JP2005077645A - Resist composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resist composition which is superior in transmission of radiation and dry etching resistance and used for far-ultraviolet rays, such as those of KrF and ArF excimer lasers and vacuum ultraviolet rays, such as those of F<SB>2</SB>excimer laser. <P>SOLUTION: The resist composition contains a fluorine polymer (A), having an acidic group blocked with an organic group containing one or more fluorine atoms, and an acidic group which is not blocked, an acid generating compound (B) for generating acid by receiving light irradiation, and an organic solvent (C). <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention relates to a novel resist composition. More specifically, the present invention relates to a chemically amplified resist composition suitable for fine processing using far ultraviolet rays such as KrF and ArF excimer lasers and vacuum ultraviolet rays such as F ₂ excimer lasers.

In recent years, in a semiconductor integrated circuit manufacturing process, a high-resolution and high-sensitivity chemically amplified photoresist material (resist composition) has been demanded as circuit patterns have become finer. As the circuit pattern becomes finer, it is essential to shorten the wavelength of the light source of the exposure apparatus, and far ultraviolet rays such as KrF or ArF excimer laser and vacuum ultraviolet rays such as F ₂ excimer laser are used. Resist materials used for these are required to have high radiation transparency. For lithography applications using a short-wavelength excimer laser of 250 nm or less, for example, a polyvinylphenol resin, an alicyclic acrylic resin, a polynorbornene resin (for example, see Patent Document 1), and a fluorine resin (for example, Patent Document 2). Photoresist materials such as the above have been proposed, but have not been able to have high radiation transmission and sufficient resolution and sensitivity.

International Publication No. 01/63362 pamphlet International Publication No. 00/17712 Pamphlet

As a photoresist material that can solve the above-mentioned problems, the present applicant has a cyclopolymerized unit based on the fluorine-containing diolefin represented by the formula (i) and an acidic group blocked by a blocking agent that is cleaved by an acid. A resist composition comprising a fluorine-containing polymer (A ′) containing a monomer-based polymer unit, an acid generating compound (B ′) that generates an acid upon receiving light irradiation, and an organic solvent (C ′) Was proposed (Japanese Patent Laid-Open No. 2002-303982).
^{_{CF 2 = CR 11 -Q-CR}} 12 = CH 2 (i)
(In the formula, R ¹¹ and R ¹² each independently represents a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group, and Q is an organic group having 2 to 5 carbon atoms.)

  As a chemically amplified resist composition, the resist composition is excellent in transparency, in particular, transparency to radiation and dry etching resistance, and can easily form a resist pattern excellent in sensitivity, resolution, flatness, heat resistance, etc. As a photoresist composition that can solve the above problems, its usefulness is very high.

However, in recent years, with the further promotion of miniaturization technology in the semiconductor industry, there is a demand for a resist composition having higher transparency, particularly higher radiation transparency.
That is, the present invention is a highly radiation transmissive resist composition suitable as a chemically amplified resist, particularly as a finely processed resist material using far ultraviolet rays such as KrF and ArF excimer lasers and vacuum ultraviolet rays such as F ₂ excimer lasers. The purpose is to provide goods.

In order to achieve the above object, the present invention provides a fluorine-containing polymer (A) having an acidic group blocked with an organic group containing one or more fluorine atoms and an acidic group not blocked. A resist composition comprising an acid generating compound (B) that generates an acid and an organic solvent (C) is provided.
In the resist composition of the present invention, the organic group containing one or more fluorine atoms is preferably an organic group represented by the formula (1).
—CHR ¹ —O—R ² (1)
In the formula, R ¹ represents a hydrogen atom or an alkyl group having 3 or less carbon atoms, and R ² represents an organic group containing one or more fluorine atoms. )

ここで式（２）中、Ｒ³は水素原子またはフッ素原子を表し、ｎは１〜８の整数を表す。式（３）中、Ｒ⁴、Ｒ⁵およびＲ⁶は、下記（ａ）および（ｂ）の条件を満たすことを条件に、それぞれ独立してフッ素原子、水素原子、炭素数３以下のアルキル基、ｔｅｒｔ−ブチル基、シクロヘキシル基、シクロペンチル基、炭素数３以下のフルオロアルキル基または−Ｃ（ＣＦ₃）₂ＯＨ基を表す。
（ａ）Ｒ⁴、Ｒ⁵およびＲ⁶のうち、少なくともいずれか１つは、フッ素原子またはフッ素原子を含む有機基である。
（ｂ）Ｒ⁴、Ｒ⁵およびＲ⁶のうち、いずれか１つが水素原子である場合、他の２つは水素原子以外である。
式（４）中、Ｒ⁷、Ｒ⁸およびＲ⁹は、少なくともいずれか１つがフッ素原子またはフッ素原子を含む有機基であることを条件に、それぞれ独立してフッ素原子、水素原子、炭素数３以下のフルオロアルキル基または−Ｃ（ＣＦ₃）₂ＯＨ基を表す。式（５）中、Ｒ¹⁰、Ｒ¹¹、Ｒ¹²およびＲ¹³は、少なくともいずれか１つがフッ素原子であることを条件に、それぞれ独立してフッ素原子または水素原子を表す。 In the resist composition of the present invention, R ² is preferably any one organic group of the following formulas (2) to (5).
—CH ₂ — (CF ₂ ) _n —R ³ (2)
―CR ⁴ R ⁵ R ⁶ (3)

Here, in Formula (2), R ³ represents a hydrogen atom or a fluorine atom, and n represents an integer of 1 to 8. In formula (3), R ⁴ , R ⁵ and R ⁶ are each independently a fluorine atom, a hydrogen atom and an alkyl group having 3 or less carbon atoms, provided that the following conditions (a) and (b) are satisfied. , A tert-butyl group, a cyclohexyl group, a cyclopentyl group, a fluoroalkyl group having 3 or less carbon atoms, or a —C (CF ₃ ) ₂ OH group.
(A) At least one of R ⁴ , R ⁵ and R ⁶ is a fluorine atom or an organic group containing a fluorine atom.
(B) When any one of R ⁴ , R ⁵ and R ⁶ is a hydrogen atom, the other two are other than a hydrogen atom.
In formula (4), R ⁷ , R ^8, and R ⁹ are each independently a fluorine atom, a hydrogen atom, or 3 carbon atoms, provided that at least one of them is a fluorine atom or an organic group containing a fluorine atom. represents the following fluoroalkyl group or -C (CF _{3) 2} OH group. In formula (5), R ¹⁰ , R ¹¹ , R ¹² and R ¹³ each independently represent a fluorine atom or a hydrogen atom, provided that at least one of them is a fluorine atom.

In the resist composition of the present invention, the non-blocked acidic group is preferably an unblocked acidic hydroxyl group.
In the resist composition of the present invention, the blocked acidic group is preferably a blocked acidic hydroxyl group.

In the resist composition of the present invention, the fluorine-containing polymer (A) is preferably a fluorine-containing polymer having an aliphatic ring structure in the main chain.
The fluorine-containing polymer (A) is preferably a fluorine-containing polymer having a monomer unit obtained by cyclopolymerizing the fluorine-containing diene represented by the formula (6).
^{_{CF 2 = CR 14 -Q-CR}} 15 = CH 2 ··· (6)
Here, in formula (6), R ¹⁴ and R ¹⁵ each independently represents a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. Q is a divalent organic group represented by the following formula (7).
^{-R 16 -C (R 18) (} R 19) -R 17 - ··· (7)
In the formula, each of R ¹⁶ and R ¹⁷ independently has a single bond, an oxygen atom, an alkylene group having 3 or less carbon atoms which may have an etheric oxygen atom, or an etheric oxygen atom. R ¹⁸ represents a hydrogen atom, a fluorine atom, an alkyl group having 3 or less carbon atoms or a fluoroalkyl group having 3 or less carbon atoms, and R ¹⁹ represents a fluorine atom. Having an acidic group blocked with an organic group containing one or more, an unblocked acidic group, an acidic group blocked with an organic group containing one or more fluorine atoms, or an unblocked acidic group Represents a monovalent organic group.

The resist composition of the present invention can be used as a chemically amplified resist. In particular, it can be used as a finely processed resist using far ultraviolet rays such as KrF and ArF excimer lasers and vacuum ultraviolet rays such as F ₂ excimer lasers. Compared with conventional resist compositions, it has a high transmittance, particularly a high radiation transmittance.
Furthermore, the resist formed from the resist composition of the present invention is excellent in dry etching resistance and can give a resist pattern excellent in sensitivity, resolution, flatness, heat resistance and the like.

  The resist composition of the present invention comprises a fluorine-containing polymer (A) having an acidic group blocked with an organic group containing one or more fluorine atoms and an unblocked acidic group, an acid that generates an acid upon irradiation with light. A resist composition comprising a generating compound (B) and an organic solvent (C) (hereinafter referred to as “the composition of the present invention”).

The fluorine-containing polymer (A) of the present invention has an acidic group blocked with an organic group containing one or more fluorine atoms.
The fluorine-containing polymer (A) of the present invention is a light beam used in a laser exposure apparatus because an organic group in which an acidic group is blocked (hereinafter sometimes referred to as “blocked group”) contains one or more fluorine atoms. In particular, it is excellent in transparency of far ultraviolet rays such as KrF or ArF excimer laser and vacuum ultraviolet rays such as F ₂ excimer laser.

In addition to being an organic group containing one or more fluorine atoms, the blocking group has a characteristic that it is easily eliminated by an acid and hardly eliminated by an alkali. Specifically, the blocking group that satisfies this condition is preferably an organic group having a structure of the formula (1).
—CHR ₁ —O—R ² (1)
Here, in formula (1), R ¹ represents a hydrogen atom or an alkyl group having 3 or less carbon atoms. Among these, a hydrogen atom or a methyl group is preferable because it is easily available. On the other hand, R ² is an organic group containing one or more fluorine atoms. The resist composition of the present invention is excellent in transparency of vacuum ultraviolet rays such as F ₂ excimer laser because R ² contains one or more fluorine atoms.

Furthermore, R ² is preferably an organic group having any one of the following formulas (2) to (5).
—CH ₂ — (CF ₂ ) _n —R ³ (2)
―CR ⁴ R ⁵ R ⁶ (3)

In the above formula (2), R ³ represents a hydrogen atom or a fluorine atom, and n represents an integer of 1 to 8.
In the above formula (3), R ⁴ , R ⁵ and R ⁶ are each independently a fluorine atom, a hydrogen atom, an alkyl having 3 or less carbon atoms, provided that the following conditions (a) and (b) are satisfied. Group, a tert-butyl group, a cyclohexyl group, a cyclopentyl group, a fluoroalkyl group having 3 or less carbon atoms, or a —C (CF ₃ ) ₂ OH group.
(A) At least one of R ⁴ , R ⁵ and R ⁶ is a fluorine atom or an organic group containing a fluorine atom.
(B) When any one of R ⁴ , R ⁵ and R ⁶ is a hydrogen atom, the other two are other than a hydrogen atom.

In the above formula (4), R ⁷ , R ⁸ and R ⁹ are each independently a fluorine atom, a hydrogen atom, or a carbon number, provided that at least one of them is a fluorine atom or an organic group containing a fluorine atom. 3 or less fluoroalkyl groups or —C (CF ₃ ) ₂ OH group
In the above formula (5), R ¹⁰ , R ¹¹ , R ¹² and R ¹³ each independently represents a fluorine atom or a hydrogen atom, provided that at least one of them is a fluorine atom.
Each independently represents a fluorine atom, a hydrogen atom, an alkyl group having 3 or less carbon atoms, a tert-butyl group, a cyclohexyl group, a cyclopentyl group, a fluoroalkyl group having 3 or less carbon atoms, or a —C (CF ₃ ) ₂ OH group.

R ² is preferably an organic group having any one structure among the above formulas (2), (4) and (5) because it is easily available. In Formula (2), since it is easy to obtain, n is more preferably an integer of 1 to 4. In particular, n is an integer of 1 to 3, and R ³ is preferably a hydrogen atom or a fluorine atom. In the formula (4), it is more preferable that at least one of R ⁷ , R ⁸ and R ⁹ is a fluorine atom because it is easily available. Furthermore, it is preferable that any one or two are fluorine atoms and the rest are hydrogen atoms.

  As described above, the fluoropolymer (A) has an acidic group that is blocked with an organic group containing one or more fluorine atoms. Hereinafter, the blocked acidic group is referred to as a blocked acidic group, and the non-blocked acidic group is referred to as an acidic group. The blocked acidic group is preferably an acidic group blocked with an organic group represented by the formula (1). Being blocked means that the acidic hydrogen of the acidic group is replaced by the blocking group. Here, the fluorine-containing polymer (A) also has an acidic group. The solubility of the resist material can be controlled by controlling the ratio of acidic groups and blocked acidic groups. In the fluoropolymer (A), the ratio of the blocked acidic group to the total of the blocked acidic group and the acidic group (hereinafter referred to as the blocking ratio) is preferably from 5 to 99 mol%, particularly from 10 to 90 mol%. preferable. When the blocking ratio is in the above range, the solubility of the resist composition is good, and other properties required for the resist, that is, excellent in radiation transparency, resolution, sensitivity, and the like.

  The fluorine-containing polymer (A) in the present invention is a polymer containing a fluorine atom bonded to a carbon atom of the main chain of the polymer. In particular, the ratio of the number of fluorine atoms to the total number of atoms is 15% to 75%, and a polymer having fluorine atoms in the main chain is preferable. A resist composition containing such a fluorine-containing polymer is excellent in radiation transmittance and excellent in dry etching resistance.

  The fluorine-containing polymer (A) in the present invention is preferably a fluorine-containing polymer having an aliphatic ring structure in the main chain. “Aliphatic ring structure” refers to a ring structure having a cyclic structure consisting of only a carbon atom or a carbon atom and another atom, and having no delocalized unsaturated double bond. Other atoms are preferably oxygen atoms. The number of atoms constituting the ring is preferably 4 to 8, particularly 5 to 7.

  The phrase “having an aliphatic ring structure in the main chain” means that one or more carbon atoms constituting the aliphatic ring are carbon atoms in the main chain. The carbon atom of the main chain has two bonds that bond to the side chain, so that when one of the carbon atoms constituting the aliphatic ring is a carbon atom of the main chain, the carbon of that one main chain A divalent group is bonded to the atom (an aliphatic ring is constituted by the main chain carbon atom and the divalent group). When two or more of the carbon atoms constituting the aliphatic ring are carbon atoms of the main chain, two different carbon atoms that are carbon atoms of the main chain are divalent to two different carbon atoms. A group is bonded (when two carbon atoms of the main chain to which a divalent group is bonded are adjacent to each other, the two carbon atoms and the divalent group form an aliphatic ring. And when there are more carbon atoms of the main chain between two carbon atoms of the main chain to which the divalent group is bonded, the three or more main chain carbon atoms and the divalent group An aliphatic ring is constructed.)

  The fluorine-containing polymer having an aliphatic ring structure in the main chain is composed of a compound having an aliphatic ring structure and one polymerizable double bond formed from at least one carbon atom forming the aliphatic ring. A fluorine-containing polymer having a monomer unit or a fluorine-containing polymer having a monomer unit obtained by cyclopolymerization of a fluorine-containing diene is preferable.

The fluorine-containing polymer (A) in the present invention is particularly preferably a fluorine-containing polymer having a monomer unit obtained by cyclopolymerizing the fluorine-containing diene represented by the formula (6).
^{_{CF 2 = CR 14 -Q-CR}} 15 = CH 2 ··· (6)
In the formula, R ¹⁴ and R ¹⁵ each independently represents a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group, and Q represents a divalent organic group represented by the formula (7). Represent.
^{-R 16 -C (R 18) (} R 19) -R 17 - ··· (7)
In the formula, each of R ¹⁶ and R ¹⁷ independently has a single bond, an oxygen atom, an alkylene group having 3 or less carbon atoms which may have an etheric oxygen atom, or an etheric oxygen atom. An optionally substituted fluoroalkylene group having 3 or less carbon atoms, R ¹⁸ represents a hydrogen atom, a fluorine atom, an alkyl group having 3 or less carbon atoms or a fluoroalkyl group having 3 or less carbon atoms, R ¹⁹ is a blocked acidic group, An acidic group or a monovalent organic group having a blocked acidic group or acidic group is represented.

It is considered that the monomer units of the following (a) to (c) are generated by cyclopolymerization of the fluorine-containing diene represented by the formula (6) (hereinafter referred to as fluorine-containing diene (6)), and spectroscopic analysis As a result, the cyclized polymer of the fluorine-containing diene (6) is a polymer having a structure containing at least one monomer unit selected from the monomer unit (a), the monomer unit (b), and the monomer unit (c). it is conceivable that. The main chain of the cyclized polymer is composed of carbon atoms constituting a polymerizable unsaturated bond (in the case of fluorine-containing diene (6), four carbon atoms constituting a polymerizable unsaturated double bond). Refers to the carbon chain.

The alkylene group in R ¹⁶ and R ¹⁷ of the fluorinated diene (6) is preferably (CH ₂ ) _m , and the fluoroalkylene group is preferably (CF ₂ ) _n (m and n are each an integer of 1 to 3). In the combination of R ¹⁶ and R ¹⁷ , both of these groups are preferred (in which case m + n is preferably 2 or 3), or one of these groups is preferred and the other is a single bond or an oxygen atom. . The alkyl group in R ¹⁸ is preferably a methyl group, and the fluoroalkyl group is preferably a trifluoromethyl group.

  Examples of the acidic group include an acidic hydroxyl group, a carboxylic acid group, and a sulfonic acid group. Particularly, an acidic hydroxyl group and a carboxylic acid group are preferable, and an acidic hydroxyl group is most preferable. An acidic hydroxyl group is an acidic hydroxyl group, for example, a hydroxyl group directly bonded to the ring of an aryl group (phenolic hydroxyl group), a hydroxyl group bonded to a carbon atom to which a perfluoroalkyl group is bonded, or a tertiary carbon atom. There are hydroxyl groups. In particular, a hydroxyl group bonded to a carbon atom to which one or two perfluoroalkyl groups are bonded is preferable. As a perfluoroalkyl group, a C1-C2 perfluoroalkyl group is preferable. When the perfluoroalkyl group is a trifluoromethyl group, for example, a hydroxyl group in the divalent group represented by the following formula (d-1) (that is, a hydroxyl group of a hydroxytrifluoromethylmethylene group), or the following formula (d- 2) or a hydroxyl group in a monovalent group represented by the following formula (d-3) (that is, a 1-hydroxy-1-trifluoromethyl-2,2,2-trifluoroethyl group or 1-hydroxy-1- A hydroxyl group of methyl-2,2,2-trifluoroethyl group) is preferred.

  The blocked acidic group is an acidic group blocked with an organic group having one or more fluorine atoms as described above, and the acidic group means the acidic group.

R ¹⁹ in the case of a blocked acidic group or a monovalent organic group having an acidic group is preferably an organic group having 8 or less carbon atoms, and the portion other than the blocked acidic group or acidic group is a hydrocarbon group or a fluorocarbon group. A hydrogen group is preferred. Among these, a blocked acidic group or an alkyl group having 2 to 6 carbon atoms, an acidic group having 2 to 6 carbon atoms, a fluoroalkyl group having 2 to 6 carbon atoms, and a phenylalkyl group having 7 to 9 carbon atoms are preferable. Specific examples of R ¹⁹ include the following groups.
_{- (CH 2) k -X,} - (CH 2) k C (CF 3) 2 -X,
_{- (CH 2) k C (} CH 3) 2 -X,
_{- (CH 2) k C (} CF 3) (CH 3) -X,
_{- (CH 2) k CH (} CH 3) -X, - (CH 2) k C 6 H 4 -X
Here, k represents an integer of 1 to 6, X represents a blocked acidic group or acidic group, and C ₆ H ₄ represents a phenylene group.

A preferred fluorine-containing diene (6) is a compound represented by the following chemical formula.
_{CF 2 = CF (CF 2)} a C (-Y) (CF 3) (CH 2) b CH = CH 2,
CF ₂ = CF (CF ₂ ) _a C (—Y) (CF ₃ ) (CF ₂ ) _b CH═CH ₂ ,
_{CF 2 = CF (CH 2)} a C (-Y) (CF 3) (CH 2) b CH = CH 2,
_{CF 2 = CF (CH 2)} a C (-Y) (CF 3) (CF 2) b CH = CH 2,
_{CF 2 = CF (CF 2)} a C (-Y) (CF 3) (CF 2) b C (CH 3) = CH 2,
_{CF 2 = C (CF 3)} (CF 2) a C (-Y) (CF 3) (CF 2) b CH = CH 2,
CF ₂ = CF (CF ₂ ) _a CH (-Z) (CH ₂ ) _b CH = CH ₂
Here, Y represents X or R ¹⁹ , Z represents R ¹⁹ , and a and b each independently represent an integer of 0 to 3 (where a + b is 1 to 3). X and R ¹⁹ are as described above.

The most preferred fluorine-containing diene (6) is a compound represented by the following formulas (9) and (10).
_{CF 2 = CFCF 2 C (-X} ) (CF 3) CH 2 CH = CH 2 ··· (9)
_{CF 2 = CFCF 2 CH (-} (CH 2) p C (CF 3) 2 -X) CH 2 CH = CH 2 ··· (10)
In formula (10), p represents an integer of 1 to 3. X is as described above.

In the fluoropolymer (A) in the present invention, an organic group represented by the formula (1) as a blocking group and a blocking group different from the group (hereinafter referred to as other blocking group) are used in combination. You can also Hereinafter, the acidic group blocked by the organic group represented by the formula (1) is also referred to as a blocked acidic group (1), and the acidic group blocked by another blocking group is also referred to as another blocked acidic group. In this case, the blocking ratio of the fluoropolymer (A) is preferably in the above-described range as a whole. That is, the ratio of the total number of blocked acidic groups (1) and other blocked acidic groups to the total number of blocked acidic groups and acidic groups of the fluoropolymer (A) is preferably 5 to 99 mol%. In particular, 10 to 90 mol% is preferable.
Further, among the blocking ratio, the ratio of the blocking group of formula (1) (the ratio of the blocking acidic group (1) to the total of the blocking acidic group (1) and other blocking acidic groups) is 5 It is preferable that it is -90 mol%.

Here, the other blocked acidic group is an ester-based blocked acidic group in which the acidic hydrogen atom of the carboxylic acid or sulfonic acid is substituted with an alkyl group or the like when the acidic group is a carboxylic acid group or a sulfonic acid group. In the case where the acidic group is an acidic hydroxyl group, an acetal or ketal other than the structure of the formula (1) obtained by substituting the hydrogen atom of the acidic hydroxyl group with an alkyl group, an alkoxycarbonyl group, an acyl group, a cyclic ether group or the like , Ester, carbonate ester such as tert-butoxycarbonyl group (—COO (t—C ₄ H ₉ )), ether type blocked acidic group.

Examples of the alkyl group include an alkyl group having 1 to 6 carbon atoms which does not have a fluorine atom and may have a substituent (such as an aryl group or an alkoxy group). Specific examples of these alkyl groups include alkyl groups having 6 or less carbon atoms (such as tert-butyl group (t-C ₄ H ₉ )) and aryl group-substituted alkyl groups having 7 to 20 carbon atoms (benzyl group, trimethyl group). Phenylmethyl group, p-methoxybenzyl group, 3,4-dimethoxybenzyl group, etc.), alkoxyalkyl groups having 8 or less carbon atoms (methoxymethyl group, (2-methoxyethoxy) methyl group, benzyloxymethyl group, etc.) Can be mentioned. Preferable alkoxycarbonyl group for substituting a hydrogen atom of a hydroxyl group includes an alkoxycarbonyl group having 8 or less carbon atoms, and examples thereof include a tert-butoxycarbonyl group. Preferred acyl groups for substituting the hydrogen atom of the hydroxyl group include acyl groups having a total carbon number of 8 or less, and examples thereof include a pivaloyl group, a benzoyl group, and an acetyl group. Preferred examples of the cyclic ether group for substituting the hydrogen atom of the hydroxyl group include a tetrahydropyranyl group (THP).

  The acidic group of the fluoropolymer in the present invention may be present in advance in the monomer for obtaining the fluoropolymer, or has a group that can be converted into an acidic group in the monomer, and is converted into an acidic group after polymerization. May be. The blocked acidic group may also be a monomer having a blocked acidic group by reacting a compound having a blocked group with the acidic group (hereinafter also referred to as a blocking agent) at the monomer stage. Alternatively, after polymerization of a monomer having a group that can be converted into an acidic group, in the case of this acidic group or a group that can be converted into an acidic group, the acidic group after conversion to an acidic group can be reacted with a blocking agent to form a blocked acidic group. Good.

The blocking agent for introducing the organic group represented by the formula (1) is not particularly limited as long as it contains the organic group represented by the formula (1) and can replace an acidic hydrogen atom. A preferred example is a halide represented by (11).
P—CHR ¹ —O—R ² (11)
Here, P represents a halogen atom. Of the halogen atoms, a chlorine atom is particularly preferable. R ¹ and R ² are as described above for Formula (1).

  Another blocked acidic group is obtained by reacting a hydroxyl group, carboxylic acid group or sulfonic acid group, which is an acidic group, with a compound having another blocking group (hereinafter also referred to as other blocking agent). Can do. These other blocking agents include halogenated methyl alkyl ethers, alkyl halides, acid chlorides, acid anhydrides, chlorocarbonates, dialkyl dicarbonates (such as di-tert-butyl dicarbonate), 3, 4 -Dihydro-2H-pyran and the like.

  Specific examples of other blocking agents useful for blocking acidic hydroxyl groups in the present invention include: J. et al. Pearson and W.W. R. Edited by Roush, Handbook of Reagents for Organic Synthesis: Activating Agents and Protecting Groups, John Wiley & Sons (1999).

The acidic hydroxyl group is blocked by another specific blocking _{group, -O (t-C 4 H} 9), - OCH 2 OCH 3, -OCH 2 OC 2 H 5, -CO 2 (t-C _{4 H 9), - OCH (} CH 3) OC 2 H 5, 2- tetrahydropyranyloxy group is preferred.

  When the fluorine-containing diene represented by the formula (6) contains a cyclopolymerized monomer unit, the fluorine-containing polymer (A) is a radical polymerizable monomer (hereinafter referred to as “other polymer”) within a range not impairing the characteristics. A monomer unit derived from “monomer”) may be included. The proportion of monomer units derived from other monomers is preferably 30 mol% or less, particularly preferably 15 mol% or less. Further, the fluorine-containing polymer (A) may contain two or more monomer units obtained by cyclopolymerization of the fluorine-containing diene represented by the formula (6).

  Examples of other monomers that can be exemplified include α-olefins such as ethylene, propylene, and isobutylene, fluorine-containing olefins such as tetrafluoroethylene and hexafluoropropylene, and perfluoro (2,2-dimethyl-1,3-dioxole). Fluorine-containing cyclic monomers, perfluorodienes that can be cyclopolymerized such as perfluoro (butenyl vinyl ether), acrylic esters such as methyl acrylate and ethyl methacrylate, vinyl esters such as vinyl acetate, vinyl benzoate, and vinyl adamantylate , Vinyl ethers such as ethyl vinyl ether and cyclohexyl vinyl ether, cyclic olefins such as cyclohexene, norbornene and norbornadiene, maleic anhydride, vinyl chloride and the like.

Further, as another monomer, a monomer having a blocked acidic group can also be used. Specific examples of such a monomer having a blocked acidic group include (meth) acrylic acid esters such as tert-butyl acrylate, tert-butyl methacrylate, and tetrahydropyranyl acrylate. ether or tert- butyl _{ether, CH 2 = CHCH 2 C (} CF 3) 2 OCO 2 -t-C 4 H 9, CH 2 = CHCH 2 C (CF 3) 2 OCH (CH 3) OC 2 H ₅ etc. are mentioned.

  The molecular weight of the fluorine-containing polymer (A) in the present invention is not particularly limited as long as it can be uniformly dissolved in an organic solvent described later and can be uniformly applied to a substrate, but the polystyrene-equivalent number average molecular weight is usually 1,000 to 100,000. Preferably, it is 2000-20,000. By setting the number average molecular weight to 1000 or more, a better resist pattern can be obtained, the remaining film ratio after development is sufficient, and the shape stability during pattern heat treatment is also improved. Further, by setting the number average molecular weight to 100,000 or less, the coating property of the composition is better and sufficient developability can be maintained.

  The fluorine-containing polymer (A) is obtained by homopolymerizing a fluorine-containing monomer having an acidic group blocked with an organic group containing one or more fluorine atoms and an unblocked acidic group under a polymerization initiation source, or It can be obtained by copolymerizing the fluorine-containing monomer and another monomer as required. Also, after producing a fluorinated polymer using the corresponding fluorinated monomer having only non-blocked acidic groups, a part of the acidic groups in the fluorinated polymer is blocked with a blocking agent to fluorinate. A polymer (A) can also be obtained. Conversely, after producing a fluoropolymer using a fluoromonomer containing only an acidic group blocked with an organic group containing one or more fluorine atoms, one of the blocked acidic groups in the fluoropolymer is produced. The part can be deblocked to obtain the fluoropolymer (A). The polymerization initiation source is not particularly limited as long as the polymerization reaction proceeds radically, and examples thereof include a radical generator, light, and ionizing radiation. In particular, radical generators are preferable, and peroxides, azo compounds, persulfates and the like are exemplified. The polymerization method is also not particularly limited, so-called bulk polymerization in which the monomer is directly subjected to polymerization, fluorinated hydrocarbon, chlorinated hydrocarbon, fluorinated chlorohydrocarbon, alcohol, hydrocarbon that dissolves the monomer. Examples include solution polymerization performed in other organic solvents, suspension polymerization performed in the presence or absence of a suitable organic solvent in an aqueous medium, and emulsion polymerization performed by adding an emulsifier to an aqueous medium.

  The acid generating compound (B) that generates an acid upon receiving light irradiation in the present invention is a compound that generates an acid upon exposure. By this acid, the blocked acidic group present in the fluorine-containing polymer (A) is cleaved (deblocked). As a result, the exposed portion of the resist film becomes readily soluble in an alkaline developer, and a positive resist pattern is formed by the alkaline developer. As the acid generating compound (B) that generates an acid upon receiving such light irradiation, an acid generating compound that is used in a normal chemically amplified resist material can be employed, and an onium salt, a halogen-containing compound, a diazoketone. A compound, a sulfone compound, a sulfonic acid compound, etc. can be mentioned. Examples of these acid generating compounds (B) include the following.

  Examples of onium salts include iodonium salts, sulfonium salts, phosphonium salts, diazonium salts, pyridinium salts, and the like. Specific examples of preferred onium salts include diphenyliodonium triflate, diphenyliodonium pyrenesulfonate, diphenyliodonium dodecylbenzenesulfonate, bis (4-tert-butylphenyl) iodonium triflate, bis (4-tert-butylphenyl) iodonium dodecylbenzene. Sulfonate, triphenylsulfonium triflate, triphenylsulfonium hexafluoroantimonate, 1- (naphthylacetomethyl) thiolanium triflate, cyclohexylmethyl (2-oxocyclohexyl) sulfonium triflate, dicyclohexyl (2-oxocyclohexyl) sulfonium triflate , Dimethyl (4-hydroxynaphthyl) sulfonium tosylate, dimethyl (4 Hydroxynaphthyl) sulfonium dodecylbenzenesulfonate, dimethyl (4-hydroxynaphthyl) sulfonium naphthalene sulfonate, triphenylsulfonium camphorsulfonate, and the (4-hydroxyphenyl) benzyl methyl sulfonium toluene sulfonate and the like.

  Examples of the halogen-containing compound include a haloalkyl group-containing hydrocarbon compound and a haloalkyl group-containing heterocyclic compound. Specific examples include (trichloromethyl) -s- such as phenyl-bis (trichloromethyl) -s-triazine, methoxyphenyl-bis (trichloromethyl) -s-triazine, and naphthyl-bis (trichloromethyl) -s-triazine. Examples include triazine derivatives and 1,1-bis (4-chlorophenyl) -2,2,2-trichloroethane.

  Examples of the sulfone compound include β-ketosulfone, β-sulfonylsulfone, and α-diazo compounds of these compounds. Specific examples include 4-trisphenacylsulfone, mesitylphenacylsulfone, bis (phenylsulfonyl) methane, and the like. 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 include benzoin tosylate and 1,8-naphthalenedicarboxylic imide triflate. In this invention, an acid generator compound (B) can be used individually or in mixture of 2 or more types.

  The organic solvent (C) in the present invention is not particularly limited as long as it dissolves both components (A) and (B). Alcohols such as methyl alcohol and ethyl alcohol, ketones such as acetone, methyl isobutyl ketone, cyclohexanone and 2-heptanone, acetates such as ethyl acetate and butyl acetate, aromatic hydrocarbons such as toluene and xylene, propylene glycol monomethyl Examples thereof include glycol monoalkyl ethers such as ether and propylene glycol monoethyl ether, and glycol monoalkyl ether esters such as propylene glycol monomethyl ether acetate and carbitol acetate.

The proportion of each component in the resist composition of the present invention is such that the acid generating compound (B) is 0.1 to 20 parts by mass and the organic solvent (C) is 50 to 2000 parts by mass with respect to 100 parts by mass of the fluoropolymer (A). Is appropriate. Preferably, they are 0.1-10 mass parts of acid generating compounds (B) and 100-1000 mass parts of organic solvent (C) with respect to 100 mass parts of fluoropolymer (A).
By setting the amount of the acid generating compound (B) used to be 0.1 parts by mass or more, sufficient sensitivity and developability can be given, and by setting it to 10 parts by mass or less, the radiation transmittance is sufficiently high. Thus, a more accurate resist pattern can be obtained.

  The resist composition of the present invention includes an acid-cleavable additive for improving pattern contrast, a surfactant for improving coating properties, a nitrogen-containing basic compound for adjusting an acid generation pattern, and adhesion to a substrate. In order to improve the property, an adhesion assistant, a storage stabilizer or the like can be appropriately blended depending on the purpose in order to improve the storage stability of the composition. The resist composition of the present invention is preferably used after being uniformly mixed with each component and then filtered through a 0.03-0.45 μm filter.

  A resist film is formed by applying and drying the resist composition of the present invention on a substrate such as a silicone wafer. As the coating method, spin coating, flow coating, roll coating or the like is employed. Light irradiation is performed on the formed resist film through a mask on which a pattern is drawn, and then development processing is performed to form a pattern.

As the irradiated light, far ultraviolet rays such as g-rays having a wavelength of 436 nm, i-rays having a wavelength of 365 nm, KrF excimer lasers having a wavelength of 248 nm, ArF excimer lasers having a wavelength of 193 nm, F ₂ excimer lasers having a wavelength of 157 nm, and vacuum ultraviolet rays. Is mentioned. The resist composition of the present invention is a resist composition useful for applications in which ultraviolet light having a wavelength of 250 nm or less, particularly ultraviolet light having a wavelength of 200 nm or less (ArF excimer laser light or F ₂ excimer laser light) is used as a light source.

  Various alkaline aqueous solutions are applied as the developing solution. Examples of the alkali include sodium hydroxide, potassium hydroxide, ammonium hydroxide, tetramethylammonium hydroxide, triethylamine and the like.

EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited only to these Examples. Note that THF represents tetrahydrofuran, R113 represents trichlorotrifluoroethane (organic solvent), TFE represents tetrafluoroethylene, MOM represents a methoxymethyl group, EOM represents an ethoxymethyl group, and tBOC represents a tert-butoxycarbonyl group.
(Synthesis Example 1)
[Synthesis example of chloromethyl 2-trifluoroethyl ether (ClCH ₂ OCH ₂ CF ₃ )]
A. Warshawsky, A .; Deshe, R.A. Gutman, British Polymer Journal, 16 (1984) 234. , And J.A. Polym. Sci. Polym. Chem. Ed. 23 (6) (1985) 1839. Synthesis was performed based on
A 500 mL glass reaction vessel was purged with nitrogen, 25.7 g of 2-trifluoroethanol and 200 mL of dehydrated chloroform were added, and the solution was stirred with a stirrer. When completely dissolved, 7.70 g of paraformaldehyde was added. The reaction vessel was then cooled to 0-5 ° C. with an ice bath. Hydrogen chloride was introduced into the system with a bubbler. When the reaction is completed, the solution is no longer suspended by paraformaldehyde, and the solution becomes transparent. After completion of the reaction, the introduction of hydrogen chloride was stopped and the two layers were separated, so the lower layer was taken, and 28.3 g of anhydrous calcium chloride powder was added and dried. The solvent was distilled off to obtain 33.0 g of the desired product (purity by NMR: 93%).
The ¹ H NMR and ¹⁹ F NMR data are shown below.
¹ H NMR (399.8 MHz, solvent: CDCl ₃ , standard: tetramethylsilane) δ (ppm): 3.95 (m, 2H), 5.43 (m, 2H).
¹⁹ F NMR (376.2 MHz, solvent: CDCl ₃ , standard: CFCl ₃ ) δ (ppm): −77.69 (m, 3F).

(Synthesis Example 2)
[Synthesis example of chloromethyl 2,2,3,3-tetrafluoropropyl ether (ClCH ₂ OCH ₂ CF ₂ CF ₂ H)]
The synthesis procedure was performed according to Synthesis Example 1. Yield 90%, purity 90% (according to NMR). The ¹ H NMR and ¹⁹ F NMR data are shown below.
¹ H NMR (399.8 MHz, solvent: CDCl ₃ , standard: tetramethylsilane) δ (ppm): 3.93 to 4.05 (m, 2H), 5.50 to 5.52 (m, 2H), 5.75-6.13 (m, 1H).
¹⁹ F NMR (376.2 MHz, solvent: CDCl ₃ , reference: CFCl ₃ ) δ (ppm): −127.33 to −127.45 (m, 2F), −139.16 to −139.35 (m, 2F).

(Synthesis Example 3)
[Synthesis example of chloromethyl 2-fluorocyclohexyl ether]
2-Fluorocyclohexanol is described in Reinhold, Karin, Helvetica Chimica Acta, 66 (8) (1983) 2534. Synthesized according to Using this 2-fluorocyclohexanol, the synthesis procedure was based on Synthesis Example 1 to synthesize chloromethyl 2-fluorocyclohexyl ether. Yield 88%, purity 90% (according to NMR). The ¹ H NMR and ¹⁹ F NMR data are shown below.
¹ H NMR (399.8 MHz, solvent: CDCl ₃ , standard: tetramethylsilane) δ (ppm): 1.19 to 1.74 (m, 8H), 3.61 (s, 1H (exo, endo body mixture) )), 4.37 (s, 1H (exo, endo isomer mixture)), 5.28-5.37 (m, 2H).
¹⁹ F NMR (376.2 MHz, solvent: CDCl ₃ , reference: CFCl ₃ ) δ (ppm): −205.00 (m, 1F).

６−フルオロ−ビシクロ[２．２．１]ヘプチル−２−オールはＧｒｏｂ，Ｃｙｒｉｌ Ａ．；Ｈａｎｒｅｉｃｈ，Ｒｅｉｎｈａｒｄ；Ｗａｌｄｎｅｒ，Ａｄｒｉａｎ．Ｔｅｔｒａｈｅｄｒｏｎ Ｌｅｔｔｅｒｓ，２２（３４）（１９８１）３２３１．に則って合成した。この６−フルオロ−ビシクロ[２．２．１]ヘプチル−２−オールを用いて合成手順は合成例１に準拠してクロロメチル６−フルオロ−ビシクロ[２．２．１]ヘプチル−２−エーテルの合成を行った。合成手順は合成例１に準拠して行った。収率８５％、純度８９％（ＮＭＲによる）。以下に、¹Ｈ ＮＭＲおよび¹⁹Ｆ ＮＭＲのデータを示す。
¹Ｈ ＮＭＲ（３９９．８ＭＨｚ、溶媒：ＣＤＣｌ₃、基準：テトラメチルシラン）δ（ｐｐｍ）:１.２５〜２．１３（ｓ，８Ｈ），２．５３（ｓ，１Ｈ），３．８４（ｓ，１Ｈ），５．３５（ｓ，２Ｈ）。
¹⁹Ｆ ＮＭＲ（３７６．２ＭＨｚ、溶媒：ＣＤＣｌ₃、基準：ＣＦＣｌ₃）δ（ｐｐｍ）:−１８２．５３（ｍ，１Ｆ）。 (Synthesis Example 4)
[Synthesis example of chloromethyl 6-fluoro-bicyclo [2.2.1] heptyl-2-ether (the following formula)]

6-Fluoro-bicyclo [2.2.1] heptyl-2-ol is described in Grob, Cyril A. et al. Hanreich, Reinhard; Waldner, Adrian. Tetrahedron Letters, 22 (34) (1981) 3231. Synthesized according to The synthesis procedure using 6-fluoro-bicyclo [2.2.1] heptyl-2-ol was performed according to Synthesis Example 1 and chloromethyl 6-fluoro-bicyclo [2.2.1] heptyl-2-ether. Was synthesized. The synthesis procedure was performed according to Synthesis Example 1. Yield 85%, purity 89% (according to NMR). The ¹ H NMR and ¹⁹ F NMR data are shown below.
¹ H NMR (399.8 MHz, solvent: CDCl ₃ , standard: tetramethylsilane) δ (ppm): 1.25 to 2.13 (s, 8H), 2.53 (s, 1H), 3.84 ( s, 1H), 5.35 (s, 2H).
¹⁹ F NMR (376.2 MHz, solvent: CDCl ₃ , standard: CFCl ₃ ) δ (ppm): 182.53 (m, 1F).

(Synthesis Example 5)
[Synthesis example of 1,1,2,3,3-pentafluoro-4-trifluoromethyl-4-hydroxy-1,6-heptadiene]
A 2 L glass reactor was charged with 108 g of CF ₂ ClCFClCF ₂ C (O) CF ₃ and 500 mL of dehydrated THF and cooled to 0 ° C. A solution obtained by further diluting 200 mL of a 2M THF solution of CH ₂ ═CHCH ₂ MgCl with 200 mL of dehydrated THF under a nitrogen atmosphere was added dropwise over about 5.5 hours. After completion of the dropwise addition, the mixture was stirred at 0 ° C. for 30 minutes and at room temperature for 17 hours, and then 2N hydrochloric acid (200 mL) was added dropwise. 200 mL of water and 300 mL of diethyl ether were added for liquid separation, and a diethyl ether layer was obtained as an organic layer. The organic layer was dried over magnesium sulfate and then filtered to obtain a crude liquid. The crude liquid was concentrated with an evaporator and then distilled under reduced pressure to obtain 85 g of CF ₂ ClCFClCF ₂ C (CF ₃ ) (OH) CH ₂ CH═CH ₂ (60 to 66 ° C./0.7 kPa).
Next, 81 g of zinc and 170 mL of dioxane were put into a 500 mL glass reactor, and zinc was activated with iodine. Then heated to 100 ° C., it was added dropwise over synthesized _{CF 2 ClCFClCF 2 C (CF 3} ) (OH) CH 2 CH = what the 84g of CH ₂ was diluted in dioxane 50 mL 1.5 hours above. After completion of dropping, the mixture was stirred at 100 ° C. for 40 hours. The reaction solution was filtered and washed with a small amount of dioxane. The filtrate was distilled under reduced pressure to obtain 30 g of CF ₂ ═CFCF ₂ C (CF ₃ ) (OH) CH ₂ CH═CH ₂ (36 to 37 ° C./1 kPa). The data of ¹ H NMR and ¹⁹ F NMR are shown below.
¹ H NMR (399.8 MHz, solvent: CDCl ₃ , standard: tetramethylsilane) δ (ppm): 2.74 (d, J = 7.3, 2H), 3.54 (load s, 1H), 5 .34 (m, 2H), 5.86 (m, 1H).
¹⁹ F NMR (376.2 MHz, solvent: CDCl ₃ , reference: CFCl ₃ ) δ (ppm): −75.7 (m, 3F), −92.2 (m, 1F), −106.57 (m, 1F), -112.6 (m, 2F), -183.5 (m, 1F).

(Synthesis Example 6)
[Synthesis example of 1,1,2,3,3-pentafluoro-4-trifluoromethyl-4-methoxymethyloxy-1,6-heptadiene]
A 10 L glass reactor was charged with 758 g of CF ₂ ClCFClCF ₂ C (O) CF ₃ and 4.5 L of dehydrated THF and cooled to 0 ° C. In a nitrogen atmosphere, 1.4 L of a 2M THF solution of CH ₂ ═CHCH ₂ MgCl was added dropwise over about 10.5 hours. After completion of the dropwise addition, the mixture was stirred at 0 ° C. for 30 minutes and at room temperature for 12 hours, 350 g of chloromethyl methyl ether was added dropwise, and the mixture was further stirred at room temperature for 92 hours. 1.5 L of water was added and liquid-separated, and the crude liquid obtained by concentrating the organic layer with an evaporator was washed twice with 1.5 L of water. Subsequently, it was distilled under reduced pressure to obtain 677 g of CF ₂ ClCFClCF ₂ C (CF ₃ ) (OCH ₂ OCH ₃ ) CH ₂ CH═CH ₂ (53-55 ° C./0.17 kPa).
Next, 577 g of zinc and 1.3 L of dioxane were placed in a 3 L glass reactor, and zinc was activated with iodine. Then heated to 100 ° C., it was added dropwise over _{CF 2 ClCFClCF 2 C (CF 3} ) (OCH 2 OCH 3) CH 2 CH = the 677g of CH ₂ 2 h synthesized above. After completion of dropping, the mixture was stirred at 100 ° C. for 47 hours. The reaction solution was filtered and washed with a small amount of dioxane. The filtrate was separated by adding 2.5 L of water and 1.5 L of ether. The organic layer was dried over anhydrous magnesium sulfate and then filtered to obtain a crude liquid. The crude liquid was concentrated with an evaporator and then distilled under reduced pressure to obtain 177 g of CF ₂ ═CFCF ₂ C (CF ₃ ) (OCH ₂ OCH ₃ ) CH ₂ CH═CH ₂ (43 to 45 ° C./0.6 kPa). . The data of ¹ H NMR and ¹⁹ F NMR are shown below.
¹ H NMR (399.8 MHz, solvent: CDCl ₃ , standard: tetramethylsilane) δ (ppm): 3.16 (road, 2H), 3.44 (s, 3H), 4.95 (m, 2H) , 5.22 (m, 2H), 5.92 (m, 1H).
¹⁹ F NMR (376.2 MHz, solvent: CDCl ₃ , reference: CFCl ₃ ) δ (ppm): −72.5 (m, 3F), −92.9 (m, 1F), −106.8 (m, 1F), -109.7 (m, 2F), -183.0 (m, 1F).

(Synthesis Example 7)
7.50 g of 1,1,2,3,3-pentafluoro-4-trifluoromethyl-4-hydroxy-1,6-heptadiene synthesized in Synthesis Example 5, 3.66 g of 1,4-dioxane and acetic acid 16.6 g of methyl was charged into a glass pressure-resistant reactor having an internal volume of 30 mL. Next, 0.22 g of perfluorobenzoyl peroxide was added as a polymerization initiator. The system was frozen and degassed, and then polymerized in a constant temperature shaking tank (70 ° C.) for 18 hours. After the polymerization, the reaction solution was dropped into hexane to reprecipitate the polymer, followed by vacuum drying at 150 ° C. for 15 hours. As a result, 5.40 g of a white powdery amorphous polymer having a fluorine-containing aliphatic ring structure in the main chain was obtained. When the molecular weight of this polymer was measured by GPC (THF solvent), the number average molecular weight (Mn) was 7,600, the weight average molecular weight (Mw) was 15,000 in terms of polystyrene, and Mw / Mn was 1. 99. The glass transition temperature measured by differential scanning calorimetry (DSC) was 152 ° C.

(Synthesis Example 8)
4.71 g of 1,1,2,3,3-pentafluoro-4-trifluoromethyl-4-hydroxy-1,6-heptadiene synthesized in Synthesis Example 5, 1,1,1,2 synthesized in Synthesis Example 6 1,3,3-pentafluoro-4-trifluoromethyl-4-methoxymethyloxy-1,6-heptadiene, 0.78 g of 1,4-dioxane and 15.4 g of methyl acetate A 30 mL glass pressure reactor was charged. Next, 0.088 g of perfluorobenzoyl peroxide was added as a polymerization initiator. The system was frozen and degassed, and then polymerized in a constant temperature shaking tank (70 ° C.) for 18 hours. After the polymerization, the reaction solution was dropped into hexane to reprecipitate the polymer, followed by vacuum drying at 150 ° C. for 15 hours. As a result, 5.21 g of a white powdery amorphous polymer (hereinafter referred to as polymer 1A) having a fluorine-containing aliphatic ring structure in the main chain was obtained. When the molecular weight of this polymer was measured by GPC (THF solvent), the number average molecular weight (Mn) was 12,800, the weight average molecular weight (Mw) was 31,000 in terms of polystyrene, and Mw / Mn was 2. 42. The glass transition point measured by differential scanning calorimetry (DSC) was 139 ° C.
^The polymer composition calculated by ¹⁹ F NMR and ¹ H NMR measurement was 1,1,2,3,3-pentafluoro-4-trifluoromethyl-4-hydroxy-1,6-heptadiene monomer unit / 1. , 1,2,3,3-pentafluoro-4-trifluoromethyl-4-methoxymethyloxy-1,6-heptadiene = 80.0 / 20.0 mol%.

(Synthesis Example 9)
5.12 g of 1,1,2,3,3-pentafluoro-4-trifluoromethyl-4-hydroxy-1,6-heptadiene synthesized in Synthesis Example 5, 1,1,1,2 synthesized in Synthesis Example 6 , 3,3-pentafluoro-4-trifluoromethyl-4-methoxymethyloxy-1,6-heptadiene, 0.66 g, 0.74 g of 1,4-dioxane and 15.4 g of methyl acetate, A 30 mL glass pressure reactor was charged. Next, 0.088 g of perfluorobenzoyl peroxide was added as a polymerization initiator. The system was frozen and degassed, and then polymerized in a constant temperature shaking tank (70 ° C.) for 18 hours. After the polymerization, the reaction solution was dropped into hexane to reprecipitate the polymer, followed by vacuum drying at 150 ° C. for 15 hours. As a result, 4.62 g of a white powdery amorphous polymer having a fluorine-containing aliphatic ring structure in the main chain was obtained. When the molecular weight of this polymer was measured by GPC (THF solvent), the polystyrene-converted number average molecular weight (Mn) was 13,200, the weight average molecular weight (Mw) was 31,500, and Mw / Mn was 2. 39. The glass transition point measured by differential scanning calorimetry (DSC) was 144 ° C.
^The polymer composition calculated by ¹⁹ F NMR and ¹ H NMR measurement was as follows: monomer unit consisting of 1,1,2,3,3-pentafluoro-4-trifluoromethyl-4-hydroxy-1,6-heptadiene / 1 , 1,2,3,3-pentafluoro-4-trifluoromethyl-4-methoxymethyloxy-1,6-heptadiene monomer unit = 90.0 / 10.0 mol%.

(Synthesis Example 10)
6.43 g of 1,1,2,3,3-pentafluoro-4-trifluoromethyl-4-hydroxy-1,6-heptadiene synthesized in Synthesis Example 5 and 0.18 g of tert-butyl methacrylate, 1, 0.93 g of 4-dioxane and 20.4 g of methyl acetate were charged into a glass pressure-resistant reactor having an internal volume of 30 mL. Next, 0.112 g of perfluorobenzoyl peroxide was added as a polymerization initiator. The system was frozen and degassed, and then polymerized in a constant temperature shaking tank (70 ° C.) for 18 hours. After the polymerization, the reaction solution was dropped into hexane to reprecipitate the polymer, followed by vacuum drying at 150 ° C. for 15 hours. As a result, 5.28 g of a white powdery amorphous polymer having a monomer unit composed of a fluorine-containing aliphatic ring structure and tert-butyl methacrylate in the main chain was obtained. When the molecular weight of this polymer was measured by GPC (THF solvent), the number average molecular weight (Mn) was 8,300, the weight average molecular weight (Mw) was 16,800 in terms of polystyrene, and Mw / Mn was 2. 01. The glass transition point measured by differential scanning calorimetry (DSC) was 162 ° C.
^The polymer composition calculated by ¹⁹ F NMR and ¹ H NMR measurement is as follows: monomer unit consisting of 1,1,2,3,3-pentafluoro-4-trifluoromethyl-4-hydroxy-1,6-heptadiene / tert -Monomer unit consisting of butyl methacrylate = 95/5 mol%.

(Synthesis Example 11)
150 g of R113 was charged into a 0.2 liter stainless steel autoclave equipped with a deaerated stirrer, TFE 14.4 g, norbornene 1.504 g, 1,1,1-trifluoro-2-trifluoromethyl-4- 33.28 g of penten-2-ol (hereinafter referred to as AF2) was introduced. The temperature was raised to 55 ° C., and 8 mL of an R113 solution containing 1.67 g of tert-butyl peroxypivalate was injected to initiate polymerization. The pressure when the temperature reached 55 ° C. was 0.69 MPa. After 10 hours of reaction, the pressure dropped to 0.62 MPa. After the autoclave was cooled to room temperature, unreacted gas was purged and the polymer solution was taken out. The obtained polymer solution was poured into methanol to precipitate a polymer, washed and vacuum dried at 50 ° C. to obtain 6.3 g of a fluoropolymer. When the molecular weight of this polymer was measured by GPC (THF solvent), the number average molecular weight (Mn) was 2,400, the weight average molecular weight (Mw) was 3,400 in terms of polystyrene, and Mw / Mn was 1. 42.
^The polymer composition calculated by ¹⁹ F NMR and ¹ H NMR measurement was TFE unit / norbornene unit / AF2 unit = 35/20/45 mol%.

(Synthesis Example 12)
The polymer 5.00g synthesize | combined in the synthesis example 7 and 100 mL of methanol were put into a 300 mL round bottom flask, and it stirred with the magnetic stirrer. When the polymer was completely dissolved, a sodium hydroxide methanol solution (2.84 g of methanol was added to 0.17 g of sodium hydroxide and dissolved in advance) was added and stirred overnight at room temperature. After the solvent was distilled off, 200 mL of dehydrated THF and 0.63 g of the chloride prepared in Synthesis Example 1 were added and stirred vigorously. After a while, the solution gradually becomes cloudy. After stirring for several days at room temperature, the solvent was distilled off. The residue was dissolved in 50 mL of diethyl ether and separated with 70 mL of pure water. After distilling off the organic layer, the organic layer was dissolved in 20 mL of acetone and dropped into hexane to reprecipitate the polymer, followed by vacuum drying at 125 ° C. for 18 hours. As a result, 4.21 g of a white powdery amorphous polymer (hereinafter referred to as polymer 2A) was obtained.
^The blocking rate calculated by ¹ H NMR measurement (the ratio of blocked acidic groups to the total acidic groups (%)) was 20%.

(Synthesis Example 13)
The polymer 5.00g synthesize | combined in the synthesis example 7 and 100 mL of methanol were put into a 300 mL round bottom flask, and it stirred with the magnetic stirrer. When the polymer was completely dissolved, a sodium hydroxide methanol solution (2.84 g of methanol was added to 0.17 g of sodium hydroxide and dissolved in advance) was added and stirred overnight at room temperature. After the solvent was distilled off, 200 mL of dehydrated THF and 0.76 g of the chloride prepared in Synthesis Example 2 were added and stirred vigorously. After a while, the solution gradually becomes cloudy. After stirring for several days at room temperature, the solvent was distilled off. The residue was dissolved in 50 mL of diethyl ether and separated with 70 mL of pure water. After distilling off the organic layer, the organic layer was dissolved in 20 mL of acetone and dropped into hexane to reprecipitate the polymer, followed by vacuum drying at 125 ° C. for 18 hours. As a result, 4.54 g of a white powdery amorphous polymer (hereinafter referred to as polymer 3A) was obtained.
^The blocking rate calculated by ¹ H NMR measurement (the ratio of blocked acidic groups to the total acidic groups (%)) was 19%.

(Synthesis Example 14)
The polymer 5.00g synthesize | combined in the synthesis example 7 and 100 mL of methanol were put into a 300 mL round bottom flask, and it stirred with the magnetic stirrer. When the polymer was completely dissolved, a sodium hydroxide methanol solution (2.84 g of methanol was added to 0.17 g of sodium hydroxide and dissolved in advance) was added and stirred overnight at room temperature. After the solvent was distilled off, 200 mL of dehydrated THF and 0.70 g of the chloride prepared in Synthesis Example 3 were added and vigorously stirred. After a while, the solution gradually becomes cloudy. After stirring for several days at room temperature, the solvent was distilled off. The residue was dissolved in 50 mL of diethyl ether and separated with 70 mL of pure water. After distilling off the organic layer, the organic layer was dissolved in 20 mL of acetone and dropped into hexane to reprecipitate the polymer, followed by vacuum drying at 125 ° C. for 18 hours. As a result, 4.40 g of a white powdery amorphous polymer (hereinafter referred to as polymer 4A) was obtained.
^The blocking rate calculated by ¹ H NMR measurement (the ratio of blocked acidic groups to the total acidic groups (%)) was 19%.

(Synthesis Example 15)
The polymer 5.00g synthesize | combined in the synthesis example 7 and 100 mL of methanol were put into a 300 mL round bottom flask, and it stirred with the magnetic stirrer. When the polymer was completely dissolved, a sodium hydroxide methanol solution (2.84 g of methanol was added to 0.17 g of sodium hydroxide and dissolved in advance) was added and stirred overnight at room temperature. After the solvent was distilled off, 200 mL of dehydrated THF and 0.76 g of the chloride prepared in Synthesis Example 4 were added and vigorously stirred. After a while, the solution gradually becomes cloudy. After stirring for several days at room temperature, the solvent was distilled off. The residue was dissolved in 50 mL of diethyl ether and separated with 70 mL of pure water. After distilling off the organic layer, the organic layer was dissolved in 20 mL of acetone and dropped into hexane to reprecipitate the polymer, followed by vacuum drying at 125 ° C. for 18 hours. As a result, 4.20 g of a white powdery amorphous polymer (hereinafter referred to as polymer 5A) was obtained.
^The blocking rate calculated by ¹ H NMR measurement (the ratio of blocked acidic groups to the total acidic groups (%)) was 21%.

(Synthesis Example 16)
5.00 g of the polymer synthesized in Synthesis Example 9 and 100 mL of methanol were placed in a 300 mL round bottom flask and stirred with a magnetic stirrer. When the polymer was completely dissolved, a sodium hydroxide methanol solution (1.42 g of methanol was added to 0.08 g of sodium hydroxide and dissolved in advance) was added and stirred overnight at room temperature. After the solvent was distilled off, 200 mL of dehydrated THF and 0.38 g of the chloride prepared in Synthesis Example 2 were added and stirred vigorously. After a while, the solution gradually becomes cloudy. After stirring for several days at room temperature, the solvent was distilled off. The residue was dissolved in 50 mL of diethyl ether and separated with 70 mL of pure water. After distilling off the organic layer, the organic layer was dissolved in 20 mL of acetone and dropped into hexane to reprecipitate the polymer, followed by vacuum drying at 125 ° C. for 18 hours. As a result, 4.04 g of a white powdery amorphous polymer (hereinafter referred to as polymer 6A) was obtained.
^The blocking ratio (ratio of blocked acidic groups to the total acidic groups (%)) calculated by ¹ H NMR measurement was 21% (breakdown: 11% (blocked groups in Synthesis Example 2), 10% (MOM ))Met.

(Synthesis Example 17)
The polymer 5.00g synthesize | combined in the synthesis example 7 and 100 mL of methanol were put into a 300 mL round bottom flask, and it stirred with the magnetic stirrer. When the polymer was completely dissolved, a sodium hydroxide methanol solution (2.84 g of methanol was added to 0.17 g of sodium hydroxide and dissolved in advance) was added and stirred overnight at room temperature. After distilling off the solvent, 200 mL of dehydrated THF and 0.38 g of chloride prepared in Synthesis Example 2 and 0.20 g of chloromethyl ethyl ether were added and vigorously stirred. After a while, the solution gradually becomes cloudy. After stirring for several days at room temperature, the solvent was distilled off. The residue was dissolved in 50 mL of diethyl ether and separated with 70 mL of pure water. After distilling off the organic layer, the organic layer was dissolved in 20 mL of acetone and dropped into hexane to reprecipitate the polymer, followed by vacuum drying at 125 ° C. for 18 hours. As a result, 4.35 g of a white powdery amorphous polymer (hereinafter referred to as polymer 7A) was obtained.
^The blocking ratio (ratio of blocked acidic groups to the total acidic groups (%)) calculated by ¹ H NMR measurement was 22% (breakdown: 11% (blocked groups in Synthesis Example 2), 11% (EOM) ))Met.

(Synthesis Example 18)
The polymer 5.00g synthesize | combined in the synthesis example 7 and 100 mL of methanol were put into a 300 mL round bottom flask, and it stirred with the magnetic stirrer. When the polymer was completely dissolved, a sodium hydroxide methanol solution (2.84 g of methanol was added to 0.17 g of sodium hydroxide and dissolved in advance) was added and stirred overnight at room temperature. After distilling off the solvent, 200 mL of dehydrated THF, 0.38 g of the chloride prepared in Synthesis Example 2, 0.10 g of chloromethyl ethyl ether, and 0.23 g of di-tert-butyl dicarbonate were added and vigorously stirred. After a while, the solution gradually becomes cloudy. After stirring for several days at room temperature, the solvent was distilled off. The residue was dissolved in 50 mL of diethyl ether and separated with 70 mL of pure water. After distilling off the organic layer, the organic layer was dissolved in 20 mL of acetone and dropped into hexane to reprecipitate the polymer, followed by vacuum drying at 125 ° C. for 18 hours. As a result, 3.88 g of a white powdery amorphous polymer (hereinafter referred to as polymer 8A) was obtained.
^The blocking ratio (ratio of blocked acidic groups to the total acidic groups (%)) calculated by ¹ H NMR measurement was 22% (breakdown: 10% (blocked groups in Synthesis Example 2), 5% (EOM) ), 7% (tBOC)).

(Synthesis Example 19)
The polymer 5.00g synthesize | combined in the synthesis example 10 and 100 mL of methanol were put into a 300 mL round bottom flask, and it stirred with the magnetic stirrer. When the polymer was completely dissolved, a sodium hydroxide methanol solution (2.13 g of methanol was added to 0.13 g of sodium hydroxide and dissolved in advance) was added and stirred overnight at room temperature. After the solvent was distilled off, 200 mL of dehydrated THF and 0.57 g of the chloride prepared in Synthesis Example 2 were added and stirred vigorously. After a while, the solution gradually becomes cloudy. After stirring for several days at room temperature, the solvent was distilled off. The residue was dissolved in 50 mL of diethyl ether and separated with 70 mL of pure water. After distilling off the organic layer, the organic layer was dissolved in 20 mL of acetone and dropped into hexane to reprecipitate the polymer, followed by vacuum drying at 125 ° C. for 18 hours. As a result, 4.23 g of a white powdery amorphous polymer (hereinafter referred to as polymer 9A) was obtained.
^The blocking ratio (ratio of blocked acidic groups to the total acidic groups (%)) calculated by ¹ H NMR measurement was 19% (breakdown: 14% (blocked groups in Synthesis Example 2), 5% (tert -Tert-butyl group of butyl methacrylate).

(Synthesis Example 20)
The polymer 5.00g synthesize | combined in the synthesis example 10 and 100 mL of methanol were put into a 300 mL round bottom flask, and it stirred with the magnetic stirrer. When the polymer was completely dissolved, a sodium hydroxide methanol solution (2.13 g of methanol was added to 0.13 g of sodium hydroxide and dissolved in advance) was added and stirred overnight at room temperature. After distilling off the solvent, 200 mL of dehydrated THF and 0.39 g of chloride prepared in Synthesis Example 2 and 0.24 g of di-tert-butyl dicarbonate were added and vigorously stirred. After a while, the solution gradually becomes cloudy. After stirring for several days at room temperature, the solvent was distilled off. The residue was dissolved in 50 mL of diethyl ether and separated with 70 mL of pure water. After distilling off the organic layer, the organic layer was dissolved in 20 mL of acetone and dropped into hexane to reprecipitate the polymer, followed by vacuum drying at 125 ° C. for 18 hours. As a result, 4.39 g of a white powdery amorphous polymer (hereinafter referred to as polymer 10A) was obtained.
^The blocking ratio (ratio of blocked acidic groups to the total acidic groups (%)) calculated by ¹ H NMR measurement was 20% (breakdown: 9% (blocked group of Synthesis Example 2), 6% (tBOC). ) 5% (tert-butyl group of tert-butyl methacrylate)).

(Synthesis Example 21)
5.0 g of the polymer synthesized in Synthesis Example 11 and 100 mL of methanol were placed in a 300 mL round bottom flask and stirred with a magnetic stirrer. When the polymer was completely dissolved, a sodium hydroxide methanol solution (3.46 g of methanol was added to 0.21 g of sodium hydroxide and dissolved in advance) was stirred overnight at room temperature. After the solvent was distilled off, 200 mL of dehydrated THF and 0.95 g of the chloride prepared in Synthesis Example 2 were added and vigorously stirred. After a while, the solution gradually becomes cloudy. After stirring for several days at room temperature, the solvent was distilled off. The residue was dissolved in 50 mL of diethyl ether and separated with 70 mL of pure water. After distilling off the organic layer, the organic layer was dissolved in 20 mL of acetone and added dropwise to hexane to reprecipitate the polymer, followed by vacuum drying at 125 ° C. for 15 hours. As a result, 5.62 g of a white powdery amorphous polymer (hereinafter referred to as polymer 11A) was obtained.
^The blocking ratio (ratio of blocked acidic groups to total acidic groups (%)) calculated by ¹ H NMR measurement was 21%.

(Synthesis Example 22)
The polymer 5.00g synthesize | combined in the synthesis example 7 and 100 mL of methanol were put into a 300 mL round bottom flask, and it stirred with the magnetic stirrer. When the polymer was completely dissolved, a sodium hydroxide methanol solution (2.84 g of methanol was added to 0.17 g of sodium hydroxide and dissolved in advance) was added and stirred overnight at room temperature. After the solvent was distilled off, 200 mL of dehydrated THF, 0.17 g of chloromethyl methyl ether, 0.10 g of chloromethyl ethyl ether, and 0.23 g of di-tert-butyl dicarbonate were added and vigorously stirred. After a while, the solution gradually becomes cloudy. After stirring for several days at room temperature, the solvent was distilled off. The residue was dissolved in 50 mL of diethyl ether and separated with 70 mL of pure water. After distilling off the organic layer, the organic layer was dissolved in 20 mL of acetone and dropped into hexane to reprecipitate the polymer, followed by vacuum drying at 125 ° C. for 18 hours. As a result, 4.18 g of a white powdery amorphous polymer (hereinafter referred to as polymer 12A) was obtained.
^The blocking ratio calculated by ¹ H NMR measurement (the ratio of blocked acidic groups to the total acidic groups (%)) was 21% (breakdown: 9% (MOM), 5% (EOM), 7% (tBOC). ))Met.

(Synthesis Example 23)
The polymer 5.00g synthesize | combined in the synthesis example 10 and 100 mL of methanol were put into a 300 mL round bottom flask, and it stirred with the magnetic stirrer. When the polymer was completely dissolved, a sodium hydroxide methanol solution (2.13 g of methanol was added to 0.13 g of sodium hydroxide and dissolved in advance) was added and stirred overnight at room temperature. After the solvent was distilled off, 200 mL of dehydrated THF and 0.26 g of chloromethyl methyl ether were added and stirred vigorously. After a while, the solution gradually becomes cloudy. After stirring for several days at room temperature, the solvent was distilled off. The residue was dissolved in 50 mL of diethyl ether and separated with 70 mL of pure water. After distilling off the organic layer, the organic layer was dissolved in 20 mL of acetone and dropped into hexane to reprecipitate the polymer, followed by vacuum drying at 125 ° C. for 18 hours. As a result, 4.10 g of a white powdery amorphous polymer (hereinafter referred to as polymer 13A) was obtained.
^The blocking rate (ratio of blocked acidic groups (%) to total acidic groups (%)) calculated by ¹ H NMR measurement was 20% (breakdown: 15% (MOM), 5% (tert-butyl methacrylate tert- Butyl group)).

(Synthesis Example 24)
The polymer 5.00g synthesize | combined in the synthesis example 10 and 100 mL of methanol were put into a 300 mL round bottom flask, and it stirred with the magnetic stirrer. When the polymer was completely dissolved, a sodium hydroxide methanol solution (2.13 g of methanol was added to 0.13 g of sodium hydroxide and dissolved in advance) was added and stirred overnight at room temperature. After the solvent was distilled off, 200 mL of dehydrated THF, 0.17 g of chloromethyl methyl ether and 0.24 g of di-tert-butyl dicarbonate were added and stirred vigorously. After a while, the solution gradually becomes cloudy. After stirring for several days at room temperature, the solvent was distilled off. The residue was dissolved in 50 mL of diethyl ether and separated with 70 mL of pure water. After distilling off the organic layer, the organic layer was dissolved in 20 mL of acetone and dropped into hexane to reprecipitate the polymer, followed by vacuum drying at 125 ° C. for 18 hours. As a result, 4.00 g of a white powdery amorphous polymer (hereinafter referred to as polymer 14A) was obtained.
^The blocking ratio (ratio of blocked acidic groups to total acidic groups (%)) calculated by ¹ H NMR measurement was 19% (breakdown: 8% (MOM), 6% (tBOC), 5% (tert -Tert-butyl group of butyl methacrylate))).

(Synthesis Example 25)
5.0 g of the polymer synthesized in Synthesis Example 11 and 100 mL of methanol were placed in a 300 mL round bottom flask and stirred with a magnetic stirrer. When the polymer was completely dissolved, a sodium hydroxide methanol solution (3.46 g of methanol was added to 0.21 g of sodium hydroxide and dissolved in advance) was stirred overnight at room temperature. After the solvent was distilled off, 200 mL of dehydrated THF and 0.43 g of chloromethyl methyl ether were added and stirred vigorously. After a while, the solution gradually becomes cloudy. After stirring for several days at room temperature, the solvent was distilled off. The residue was dissolved in 50 mL of diethyl ether and separated with 70 mL of pure water. After distilling off the organic layer, the organic layer was dissolved in 20 mL of acetone and added dropwise to hexane to reprecipitate the polymer, followed by vacuum drying at 125 ° C. for 15 hours. As a result, 4.29 g of a white powdery amorphous polymer (hereinafter referred to as polymer 15A) was obtained.
The blocking rate calculated by 1H NMR measurement (the ratio (%) of blocked acidic groups to the total acidic groups) was 20%.

(Examples 1 to 10)
1 g of each of the polymers 2A to 11A synthesized in Synthesis Examples 12 to 21 and 0.05 g of trimethylsulfonium triflate were dissolved in 10 g of propylene glycol monomethyl ether acetate, and filtered using a PTFE filter having a pore size of 0.2 μm. Then, a resist composition was manufactured.
The above resist composition was spin-coated on a silicon substrate treated with hexamethyldisilazane, and was heat-treated at 80 ° C. for 2 minutes after coating to form a resist film having a thickness of 0.3 μm. The absorption spectrum of this resist film was measured with ultraviolet visible light photometry, and a transmittance of 157 nm was obtained. Further, a development test was performed on the resist film. As an actual procedure, a substrate on which the above resist film was formed was placed in an exposure experimental apparatus substituted with nitrogen, and a mask having a chromium pattern on a quartz plate was in close contact therewith. KrF excimer laser light was irradiated through the mask, and then post-exposure baking was performed at 100 ° C. for 2 minutes. Development was performed at 23 ° C. for 1 minute using an aqueous tetramethylammonium hydroxide solution (2.38% by mass), followed by washing with pure water for 1 minute. The light transmittance of the resist film and the development test results are shown in Table 1.

(Comparative Examples 1-5)
The same operations as in Examples 1 to 10 were performed except that the polymers of Examples 1 to 10 were 1A, 12A, 13A, 14A, and 15A, respectively. The light transmittance of the resist film and the development test results are shown in Table 1.

  In the resist patterns of Examples 1 to 10, not only the flatness of the surface but also the flatness of the surface in the vertical direction of the pattern (also referred to as line edge roughness) was superior to the resist patterns of Comparative Examples 1 to 5. .

Claims (7)

A fluorine-containing polymer (A) having an acidic group blocked with an organic group containing one or more fluorine atoms and an acidic group not blocked;
An acid-generating compound (B) that generates an acid upon irradiation with light; and
A resist composition comprising an organic solvent (C). The resist composition according to claim 1, wherein the organic group containing one or more fluorine atoms is an organic group represented by the formula (1).
—CHR ¹ —O—R ² (1)
(In the formula, R ¹ represents a hydrogen atom or an alkyl group having 3 or less carbon atoms, and R ² represents an organic group containing one or more fluorine atoms.) The resist composition according to claim 2, wherein R ² is any one organic group of the following formulas (2) to (5).
—CH ₂ — (CF ₂ ) _n —R ³ (2)
―CR ⁴ R ⁵ R ⁶ (3)

(In the formula (2), R ³ represents a hydrogen atom or a fluorine atom, and n represents an integer of 1 to 8. In the formula (3), R ⁴ , R ⁵ and R ⁶ represent the following (a) and ( and b) satisfying the condition of b), each independently a fluorine atom, a hydrogen atom, an alkyl group having 3 or less carbon atoms, a tert-butyl group, a cyclohexyl group, a cyclopentyl group, a fluoroalkyl group having 3 or less carbon atoms, or- Represents a C (CF ₃ ) ₂ OH group.
(A) At least one of R ⁴ , R ⁵ and R ⁶ is a fluorine atom or an organic group containing a fluorine atom.
(B) When any one of R ⁴ , R ⁵ and R ⁶ is a hydrogen atom, the other two are other than a hydrogen atom.
In formula (4), R ⁷ , R ^8, and R ⁹ are each independently a fluorine atom, a hydrogen atom, or 3 carbon atoms, provided that at least one of them is a fluorine atom or an organic group containing a fluorine atom. represents the following fluoroalkyl group or -C (CF _{3) 2} OH group. In formula (5), R ¹⁰ , R ¹¹ , R ¹² and R ¹³ each independently represent a fluorine atom or a hydrogen atom, provided that at least one of them is a fluorine atom. )   The resist composition according to claim 1, wherein the non-blocked acidic group is an unblocked acidic hydroxyl group.   The resist composition according to claim 1, wherein the blocked acidic group is a blocked acidic hydroxyl group.   The resist composition according to claim 1, wherein the fluoropolymer (A) is a fluoropolymer having an aliphatic ring structure in the main chain. The resist composition according to claim 1, wherein the fluorine-containing polymer (A) is a fluorine-containing polymer having a monomer unit obtained by cyclopolymerization of the fluorine-containing diene represented by the formula (6).
^{_{CF 2 = CR 14 -Q-CR}} 15 = CH 2 ··· (6)
(Wherein R ¹⁴ and R ¹⁵ each independently represents a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group, and Q is a divalent organic group represented by the following formula (7): is there.)
^{-R 16 -C (R 18) (} R 19) -R 17 - ··· (7)
(In the formula, R ¹⁶ and R ¹⁷ each independently have a single bond, an oxygen atom, an alkylene group having 3 or less carbon atoms which may have an etheric oxygen atom, or an etheric oxygen atom. An optionally substituted fluoroalkylene group having 3 or less carbon atoms, R ¹⁸ represents a hydrogen atom, a fluorine atom, an alkyl group having 3 or less carbon atoms or a fluoroalkyl group having 3 or less carbon atoms, and R ¹⁹ represents a fluorine atom. 1 having an acidic group blocked with an organic group containing one or more, an acidic group not blocked, an acidic group blocked with an organic group containing one or more fluorine atoms, or an acidic group not blocked Represents a valent organic group.)