⁸ is a hydrogen atom, a methyl group, or trifluoromethyl group, X is an alicyclic hydrocarbon group having 4 to 20 carbon atoms. ]

Examples of the alicyclic hydrocarbon group having 4 to 20 carbon atoms in X of the general formula (4) include cyclobutane, cyclopentane, cyclohexane, bicyclo [2.2.1] heptane, and bicyclo [2.2. 2] Octane, tricyclo [5.2.1.0 ^2,6 ] decane, tetracyclo [6.2.1.1 ^3,6 . And hydrocarbon groups composed of alicyclic rings derived from cycloalkanes such as 0 ^2,7 ] dodecane and tricyclo [3.3.1.1 ^3,7 ] decane.
These cycloalkane-derived alicyclic rings may have a substituent, for example, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, 2-methylpropyl group. , 1-methylpropyl group, t-butyl group, etc. may be substituted with one or more of linear, branched or cyclic alkyl groups having 1 to 4 carbon atoms. These are not limited to those substituted with these alkyl groups, but may be those substituted with a hydroxyl group, a cyano group, a hydroxyalkyl group having 1 to 10 carbon atoms, a carboxyl group, or oxygen. .

Preferred monomers that give the repeating unit (4) include (meth) acrylic acid-bicyclo [2.2.1] hept-2-yl ester, (meth) acrylic acid-bicyclo [2.2.2]. Oct-2-yl ester, (meth) acrylic acid-tricyclo [5.2.1.0 ^2,6 ] dec-7-yl ester, (meth) acrylic acid-tetracyclo [6.2.1.13 ^{, 6} . 0 ^2,7 ] dodec-9-yl ester, (meth) acrylic acid-tricyclo [3.3.1.1 ^3,7 ] dec-1-yl ester, (meth) acrylic acid-tricyclo [3.3. ^1.1,7 ] dec-2-yl ester and the like.

  Moreover, as a preferable monomer which produces the repeating unit (henceforth "repeating unit (5)") derived from the said aromatic compound, styrene, (alpha) -methylstyrene, 2-methylstyrene, 3-methyl-styrene, for example Methylstyrene, 4-methylstyrene, 2-methoxystyrene, 3-methoxystyrene, 4-methoxystyrene, 4- (2-t-butoxycarbonylethyloxy) styrene 2-hydroxystyrene, 3-hydroxystyrene, 4-hydroxystyrene 2-hydroxy-α-methylstyrene, 3-hydroxy-α-methylstyrene, 4-hydroxy-α-methylstyrene, 2-methyl-3-hydroxystyrene, 4-methyl-3-hydroxystyrene, 5-methyl- 3-hydroxystyrene, 2-methyl-4-hydroxystyrene, 3-methyl 4-hydroxystyrene, 3,4-dihydroxystyrene, 2,4,6-trihydroxystyrene, 4-t-butoxystyrene, 4-t-butoxy-α-methylstyrene, 4- (2-ethyl-2) -Propoxy) styrene, 4- (2-ethyl-2-propoxy) -α-methylstyrene, 4- (1-ethoxyethoxy) styrene, 4- (1-ethoxyethoxy) -α-methylstyrene, (meth) acrylic Acid phenyl, benzyl (meth) acrylate, acenaphthylene, 5-hydroxyacenaphthylene, 1-vinylnaphthalene, 2-vinylnaphthalene, 2-hydroxy-6-vinylnaphthalene, 1-naphthyl (meth) acrylate, 2-naphthyl ( (Meth) acrylate, 1-naphthylmethyl (meth) acrylate, 1-anthryl (meth) acrylate And 2-anthryl (meth) acrylate, 9-anthryl (meth) acrylate, 9-anthrylmethyl (meth) acrylate, 1-vinylpyrene and the like.

  In the polymer (A) in the present invention, the “other repeating unit” represented by the repeating unit (3), the repeating unit (4), and the repeating unit (5) may be contained alone, Two or more kinds may be contained.

  In addition, the polymer (A) in the present invention includes, for example, a polymerizable unsaturated monomer corresponding to each predetermined repeating unit such as hydroperoxides, dialkyl peroxides, diacyl peroxides, and azo compounds. It can be produced by using a radical polymerization initiator and polymerizing in an appropriate solvent in the presence of a chain transfer agent as required.

Examples of the solvent used for the polymerization include alkanes such as n-pentane, n-hexane, n-heptane, n-octane, n-nonane, and n-decane; cyclohexane, cycloheptane, cyclooctane, decalin, Cycloalkanes such as norbornane; aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, cumene; halogenated hydrocarbons such as chlorobutanes, bromohexanes, dichloroethane, hexamethylene dibromide, chlorobenzene; ethyl acetate Saturated carboxylic acid esters such as n-butyl acetate, i-butyl acetate and methyl propionate; ketones such as acetone, 2-butanone, 4-methyl-2-pentanone and 2-heptanone; tetrahydrofuran, dimethoxyethanes, Ethers such as diethoxyethanes; Methanol, ethanol, 1-propanol, 2-propanol, may be mentioned alcohols such as 4-methyl-2-pentanol. These solvents can be used alone or in admixture of two or more.
The reaction temperature in the polymerization is usually 40 to 150 ° C., preferably 50 to 120 ° C., and the reaction time is usually 1 to 48 hours, preferably 1 to 24 hours.

In addition, the weight average molecular weight (hereinafter referred to as “Mw”) in terms of polystyrene by gel permeation chromatography (GPC) of the polymer (A) in the present invention is preferably 1,000 to 50,000, more preferably. Preferably it is 1,000-40,000, More preferably, it is 1,000-30,000. When Mw of this polymer (A) is less than 1,000, a sufficient advancing contact angle may not be obtained. On the other hand, when this Mw exceeds 50,000, the developability when resist is formed tends to be lowered.
Further, the ratio (Mw / Mn) of Mw of the polymer (A) and polystyrene-reduced number average molecular weight (hereinafter referred to as “Mn”) by GPC method is usually 1 to 5, preferably 1 to 4. is there.

The polymer (A) is preferably as low as possible in the content of impurities such as halogen and metal, whereby the sensitivity, resolution, process stability, pattern shape, etc. when used as a resist can be further improved.
Examples of the purification method for the polymer (A) include chemical purification methods such as washing with water and liquid-liquid extraction, and combinations of these chemical purification methods and physical purification methods such as ultrafiltration and centrifugation. Etc.

In this invention, a polymer (A) can be used individually or in mixture of 2 or more types.
In the present invention, the content of the polymer (A) is such that the photoresist film can secure a sufficient advancing contact angle and can sufficiently suppress elution of an acid generator and the like from the photoresist film. When the total of the polymer (A) and the resin (B) described later is 100% by mass, it is preferably 0.1% by mass or more, more preferably 0.1 to 40% by mass, and still more preferably 0. It is 5-35 mass%. When the content of the polymer (A) is less than 0.1% by mass, a photoresist film having a predetermined advancing contact angle cannot be formed, and elution of an acid generator or the like from the photoresist film cannot be suppressed. Tend. On the other hand, when the content exceeds 40% by mass, the depth of focus of the isolated line may be reduced or a development defect may occur.

<Resin (B)>
Resin (B) which becomes alkali-soluble by the action of acid in the present invention and has a fluorine content of less than 3 atom% [hereinafter also referred to simply as “resin (B)”. ] Is an alkali-insoluble or hardly alkali-soluble resin that becomes alkali-soluble by the action of an acid. The term “alkali-insoluble or alkali-insoluble” as used herein refers to an alkali development condition employed when forming a resist pattern from a photoresist film formed from a radiation-sensitive resin composition containing the resin (B). When a film using only the resin (B) instead of the photoresist film is developed, it means that 50% or more of the initial film thickness of the film remains after development.

  Examples of the resin (B) include a resin having an alicyclic skeleton such as a norbornane ring in a main chain obtained by polymerizing a norbornene derivative or the like, and a main chain obtained by copolymerizing a norbornene derivative and maleic anhydride. A resin having a norbornane ring and a maleic anhydride derivative, a resin having a norbornane ring and a (meth) acryl skeleton mixed in a main chain obtained by copolymerizing a norbornene derivative and a (meth) acrylic compound, a norbornene derivative and maleic anhydride, ( Resin in which norbornane ring, maleic anhydride derivative and (meth) acrylic skeleton are mixed in the main chain obtained by copolymerizing (meth) acrylic compound, main chain obtained by copolymerizing (meth) acrylic compound is (meth) Examples thereof include acrylic skeleton resins. Note that “(meth) acryl” means either “acryl” or “methacryl” or both.

Among the resins (B), preferred examples include those containing a repeating unit containing a skeleton that becomes alkali-soluble by the action of an acid and a repeating unit containing a lactone structure.
Examples of the repeating unit containing a skeleton that becomes alkali-soluble by the action of an acid include the aforementioned repeating unit (2). In addition, the preferable monomer which gives this repeating unit (2) is the same as that of the above-mentioned thing.
Moreover, resin (B) may contain only 1 type of this repeating unit (2), and may contain 2 or more types.

  In the resin (B), the content of the repeating unit (2) is preferably from 10 to 70 mol%, more preferably from 15 to 70% when the total repeating units in the resin (B) are 100 mol%. It is 60 mol%, More preferably, it is 20-50 mol%. When the content rate of this repeating unit (2) is less than 10 mol%, there exists a possibility that the resolution as a resist may fall. On the other hand, when this content rate exceeds 70 mol%, the developability and exposure margin may be deteriorated.

Moreover, as a repeating unit containing a lactone structure, the above-mentioned repeating unit (3) can be mentioned. In addition, the preferable monomer which gives this repeating unit (3) is the same as that of the above-mentioned thing.
Moreover, resin (B) may contain only 1 type of this repeating unit (3), and may contain 2 or more types.

  In the resin (B), the content of the repeating unit (3) is preferably 5 to 85 mol%, more preferably 10 to 70, when the total repeating unit in the resin (B) is 100 mol%. It is mol%, More preferably, it is 15-60 mol%. When the content of the repeating unit (3) is less than 5 mol%, developability and exposure margin tend to be deteriorated. On the other hand, when this content rate exceeds 85 mol%, there exists a tendency for the solubility to the solvent of resin (B) to deteriorate, and the resolution to deteriorate.

The resin (B) in the present invention may contain one or more repeating units other than the repeating units (2) and (3) (hereinafter referred to as “other repeating units”).
As other repeating units, the repeating unit (4) containing the aforementioned alicyclic compound, the repeating unit derived from the aforementioned aromatic compound (5), and the repeating unit represented by the following general formula (5) (hereinafter referred to as “repeating unit”) , Repeating unit (6)), repeating unit represented by the following general formula (6) (hereinafter referred to as repeating unit (7)), and the like. In addition, the preferable monomer which gives repeating unit (4) and (5) is the same as that of the above-mentioned respectively.

[In General Formula (5), R ⁹ represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a trifluoromethyl group, or a hydroxymethyl group, and R ¹⁰ represents a divalent organic group. ]

Examples of the alkyl group having 1 to 4 carbon atoms in R ⁹ of the general formula (5) include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, a 2-methylpropyl group, 1 -Alkyl groups, such as a methyl propyl group and t-butyl group, are mentioned.
In addition, the divalent organic group in R ¹⁰ of the general formula (5) is preferably a divalent hydrocarbon group, and among the divalent hydrocarbon groups, a chain or cyclic hydrocarbon group is preferable. It may be a glycol group or an alkylene ester group.

Preferred as R ¹⁰ is a methylene group, an ethylene group, a propylene group such as a 1,3-propylene group or a 1,2-propylene group, a tetramethylene group, a pentamethylene group, a hexamethylene group, a heptamethylene group, an octamethylene group. , Nonamethylene group, decamethylene group, undecamethylene group, dodecamethylene group, tridecamethylene group, tetradecamethylene group, pentadecamethylene group, hexadecamethylene group, heptacamethylene group, octadecamethylene group, nonadecamethylene group , Insalene group, 1-methyl-1,3-propylene group, 2-methyl-1,3-propylene group, 2-methyl-1,2-propylene group, 1-methyl-1,4-butylene group, 2-methyl -1,4-butylene group, methylidene group, ethylidene group, propylidene group, or 2-propylene Saturated chain hydrocarbon groups such as redene groups, cyclobutylene groups such as 1,3-cyclobutylene groups, cyclopentylene groups such as 1,3-cyclopentylene groups, and cyclohexylene groups such as 1,4-cyclohexylene groups Group, monocyclic hydrocarbon ring group such as cycloalkylene group having 3 to 10 carbon atoms such as cyclooctylene group such as 1,5-cyclooctylene group, 1,4-norbornylene group or 2,5-norbornylene group Such as norbornylene group, 1,5-adamantylene group, 2,6-adamantylene group, etc., a bridged cyclic hydrocarbon ring, such as a 2-4 cyclic hydrocarbon group having 4-30 carbon atoms, such as adamantylene group, etc. Groups and the like.

In particular, when R ¹⁰ contains a divalent aliphatic cyclic hydrocarbon group, an alkylene having 1 to 4 carbon atoms as a spacer between the bistrifluoromethyl-hydroxy-methyl group and the aliphatic cyclic hydrocarbon group. It is preferred to insert a group.
R ¹⁰ is preferably a hydrocarbon group containing a 2,5-norbornylene group, a 1,2-ethylene group, or a propylene group.

Furthermore, as a particularly preferred monomer that gives the repeating unit (6), (meth) acrylic acid (1,1,1-trifluoro-2-trifluoromethyl-2-hydroxy-3-propyl) ester, (meth) ) Acrylic acid (1,1,1-trifluoro-2-trifluoromethyl-2-hydroxy-4-butyl) ester, (meth) acrylic acid (1,1,1-trifluoro-2-trifluoromethyl-) 2-hydroxy-5-pentyl) ester, (meth) acrylic acid (1,1,1-trifluoro-2-trifluoromethyl-2-hydroxy-4-pentyl) ester, (meth) acrylic acid 2-{[ 5- (1 ′, 1 ′, 1′-trifluoro-2′-trifluoromethyl-2′-hydroxy) propyl] bicyclo [2.2.1] heptyl} ester, (meth) acryl Acid 3 - {[8- (1 ', 1', 1'-trifluoro-2'-trifluoromethyl-2'-hydroxy) propyl] tetracyclo [6.2.1.1 ^{3, 6.} 0 ^2,7 ] dodecyl} ester and the like.

[In General Formula (6), R ¹¹ represents hydrogen or a methyl group, Y represents a single bond or a divalent organic group having 1 to 3 carbon atoms, and Z represents a single bond or 1 to 1 carbon atoms independently of each other. 3 represents a divalent organic group, and R ¹² independently represents a hydrogen atom, a hydroxyl group, a cyano group, or a COOR ¹³ group. ]

As a C1-C3 bivalent organic group in Y and Z in General formula (6), a methylene group, ethylene group, and a propylene group are mentioned.
In addition, R ¹³ of the COOR ¹³ group in R ¹² of the general formula (6) is a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or an alicyclic alkyl having 3 to 20 carbon atoms. Represents a group. Examples of the linear or branched alkyl group having 1 to 4 carbon atoms in R ¹³ include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, and a 2-methylpropyl group. , 1-methylpropyl group and t-butyl group.
Examples of the alicyclic alkyl group of said 3 to 20 carbon _atoms, -C _{n H 2n-1} cycloalkyl group (n is an integer of 3 to 20) represented by, for example, cyclopropyl group, cyclobutyl group , Cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group and the like. Furthermore, polycyclic alicyclic alkyl groups such as bicyclo [2.2.1] heptyl group, tricyclo [5.2.1.0 ^2,6 ] decyl group, tetracyclo [6.2.1 ^{3, 6} . 0 ^2,7 ] dodecanyl group, adamantyl group or the like, or one or more of linear, branched or cyclic alkyl groups, or a part of cycloalkyl group or polycyclic alicyclic alkyl group Examples include substituted groups.
In addition, when at least one of the three R ¹² is not a hydrogen atom and Y is a single bond, at least one of the three Z is the divalent organic group having 1 to 3 carbon atoms. Is preferred.

  Preferred monomers for producing the repeating unit (7) include (meth) acrylic acid 3-hydroxyadamantan-1-ylmethyl ester, (meth) acrylic acid 3,5-dihydroxyadamantan-1-ylmethyl ester, (Meth) acrylic acid 3-hydroxy-5-cyanoadamantan-1-ylmethyl ester, (meth) acrylic acid 3-hydroxy-5-carboxyladamantan-1-ylmethyl ester, (meth) acrylic acid 3-hydroxy-5 -Methoxycarbonyladamantan-1-ylmethyl ester, (meth) acrylic acid 3-hydroxymethyladamantan-1-ylmethyl ester, (meth) acrylic acid 3,5-dihydroxymethyladamantan-1-ylmethyl ester, (meth) 3-hydroxy-5-acrylic acid Roxymethyladamantan-1-ylmethyl ester, (meth) acrylic acid 3-cyano-5-hydroxymethyladamantan-1-ylmethyl ester, (meth) acrylic acid 3-hydroxymethyl-5-carboxyladamantan-1-ylmethyl Esters, (meth) acrylic acid 3-hydroxymethyl-5-methoxycarbonyladamantan-1-ylmethyl ester, (meth) acrylic acid 3-cyanoadamantan-1-ylmethyl ester, (meth) acrylic acid 3,5-dicyano Adamantane-1-ylmethyl ester, (meth) acrylic acid 3-cyano-5-carboxyladamantan-1-ylmethyl ester, (meth) acrylic acid 3-cyano-5-methoxycarbonyladamantan-1-ylmethyl ester, ( Meta) acrylic acid 3 Carboxydamantane-1-ylmethyl ester, (meth) acrylic acid 3,5-dicarboxyladamantan-1-ylmethyl ester, (meth) acrylic acid 3-carboxyl-5-methoxycarbonyladamantan-1-ylmethyl ester, ( (Meth) acrylic acid 3-methoxycarbonyladamantan-1-ylmethyl ester, (meth) acrylic acid 3,5-dimethoxycarbonyladamantan-1-ylmethyl ester,

  (Meth) acrylic acid 3-hydroxy-5-methyladamantan-1-yl ester, (meth) acrylic acid 3,5-dihydroxy-7-methyladamantan-1-yl ester, (meth) acrylic acid 3-hydroxy-5 -Cyano-7-methyladamantan-1-yl ester, (meth) acrylic acid 3-hydroxy-5-carboxyl-7-methyladamantan-1-yl ester, (meth) acrylic acid 3-hydroxy-5-methoxycarbonyl- 7-methyladamantan-1-yl ester, (meth) acrylic acid 3-hydroxymethyl-5-methyladamantan-1-yl ester, (meth) acrylic acid 3,5-dihydroxymethyl-7-methyladamantan-1-yl Ester, (meth) acrylic acid 3-hydroxy-5-hydroxymethyl- -Methyladamantan-1-yl ester, (meth) acrylic acid 3-cyano-5-hydroxymethyl-7-methyladamantan-1-yl ester, (meth) acrylic acid 3-hydroxymethyl-5-carboxyl-7-methyl Adamantan-1-yl ester, (meth) acrylic acid 3-hydroxymethyl-5-methoxycarbonyl-7-methyladamantan-1-yl ester, (meth) acrylic acid 3-cyano-5-methyladamantan-1-yl ester (Meth) acrylic acid 3,5-dicyano-7-methyladamantan-1-yl ester, (meth) acrylic acid 3-cyano-5-carboxyl-7-methyladamantan-1-yl ester, (meth) acrylic acid 3-cyano-5-methoxycarbonyl-7-methyladamantan-1-y Ester, (meth) acrylic acid 3-carboxyl-5-methyladamantan-1-yl ester, (meth) acrylic acid 3,5-dicarboxyl-7-methyladamantan-1-yl ester, (meth) acrylic acid 3- Carboxyl-5-methoxycarbonyl-7-methyladamantan-1-yl ester, (meth) acrylic acid 3-methoxycarbonyl-5-methyladamantan-1-yl ester, (meth) acrylic acid 3,5-dimethoxycarbonyl-7 -Methyladamantan-1-yl ester,

  (Meth) acrylic acid 3-hydroxy-5-methyladamantan-1-ylmethyl ester, (meth) acrylic acid 3,5-dihydroxy-7-methyladamantan-1-ylmethyl ester, (meth) acrylic acid 3-hydroxy -5-cyano-7-methyladamantan-1-ylmethyl ester, (meth) acrylic acid 3-hydroxy-5-carboxyl-7-methyladamantan-1-ylmethyl ester, (meth) acrylic acid 3-hydroxy-5 -Methoxycarbonyl-7-methyladamantan-1-ylmethyl ester, (meth) acrylic acid 3-hydroxymethyl-5-methyladamantan-1-ylmethyl ester, (meth) acrylic acid 3,5-dihydroxymethyl-7- Methyl adamantane-1-ylmethyl ester, (meth) acrylic Acid 3-hydroxy-5-hydroxymethyl-7-methyladamantan-1-ylmethyl ester, (meth) acrylic acid 3-cyano-5-hydroxymethyl-7-methyladamantan-1-ylmethyl ester, (meth) acrylic Acid 3-hydroxymethyl-5-carboxyl-7-methyladamantan-1-ylmethyl ester, (meth) acrylic acid 3-hydroxymethyl-5-methoxycarbonyl-7-methyladamantan-1-ylmethyl ester, (meth) Acrylic acid 3-cyano-5-methyladamantan-1-ylmethyl ester, (meth) acrylic acid 3,5-dicyano-7-methyladamantan-1-ylmethyl ester, (meth) acrylic acid 3-cyano-5- Carboxyl-7-methyladamantan-1-ylmethyl ester, (Meth) acrylic acid 3-cyano-5-methoxycarbonyl-7-methyladamantan-1-ylmethyl ester, (meth) acrylic acid 3-carboxyl-5-methyladamantan-1-ylmethyl ester, (meth) acrylic acid 3 , 5-Dicarboxyl-7-methyladamantan-1-ylmethyl ester, (meth) acrylic acid 3-carboxyl-5-methoxycarbonyl-7-methyladamantan-1-ylmethyl ester, (meth) acrylic acid 3-methoxy Carbonyl-5-methyladamantan-1-ylmethyl ester, (meth) acrylic acid 3,5-dimethoxycarbonyl-7-methyladamantan-1-ylmethyl ester,

  (Meth) acrylic acid 3-hydroxy-5,7-dimethyladamantan-1-yl ester, (meth) acrylic acid 3-hydroxymethyl-5,7-dimethyladamantan-1-yl ester, (meth) acrylic acid 3- Cyano-5,7-dimethyladamantan-1-yl ester, (meth) acrylic acid 3-carboxyl-5,7-dimethyladamantan-1-yl ester, (meth) acrylic acid 3-methoxycarbonyl-5,7-dimethyl Adamantane-1-yl ester, (meth) acrylic acid 3-hydroxy-5,7-dimethyladamantan-1-ylmethyl ester, (meth) acrylic acid 3-hydroxymethyl-5,7-dimethyladamantan-1-ylmethyl Ester, (meth) acrylic acid 3-cyano-5,7-dimethyladamantane-1 Ylmethyl ester, (meth) acrylic acid 3-carboxyl-5,7-dimethyladamantan-1-ylmethyl ester, (meth) acrylic acid 3-methoxycarbonyl-5,7-dimethyladamantan-1-ylmethyl ester, etc. Can be mentioned.

  Among these, particularly preferred monomers include (meth) acrylic acid 3-hydroxyadamantan-1-ylmethyl ester, (meth) acrylic acid 3,5-dihydroxyadamantan-1-ylmethyl ester, and (meth) acrylic. Acid 3-cyanoadamantan-1-ylmethyl ester, (meth) acrylic acid 3-carboxyladamantan-1-ylmethyl ester, (meth) acrylic acid 3-hydroxy-5-methyladamantan-1-yl ester, (meth) Acrylic acid 3,5-dihydroxy-7-methyladamantan-1-yl ester, (meth) acrylic acid 3-hydroxy-5,7-dimethyladamantan-1-yl ester, (meth) acrylic acid 3-carboxyl-5 7-dimethyladamantan-1-yl ester, (meth) acrylic 3-hydroxy-5,7-dimethyl-adamantan-1-yl methyl ester.

In addition to the repeating units (4), (5), (6), and (7), the resin (B) in the present invention has other repeating units (hereinafter referred to as “further repeating units”). May further be contained.
As other repeating units, for example, (meth) acrylic acid esters having a bridged hydrocarbon skeleton such as dicyclopentenyl (meth) acrylate and adamantylmethyl (meth) acrylate; (meth) acrylic acid Carboxyl group-containing esters having a bridged hydrocarbon skeleton of unsaturated carboxylic acid such as carboxynorbornyl, carboxytricyclodecanyl (meth) acrylate, carboxytetracycloundecanyl (meth) acrylate;

  Methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, 2-methylpropyl (meth) acrylate, 1-methyl (meth) acrylate Propyl, t-butyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, cyclopropyl (meth) acrylate, ( (Meth) acrylic acid cyclopentyl, (meth) acrylic acid cyclohexyl, (meth) acrylic acid 4-methoxycyclohexyl, (meth) acrylic acid 2-cyclopentyloxycarbonylethyl, (meth) acrylic acid 2-cyclohexyloxycarbonylethyl, (meth) 2- (4-Methoxycyclohexyl) acrylic acid No bridged hydrocarbon skeleton such as aryloxycarbonyl ethyl (meth) acrylate;

  α-hydroxymethyl acrylate esters such as methyl α-hydroxymethyl acrylate, ethyl α-hydroxymethyl acrylate, n-propyl α-hydroxymethyl acrylate, n-butyl α-hydroxymethyl acrylate; (meth) acrylonitrile , Α-chloroacrylonitrile, crotonnitrile, maleinonitrile, fumaronitrile, mesacononitrile, citraconitrile, itaconnitrile, and other unsaturated nitrile compounds; (meth) acrylamide, N, N-dimethyl (meth) acrylamide, crotonamide, maleinamide , Fumaramide, mesaconamide, citraconic amide, itaconic amide, etc .; N- (meth) acryloylmorpholine, N-vinyl-ε-caprolactam, N-vinylpyrrolidone, vinyl Other nitrogen-containing vinyl compounds such as lysine and vinylimidazole; (meth) acrylic acid, crotonic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, itaconic anhydride, citraconic acid, citraconic anhydride, mesaconic acid Unsaturated carboxylic acids (anhydrides); 2-carboxyethyl (meth) acrylate, 2-carboxypropyl (meth) acrylate, 3-carboxypropyl (meth) acrylate, 4-carboxybutyl (meth) acrylate, Carboxyl group-containing esters having no bridged hydrocarbon skeleton of unsaturated carboxylic acid such as (meth) acrylic acid 4-carboxycyclohexyl;

  1,2-adamantanediol di (meth) acrylate, 1,3-adamantanediol di (meth) acrylate, 1,4-adamantanediol di (meth) acrylate, tricyclodecanyl dimethylol di (meth) acrylate, etc. A polyfunctional monomer having a bridged hydrocarbon skeleton;

Methylene glycol di (meth) acrylate, ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 2,5-dimethyl-2,5-hexanediol di ( (Meth) acrylate, 1,8-octanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, 1,4-bis (2-hydroxypropyl) benzenedi (meth) acrylate, 1,3-bis List units in which a polymerizable unsaturated bond of a polyfunctional monomer such as a polyfunctional monomer having no bridged hydrocarbon skeleton such as (2-hydroxypropyl) benzenedi (meth) acrylate is cleaved Can do.
Among these other repeating units, a unit in which a polymerizable unsaturated bond of a (meth) acrylic acid ester having a bridged hydrocarbon skeleton is cleaved is preferable.

  Resin (B) in the present invention contains only one type of repeating unit selected from these repeating units (4), (5), (6), (7) and other repeating units regardless of the type. It may be contained, or two or more kinds may be contained.

In the resin (B), the content of the repeating unit (4) is usually 30 mol% or less, preferably 25 mol% or less, assuming that all repeating units in the resin (B) are 100 mol%. When the content rate of this repeating unit (4) exceeds 30 mol%, there exists a possibility that a resist pattern shape may deteriorate or the resolution may fall.
Moreover, the content rate of the said repeating unit (5) is 40 mol% or less normally, Preferably it is 30 mol% or less when all the repeating units in resin (B) are 100 mol%. When the content rate of this repeating unit (5) exceeds 40 mol%, there exists a possibility that a radiation transmittance may become low and a pattern profile may deteriorate.
Moreover, the content rate of the said repeating unit (6) is 30 mol% or less normally, Preferably it is 25 mol% or less when all the repeating units in resin (B) are 100 mol%. When the content rate of this repeating unit (6) exceeds 30 mol%, the obtained photoresist film may be easily swollen by an alkali developer.
The content of the repeating unit (7) is usually 30 mol% or less, preferably 25 mol% or less, assuming that all repeating units in the resin (B) are 100 mol%. When the content of the repeating unit (7) exceeds 30 mol%, the resulting photoresist film may be easily swollen by the alkali developer, or the solubility in the alkali developer may be reduced.
Further, the content of other repeating units is usually 50 mol% or less, preferably 40 mol% or less, assuming that all the repeating units in the resin (B) are 100 mol%.

When the resin (B) contains a fluorinated alkyl group, the fluorine content is less than 3 atom%, preferably 0 to 2.9 atom%, when the entire resin (B) is 100 atom%. Preferably it is 0-1.5 atom%.
The fluorine content can be measured in the same manner as described above.

  In addition, the resin (B) in the present invention includes, for example, a polymerizable unsaturated monomer corresponding to each predetermined repeating unit as a radical such as hydroperoxides, dialkyl peroxides, diacyl peroxides, and azo compounds. It can manufacture by superposing | polymerizing in a suitable solvent using a polymerization initiator in presence of a chain transfer agent as needed.

Examples of the solvent used for the polymerization include alkanes such as n-pentane, n-hexane, n-heptane, n-octane, n-nonane, and n-decane; cyclohexane, cycloheptane, cyclooctane, decalin, Cycloalkanes such as norbornane; aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, cumene; halogenated hydrocarbons such as chlorobutanes, bromohexanes, dichloroethanes, hexamethylene dibromide, chlorobenzene; ethyl acetate Saturated carboxylic acid esters such as n-butyl acetate, i-butyl acetate and methyl propionate; ketones such as acetone, 2-butanone, 4-methyl-2-pentanone and 2-heptanone; tetrahydrofuran, dimethoxyethanes, Ethers such as diethoxyethanes It can be mentioned. These solvents can be used alone or in admixture of two or more.
The reaction temperature in the polymerization is usually 40 to 150 ° C., preferably 50 to 120 ° C., and the reaction time is usually 1 to 48 hours, preferably 1 to 24 hours.

The Mw of the resin (B) in the present invention by the GPC method is not particularly limited, but is preferably 1,000 to 100,000, more preferably 1,000 to 30,000, and still more preferably 1,000 to 20 , 000. When the Mw of the resin (B) is less than 1,000, the heat resistance when used as a resist tends to decrease. On the other hand, when the Mw exceeds 100,000, the developability of the resist tends to decrease.
Moreover, ratio (Mw / Mn) of Mw of resin (B) and Mn by GPC method is normally 1-5, Preferably it is 1-3.

Moreover, in resin (B), content of the low molecular-weight component derived from the monomer used when preparing this resin (B) is 0.1 with respect to 100 mass% of this resin in conversion of solid content. It is preferably at most mass%, more preferably at most 0.07 mass%, still more preferably at most 0.05 mass%. When the content is 0.1% by mass or less, it is possible to reduce the amount of eluate in the immersion medium such as water that has been in contact with the immersion exposure. Furthermore, foreign matters are not generated in the resist during resist storage, and coating unevenness does not occur during resist application, and the occurrence of defects during resist pattern formation can be sufficiently suppressed.
Examples of the low molecular weight component derived from the monomer include a monomer, a dimer, a trimer, and an oligomer, and can be a component having an Mw of 500 or less. The components having an Mw of 500 or less can be removed by, for example, chemical purification methods such as washing with water and liquid-liquid extraction, or a combination of these chemical purification methods and physical purification methods such as ultrafiltration and centrifugation. it can. Moreover, it can analyze by the high performance liquid chromatography (HPLC) of resin.
In addition, resin (B) is so preferable that there is little content of impurities, such as a halogen and a metal, Thereby, the sensitivity at the time of using a resist, resolution, process stability, a pattern shape, etc. can be improved further.
Examples of the purification method for the resin (B) include chemical purification methods such as washing with water and liquid-liquid extraction, and combinations of these chemical purification methods with physical purification methods such as ultrafiltration and centrifugation. Can be mentioned.

In this invention, resin (B) can be used individually or in mixture of 2 or more types.
In the present invention, the content of the resin (B) is preferably 99.9% by mass or less when the total of the polymer (A) and the resin (B) is 100% by mass, Preferably it is 60-99.9 mass%, More preferably, it is 65-99.5 mass%. When the content of the resin (B) is in the above range, the photoresist film can secure a sufficient advancing contact angle, and the elution of the acid generator and the like from the photoresist film can be sufficiently suppressed.

<Radiosensitive acid generator (C)>
Radiation-sensitive acid generator (C) in the present invention [hereinafter also simply referred to as “acid generator (C)”. ] Generates an acid upon exposure, and dissociates an acid dissociable group present in the resin component, specifically, an acid dissociable group of the repeating unit (2) by the action of the generated acid ( As a result, the exposed portion of the photoresist film becomes readily soluble in an alkali developer, and has a function of forming a positive resist pattern.
As such an acid generator (C), what contains the compound (henceforth "the acid generator 1") represented by following General formula (7) is preferable.

In the general formula (7), R ¹⁴ represents a hydrogen atom, a fluorine atom, a hydroxyl group, a linear or branched alkyl group having 1 to 10 carbon atoms, or a linear or branched alkoxyl having 1 to 10 carbon atoms. A straight chain or branched alkoxycarbonyl group having 2 to 11 carbon atoms; R ¹⁵ represents a linear or branched alkyl group having 1 to 10 carbon atoms, an alkoxyl group, or a linear, branched or cyclic alkanesulfonyl group having 1 to 10 carbon atoms. Further, R ¹⁶ independently represents a linear or branched alkyl group having 1 to 10 carbon atoms, an optionally substituted phenyl group or an optionally substituted naphthyl group, or two R ¹⁶ is bonded to each other to form a divalent group having 2 to 10 carbon atoms, the divalent group may be substituted, k is an integer of 0 to 2, and X ⁻ is Formula: R ¹⁷ C _n F _2n SO ₃ ⁻ , R ¹⁷ SO ₃ ⁻ (wherein R ¹⁷ represents a fluorine atom or an optionally substituted hydrocarbon group having 1 to 12 carbon atoms, and n is 1 Or an anion represented by the following general formula (8-1) or (8-2), and r is an integer of 0 to 10.
(In each formula, R ¹⁸ are independently of each other a fluorine atom and a linear or branched alkyl group having 1 to 10 carbon atoms, or two R ¹⁸ are bonded to each other, (It is a divalent organic group having 2 to 10 carbon atoms and having a fluorine atom, and the divalent organic group may have a substituent.)

In the general formula (7), examples of the linear or branched alkyl group having 1 to 10 carbon atoms of R ¹⁴ , R ¹⁵ and R ¹⁶ include a methyl group, an ethyl group, an n-propyl group, i- Propyl group, n-butyl group, 2-methylpropyl group, 1-methylpropyl group, t-butyl group, n-pentyl group, neopentyl group, n-hexyl group, n-heptyl group, n-octyl group, 2- Examples thereof include an ethylhexyl group, an n-nonyl group, and an n-decyl group. Of these alkyl groups, a methyl group, an ethyl group, an n-butyl group, a t-butyl group, and the like are preferable.

^Examples of the linear or branched alkoxy group having 1 to 10 carbon atoms of ^{R 14} and ^{R 15,} for example, a methoxy group, an ethoxy group, n- propoxy group, i- propoxy, n- butoxy group, 2-methylpropoxy group, 1-methylpropoxy group, t-butoxy group, n-pentyloxy group, neopentyloxy group, n-hexyloxy group, n-heptyloxy group, n-octyloxy group, 2-ethylhexyloxy Group, n-nonyloxy group, n-decyloxy group and the like. Of these alkoxyl groups, a methoxy group, an ethoxy group, an n-propoxy group, an n-butoxy group, and the like are preferable.

Examples of the linear or branched alkoxycarbonyl group having 2 to 11 carbon atoms of R ¹⁴ include a methoxycarbonyl group, an ethoxycarbonyl group, an n-propoxycarbonyl group, an i-propoxycarbonyl group, and n-butoxy. Carbonyl group, 2-methylpropoxycarbonyl group, 1-methylpropoxycarbonyl group, t-butoxycarbonyl group, n-pentyloxycarbonyl group, neopentyloxycarbonyl group, n-hexyloxycarbonyl group, n-heptyloxycarbonyl group, An n-octyloxycarbonyl group, a 2-ethylhexyloxycarbonyl group, an n-nonyloxycarbonyl group, an n-decyloxycarbonyl group, and the like can be given. Of these alkoxycarbonyl groups, a methoxycarbonyl group, an ethoxycarbonyl group, an n-butoxycarbonyl group, and the like are preferable.

Examples of the linear, branched or cyclic alkanesulfonyl group having 1 to 10 carbon atoms of R ¹⁵ include a methanesulfonyl group, ethanesulfonyl group, n-propanesulfonyl group, n-butanesulfonyl group, tert. -Butanesulfonyl group, n-pentanesulfonyl group, neopentanesulfonyl group, n-hexanesulfonyl group, n-heptanesulfonyl group, n-octanesulfonyl group, 2-ethylhexanesulfonyl group n-nonanesulfonyl group, n-decanesulfonyl Group, cyclopentanesulfonyl group, cyclohexanesulfonyl group and the like. Of these alkanesulfonyl groups, a methanesulfonyl group, an ethanesulfonyl group, an n-propanesulfonyl group, an n-butanesulfonyl group, a cyclopentanesulfonyl group, a cyclohexanesulfonyl group, and the like are preferable.

  Moreover, as r, 0-2 are preferable.

In the general formula (7), examples of the optionally substituted phenyl group represented by R ¹⁶ include a phenyl group, an o-tolyl group, an m-tolyl group, a p-tolyl group, a 2,3-dimethylphenyl group, 2 , 4-dimethylphenyl group, 2,5-dimethylphenyl group, 2,6-dimethylphenyl group, 3,4-dimethylphenyl group, 3,5-dimethylphenyl group, 2,4,6-trimethylphenyl group, 4 -Substituted with phenyl groups such as ethylphenyl group, 4-t-butylphenyl group, 4-cyclohexylphenyl group, 4-fluorophenyl group or linear, branched or cyclic alkyl groups having 1 to 10 carbon atoms. These phenyl groups or alkyl-substituted phenyl groups can be converted into hydroxyl groups, carboxyl groups, cyano groups, nitro groups, alkoxyl groups, alkoxyalkyl groups. And a group substituted with at least one group such as an alkyl group, an alkoxycarbonyl group, and an alkoxycarbonyloxy group.

  Among the substituents for the phenyl group and the alkyl-substituted phenyl group, examples of the alkoxyl group include methoxy group, ethoxy group, n-propoxy group, i-propoxy group, n-butoxy group, 2-methylpropoxy group, 1- Examples thereof include a linear, branched or cyclic alkoxyl group having 1 to 20 carbon atoms such as a methylpropoxy group, a t-butoxy group, a cyclopentyloxy group and a cyclohexyloxy group.

Examples of the alkoxyalkyl group include 2 to 21 carbon atoms such as a methoxymethyl group, an ethoxymethyl group, a 1-methoxyethyl group, a 2-methoxyethyl group, a 1-ethoxyethyl group, and a 2-ethoxyethyl group. And linear, branched or cyclic alkoxyalkyl groups.
Examples of the alkoxycarbonyl group include a methoxycarbonyl group, an ethoxycarbonyl group, an n-propoxycarbonyl group, an i-propoxycarbonyl group, an n-butoxycarbonyl group, a 2-methylpropoxycarbonyl group, and a 1-methylpropoxycarbonyl group. , T-butoxycarbonyl group, cyclopentyloxycarbonyl group, cyclohexyloxycarbonyl and the like, and straight chain, branched or cyclic alkoxycarbonyl groups having 2 to 21 carbon atoms.

Examples of the alkoxycarbonyloxy group include methoxycarbonyloxy group, ethoxycarbonyloxy group, n-propoxycarbonyloxy group, i-propoxycarbonyloxy group, n-butoxycarbonyloxy group, t-butoxycarbonyloxy group, Examples thereof include linear, branched or cyclic alkoxycarbonyloxy groups having 2 to 21 carbon atoms such as cyclopentyloxycarbonyl group and cyclohexyloxycarbonyl.
Examples of the optionally substituted phenyl group represented by R ¹⁵ in the general formula (7) include a phenyl group, a 4-cyclohexylphenyl group, a 4-t-butylphenyl group, a 4-methoxyphenyl group, and a 4-t-butoxyphenyl group. Etc. are preferred.

Examples of the optionally substituted naphthyl group for R ¹⁶ include 1-naphthyl group, 2-methyl-1-naphthyl group, 3-methyl-1-naphthyl group, 4-methyl-1-naphthyl group, 4-methyl-1-naphthyl group, 5-methyl-1-naphthyl group, 6-methyl-1-naphthyl group, 7-methyl-1-naphthyl group, 8-methyl-1-naphthyl group, 2,3-dimethyl -1-naphthyl group, 2,4-dimethyl-1-naphthyl group, 2,5-dimethyl-1-naphthyl group, 2,6-dimethyl-1-naphthyl group, 2,7-dimethyl-1-naphthyl group, 2,8-dimethyl-1-naphthyl group, 3,4-dimethyl-1-naphthyl group, 3,5-dimethyl-1-naphthyl group, 3,6-dimethyl-1-naphthyl group, 3,7-dimethyl- 1-naphthyl group, 3,8-dimethyl-1-na Butyl group, 4,5-dimethyl-1-naphthyl group, 5,8-dimethyl-1-naphthyl group, 4-ethyl-1-naphthyl group 2-naphthyl group, 1-methyl-2-naphthyl group, 3-methyl A naphthyl group substituted with a naphthyl group such as a 2-naphthyl group or 4-methyl-2-naphthyl group or a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms; these naphthyl group or alkyl Examples include a group in which a substituted naphthyl group is substituted with at least one group such as a hydroxyl group, a carboxyl group, a cyano group, a nitro group, an alkoxyl group, an alkoxyalkyl group, an alkoxycarbonyl group, and an alkoxycarbonyloxy group. Can do.

  Examples of the alkoxyl group, alkoxyalkyl group, alkoxycarbonyl group and alkoxycarbonyloxy group as the substituent include the groups exemplified for the phenyl group and the alkyl-substituted phenyl group.

The naphthyl group optionally substituted by R ¹⁶ in the general formula (7) includes a 1-naphthyl group, a 1- (4-methoxynaphthyl) group, a 1- (4-ethoxynaphthyl) group, and a 1- (4- n-propoxynaphthyl) group, 1- (4-n-butoxynaphthyl) group, 2- (7-methoxynaphthyl) group, 2- (7-ethoxynaphthyl) group, 2- (7-n-propoxynaphthyl) group , 2- (7-n-butoxynaphthyl) group and the like are preferable.

Further, the divalent group having 2 to 10 carbon atoms formed by bonding two R ¹⁶ to each other, together with the sulfur atom in the general formula (7), a 5-membered or 6-membered ring, particularly preferably 5 Groups that form member rings (ie, tetrahydrothiophene rings) are desirable.

Examples of the substituent for the divalent group include a hydroxyl group, a carboxyl group, a cyano group, a nitro group, an alkoxyl group, an alkoxyalkyl group, an alkoxy group exemplified as the substituent for the phenyl group and the alkyl-substituted phenyl group. Examples thereof include a carbonyl group and an alkoxycarbonyloxy group.
As R ¹⁶ in the general formula (7), a methyl group, an ethyl group, a phenyl group, a 4-methoxyphenyl group, a 1-naphthyl group, and two R ¹⁶ are bonded to each other to form a tetrahydrothiophene ring structure together with a sulfur atom. A divalent group is preferred.

X ⁻ in the general formula (7) is R ¹⁷ C _n F _2n SO ₃ ⁻ , R ¹⁷ SO ₃ ⁻ or an anion represented by the general formula (8-1) or (8-2). The —C _n F _2n — group in the case where X ⁻ is R ¹⁷ C _n F _2n SO ₃ ^— is a perfluoroalkylene group having n carbon atoms, but this group may be linear. However, it may be branched. Here, n is preferably 1, 2, 4 or 8.
As the hydrocarbon group which carbon atoms which may have 1 to 12 substituents of R ^17, an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group, a bridged alicyclic hydrocarbon group.
Specifically, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, 2-methylpropyl group, 1-methylpropyl group, t-butyl group, n-pentyl group, neopentyl group N-hexyl group, cyclohexyl group, n-heptyl group, n-octyl group, 2-ethylhexyl group, n-nonyl group, n-decyl group, norbornyl group, norbornylmethyl group, hydroxynorbornyl group, adamantyl group Etc.

Moreover, when X < ^- > is an anion represented by the general formula (8-1) or (8-2), R < ¹⁸ > has a fluorine atom independently of each other, and has 1 to 10 carbon atoms. May be a linear or branched alkyl group, or two R ¹⁸ may be bonded to each other to have a fluorine atom and be a divalent organic group having 2 to 10 carbon atoms. In that case, the divalent organic group may have a substituent.
In General Formula (8-1) or (8-2), when R ¹⁸ is a linear or branched alkyl group having 1 to 10 carbon atoms, a trifluoromethyl group, a pentafluoroethyl group, or a heptafluoro group. A propyl group, a nonafluorobutyl group, a dodecafluoropentyl group, a perfluorooctyl group, etc. are mentioned.
Further, when R ¹⁸ is a divalent organic group having 2 to 10 carbon atoms, a tetrafluoroethylene group, a hexafluoropropylene group, an octafluorobutylene group, a decafluoropentylene group, an undecafluorohexylene group, etc. Can be mentioned.

Accordingly, preferable anions X ⁻ in the general formula (7) include trifluoromethanesulfonate anion, perfluoro-n-butanesulfonate anion, perfluoro-n-octanesulfonate anion, 2-bicyclo [2.2.1] hepta. 2-yl-1,1,2,2-tetrafluoroethanesulfonate anion, 2-bicyclo [2.2.1] hept-2-yl-1,1-difluoroethanesulfonate anion, the following formula (9-1) Anion represented by (9-7).

  Preferred examples of the general formula (7) include triphenylsulfonium trifluoromethanesulfonate, tri-tert-butylphenylsulfonium trifluoromethanesulfonate, 4-cyclohexylphenyl-diphenylsulfonium trifluoromethanesulfonate, 4-methanesulfonylphenyl-diphenyl. Sulfonium trifluoromethanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium trifluoromethanesulfonate, 1- (4-n-butoxynaphthyl) tetrahydrothiophenium trifluoromethanesulfonate,

  Triphenylsulfonium perfluoro-n-butanesulfonate, tri-tert-butylphenylsulfonium perfluoro-n-butanesulfonate, 4-cyclohexylphenyl-diphenylsulfonium perfluoro-n-butanesulfonate, 4-methanesulfonylphenyl-diphenylsulfonium per Fluoro-n-butanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium perfluoro-n-butanesulfonate, 1- (4-n-butoxynaphthyl) tetrahydrothiophenium perfluoro- n-butanesulfonate,

  Triphenylsulfonium perfluoro-n-octane sulfonate, tri-tert-butylphenylsulfonium perfluoro-n-octane sulfonate, 4-cyclohexylphenyl-diphenylsulfonium perfluoro-n-octane sulfonate, 4-methanesulfonylphenyl-diphenylsulfonium per Fluoro-n-octanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium perfluoro-n-octanesulfonate, 1- (4-n-butoxynaphthyl) tetrahydrothiophenium perfluoro- n-octane sulfonate,

  Triphenylsulfonium 2- (bicyclo [2.2.1] hepta-2'-yl) -1,1,2,2-tetrafluoroethanesulfonate, tri-tert-butylphenylsulfonium 2- (bicyclo [2.2 .1] Hepta-2'-yl) -1,1,2,2-tetrafluoroethanesulfonate, 4-cyclohexylphenyl-diphenylsulfonium 2- (bicyclo [2.2.1] hepta-2'-yl)- 1,1,2,2-tetrafluoroethanesulfonate, 4-methanesulfonylphenyl-diphenylsulfonium 2- (bicyclo [2.2.1] hepta-2'-yl) -1,1,2,2-tetrafluoro Ethanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium 2- (bicyclo [2.2. ] Hepta-2'-yl) -1,1,2,2-tetrafluoroethanesulfonate, 1- (4-n-butoxynaphthyl) tetrahydrothiophenium 2- (bicyclo [2.2.1] hepta-2 '-Yl) -1,1,2,2-tetrafluoroethanesulfonate,

Triphenylsulfonium 2- (bicyclo [2.2.1] hepta-2'-yl) -1,1-difluoroethanesulfonate, tri-tert-butylphenylsulfonium 2- (bicyclo [2.2.1] hepta-2 '-Yl) -1,1-difluoroethanesulfonate, 4-cyclohexylphenyl-diphenylsulfonium 2- (bicyclo [2.2.1] hepta-2'-yl) -1,1-difluoroethanesulfonate, 4-methanesulfonylphenyl -Diphenylsulfonium 2- (bicyclo [2.2.1] hepta-2'-yl) -1,1-difluoroethanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium 2- ( Bicyclo [2.2.1] hepta-2'-yl) -1,1-difluoroethanesulfur 1- (4-n-butoxynaphthyl) tetrahydrothiophenium 2- (bicyclo [2.2.1] hepta-2′-yl) -1,1-difluoroethanesulfonate, represented by the following formulas B1 to B15 And the like.
In addition, in this invention, the acid generator 1 can be used individually or in mixture of 2 or more types.

  Examples of the radiation sensitive acid generator other than the acid generator 1 (hereinafter referred to as “other acid generator”) that can be used as the radiation sensitive acid generator (C) include, for example, onium. Examples thereof include a salt compound, a halogen-containing compound, a diazoketone compound, a sulfone compound, and a sulfonic acid compound. Examples of these other acid generators include the following.

Onium salt compounds:
Examples of the onium salt compound include iodonium salts, sulfonium salts, phosphonium salts, diazonium salts, pyridinium salts, and the like.
Specific examples of the onium salt compound include diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoro-n-butanesulfonate, diphenyliodonium perfluoro-n-octanesulfonate, diphenyliodonium 2-bicyclo [2.2.1] hepta-2. -Yl-1,1,2,2-tetrafluoroethanesulfonate, bis (4-t-butylphenyl) iodonium trifluoromethanesulfonate, bis (4-t-butylphenyl) iodonium nonafluoro-n-butanesulfonate, bis ( 4-t-butylphenyl) iodonium perfluoro-n-octanesulfonate, bis (4-t-butylphenyl) iodonium 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2- Te La tetrafluoroethane sulfonate, cyclohexyl 2-oxo-cyclohexyl methyl trifluoromethanesulfonate, dicyclohexyl-2-oxo-cyclohexyl trifluoromethane sulfonate, and 2-oxo-cyclohexyl dimethyl sulfonium trifluoromethanesulfonate, and the like.

Halogen-containing compounds:
Examples of the halogen-containing compound include a haloalkyl group-containing hydrocarbon compound and a haloalkyl group-containing heterocyclic compound.
Specific examples of halogen-containing compounds include (trichloromethyl such as phenylbis (trichloromethyl) -s-triazine, 4-methoxyphenylbis (trichloromethyl) -s-triazine, 1-naphthylbis (trichloromethyl) -s-triazine. ) -S-triazine derivatives and 1,1-bis (4-chlorophenyl) -2,2,2-trichloroethane.

Diazo ketone compounds:
Examples of the diazo ketone compound include a 1,3-diketo-2-diazo compound, a diazobenzoquinone compound, a diazonaphthoquinone compound, and the like.
Specific examples of diazoketone include 1,2-naphthoquinonediazide-4-sulfonyl chloride, 1,2-naphthoquinonediazide-5-sulfonyl chloride, 1,2, naphthoquinonediazide of 2,3,4,4′-tetrahydroxybenzophenone. -4-sulfonic acid ester or 1,2-naphthoquinonediazide-5-sulfonic acid ester, 1,1,1-naphthoquinonediazide-4-sulfonic acid ester of 1,1,1-tris (4-hydroxyphenyl) ethane Examples include 2-naphthoquinonediazide-5-sulfonic acid ester.

Sulfone compounds:
Examples of the sulfone compound include β-ketosulfone, β-sulfonylsulfone, and α-diazo compounds of these compounds.
Specific examples of the sulfone compound include 4-trisphenacylsulfone, mesitylphenacylsulfone, bis (phenylsulfonyl) methane, and the like.

Sulfonic acid compounds:
Examples of the sulfonic acid compounds include alkyl sulfonic acid esters, alkyl sulfonic acid imides, haloalkyl sulfonic acid esters, aryl sulfonic acid esters, and imino sulfonates.
Specific examples of the sulfonic acid compound include benzoin tosylate, pyrogallol tris (trifluoromethanesulfonate), nitrobenzyl-9,10-diethoxyanthracene-2-sulfonate, trifluoromethanesulfonylbicyclo [2.2.1] hept- 5-ene-2,3-dicarbodiimide, nonafluoro-n-butanesulfonylbicyclo [2.2.1] hept-5-ene-2,3-dicarbodiimide, perfluoro-n-octanesulfonylbicyclo [2.2 .1] Hept-5-ene-2,3-dicarbodiimide, 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonylbicyclo [2.2. 1] Hept-5-ene-2,3-dicarbodiimide, N- (trifluoromethanesulfonyl Xyl) succinimide, N- (nonafluoro-n-butanesulfonyloxy) succinimide, N- (perfluoro-n-octanesulfonyloxy) succinimide, N- (2-bicyclo [2.2.1] hept-2-yl- 1,1,2,2-tetrafluoroethanesulfonyloxy) succinimide, 1,8-naphthalenedicarboxylic acid imide trifluoromethanesulfonate, 1,8-naphthalenedicarboxylic acid imidononafluoro-n-butanesulfonate, 1,8-naphthalenedicarboxylic acid Examples include acid imido perfluoro-n-octane sulfonate.

  Among these other acid generators, diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoro-n-butanesulfonate, diphenyliodonium perfluoro-n-octanesulfonate, diphenyliodonium 2-bicyclo [2.2.1] hepta- 2-yl-1,1,2,2-tetrafluoroethanesulfonate, bis (4-t-butylphenyl) iodonium trifluoromethanesulfonate, bis (4-t-butylphenyl) iodonium nonafluoro-n-butanesulfonate, bis (4-t-Butylphenyl) iodonium perfluoro-n-octanesulfonate, bis (4-t-butylphenyl) iodonium 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2 -Tetraph Oro ethanesulfonate, cyclohexyl 2-oxo-cyclohexyl methyl trifluoromethanesulfonate, dicyclohexyl-2-oxo-cyclohexyl trifluoromethane sulfonate, 2-oxo-cyclohexyl dimethyl sulfonium trifluoromethane sulfonate,

Trifluoromethanesulfonylbicyclo [2.2.1] hept-5-ene-2,3-dicarbodiimide, nonafluoro-n-butanesulfonylbicyclo [2.2.1] hept-5-ene-2,3-dicarbodiimide Perfluoro-n-octanesulfonylbicyclo [2.2.1] hept-5-ene-2,3-dicarbodiimide, 2-bicyclo [2.2.1] hept-2-yl-1,1,2 , 2-tetrafluoroethanesulfonylbicyclo [2.2.1] hept-5-ene-2,3-dicarbodiimide, N- (trifluoromethanesulfonyloxy) succinimide, N- (nonafluoro-n-butanesulfonyloxy) succinimide N- (perfluoro-n-octanesulfonyloxy) succinimide, N- (2-bicyclo [2.2 1] hept-2-yl-1,1,2,2-tetrafluoroethane sulfonyloxy) succinimide, 1,8-naphthalenedicarboxylic acid imide trifluoromethanesulfonate and the like are preferable.
The other acid generators can be used alone or in admixture of two or more.

In this invention, the total usage-amount of the acid generator 1 and another acid generator is with respect to a total of 100 mass parts of a polymer (A) and resin (B) from a viewpoint of ensuring the sensitivity and developability as a resist. Usually, it is 0.1 to 20 parts by mass, preferably 0.5 to 10 parts by mass. When the total amount used is less than 0.1 parts by mass, the sensitivity and developability tend to decrease. On the other hand, when it exceeds 20 parts by mass, the transparency to radiation is lowered, and it becomes difficult to obtain a rectangular resist pattern.
Moreover, the usage-amount of another acid generator is 80 mass% or less normally with respect to 100 mass% of the sum total of the acid generator 1 and another acid generator, Preferably it is 60 mass% or less.

<Nitrogen-containing compound (D)>
In addition, the radiation sensitive resin composition of the present invention has an acid diffusion effect that controls the diffusion phenomenon of an acid generated from an acid generator upon exposure in a photoresist film and suppresses an undesirable chemical reaction in a non-exposed region. As a control agent, a nitrogen-containing compound [hereinafter referred to as nitrogen-containing compound (D). ] Can be contained. By blending such an acid diffusion controller, the storage stability of the resulting radiation-sensitive resin composition can be improved. In addition, the resolution of the resist can be further improved, and the change in the line width of the resist pattern due to fluctuations in the holding time (PED) from exposure to post-exposure heat treatment can be suppressed, which greatly improves process stability. An excellent composition can be obtained.

Examples of the nitrogen-containing compound (D) include tertiary amine compounds, other amine compounds, amide group-containing compounds, urea compounds, and other nitrogen-containing heterocyclic compounds.
Examples of the tertiary amine compounds include mono (cyclo) alkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine, cyclohexylamine; di-n-butylamine Di-n-pentylamine, di-n-hexylamine, di-n-heptylamine, di-n-octylamine, di-n-nonylamine, di-n-decylamine, cyclohexylmethylamine, dicyclohexylamine, etc. (Cyclo) alkylamines; triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n-octylamine, Tri-n-nonylamine, tri-n-decylamine, cyclohex Tri (cyclo) alkylamines such as dimethylamine, methyldicyclohexylamine, tricyclohexylamine; substituted alkylamines such as 2,2 ′, 2 ″ -nitrotriethanol; aniline, N-methylaniline, N, N— Dimethylaniline, 2-methylaniline, 3-methylaniline, 4-methylaniline, 4-nitroaniline, diphenylamine, triphenylamine, naphthylamine, 2,4,6-tri-tert-butyl-N-methylaniline, N- Phenyldiethanolamine, 2,6-diisopropylaniline and the like are preferable.

  Examples of the other amine compounds include ethylenediamine, N, N, N ′, N′-tetramethylethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl ether, 4,4′-diaminobenzophenone, 4,4′-diaminodiphenylamine, 2,2-bis (4-aminophenyl) propane, 2- (3-aminophenyl) -2- (4-aminophenyl) propane, 2- (4-aminophenyl) -2- (3-hydroxyphenyl) propane, 2- (4-aminophenyl) -2- (4-hydroxyphenyl) propane, 1,4-bis [1- (4-aminophenyl) -1-methylethyl] benzene, 1,3-bis [1- (4-aminophenyl) -1-methyl ester Benzene], bis (2-dimethylaminoethyl) ether, bis (2-diethylaminoethyl) ether, 1- (2-hydroxyethyl) -2-imidazolidinone, 2-quinoxalinol, N, N, N ′ , N′-tetrakis (2-hydroxypropyl) ethylenediamine, N, N, N ′, N ″, N ″ -pentamethyldiethylenetriamine and the like are preferable.

  Examples of the amide group-containing compound include Nt-butoxycarbonyldi-n-octylamine, Nt-butoxycarbonyldi-n-nonylamine, Nt-butoxycarbonyldi-n-decylamine, Nt -Butoxycarbonyldicyclohexylamine, Nt-butoxycarbonyl-1-adamantylamine, Nt-butoxycarbonyl-2-adamantylamine, Nt-butoxycarbonyl-N-methyl-1-adamantylamine, (S)- (-)-1- (t-butoxycarbonyl) -2-pyrrolidinemethanol, (R)-(+)-1- (t-butoxycarbonyl) -2-pyrrolidinemethanol, Nt-butoxycarbonyl-4-hydroxy Piperidine, Nt-butoxycarbonylpyrrolidine, Nt-butoxycarbo Lupiperazine, Nt-butoxycarbonylpiperidine, N, N-di-t-butoxycarbonyl-1-adamantylamine, N, N-di-t-butoxycarbonyl-N-methyl-1-adamantylamine, Nt- Butoxycarbonyl-4,4'-diaminodiphenylmethane, N, N'-di-t-butoxycarbonylhexamethylenediamine, N, N, N'N'-tetra-t-butoxycarbonylhexamethylenediamine, N, N'- Di-t-butoxycarbonyl-1,7-diaminoheptane, N, N′-di-t-butoxycarbonyl-1,8-diaminooctane, N, N′-di-t-butoxycarbonyl-1,9-diaminononane N, N′-di-t-butoxycarbonyl-1,10-diaminodecane, N, N′-di-t-butoxycal Nyl-1,12-diaminododecane, N, N′-di-t-butoxycarbonyl-4,4′-diaminodiphenylmethane, Nt-butoxycarbonylbenzimidazole, Nt-butoxycarbonyl-2-methylbenzimidazole Nt-butoxycarbonyl group-containing amino compounds such as Nt-butoxycarbonyl-2-phenylbenzimidazole, formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N-methylacetamide, N , N-dimethylacetamide, propionamide, benzamide, pyrrolidone, N-methylpyrrolidone, N-acetyl-1-adamantylamine, isocyanuric acid tris (2-hydroxyethyl) and the like are preferable.

  Examples of the urea compound include urea, methylurea, 1,1-dimethylurea, 1,3-dimethylurea, 1,1,3,3-tetramethylurea, 1,3-diphenylurea, tri-n-butyl. Thiourea and the like are preferable.

  Examples of the other nitrogen-containing heterocyclic compounds include imidazole, 4-methylimidazole, 4-methyl-2-phenylimidazole, benzimidazole, 2-phenylbenzimidazole, 1-benzyl-2-methylimidazole, 1-benzyl. Imidazoles such as 2-methyl-1H-imidazole; pyridine, 2-methylpyridine, 4-methylpyridine, 2-ethylpyridine, 4-ethylpyridine, 2-phenylpyridine, 4-phenylpyridine, 2-methyl-4 -Pyridines such as phenylpyridine, nicotine, nicotinic acid, nicotinamide, quinoline, 4-hydroxyquinoline, 8-oxyquinoline, acridine, 2,2 ': 6', 2 ''-terpyridine; piperazine, 1- ( Piperazines such as 2-hydroxyethyl) piperazine In addition, pyrazine, pyrazole, pyridazine, quinosaline, purine, pyrrolidine, piperidine, piperidine ethanol, 3-piperidino-1,2-propanediol, morpholine, 4-methylmorpholine, 1- (4-morpholinyl) ethanol, 4-acetylmorpholine 3- (N-morpholino) -1,2-propanediol, 1,4-dimethylpiperazine, 1,4-diazabicyclo [2.2.2] octane and the like are preferable.

The said nitrogen containing compound (D) can be used individually or in mixture of 2 or more types.
The blending amount of such an acid diffusion controller [nitrogen-containing compound (D)] is preferably 15 parts by mass or less with respect to 100 parts by mass in total of the polymer (A) and the resin (B). Preferably it is 0.001-10 mass parts, More preferably, it is 0.01-5 mass parts. When the amount of the acid diffusion controller exceeds 15 parts by mass, the sensitivity as a resist may be lowered. On the other hand, if it is less than 0.001 part by mass, the pattern shape and dimensional fidelity as a resist may be lowered depending on the process conditions.

<Solvent (E)>
When the radiation-sensitive resin composition of the present invention is used, it is dissolved in a solvent so that the total solid content is usually 1 to 50% by mass, preferably 1 to 25% by mass. A resin composition solution is prepared by filtering with a filter of about 2 μm.

  Examples of the solvent (E) include 2-butanone, 2-pentanone, 3-methyl-2-butanone, 2-hexanone, 4-methyl-2-pentanone, 3-methyl-2-pentanone, 3,3- Linear or branched ketones such as dimethyl-2-butanone, 2-heptanone, 2-octanone; cyclopentanone, 3-methylcyclopentanone, cyclohexanone, 2-methylcyclohexanone, 2,6-dimethylcyclohexanone, Cyclic ketones such as isophorone; propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol mono-n-propyl ether acetate, propylene glycol mono-i-propyl ether acetate, propylene glycol mono-n-butyl Propylene glycol monoalkyl ether acetates such as ether acetate, propylene glycol mono-i-butyl ether acetate, propylene glycol mono-sec-butyl ether acetate, propylene glycol mono-t-butyl ether acetate; methyl 2-hydroxypropionate, 2-hydroxypropionic acid Ethyl, 2-hydroxypropionate n-propyl, 2-hydroxypropionate i-propyl, 2-hydroxypropionate n-butyl, 2-hydroxypropionate i-butyl, 2-hydroxypropionate sec-butyl, 2-hydroxy Alkyl 2-hydroxypropionates such as t-butyl propionate; methyl 3-methoxypropionate, ethyl 3-methoxypropionate, 3-ethoxy Methyl propionate, other 3-alkoxy propionic acid alkyl such as ethyl 3-ethoxypropionate,

  n-propyl alcohol, i-propyl alcohol, n-butyl alcohol, t-butyl alcohol, cyclohexanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-n-propyl ether, ethylene glycol mono-n-butyl ether , Diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol di-n-propyl ether, diethylene glycol di-n-butyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol mono-n-propyl ether acetate, propylene glycol monomethyl ether , Propylene glycol monoethyl Ether, propylene glycol mono-n-propyl ether, toluene, xylene, ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxyacetate, ethyl hydroxyacetate, methyl 2-hydroxy-3-methylbutyrate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-methyl-3-methoxybutyl propionate, 3-methyl-3-methoxybutyl butyrate, ethyl acetate, n-propyl acetate, n-butyl acetate, methyl acetoacetate, Ethyl acetoacetate, methyl pyruvate, ethyl pyruvate, N-methylpyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, benzyl ethyl ether, di-n-hexyl ether, diethylene glycol monomethyl ether, diethylene glycol Cole monoethyl ether, caproic acid, caprylic acid, 1-octanol, 1-nonanol, benzyl alcohol, benzyl acetate, ethyl benzoate, diethyl oxalate, diethyl maleate, γ-butyrolactone, ethylene carbonate, propylene carbonate, etc. Can do.

Among these, linear or branched ketones, cyclic ketones, propylene glycol monoalkyl ether acetates, alkyl 2-hydroxypropionate, alkyl 3-alkoxypropionate, γ-butyrolactone and the like are preferable. .
These solvent (E) can be used individually or in mixture of 2 or more types.

<Additives>
In the radiation sensitive resin composition of the present invention, various additives such as alicyclic additives, surfactants, and sensitizers can be blended as necessary.

The alicyclic additive is a component having an action of further improving dry etching resistance, pattern shape, adhesion to a substrate, and the like.
Examples of such alicyclic additives include 1-adamantanecarboxylic acid, 2-adamantanone, 1-adamantanecarboxylic acid t-butyl, 1-adamantanecarboxylic acid t-butoxycarbonylmethyl, 1-adamantanecarboxylic acid α. -Butyrolactone ester, 1,3-adamantane dicarboxylic acid di-t-butyl, 1-adamantane acetate t-butyl, 1-adamantane acetate t-butoxycarbonylmethyl, 1,3-adamantane diacetate di-t-butyl, 2, Adamantane derivatives such as 5-dimethyl-2,5-di (adamantylcarbonyloxy) hexane; t-butyl deoxycholic acid, t-butoxycarbonylmethyl deoxycholic acid, 2-ethoxyethyl deoxycholic acid, 2-deoxycholic acid 2- Cyclohexyloxyethyl, deoxy Deoxycholic acid esters such as 3-oxocyclohexyl cholic acid, tetrahydropyranyl deoxycholic acid, mevalonolactone ester of deoxycholic acid; t-butyl lithocholic acid, t-butoxycarbonylmethyl lithocholic acid, 2-ethoxyethyl lithocholic acid, Lithocholic acid esters such as lithocholic acid 2-cyclohexyloxyethyl, lithocholic acid 3-oxocyclohexyl, lithocholic acid tetrahydropyranyl, lithocholic acid mevalonolactone ester; dimethyl adipate, diethyl adipate, dipropyl adipate, di-n - butyl, alkyl carboxylic acid esters such as adipate t- butyl or 3- [2-hydroxy-2,2-bis (trifluoromethyl) ethyl] tetracyclo [4.4.0.1 ^{2, 5} 1 ^7,10 ] dodecane and the like. These alicyclic additives can be used alone or in admixture of two or more.

The surfactant is a component having an action of improving coating properties, striation, developability and the like.
Examples of such surfactants include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene n-octylphenyl ether, polyoxyethylene n-nonylphenyl ether, and polyethylene glycol dilaurate. In addition to nonionic surfactants such as polyethylene glycol distearate, KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.), Polyflow No. 75, no. 95 (manufactured by Kyoeisha Chemical Co., Ltd.), F-top EF301, EF303, EF352 (manufactured by Tochem Products Co., Ltd.), Megafax F171, F173 (manufactured by Dainippon Ink & Chemicals, Inc.), Florard FC430, FC431 ( Sumitomo 3M Limited), Asahi Guard AG710, Surflon S-382, SC-101, SC-102, SC-103, SC-104, SC-105, SC-105, SC-106 (Asahi Glass Co., Ltd.) And the like. These surfactants can be used alone or in admixture of two or more.

The sensitizer absorbs radiation energy and transmits the energy to the acid generator (C), thereby increasing the amount of acid produced. The radiation-sensitive resin composition It has the effect of improving the apparent sensitivity.
Examples of such sensitizers include carbazoles, acetophenones, benzophenones, naphthalenes, phenols, biacetyl, eosin, rose bengal, pyrenes, anthracenes, phenothiazines, and the like. These sensitizers can be used alone or in admixture of two or more.
In addition, by blending a dye or pigment, the latent image of the exposed area can be visualized, and the influence of halation during exposure can be alleviated. By blending an adhesion aid, adhesion to the substrate can be improved. it can.
Furthermore, examples of additives other than the above include alkali-soluble resins, low-molecular alkali solubility control agents having an acid-dissociable protecting group, antihalation agents, storage stabilizers, antifoaming agents, and the like.

<Method for forming photoresist pattern>
The radiation sensitive resin composition for immersion exposure of the present invention is particularly useful as a chemically amplified resist. In the chemically amplified resist, the acid dissociable group in the resin component [mainly resin (B)] is dissociated by the action of the acid generated from the acid generator by exposure to generate a carboxyl group, and as a result, The solubility of the exposed portion of the resist in the alkaline developer is increased, and the exposed portion is dissolved and removed by the alkaline developer to obtain a positive photoresist pattern.
The method for forming a photoresist pattern of the present invention includes (1) a step of forming a photoresist film on a substrate using the radiation-sensitive resin composition for immersion exposure [hereinafter also referred to as “step (1)”]. And (2) a step of irradiating the exposed photoresist film with radiation through an immersion medium and a mask having a predetermined pattern and exposing the same [hereinafter also referred to as “step (2)”]. And (3) a step of forming an exposed photoresist film to form a photoresist pattern [hereinafter also referred to as “step (3)”. ].

In the step (1), the resin composition solution obtained by dissolving the resin composition of the present invention in a solvent is applied by appropriate coating means such as spin coating, cast coating, roll coating, etc., for example, a silicon wafer, A photoresist film is formed by applying on a substrate such as a wafer coated with aluminum. Specifically, after applying the resin composition solution so that the obtained resist film has a predetermined film thickness, the solvent in the coating film is volatilized by pre-baking (PB) to form a resist film.
Although the thickness of a resist film is not specifically limited, Usually, it is 0.1-5 micrometers, Preferably it is 0.1-2 micrometers.
Moreover, although the prebaking heating conditions change with composition of a radiation sensitive resin composition, it is about 30-200 degreeC normally, Preferably it is 50-150 degreeC.

  In the present invention, in order to maximize the potential of the radiation-sensitive resin composition, as disclosed in, for example, Japanese Patent Publication No. 6-12252 (Japanese Patent Laid-Open No. 59-93448). An organic or inorganic antireflection film may be formed on the substrate to be used. In order to prevent the influence of basic impurities contained in the environmental atmosphere, a protective film can be provided on the photoresist film as disclosed in, for example, Japanese Patent Laid-Open No. 5-188598. Furthermore, in order to prevent the acid generator and the like from flowing out of the photoresist film, an immersion protective film can be provided on the photoresist film as disclosed in, for example, Japanese Patent Application Laid-Open No. 2005-352384. . These techniques can be used in combination.

In the step (2), the photoresist film formed in the step (1) is exposed to radiation through an immersion medium such as water. At this time, radiation is irradiated through a mask having a predetermined pattern.
As the radiation, visible rays, ultraviolet rays, far ultraviolet rays, X-rays, charged particle beams and the like are appropriately selected and used depending on the type of the acid generator used. ArF excimer laser (wavelength: 193 nm) or Far ultraviolet rays represented by a KrF excimer laser (wavelength 248 nm) are preferable, and an ArF excimer laser (wavelength 193 nm) is particularly preferable.
Moreover, exposure conditions, such as exposure amount, are suitably selected according to the compounding composition of a radiation sensitive resin composition, the kind of additive, etc. In the present invention, it is preferable to perform heat treatment (PEB) after exposure. By PEB, the dissociation reaction of the acid dissociable group in the resin component proceeds smoothly. The heating condition of PEB varies depending on the composition of the radiation sensitive resin composition, but is usually 30 to 200 ° C, preferably 50 to 170 ° C.

  In the step (3), a predetermined photoresist pattern is formed by developing the exposed photoresist film. Examples of the developer used for this development include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, n-propylamine, diethylamine, and di-n-propyl. Amine, triethylamine, methyldiethylamine, ethyldimethylamine, triethanolamine, tetramethylammonium hydroxide, pyrrole, piperidine, choline, 1,8-diazabicyclo- [5.4.0] -7-undecene, 1,5-diazabicyclo -An alkaline aqueous solution in which at least one of alkaline compounds such as [4.3.0] -5-nonene is dissolved is preferable. The concentration of the alkaline aqueous solution is usually 10% by mass or less. In this case, if the concentration of the alkaline aqueous solution exceeds 10% by mass, the unexposed area may be dissolved in the developer, which is not preferable.

In addition, for example, an organic solvent can be added to the developer composed of the alkaline aqueous solution. Examples of the organic solvent include ketones such as acetone, methyl ethyl ketone, methyl i-butyl ketone, cyclopentanone, cyclohexanone, 3-methylcyclopentanone, and 2,6-dimethylcyclohexanone; methyl alcohol, ethyl alcohol, and n-propyl. Alcohols such as alcohol, i-propyl alcohol, n-butyl alcohol, t-butyl alcohol, cyclopentanol, cyclohexanol, 1,4-hexanediol, 1,4-hexanedimethylol; ethers such as tetrahydrofuran and dioxane And esters such as ethyl acetate, n-butyl acetate, and i-amyl acetate; aromatic hydrocarbons such as toluene and xylene; phenol, acetonylacetone, and dimethylformamide. These organic solvents can be used alone or in admixture of two or more. The amount of the organic solvent used is preferably 100% by volume or less with respect to the alkaline aqueous solution. In this case, if the amount of the organic solvent used exceeds 100% by volume, the developability is lowered, and there is a possibility that the remaining development in the exposed area increases. An appropriate amount of a surfactant or the like can be added to the developer composed of the alkaline aqueous solution.
In addition, after developing with the developing solution which consists of alkaline aqueous solution, generally it wash | cleans with water and dries.

  Hereinafter, the embodiment of the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples. Here, the part is based on mass unless otherwise specified.

<Synthesis of Polymers (A-1) to (A-3) and Resins (B-1) to (B-4)>
Hereinafter, the synthesis example of each polymer (A) and each resin (B) is demonstrated. In addition, each measurement and evaluation in each following synthesis example were performed in the following way.

(1) Mw and Mn
Gel permeation based on monodisperse polystyrene using GPC columns (2 G2000HXL, 1 G3000HXL, 1 G4000HXL) manufactured by Tosoh Corporation under the analysis conditions of flow rate 1.0 ml / min, elution solvent tetrahydrofuran, column temperature 40 ° C. It was measured by an association chromatography (GPC). The degree of dispersion Mw / Mn was calculated from the measurement results.
⁽²⁾ 13 C-NMR analysis of ¹³ C-NMR analysis the polymer, using a Nippon Denshi Co. "JNM-EX270", was measured.

  Moreover, the structure of the monomer [(M-1)-(M-9)] used for each synthesis below is shown below.

[Synthesis of Polymer (A-1)]
40.70 g (85 mol%) of the monomer (M-1) and 9.30 g (15 mol%) of the monomer (M-3) were dissolved in 70 g of 2-butanone, and further dimethyl 2,2 ′. A monomer solution charged with 5.44 g of azobis (2-methylpropionate) was prepared, and a 500 mL three-necked flask charged with 30 g of 2-butanone was purged with nitrogen for 30 minutes. After the nitrogen purge, the reaction kettle was heated to 80 ° C. with stirring, and the monomer solution prepared in advance was added dropwise over 3 hours using a dropping funnel. The polymerization start was carried out for 6 hours with the start of dropping as the polymerization start time. After completion of the polymerization, the polymerization solution was cooled to 30 ° C. or less by water cooling, and the polymerization solution was transferred to a 2 L separatory funnel. Next, the polymerization solution was diluted with 150 g of n-hexane, mixed with 600 g of methanol, then stirred with 30 g of distilled water, and allowed to stand for 30 minutes. Thereafter, the lower layer was recovered to obtain a propylene glycol monomethyl ether acetate solution. The physical property values of the solid content (polymer) of the resin solution were as follows, and the yield was 50%. This polymer has Mw = 4300, Mw / Mn = 1.3, and as a result of ¹³ C-NMR analysis, fluorine content = 8.98 atom%, each derived from monomers (M-1) and (M-3). It was a copolymer having a content of repeating units of 86.3: 13.7 (mol%). This polymer is referred to as “polymer (A-1)”.

[Synthesis of Polymer (A-2)]
35.81 g (70 mol%) of the monomer (M-1) and 14.17 g (30 mol%) of the monomer (M-2) were dissolved in 70 g of 2-butanone, and further dimethyl 2,2 ′. -A monomer solution charged with 3.23 g of azobis (2-methylpropionate) was prepared, and a 500 mL three-necked flask charged with 30 g of 2-butanone was purged with nitrogen for 30 minutes. After the nitrogen purge, the reaction kettle was heated to 80 ° C. with stirring, and the monomer solution prepared in advance was added dropwise over 3 hours using a dropping funnel. The polymerization start was carried out for 6 hours with the start of dropping as the polymerization start time. After completion of the polymerization, the polymerization solution was cooled to 30 ° C. or less by water cooling, and the polymerization solution was transferred to a 2 L separatory funnel. Next, the polymerization solution was diluted with 150 g of n-hexane, mixed with 600 g of methanol, then stirred with 21 g of distilled water, and allowed to stand for 30 minutes. Thereafter, the lower layer was recovered to obtain a propylene glycol monomethyl ether acetate solution. The physical properties of the solid content (polymer) of the resin solution were as follows, and the yield was 60%. This polymer has Mw = 7300, Mw / Mn = 1.6, and as a result of ¹³ C-NMR analysis, fluorine content = 9.60 atom%, each derived from monomers (M-1) and (M-2). It was a copolymer having a repeating unit content of 70.5: 29.5 (mol%). This polymer is referred to as “polymer (A-2)”.

[Synthesis of Polymer (A-3)]
35.81 g (70 mol%) of the monomer (M-1) and 14.17 g (30 mol%) of the monomer (M-2) were dissolved in 70 g of 2-butanone, and further dimethyl 2,2 ′. A monomer solution charged with 5.81 g of azobis (2-methylpropionate) was prepared, and a 500 mL three-necked flask charged with 30 g of 2-butanone was purged with nitrogen for 30 minutes. After the nitrogen purge, the reaction kettle was heated to 80 ° C. with stirring, and the monomer solution prepared in advance was added dropwise over 3 hours using a dropping funnel. The polymerization start was carried out for 6 hours with the start of dropping as the polymerization start time. After completion of the polymerization, the polymerization solution was cooled to 30 ° C. or less by water cooling, and the polymerization solution was transferred to a 2 L separatory funnel. Next, the polymerization solution was diluted with 150 g of n-hexane, mixed with 600 g of methanol, then stirred with 30 g of distilled water, and allowed to stand for 30 minutes. Thereafter, the lower layer was recovered to obtain a propylene glycol monomethyl ether acetate solution. The physical property values of the solid content (polymer) of the resin solution were as follows, and the yield was 55%. This polymer has Mw = 4300, Mw / Mn = 1.46, ¹³ C-NMR analysis, fluorine content = 9.60 atom%, monomers (M-1) and (M-2) This was a copolymer having a content of repeating units of 70.9: 29.1 (mol%). This polymer is referred to as “polymer (A-3)”.

[Synthesis of Resin (B-1)]
Monomer (M-6) 55.44 g (50 mol%), monomer (M-4) 33.57 g (40 mol%), and monomer (M-5) 10.99 g (10 mol) %) Was dissolved in 200 g of 2-butanone, and a monomer solution containing 5.74 g of dimethyl 2,2′-azobis (2-methylpropionate) was further prepared, and 100 g of 2-butanone was added. A 500 mL three neck flask was purged with nitrogen for 30 minutes. After the nitrogen purge, the reaction kettle was heated to 80 ° C. with stirring, and the monomer solution prepared in advance was added dropwise over 3 hours using a dropping funnel. The polymerization start was carried out for 6 hours with the start of dropping as the polymerization start time. After completion of the polymerization, the polymerization solution was cooled with water to 30 ° C. or lower, poured into 2000 g of methanol, and the precipitated white powder was separated by filtration. The filtered white powder was washed twice with 400 g of methanol as a slurry, then filtered and dried at 50 ° C. for 17 hours to obtain a white powder polymer (72 g, yield 72%). .
This polymer had Mw = 6400, Mw / Mn = 1.67, ¹³ C-NMR analysis, fluorine content = 0 atom%, monomers (M-6), (M-4), and (M-5). ), The content of each repeating unit was 52.2: 38.1: 9.7 (mol%). This polymer is referred to as “resin (B-1)”.

[Synthesis of Resin (B-2)]
Monomer (M-6) 47.54 g (46 mol%), monomer (M-1) 12.53 g (15 mol%), monomer (M-7) 39.93 g (39 mol%) ) Was dissolved in 200 g of 2-butanone, and a monomer solution charged with 4.08 g of 2,2′-azobis (isobutyronitrile) was prepared.
On the other hand, a 1000 mL three-necked flask charged with 100 g of 2-butanone was prepared and purged with nitrogen for 30 minutes. After purging with nitrogen, the contents in the three-necked flask were heated to 80 ° C. with stirring, and the monomer solution prepared in advance was added dropwise using a dropping funnel over 3 hours. The polymerization start was carried out for 6 hours with the start of dropping as the polymerization start time. After completion of the polymerization, the polymerization solution was cooled with water to 30 ° C. or lower, poured into 2000 g of methanol, and the precipitated white powder was separated by filtration. The filtered white powder was washed twice with 400 g of methanol as a slurry, then filtered and dried at 50 ° C. for 17 hours to obtain a white powder polymer (73 g, yield 73%). .
This polymer has Mw = 5700, Mw / Mn of 1.7, and as a result of ¹³ C-NMR analysis, fluorine content = 0 atom%, monomers (M-6), (M-1), and (M-7). ), The content of each repeating unit was 51.4: 14.6: 34.0 (mol%). This polymer is referred to as “resin (B-2)”.

[Synthesis of Resin (B-3)]
45.81 g (40 mol%) of the monomer (M-6), 34.68 g (40 mol%) of the monomer (M-4), 6.71 g (10 mol%) of the monomer (M-9) ) Is dissolved in 200 g of 2-butanone, and a monomer solution into which 4.23 g of azobisisobutyronitrile is further added is prepared, and 12.80 g (10 mol%) of the monomer (M-8) and A 1000 mL three-necked flask charged with 100 g of 2-butanone was purged with nitrogen for 30 minutes. After the nitrogen purge, the reaction kettle was heated to 80 ° C. with stirring, and the monomer solution prepared in advance was added dropwise over 3 hours using a dropping funnel. The polymerization start was carried out for 6 hours with the start of dropping as the polymerization start time. After completion of the polymerization, the polymerization solution is cooled with water to 30 ° C. or less, put into 2000 g of hexane, and the precipitated white powder is filtered off. Further, the filtered white powder is redissolved in 300 g of 2-butanone, charged again into 2000 g of hexane, and the precipitated white powder is filtered off. This redissolving and filtering operation was repeated three times, followed by drying at 50 ° C. for 17 hours to obtain a white powder polymer (75 g, yield 75%).
This polymer has Mw = 6000, Mw / Mn = 1.7, and as a result of ¹³ C-NMR analysis, fluorine content = 0 atom%, monomers (M-6), (M-4) and (M-9). And the content rate of each repeating unit derived from (M-8) was a copolymer of 41.3: 39.5: 9.2: 10.0 (mol%). This polymer is referred to as “resin (B-3)”.

[Synthesis of Resin (B-4)]
43.48 g (40 mol%) of the monomer (M-6), 32.91 g (40 mol%) of the monomer (M-4), 11.46 g (10 mol%) of the monomer (M-7) ) Is dissolved in 200 g of 2-butanone, and a monomer solution in which 4.26 g of azobisisobutyronitrile is further added is prepared. 12.15 g (10 mol%) of the monomer (M-8) A 1000 mL three-necked flask charged with 100 g of 2-butanone is purged with nitrogen for 30 minutes. After the nitrogen purge, the reaction kettle was heated to 80 ° C. with stirring, and the monomer solution prepared in advance was added dropwise over 3 hours using a dropping funnel. The polymerization start was carried out for 6 hours with the start of dropping as the polymerization start time. After completion of the polymerization, the polymerization solution was cooled with water to 30 ° C. or lower, poured into 2000 g of methanol, and the precipitated white powder was separated by filtration. The filtered white powder was washed twice with 400 g of methanol as a slurry, then filtered and dried at 50 ° C. for 17 hours to obtain a white powder polymer (76 g, yield 76%). .
This polymer has Mw = 5800, Mw / Mn = 1.6, and as a result of ¹³ C-NMR analysis, fluorine content = 0 atom%, monomers (M-6), (M-4) and (M-7). And the content rate of each repeating unit derived from (M-8) was a copolymer of 41.6: 39.5: 8.9: 10.0 (mol%). This polymer is referred to as “resin (B-4)”.

<Preparation of radiation-sensitive resin composition>
In the ratio shown in Table 1, the polymer (A), the resin (B), the acid generator (C), the nitrogen-containing compound (D) and the solvent (E) were mixed, and Examples 1 to 6 and Comparative Examples 1 to 1 were mixed. Each radiation sensitive resin composition of 2 was prepared.

Details of the acid generator (C), nitrogen-containing compound (D) and solvent (E) shown in Table 1 are shown below. In the table, “part” is based on mass unless otherwise specified.
[Acid generator (C)]
(C-1): Triphenylsulfonium nonafluoro-n-butanesulfonate (C-2): 1- (4-n-butoxynaphthyl) tetrahydrothiophenium perfluoro-n-butanesulfonate (C-3): Tri Phenylsulfonium 2- (bicyclo [2.2.1] hepta-2'-yl) -1,1,2,2-tetrafluoroethanesulfonate (C-4): 1- (4-n-butoxynaphthyl) tetrahydro Thiophenium 2- (bicyclo [2.2.1] hepta-2'-yl) -1,1,2,2-tetrafluoroethanesulfonate [nitrogen-containing compound (D)]
(D-1): Nt-butoxycarbonyl-4-hydroxypiperidine [solvent (E)]
(E-1): Propylene glycol monomethyl ether acetate (E-2): Gamma-butyrolactone (E-3): Cyclohexanone

<Evaluation of radiation-sensitive resin composition>
About each radiation sensitive resin composition of Examples 1-6 and Comparative Examples 1-2, various evaluation of following [1]-[6] was performed as follows. These evaluation results are shown in Table 2.

Each evaluation method is as follows.
[1] Measurement of Elution Amount As shown in FIG. 1, an 8-inch silicon wafer that has been subjected to HMDS (hexamethyldisilazane) 11 treatment (100 ° C., 60 seconds) in advance using CLEAN TRACK ACT8 (manufactured by Tokyo Electron Limited). A silicon rubber sheet 2 (manufactured by Kureha Elastomer Co., Ltd., thickness: 1.0 mm, shape: square with a side of 30 cm) was placed on the central part of 1. Next, 10 mL of ultrapure water 3 was filled in the hollowed portion at the center of the silicon rubber using a 10 mL hole pipette.
Thereafter, a lower antireflection film (“ARC29A”, manufactured by Brewer Science) 41 having a film thickness of 77 nm is formed in advance by CLEAN TRACK ACT8. The silicon wafer 4 on which the photoresist film 42 having a film thickness of 205 nm is formed by spin coating on the antireflection film 41 and baking under the conditions shown in Table 2 is aligned so that the resist coating surface is in contact with the ultrapure water 3. In addition, the ultrapure water 3 was placed on the silicon rubber sheet 2 so as not to leak from the silicon rubber 2.
And it kept for 10 seconds with the state. Thereafter, the 8-inch silicon wafer 4 was removed, and ultrapure water 3 was collected with a glass syringe, and this was used as a sample for analysis. The recovery rate of ultrapure water after the experiment was 95% or more.
Subsequently, the peak intensity of the anion part of the photoacid generator in the ultrapure water obtained above was calculated by LC-MS (liquid chromatograph mass spectrometer, LC part: SERIES1100 manufactured by AGILENT, MS part: Perseptive Biosystems, Inc. (Manufactured by Mariner) was measured under the following measurement conditions. At that time, each of the peak intensities of the 1 ppb, 10 ppb, and 100 ppb aqueous solutions of the photoacid generator was measured under the measurement conditions to prepare a calibration curve, and the elution amount was calculated from the peak intensity using the calibration curve. Similarly, each peak intensity of the 1 ppb, 10 ppb, and 100 ppb aqueous solutions of the acid diffusion control agent is measured under the measurement conditions to create a calibration curve, and the calibration curve is used to calculate the acid diffusion control agent from the peak intensity. The amount of elution was calculated. When the elution amount was 5.0 × 10 ⁻¹² mol / cm ² / sec or more, it was judged as “poor”, and when it was less than “good”.

(Column condition)
Column used: “CAPCELL PAK MG”, manufactured by Shiseido Co., Ltd., 1 flow rate: 0.2 mL / min Outflow solvent: water / methanol (3/7) with 0.1% by mass of formic acid Measurement temperature: 35 ℃

[2] Measurement of dynamic contact angle (advance contact angle and receding contact angle) Measurement of advancing contact angle and receding contact angle is based on each radiation-sensitive resin composition using “DSA-10” manufactured by KRUS. After forming a photoresist film and baking the substrate (wafer) prepared under the conditions shown in Table 2, immediately under the environment of room temperature: 23 ° C., humidity: 45%, normal pressure, as follows: It was measured.
(1) Adjust the wafer stage position.
(2) Set the wafer on the stage.
(3) Inject water into the needle.
(4) Finely adjust the position of the needle.
(5) Drain water from the needle to form 25 μL water droplets on the wafer.
(6) Pull out the needle from the water drop.
(7) Pull the needle down again to the position adjusted in <4> above.
(8-1) A water droplet is sucked from the needle at a speed of 10 μL / min for 90 seconds. At the same time, the receding contact angle is measured every second (total 90 times).
(8-2) Water droplets are injected from the needle at a rate of 10 μL / min for 90 seconds. Simultaneously, the advancing contact angle is measured every second (total 90 times).
(9) From the time when each contact angle is stabilized, an average value is calculated for each of the 20 contact angles (advance contact angle and receding contact angle), and set as the advancing contact angle and the receding contact angle.

[3] Sensitivity A 12-inch silicon wafer having a 77 nm-thick lower layer antireflection film (“ARC29A”, manufactured by Brewer Science) on the surface was used as the substrate. For the formation of this antireflection film, “CLEAN TRACK ACT12” (manufactured by Tokyo Electron Ltd.) was used.
Subsequently, the resist composition of Table 1 was spin-coated on the said board | substrate by the said CLEAN TRACK ACT12, and the photoresist film with a film thickness of 120 nm was formed by baking (PB) on the conditions of Table 2. This photoresist film is exposed through a mask pattern using an ArF excimer laser immersion exposure apparatus (“ASML AT1250i”, manufactured by ASML) with NA = 0.85, σ0 / σ1 = 0.96 / 0.76, and Dipole. did. At this time, pure water was used as an immersion solvent between the resist upper surface and the immersion exposure machine lens. Then, after performing PEB under the conditions shown in Table 2, it was developed with a 2.38 mass% tetramethylammonium hydroxide aqueous solution at 23 ° C. for 60 seconds, washed with water, and dried to form a positive resist pattern. did. At this time, the exposure amount for forming a line-and-space pattern (1L1S) having a line width of 65 nm in a one-to-one line width was defined as the optimum exposure amount, and this optimum exposure amount was defined as sensitivity. A scanning electron microscope (“S-9380”, manufactured by Hitachi High-Technologies Corporation) was used for this length measurement.

[4] Depth of focus (DOF)
A line and space pattern (1L1S) having a line width of 65 nm was formed in the same manner as in [3] above. In this case, the exposure amount for forming the line-and-space pattern with a one-to-one line width, that is, the depth of focus performance (DOF performance) at the sensitivity (optimum exposure amount) shown in Table 2, was measured using a scanning electron microscope. ("S-9380", manufactured by Hitachi High-Technologies Corporation).

[5] Cross-sectional shape of pattern In the same manner as in [3] above, the cross-sectional shape of the line and space pattern (1L1S) having a line width of 65 nm formed on the substrate 5 is shown in FIG. Observed with “S-4800” manufactured by High Technologies, measuring the line width Lb in the middle of the resist pattern 6 and the line width La at the top of the film, and the range of 0.9 ≦ La / Lb ≦ 1.1 The case of being within the range was defined as “good”, and the case of being within the range was defined as “defective”.

[6] Defect performance (measurement of the number of occurrences of watermark defects and bubble defects)
As a substrate, a 12-inch silicon wafer having a 77 nm-thick lower layer antireflection film (“ARC29A”, manufactured by Brewer Science) on the surface was used. For the formation of this antireflection film, “CLEAN TRACK ACT12” (manufactured by Tokyo Electron Ltd.) was used.
Next, the resist composition of Table 1 was spin-coated on the substrate by the CLEAN TRACK ACT12 and baked (PB) under the conditions of Table 2 to form a photoresist film having a thickness of 150 nm. This photoresist film is exposed through a mask pattern using an ArF excimer laser immersion exposure apparatus (“ASML AT1250i”, manufactured by ASML) with NA = 0.85, σ0 / σ1 = 0.96 / 0.76, and Annular. did. At this time, pure water was used as an immersion solvent between the resist upper surface and the immersion exposure machine lens. Then, after performing PEB under the conditions shown in Table 2, it was developed with a 2.38 mass% tetramethylammonium hydroxide aqueous solution at 23 ° C. for 60 seconds, washed with water, and dried to form a positive resist pattern. did. At this time, an exposure amount for forming a line-and-space pattern (1L1S) having a line width of 100 nm with a one-to-one line width was defined as an optimum exposure amount, and this optimum exposure amount was defined as sensitivity. A scanning electron microscope (“S-9380”, manufactured by Hitachi High-Technologies Corporation) was used for this length measurement.
Thereafter, the number of defects on the line and space pattern (1L1S) having a line width of 100 nm was measured using “KLA2351” manufactured by KLA-Tencor. Further, the defects measured by “KLA2351” were observed using a scanning electron microscope (“S-9380”, manufactured by Hitachi High-Technologies Corporation), and water expected to be derived from ArF excimer laser immersion exposure. Mark defects (water-mark defects) and bubble defects were distinguished, and the number of each defect was measured. A typical watermark defect is shown in FIG. 3, and a typical bubble defect is shown in FIG.

According to Table 2, when the radiation-sensitive resin composition of the present invention was used, the amount of eluate in water contacted during immersion exposure was small, and general resist performance (sensitivity, depth of focus, pattern) It was possible to confirm the effect of greatly reducing bubble defects that are expected to be derived from ArF excimer laser immersion exposure. Furthermore, when the resin composition of the present invention was used, it was confirmed that a high receding contact angle was given and the watermark defect expected from ArF excimer laser immersion exposure could be suppressed.
From the above, it can be seen that the resin composition of the present invention works well for immersion exposure, and is considered to work well in lithography that will be miniaturized in the future.

Claims (6)

A polymer (A) containing a fluorinated alkyl group, having a fluorine content of 3 atom% or more and becoming alkali-soluble by the action of an acid, and alkali-soluble by the action of an acid, and having a fluorine content of less than 3 atom% A radiation-sensitive resin composition for immersion exposure comprising a resin (B) and a radiation-sensitive acid generator (C),
Radiation-sensitive resin composition for immersion exposure, wherein a forward contact angle to water of a photoresist film formed by applying the radiation-sensitive resin composition for immersion exposure on a substrate is 95 degrees or less object.   The radiation-sensitive resin composition for immersion exposure according to claim 1, wherein the resin (B) comprises a repeating unit containing a lactone structure and a repeating unit containing a skeleton that becomes alkali-soluble by the action of an acid. . The liquid immersion according to claim 1 or 2, wherein the polymer (A) includes a repeating unit represented by the following general formula (1) and a repeating unit containing a skeleton that becomes alkali-soluble by the action of an acid. Radiation sensitive resin composition for exposure.
[In General Formula (1), R ¹ represents hydrogen, a methyl group or a trifluoromethyl group, A represents a single bond, a methylene group, an alkylene group having 2 to 6 carbon atoms, an oxygen atom, a sulfur atom, a carbonyloxy group, An oxycarbonyl group, an amide group, a sulfonylamide group or a urethane group is shown. R ² represents a linear or branched alkyl group having 1 to 6 carbon atoms, a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof containing at least one fluorine atom. Show. ]   The monomer giving the repeating unit represented by the general formula (1) is 2,2,2-trifluoroethyl (meth) acrylate, 2- (1,1,1,3,3,3-hexafluoro ) Propyl (meth) acrylate, 1- (2,2,3,3,4,4,5,5-octafluoro) hexyl (meth) acrylate, 1- (2,2,3,3,4,4,4) The radiation-sensitive resin composition for immersion exposure according to any one of claims 1 to 3, which is at least one selected from 4-heptafluoro) penta (meth) acrylate and perfluorocyclohexyl (meth) acrylate.   The content of the polymer (A) is 0.1% by mass or more when the total of the polymer (A) and the resin (B) is 100% by mass. A radiation-sensitive resin composition for immersion exposure as described in 1. (1) A step of forming a photoresist film on a substrate using the radiation-sensitive resin composition for immersion exposure according to any one of claims 1 to 5;
(2) irradiating the photoresist film with radiation through an immersion medium and a mask having a predetermined pattern, and exposing;
(3) A step of causing a phenomenon of the exposed photoresist film to form a resist pattern, and a method for forming a photoresist pattern.