JP2006160988A - Fluorine-containing polymer, method for producing the same and resist protective coat composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fluorine-containing polymer having high transparency in a wide wave length range; to provide a method for producing the polymer; and to provide a resist protective coat composition having excellent transparency to far ultraviolet rays and vacuum ultraviolet rays, and high effects for suppressing a PED effect (Postexposure Delay effect), soluble in an alkali developing liquid to enable the coat to be removed by a developing step in a current resist process, and capable of protecting a resist membrane from an immersion solvent even in an immersion lithography step. <P>SOLUTION: The fluorine-containing polymer has a monomer unit obtained by subjecting a fluorine-containing diene represented by formula (1): CF<SB>2</SB>=CFCF<SB>2</SB>C(CF<SB>3</SB>)(OR<SP>1</SP>)-(CH<SB>2</SB>)<SB>n</SB>CR<SP>2</SP>=CHR<SP>3</SP>(1) (wherein, R<SP>1</SP>is a ≤20C organic group having at least one substituent selected from the group consisting of a carboxy group, a sulfo group and a sulfonylfluoride group; R<SP>2</SP>and R<SP>3</SP>are each independently a hydrogen atom or a ≤12C alkyl group; and n is an integer of 0-2) to cyclic polymerization. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a fluorine-containing polymer, a method for producing the same, and a resist protective film composition containing the same.

Resist materials that use acid-catalyzed reaction as a reaction mechanism like chemically amplified resists are patterned through processes such as resist coating formation, exposure, post-exposure baking, and development. In addition, the acid generated by exposure (for example, active actinic radiation) reacts with amines floating as impurities in the atmosphere and deactivates, thereby preventing the formation of a resist image in the development process or increasing the sensitivity. It is known that a change is caused (for example, refer nonpatent literature 1).
In addition, it is known that exposure between exposure and post-exposure bake (PEB treatment) has a significant adverse effect on resist characteristics. Specifically, if the exposure time between exposure and post-exposure bake becomes longer, the resist It is known that the PED effect (Postexposure Delay effect) that the sensitivity rapidly decreases and the pattern cannot be formed is generated.

As one method for reducing the PED effect, a method of applying a polymer film (resist protective film) that is incompatible with the resist film on the resist film is known (see, for example, Patent Document 1). ).
However, although this method is to apply a resist protective film (topcoat) in order to prevent amines etc. floating in the atmosphere from entering the resist film, There was a drawback that the number of processes increased.

The resist protective film composition for forming the resist protective film is resistant to radiation such as X-rays and ultraviolet rays used in resist processes (especially photoresist processes and photolithography processes) in order not to impair the characteristics of the resist material. It must be “transparent”. That is, it is required that the resist protective film composition does not absorb radiation such as X-rays and ultraviolet rays and does not cause side reactions such as insolubilization.
However, many of the substances used in conventionally known resist protective film compositions that have the effect of suppressing the PED effect do not satisfy the above requirements, and in particular, ArF excimer laser (193 nm) and F ₂ In the excimer laser (157 nm), a resist protective film composition having both an effect of being transparent and sufficiently suppressing the PED effect has not been found so far.

  On the other hand, in recent years, there has been known an immersion exposure technique that enables high-resolution exposure by using a liquid having a large refractive index (particularly water) between the projection lens and the resist film. However, in this immersion exposure technique, there is a problem that the resist film is swollen and impurities generated from the resist film are dissolved in the upper liquid to contaminate the lens.

One method for solving this problem is to apply a resist protective film on the resist film that is not compatible with either a liquid having a large refractive index or a resist film and that can also reduce the above-described PED effect. It is desired.
For example, Patent Document 2 states that “a resist protective film forming material for an immersion exposure process provided on a resist film, which is transparent to exposure light and substantially free from immersion exposure liquid. A resist protective film forming material for an immersion exposure process characterized by having no compatible properties and having no mixing with the resist film. It is described that the formula perfluoroalkyl polyether is effective as a resist protective film forming material. However, there is no description about the reduction of the PED effect, and there is a problem that the process is complicated because a perfluoro organic compound is used to remove the resist protective film.

Japanese Patent Laid-Open No. 4-204848 International Publication No. 2004/074937 Pamphlet S. A. MacDonald et al. "PROCEEDINGS OF SPIE", 31 (1993), p. 1925 (USA)

Then, an object of this invention is to provide the fluoropolymer which has high transparency in a wide wavelength range, and its manufacturing method. In addition, the present invention is excellent in transparency to deep ultraviolet rays such as KrF and ArF excimer lasers and vacuum ultraviolet rays such as F ₂ excimer lasers and suppresses the PED effect when used as a resist protective film of a chemically amplified resist. Protective film composition that is highly soluble, soluble in an alkaline developer, can be removed in the development process of the current resist process, and can also protect the resist film from the immersion solvent in the immersion lithography process The purpose is to provide goods. Furthermore, this invention aims at providing the photoresist pattern formation method using this resist protective film composition.

As a result of intensive studies to achieve the above object, the present inventor has found that a resist protective film made of a composition containing a specific fluorine-containing polymer is a far ultraviolet ray such as KrF or ArF excimer laser or a vacuum such as F ₂ excimer laser. Excellent transparency to ultraviolet rays, sufficiently suppresses the PED effect, is soluble in an alkaline developer and eliminates the need to remove the resist protective film alone, and further protects the resist film from the immersion solvent in the immersion lithography process. As a result, the present invention has been achieved.
That is, the present invention is a fluoropolymer (first embodiment) shown in the following (I) to (VI), a method for producing a fluoropolymer shown in (VII) to (XII) (second embodiment), ( A resist protective film composition (third aspect) shown in XIII) and a photoresist pattern forming method (fourth aspect) shown in (XIV) are provided.

(I) A fluorine-containing polymer having a monomer unit obtained by cyclopolymerizing a fluorine-containing diene represented by the following formula (1).
_{CF 2 = CFCF 2 C (CF} 3) (OR 1) - (CH 2) n CR 2 = CHR 3 ··· (1)
Wherein R ¹ is selected from the group consisting of a carboxy group (carboxylic acid group: —CO ₂ H), a sulfo group (sulfonic acid group: —SO ₃ H) and a sulfonyl fluoride group (—SO ₂ F). And R ² and R ³ each independently represents a hydrogen atom or an alkyl group having 12 or less carbon atoms, and n is an integer of 0 to 2. .)

(II) A fluorine-containing polymer having a monomer unit obtained by cyclopolymerizing a fluorine-containing diene represented by the following formula (2).
^{_{CF 2 = CFCH 2 CHQ 1 -}} (CH 2) n CR 2 = CHR 3 ··· (2)
(In the formula, R ² and R ³ each independently represent a hydrogen atom or an alkyl group having 12 or less carbon atoms, and Q ¹ represents (CH ₂ ) _b C (CF ₃ ) _c (R ⁴ ) _d OR ¹ (b Is an integer of 0 to 3, c and d are integers of 0 to 2 satisfying c + d = 2, R ⁴ is a hydrogen atom, a fluorine atom or a methyl group, R ¹ is a carboxy group, a sulfo group and a sulfonyl group An organic group having 20 or less carbon atoms having at least one substituent selected from the group consisting of fluoride groups.), N is an integer of 0 to 2.)

(III) a monomer unit obtained by cyclopolymerizing a fluorine-containing diene represented by the following formula (3);
A monomer unit obtained by polymerizing a monomer having at least one substituent selected from the group consisting of a carboxy group, a sulfo group and a sulfonyl fluoride group and a carbon-carbon double bond;
A fluorine-containing polymer.
_{CF 2 = CFCF 2 C (CF} 3) (OH) - (CH 2) n CR 2 = CHR 3 ··· (3)
(In the formula, R ² and R ³ each independently represents a hydrogen atom or an alkyl group having 12 or less carbon atoms. N is an integer of 0 to 2.)

(IV) a monomer unit obtained by cyclopolymerizing a fluorine-containing diene represented by the following formula (3);
Monomer having an alkoxycarbonyl group (C (O) OR ⁵ , R ⁵ represents an alkyl group having 6 or less carbon atoms) and a carbon-carbon double bond (CF ₂ ═CF—) substituted with a fluorine atom. Monomer units obtained by polymerizing the body,
A fluorine-containing polymer.
_{CF 2 = CFCF 2 C (CF} 3) (OH) - (CH 2) n CR 2 = CHR 3 ··· (3)
(In the formula, R ² and R ³ each independently represents a hydrogen atom or an alkyl group having 12 or less carbon atoms. N is an integer of 0 to 2.)

(V) a monomer unit obtained by cyclopolymerizing a fluorine-containing diene represented by the following formula (4);
A monomer unit obtained by polymerizing a monomer having at least one substituent selected from the group consisting of a carboxy group, a sulfo group and a sulfonyl fluoride group and a carbon-carbon double bond;
A fluorine-containing polymer.
^{_{CF 2 = CFCH 2 CHQ 2 -}} (CH 2) n CR 2 = CHR 3 ··· (4)
(In the formula, R ² and R ³ each independently represent a hydrogen atom or an alkyl group having 12 or less carbon atoms, and Q ² is (CH ₂ ) _b C (CF ₃ ) _c (R ⁴ ) _d OH (b is N is an integer of 0 to 3, c and d are integers of 0 to 2 satisfying c + d = 2, and R ⁴ is a hydrogen atom, a fluorine atom or a methyl group. .)

(VI) a monomer unit obtained by cyclopolymerizing a fluorine-containing diene represented by the following formula (4);
Obtained by polymerizing a monomer having an alkoxycarbonyl group (C (O) OR ⁵ , R ⁵ represents an alkyl group having 6 or less carbon atoms) and a carbon-carbon double bond substituted with a fluorine atom. Monomer units;
A fluorine-containing polymer.
^{_{CF 2 = CFCH 2 CHQ 2 -}} (CH 2) n CR 2 = CHR 3 ··· (4)
(In the formula, R ² and R ³ each independently represent a hydrogen atom or an alkyl group having 12 or less carbon atoms, and Q ² is (CH ₂ ) _b C (CF ₃ ) _c (R ⁴ ) _d OH (b is N is an integer of 0 to 3, c and d are integers of 0 to 2 satisfying c + d = 2, and R ⁴ is a hydrogen atom, a fluorine atom or a methyl group. .)

(VII) a polymerization step for producing a polymer by cyclopolymerizing a fluorine-containing diene represented by the following formula (3), and the polymer is selected from the group consisting of a carboxy group, a sulfo group and a sulfonyl fluoride group. A process for producing a fluoropolymer according to the above (I), which comprises an introducing step of introducing at least one substituent.
_{CF 2 = CFCF 2 C (CF} 3) (OH) - (CH 2) n CR 2 = CHR 3 ··· (3)
(In the formula, R ² and R ³ each independently represents a hydrogen atom or an alkyl group having 12 or less carbon atoms. N is an integer of 0 to 2.)

(VIII) A polymerization step of cyclopolymerizing a fluorine-containing diene represented by the following formula (4) to produce a polymer, and the polymer is selected from the group consisting of a carboxy group, a sulfo group and a sulfonyl fluoride group. A process for producing a fluoropolymer according to the above (II), which comprises an introduction step of introducing at least one substituent.
^{_{CF 2 = CFCH 2 CHQ 2 -}} (CH 2) n CR 2 = CHR 3 ··· (4)
(In the formula, R ² and R ³ each independently represent a hydrogen atom or an alkyl group having 12 or less carbon atoms, and Q ² is (CH ₂ ) _b C (CF ₃ ) _c (R ⁴ ) _d OH (b is N is an integer of 0 to 3, c and d are integers of 0 to 2 satisfying c + d = 2, and R ⁴ is a hydrogen atom, a fluorine atom or a methyl group. .)

(IX) A single molecule having a fluorine-containing diene represented by the following formula (3), at least one substituent selected from the group consisting of a carboxy group, a sulfo group and a sulfonyl fluoride group, and a carbon-carbon double bond. A method for producing a fluorine-containing polymer, which comprises a copolymerization step of copolymerizing with a monomer, to obtain the fluorine-containing polymer according to (III).
_{CF 2 = CFCF 2 C (CF} 3) (OH) - (CH 2) n CR 2 = CHR 3 ··· (3)
(In the formula, R ² and R ³ each independently represents a hydrogen atom or an alkyl group having 12 or less carbon atoms. N is an integer of 0 to 2.)

(X) a fluorine-containing diene represented by the following formula (3), an alkoxycarbonyl group (C (O) OR ⁵ , R ⁵ represents an alkyl group having 6 or less carbon atoms) and carbon substituted with a fluorine atom -The manufacturing method of the fluorine-containing polymer which obtains the fluorine-containing polymer as described in said (IV) which comprises the copolymerization process of copolymerizing the monomer which has a carbon double bond.
_{CF 2 = CFCF 2 C (CF} 3) (OH) - (CH 2) n CR 2 = CHR 3 ··· (3)
(In the formula, R ² and R ³ each independently represents a hydrogen atom or an alkyl group having 12 or less carbon atoms. N is an integer of 0 to 2.)

(XI) A single molecule having a fluorine-containing diene represented by the following formula (4), at least one substituent selected from the group consisting of a carboxy group, a sulfo group and a sulfonyl fluoride group, and a carbon-carbon double bond. A method for producing a fluorine-containing polymer, which comprises a copolymerization step of copolymerizing with a monomer, to obtain the fluorine-containing polymer according to (V) above.
^{_{CF 2 = CFCH 2 CHQ 2 -}} (CH 2) n CR 2 = CHR 3 ··· (4)
(In the formula, R ² and R ³ each independently represent a hydrogen atom or an alkyl group having 12 or less carbon atoms, and Q ² is (CH ₂ ) _b C (CF ₃ ) _c (R ⁴ ) _d OH (b is N is an integer of 0 to 3, c and d are integers of 0 to 2 satisfying c + d = 2, and R ⁴ is a hydrogen atom, a fluorine atom or a methyl group. .)

(XII) a fluorine-containing diene represented by the following formula (4), an alkoxycarbonyl group (C (O) OR ⁵ , R ⁵ represents an alkyl group having 6 or less carbon atoms), and carbon substituted with a fluorine atom -The manufacturing method of the fluorine-containing polymer which obtains the fluorine-containing polymer as described in said (VI) which comprises the copolymerization process of copolymerizing the monomer which has a carbon double bond.
^{_{CF 2 = CFCH 2 CHQ 2 -}} (CH 2) n CR 2 = CHR 3 ··· (4)
(In the formula, R ² and R ³ each independently represent a hydrogen atom or an alkyl group having 12 or less carbon atoms, and Q ² is (CH ₂ ) _b C (CF ₃ ) _c (R ⁴ ) _d OH (b is N is an integer of 0 to 3, c and d are integers of 0 to 2 satisfying c + d = 2, and R ⁴ is a hydrogen atom, a fluorine atom or a methyl group. .)

  (XIII) A resist protective film composition comprising the fluoropolymer according to any one of (I) to (VI) above and a solvent for dissolving the fluoropolymer.

(XIV) a resist layer forming step of forming a resist layer on the surface of the substrate;
A resist protective film forming step of forming a resist protective film on the resist layer using the resist protective film composition described in (XIII) above;
A base material on which the resist protective film is formed is exposed by an immersion lithography method and subjected to alkali development;
A photoresist pattern forming method comprising:

As described below, according to the present invention, it is possible to provide a fluorine-containing polymer having high transparency in a wide wavelength region and a method for producing the same.
Further, according to the present invention, when used as a resist protective film of a chemically amplified resist, it is excellent in transparency to deep ultraviolet rays such as KrF and ArF excimer lasers and vacuum ultraviolet rays such as F ₂ excimer lasers, and suppresses the PED effect. Resist protection that can be removed in the development process of the current resist process, and is also soluble in an alkaline developer, and can protect the resist film from the immersion solvent in the immersion lithography process. A film composition and a method for forming a photoresist pattern using the same can be provided.
Furthermore, the fluorine-containing polymer of the present invention can be used, for example, as an ion protective resin composition, an ion exchange resin, an ion exchange membrane, a fuel cell, various battery materials, an optical fiber, an electronic member, a transparent film material, an agricultural film, and the like. It is very useful because it can be used for film for film, adhesive, fiber material, weather-resistant paint and the like.

The fluorine-containing polymer according to the first aspect of the present invention is
Fluorine-containing polymer having monomer units obtained by cyclopolymerization of the fluorine-containing diene represented by the above formula (1) (hereinafter simply referred to as “fluorine-containing diene (1)”) (hereinafter simply referred to as “fluorine-containing polymer”). (A) "));
Fluorine-containing polymer having monomer units obtained by cyclopolymerization of the fluorine-containing diene represented by the above formula (2) (hereinafter simply referred to as “fluorine-containing diene (2)”) (hereinafter simply referred to as “fluorine-containing polymer”). (B) ");
From a monomer unit obtained by cyclopolymerizing a fluorinated diene represented by the above formula (3) (hereinafter simply referred to as “fluorinated diene (3)”), a carboxy group, a sulfo group, and a sulfonyl fluoride group. A monomer unit obtained by polymerizing a monomer (hereinafter simply referred to as “monomer (5)”) having at least one substituent selected from the group consisting of and a carbon-carbon double bond. A fluorine-containing polymer (hereinafter, simply referred to as “fluorine-containing polymer (C-1)”);
A monomer unit obtained by cyclopolymerizing the above fluorinated diene (3), an alkoxycarbonyl group (C (O) OR ⁵ , R ⁵ represents an alkyl group having 6 or less carbon atoms) and a fluorine atom are substituted. And a monomer having a carbon-carbon double bond (hereinafter simply referred to as “monomer (6)”) and a monomer unit obtained by polymerizing the monomer unit (hereinafter simply referred to as “fluorine-containing”). Polymer (C-2) "));
A monomer unit obtained by cyclopolymerizing the fluorine-containing diene represented by the above formula (4) (hereinafter simply referred to as “fluorine-containing diene (4)”) and the monomer (5) are polymerized. A fluorine-containing polymer having a monomer unit (hereinafter, simply referred to as “fluorine-containing polymer (D-1)”);
A fluorine-containing polymer (hereinafter simply referred to as “fluorine-containing polymer”) having a monomer unit obtained by cyclopolymerizing the fluorine-containing diene (4) and a monomer unit obtained by polymerizing the monomer (6). D-2) ").

  Hereinafter, the fluorine-containing dienes (1) to (4) and the monomers (5) and (6) will be described in detail.

<Fluorine-containing diene (1)>
The fluorine-containing diene (1) is a diene represented by the following formula (1).
_{CF 2 = CFCF 2 C (CF} 3) (OR 1) - (CH 2) n CR 2 = CHR 3 ··· (1)
(In the formula, R ¹ represents an organic group having 20 or less carbon atoms having at least one substituent selected from the group consisting of a carboxy group, a sulfo group and a sulfonyl fluoride group, and R ² and R ³ are respectively Independently represents a hydrogen atom or an alkyl group having 12 or less carbon atoms, n is an integer of 0 to 2.)

Here, in the above formula (1), R ¹ is particularly limited as long as it is an organic group having 20 or less carbon atoms having at least one substituent selected from the group consisting of a carboxy group, a sulfo group and a sulfonyl fluoride group. The organic group is preferably an alkyl group which may have an etheric oxygen atom or a carbonyl group or a fluorine-containing alkyl group.
The alkyl group having 20 or less carbon atoms or the fluorinated alkyl group which may have an etheric oxygen atom or a carbonyl group includes not only a linear or branched aliphatic hydrocarbon group but also a cyclic aliphatic hydrocarbon group. You may have. Examples of the cyclic aliphatic hydrocarbon group include those shown below, and the ring structure may have an etheric oxygen atom or a carbonyl group.

  The cyclic aliphatic hydrocarbon group is preferably a hydrocarbon group having at least one cyclic structure. Specifically, for example, a monocyclic ring such as a cyclobutyl group, a cycloheptyl group, or a cyclohexyl group as shown below. Saturated hydrocarbon group; bicyclic saturated hydrocarbon group such as 4-cyclohexylcyclohexyl group; polycyclic saturated hydrocarbon group such as 1-decahydronaphthyl group and 2-decahydronaphthyl group; 1-norbornyl group, 1 -Bridged cyclic saturated hydrocarbon group such as adamantyl group; Spiro hydrocarbon group such as spiro [3.4] octyl group: and the like.

As such R ¹ , CH ₂ C (O) OH, CH (CH ₃ ) C (O) OH, CH ₂ CH ₂ C (O) OH, CF ₂ C (O) OH, CF (CF ₃ ) C (O) OH, CF ₂ CF ₂ C (O) OH, CHFC (O) OH, C (O) CH ₂ C (O) OH, CH ₂ SO ₃ H, CH ₂ CH ₂ SO ₃ H, CF ₂ CF (CF ₃ ) OCF ₂ CF ₂ SO ₂ F and those shown below (shown in the form of —OR ¹ in order to clarify the bonding position) and the like are preferably exemplified, and the resulting fluorine-containing polymer (A In order to maintain the Tg (glass transition point) of), it is preferably a short chain alkyl group, CH ₂ C (O) OH, CH ₂ CH ₂ C (O) OH, CH ₂ SO ₃ H, CH ₂ CH ₂ SO ₃ H is particularly preferred.

Next, in the above formula (1), the alkyl group having 12 or less carbon atoms of R ² and R ³ has not only a linear or branched aliphatic hydrocarbon group but also a cyclic aliphatic hydrocarbon group. It may be. In addition, some or all of the hydrogen atoms may be substituted with fluorine atoms, and may have etheric oxygen atoms. Examples of the cyclic aliphatic hydrocarbon group include the same groups as those exemplified above.

Examples of such R ² and R ³ are preferably a hydrogen atom, a methyl group, a trifluoromethyl group, and a cyclic aliphatic hydrocarbon group having 6 or less carbon atoms, more preferably a hydrogen atom or a methyl group. , R ² and R ³ are particularly preferably hydrogen atoms.

The fluorine-containing diene (1) represented by the above formula (1) is a fluorine-containing diene represented by the following formulas (5) to (7), and is obtained by cyclopolymerizing these fluorine-containing dienes. The fluorine-containing polymer (A) having a monomer unit is preferable because it becomes a polymer that can be easily synthesized and manufactured at low cost. In the following formulas (5) ~ (7), R ¹ is the same as R ¹ in the formula (1).
_{CF 2 = CFCF 2 C (CF} 3) (OR 1) -CH = CH 2 ··· (5)
CF ₂ = CFCF ₂ C (CF ₃ ) (OR ¹ ) —CH ₂ CH═CH ₂ (6)
CF ₂ = CFCF ₂ C (CF ₃ ) (OR ¹ ) − (CH ₂ ) ₂ CH═CH ₂ (7)

<Fluorine-containing diene (2)>
The fluorine-containing diene (2) is a diene represented by the following formula (2).
^{_{CF 2 = CFCH 2 CHQ 1 -}} (CH 2) n CR 2 = CHR 3 ··· (2)
(In the formula, R ² and R ³ each independently represent a hydrogen atom or an alkyl group having 12 or less carbon atoms, and Q ¹ represents (CH ₂ ) _b C (CF ₃ ) _c (R ⁴ ) _d OR ¹ (b Is an integer of 0 to 3, c and d are integers of 0 to 2 satisfying c + d = 2, R ⁴ is a hydrogen atom, a fluorine atom or a methyl group, R ¹ is a carboxy group, a sulfo group and a sulfonyl group An organic group having 20 or less carbon atoms having at least one substituent selected from the group consisting of fluoride groups.), N is an integer of 0 to 2.)

Here, in the above formula (2), R ² and R ³ are basically the same as R ² and R ³ in the formula (1).

Next, in the above formula (2), Q ¹ is represented by (CH ₂ ) _b C (CF ₃ ) _c (R ⁴ ) _d OR ¹ , and b is an integer of 0 to 3, preferably 0 or 1. C and d are integers of 0 to 2 satisfying c + d = 2, preferably c = 2 and d = 0. Here, when b = 0 or 1, the fluorine-containing polymer (B) having a monomer unit obtained by cyclopolymerizing the fluorine-containing diene (2) is used as a resist composition or a resist protective film composition described later. When used, it is preferable because the solubility in a basic developer is good. Further, R ⁴ is a hydrogen atom, a fluorine atom or a methyl group, R ¹ is basically the same as R ¹ in the formula (1).

The fluorinated diene (2) represented by the above formula (2) is a fluorinated diene represented by the following formulas (8) to (13), and is obtained by cyclopolymerizing these fluorinated dienes. The fluorine-containing polymer (B) having a monomer unit is preferable because it becomes a polymer that can be easily synthesized and manufactured at low cost. In the following formulas (8) ~ (13), R ¹ is basically the same as R ¹ in the formula (1).
_{CF 2 = CFCH 2 CH ((} CF 3) 2 OR 1) -CH = CH 2 ··· (8)
_{CF 2 = CFCH 2 CH ((} CF 3) 2 OR 1) -CH 2 CH = CH 2 ··· (9)
_{CF 2 = CFCH 2 CH ((} CF 3) 2 OR 1) - (CH 2) 2 CH = CH 2 ··· (10)
_{CF 2 = CFCH 2 CH (CH} 2 (CF 3) 2 OR 1) -CH = CH 2 ··· (11)
_{CF 2 = CFCH 2 CH (CH} 2 (CF 3) 2 OR 1) -CH 2 CH = CH 2 ··· (12)
_{CF 2 = CFCH 2 CH (CH} 2 (CF 3) 2 OR 1) - (CH 2) 2 CH = CH 2 ··· (13)

<Fluorine-containing diene (3)>
The fluorine-containing diene (3) is a diene represented by the following formula (3).
_{CF 2 = CFCF 2 C (CF} 3) (OH) - (CH 2) n CR 2 = CHR 3 ··· (3)
(In the formula, R ² and R ³ each independently represents a hydrogen atom or an alkyl group having 12 or less carbon atoms. N is an integer of 0 to 2.)

Here, in the above formula (3), R ² and R ³ are basically the same as R ² and R ³ in the formula (1).

The fluorinated diene (3) represented by the above formula (3) is a fluorinated diene represented by the following formulas (14) to (16), and is obtained by cyclopolymerizing these fluorinated dienes. A fluorine-containing polymer (C-1) or (C-2) having a monomer unit and a monomer unit obtained by polymerizing the monomer (5) or (6) described later is easy to synthesize and manufactured at low cost It is preferable because it becomes a polymer that can be produced.
_{CF 2 = CFCF 2 C (CF} 3) (OH) -CH = CH 2 ··· (14)
_{CF 2 = CFCF 2 C (CF} 3) (OH) -CH 2 CH = CH 2 ··· (15)
_{CF 2 = CFCF 2 C (CF} 3) (OH) - (CH 2) 2 CH = CH 2 ··· (16)

<Fluorine-containing diene (4)>
The fluorine-containing diene (4) is a diene represented by the following formula (4).
^{_{CF 2 = CFCH 2 CHQ 2 -}} (CH 2) n CR 2 = CHR 3 ··· (4)
(In the formula, R ² and R ³ each independently represent a hydrogen atom or an alkyl group having 12 or less carbon atoms, and Q ² is (CH ₂ ) _b C (CF ₃ ) _c (R ⁴ ) _d OH (b is N is an integer of 0 to 3, c and d are integers of 0 to 2 satisfying c + d = 2, and R ⁴ is a hydrogen atom, a fluorine atom or a methyl group. .)

Here, in the above formula (4), R ² and R ³ are basically the same as R ² and R ³ in the formula (1).

Next, in the above formula (4), Q ² is represented by (CH ₂ ) _b C (CF ₃ ) _c (R ⁴ ) _d OH, and b, c, d and R ⁴ are represented by the above formula (2) it is basically the same as those in the to Q ¹ in.

The fluorine-containing diene (4) represented by the above formula (4) is a fluorine-containing diene represented by the following formulas (17) to (22), and is obtained by cyclopolymerizing these fluorine-containing dienes. A fluorine-containing polymer (D-1) or (D-2) having a monomer unit and a monomer unit obtained by polymerizing the monomer (5) or (6) described later is easy to synthesize and manufactured at low cost It is preferable because it becomes a polymer that can be produced.
_{CF 2 = CFCH 2 CH ((} CF 3) 2 OH) -CH = CH 2 ··· (17)
_{CF 2 = CFCH 2 CH ((} CF 3) 2 OH) -CH 2 CH = CH 2 ··· (18)
_{CF 2 = CFCH 2 CH ((} CF 3) 2 OH) - (CH 2) 2 CH = CH 2 ··· (19)
_{CF 2 = CFCH 2 CH (CH} 2 (CF 3) 2 OH) -CH = CH 2 ··· (20)
_{CF 2 = CFCH 2 CH (CH} 2 (CF 3) 2 OH) -CH 2 CH = CH 2 ··· (21)
_{CF 2 = CFCH 2 CH (CH} 2 (CF 3) 2 OH) - (CH 2) 2 CH = CH 2 ··· (22)

<Monomer (5)>
The monomer (5) has at least one substituent selected from the group consisting of a carboxy group, a sulfo group and a sulfonyl fluoride group, and has a carbon-carbon double bond as a polymerizable site. It does not specifically limit, The carbon-carbon double bond may form the ring structure of an alicyclic compound.

As such a monomer, a compound represented by the following formula (23) is preferably exemplified.
CR ⁶ R ⁷ = CR ⁸ -R ⁹ (23)
(Wherein R ⁶ and R ⁷ each independently represents a hydrogen atom, a fluorine atom or a trifluoromethyl group, R ⁸ represents a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group, and R ⁹ represents And represents an organic group having at least one substituent selected from the group consisting of a carboxy group, a sulfo group and a sulfonyl fluoride group.

Here, in the formula (23), R ⁹ is particularly limited as long as it is at least one substituent selected from the group consisting of a carboxy group, a sulfo group, and a sulfonyl fluoride group, or an organic group having the substituent. The organic group is preferably an alkyl group or a fluorinated alkyl group which may have an etheric oxygen atom or a carbonyl group.
The alkyl group or fluorine-containing alkyl group which may have an etheric oxygen atom or carbonyl group may have not only a linear or branched aliphatic hydrocarbon group but also a cyclic aliphatic hydrocarbon group. Good. Examples of the cyclic aliphatic hydrocarbon group include the same groups as those exemplified above, and the ring structure may have an etheric oxygen atom or a carbonyl group.
When R ⁹ is an organic group having a sulfonyl fluoride group, the organic group is particularly preferably a fluorine-containing alkyl group that may have an etheric oxygen atom.

Such R ⁹ includes C (O) OH, SO ₃ H, SO ₂ F, CH ₂ CH ₂ C (O) OH, OCF ₂ CF ₂ CF ₂ C (O) OH, CH ₂ OCF ₂ CF _2. SO ₃ H, CH ₂ O (OCF ₂ CF ₂ ) ₂ SO ₃ H, OCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ SO ₃ H, OCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ SO ₂ F and below The compounds shown (in the form of -R ⁹ in order to clarify the bonding position) and the like are preferably exemplified, and an ester group (carbonyloxy) is used to facilitate copolymerization with the fluorine-containing dienes (3) and (4). Group) or a fluorine atom, and C (O) OH or OCF ₂ CF ₂ CF ₂ C (O) OH is particularly preferable.

Specific examples of the compound represented by the formula (23) include CH ₂ ═CH—C (O) OH, CH ₂ ═C (CH ₃ ) C (O) OH, and CH ₂ ═CFC ( _{O) OH, CH 2 = C} (CF 3) C (O) OH, CF 3 CH = CHC (O) OH, CF 3 C (CH 3) = CHC (O) OH,
_{(CF 3) 2 C = CHC} (O) OH, CF 2 = CF-C (O) OH, CF 2 = CFCH 2 CH 2 C (O) OH, CF 2 = CFOCF 2 CF 2 CF 2 C (O) _{OH, CH 2 = CH-SO} 3 H, CH 2 = CH-CH 2 OCF 2 CF 2 SO 3 H, CH 2 = CH-CH 2 (OCF 2 CF 2) 2 SO 3 H, CF 2 = CFOCF 2 CF _{(CF 3) OCF 2 CF 2} SO 3 H, CH 2 = CH-SO 2 F, CH 2 = CH-CH 2 OCF 2 CF 2 SO 2 F, CH 2 = CH-CH 2 (OCF 2 CF 2) 2 SO ₂ F, CF ₂ ═CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ SO ₂ F and the compounds shown below are exemplified.

  Specific examples of the compound in which the carbon-carbon double bond forms the ring structure of the alicyclic compound include the compounds shown below.

<Monomer (6)>
The monomer (6) has an alkoxycarbonyl group (C (O) OR ⁵ , R ⁵ represents an alkyl group having 6 or less carbon atoms), and is a carbon-carbon substituted with a fluorine atom as a polymerizable site. It will not specifically limit if it has a double bond, The carbon-carbon double bond may form the ring structure of an alicyclic compound.

As such a monomer, a compound represented by the following formula (24) is preferably exemplified.
CF ₂ = CF-R ¹⁰ (24)
(Wherein R ¹⁰ represents an alkoxycarbonyl group (C (O) OR ⁵ , R ⁵ represents an alkyl group having 6 or less carbon atoms) or an organic group having the alkoxycarbonyl group.)

Here, in the above formula (24), R ¹⁰ may be an alkoxycarbonyl group (C (O) OR ⁵ , R ⁵ represents an alkyl group having 6 or less carbon atoms) or an organic group having the alkoxycarbonyl group. The organic group is preferably an alkyl group or a fluorine-containing alkyl group which may have an etheric oxygen atom or a carbonyl group.
The alkyl group or fluorine-containing alkyl group which may have an etheric oxygen atom or carbonyl group may have not only a linear or branched aliphatic hydrocarbon group but also a cyclic aliphatic hydrocarbon group. Good. Examples of the cyclic aliphatic hydrocarbon group include the same groups as those exemplified above, and the ring structure may have an etheric oxygen atom or a carbonyl group.
When R ¹⁰ is an organic group having an alkoxycarbonyl group (C (O) OR ⁵ , R ⁵ represents an alkyl group having 6 or less carbon atoms), the organic group may contain an etheric oxygen atom. Particularly preferred is a fluorine alkyl group.

As such R ¹⁰ , C (O) OCH ₃ , C (O) OCH ₂ CH ₃ , C (O) OCH ₂ CH ₂ CH ₃ , C (O) OCH ₂ CH ₂ CH ₂ CH ₃ , C ( _{O) OCH 2 CH 2 CH 2} CH 2 CH 3, C (O) OCH 2 CH 2 CH 2 CH 2 CH 2 CH 3, OCF 2 CF 2 CF 2 C (O) OCH 3, OCF 2 CF 2 CF 2 C (O) OCH ₂ CH _{3 and the} like are suitably exemplified, and OCF ₂ CF ₂ CF ₂ C (O) OCH ₃ and OCF ₂ CF ₂ CF ₂ C (O) OCH ₂ CH ₃ are more preferable.

Examples of the compound represented by the formula (24), specifically, for _{example, CF 2 = CF-C (} O) OCH 3, CF 2 = CF-C (O) OCH 2 CH 3, CF 2 = CF _{-C (O) OCH 2 CH 2} CH 3, CF 2 = CF-C (O) OCH 2 CH 2 CH 2 CH 3, CF 2 = CF-C (O) OCH 2 CH 2 CH 2 CH 2 CH 3, _{CF 2 = CF-C (O} ) OCH 2 CH 2 CH 2 CH 2 CH 2 CH 3, CF 2 = CF-OCF 2 CF 2 CF 2 C (O) OCH 3, CF 2 = CF-OCF 2 CF 2 CF ₂ C (O) OCH ₂ CH _{3 and the} like.

  Hereinafter, the fluoropolymers (A), (B), (C-1), (C-2), (D-1) and (D-2) of the present invention will be described in detail.

<Fluoropolymer (A)>
The fluorine-containing polymer (A) of the present invention is a fluorine-containing polymer having a monomer unit obtained by cyclopolymerizing the fluorine-containing diene (1).
The fluorinated diene (1) undergoes cyclization polymerization under relatively mild conditions, and cyclization having at least one substituent selected from the group consisting of a carboxy group, a sulfo group and a sulfonyl fluoride group as a ring side chain A polymer is obtained. This cyclopolymerization is considered to produce the following monomer units (a) to (f) from the results of spectroscopic analysis and the like. Incidentally, (a) in ~ (f), R ¹ is the same as R ¹ in the formula (1).
Specifically, it is considered that a cyclized polymer having the monomer unit (a) or the monomer unit (b) is obtained from the fluorine-containing diene (1) in the case where n in the above formula (1) is 0. It is considered that a cyclized polymer having monomer unit (c), monomer unit (d) or monomer unit (e) is obtained from fluorine-containing diene (1) when n = 1. From the fluorine-containing diene (1) in this case, it is considered that a cyclized polymer having the monomer unit (f) is obtained.

In the present invention, the fluorine-containing polymer (A) is a monomer unit obtained by cyclopolymerizing the fluorine-containing diene (1), that is, a polymer having such monomer units (a) to (f). There is no particular limitation as long as it does not impair the characteristics, and in addition to the monomer unit, a monomer unit derived from a radical polymerizable monomer (hereinafter referred to as “other monomer unit”) may be included. In the fluorine-containing polymer (A) of the present invention, the proportion of other monomer units is preferably 50 mol% or less, particularly preferably 15 mol% or less.
Specific examples of the radical polymerizable monomer include α-olefins such as ethylene, propylene and isobutylene; fluorine-containing olefins such as tetrafluoroethylene and hexafluoropropylene; perfluoro (2,2-dimethyl- Fluorine-containing cyclic monomers such as 1,3-dioxole; perfluorodienes and hydrofluorodienes capable of cyclopolymerization 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 Acid, vinyl chloride and the like.

Therefore, the fluorinated polymer (A) of the present invention may be a cyclized polymer itself obtained by cyclization polymerization of the fluorinated diene (1), and relates to the second aspect of the present invention described later. As shown in the production method, the cyclized polymer obtained by cyclopolymerizing the fluorine-containing diene represented by the above formula (3) is at least selected from the group consisting of a carboxy group, a sulfo group and a sulfonyl fluoride group. A polymer obtained by introducing one substituent may be used, and a cyclized polymer obtained by cyclopolymerizing a fluorinated diene represented by the following formulas (25) to (27) may be hydrolyzed. It may be a polymer.
Further, the fluorine-containing polymer (A) of the present invention polymerizes monomer units obtained by cyclopolymerizing the fluorine-containing dienes (2) to (4) and the monomers (5) and (6). The monomer unit may be obtained.
_{· CF 2 = CFCF 2 C (} CF 3) (OR 11 C (O) OR 12) - (CH 2) n CR 2 = CHR 3 ··· (25)
_{· CF 2 = CFCF 2 C (} CF 3) (OR 11 SO 3 R 12) - (CH 2) n CR 2 = CHR 3 ··· (26)
_{· CF 2 = CFCF 2 C (} CF 3) (OR 11 S (O) 2 F) - (CH 2) n CR 2 = CHR 3 ··· (27)
(In the formula, R ¹¹ and R ¹² each independently represents an organic group having 6 or less carbon atoms, and R ² and R ³ each independently represent a hydrogen atom or an alkyl group having 12 or less carbon atoms. N is 0. It is an integer of ~ 2.)

Here, in the above formulas (25) to (27), R ¹¹ and R ¹² are not particularly limited as long as they are organic groups having 6 or less carbon atoms. Specifically, methyl group, ethyl group, propyl group and the like The alkyl group is preferably exemplified.
In the formulas (25) to (27), R ² and R ³ are basically the same as R ² and R ³ in the formula (1).

Since the fluorine-containing polymer (A) of the present invention has a monomer unit obtained by cyclopolymerization of the fluorine-containing diene (1), it has an aliphatic ring structure in the main chain and a functional group in the side chain. It becomes a fluorine-containing polymer, has high chemical stability and heat resistance, and has high transparency in a wide wavelength range, especially transparency to far ultraviolet rays such as KrF and ArF excimer lasers and vacuum ultraviolet rays such as F ₂ excimer lasers. become. In addition, since the fluorine-containing polymer (A) of the present invention has at least one substituent selected from the group consisting of a carboxy group, a sulfo group, and a sulfonyl fluoride group as an acidic group, a chemically amplified resist substrate is used. It is excellent in the effect of suppressing the PED effect seen when left in the atmosphere after drawing, and can be suitably used for high-precision pattern production. Furthermore, since the fluoropolymer (A) of the present invention is insoluble in the immersion solvent (water) and dissolves in the developer, the resist film is used as a resist protective film in immersion lithography. It is possible to protect from the immersion solvent, eliminating the need for a step of removing the protective film alone.

<Fluoropolymer (B)>
The fluorine-containing polymer (B) of the present invention is a fluorine-containing polymer having a monomer unit obtained by cyclopolymerizing the fluorine-containing diene (2).
The fluorinated diene (2) undergoes cyclization polymerization under relatively mild conditions, and cyclization having at least one substituent selected from the group consisting of a carboxy group, a sulfo group and a sulfonyl fluoride group as a ring side chain A polymer is obtained. This cyclopolymerization is considered to produce the following monomer units (g) to (l) from the results of spectroscopic analysis and the like. Incidentally, (g) in ~ (l), Q ¹ is are the same as defined in Q ¹ in the formula (2).
Specifically, it is considered that a cyclized polymer having a monomer unit (g) or a monomer unit (h) is obtained from the fluorine-containing diene (2) when n in the above formula (2) is 0. It is considered that a cyclized polymer having a monomer unit (i), a monomer unit (j) or a monomer unit (k) is obtained from the fluorine-containing diene (2) when n = 1. From the fluorine-containing diene (2) in this case, it is considered that a cyclized polymer having the monomer unit (1) is obtained.

  In the present invention, the fluorine-containing polymer (B) is a monomer unit obtained by cyclopolymerization of the fluorine-containing diene (2), that is, a polymer having such monomer units (g) to (l). If it is, it will not specifically limit, In the range which does not impair the characteristic, you may have the other monomer unit mentioned above similarly to a fluorine-containing polymer (A) other than the said monomer unit. In the fluorine-containing polymer (B) of the present invention, the proportion of other monomer units is preferably 50 mol% or less, particularly preferably 15 mol% or less.

Therefore, the fluorinated polymer (B) of the present invention may be a cyclized polymer itself obtained by cyclization polymerization of the fluorinated diene (2), or according to the second aspect of the present invention described later. As shown in the production method, the cyclized polymer obtained by cyclopolymerizing the fluorine-containing diene represented by the above formula (4) is at least selected from the group consisting of a carboxy group, a sulfo group and a sulfonyl fluoride group. A polymer formed by introducing one substituent may be a polymer obtained by hydrolyzing a cyclized polymer obtained by cyclopolymerizing a fluorinated diene represented by the following formula (28). There may be.
The fluorine-containing polymer (B) of the present invention is a monomer unit obtained by cyclopolymerizing the fluorine-containing dienes (1), (3) and (4), and the monomers (5) and (6). ) May be obtained by polymerizing the monomer unit.
^{_{CF 2 = CFCH 2 CHQ 3 -}} (CH 2) n CR 2 = CHR 3 ··· (28)
(Wherein R ² and R ³ each independently represents a hydrogen atom or an alkyl group having 12 or less carbon atoms, and Q ³ represents (CH ₂ ) _b C (CF ₃ ) _c (R ⁴ ) _d (OR ¹¹ C (O) OR ¹² ), (CH ₂ ) _b C (CF ₃ ) _c (R ⁴ ) _d (OR ¹¹ SO ₃ R ¹² ) or (CH ₂ ) _b C (CF ₃ ) _c (R ⁴ ) _d ( OR ¹¹ S (O) ₂ F) (b is an integer of 0 to 3, c and d are integers of 0 to 2 satisfying c + d = 2, and R ⁴ is a hydrogen atom, a fluorine atom or a methyl group. , R ¹¹ and R ¹² each independently represents an organic group having 6 or less carbon atoms.) N represents an integer of 0 to 2.)

Here, in the above formula (28), R ² and R ³ are basically the same as R ² and R ³ in the formula (1).
In the above formula (28), Q ³ is (CH ₂ ) _b C (CF ₃ ) _c (R ⁴ ) _d (OR ¹¹ C (O) OR ¹² ), (CH ₂ ) _b C (CF ₃ ). _c (R ⁴ ) _d (OR ¹¹ SO ₃ R ¹² ) or (CH ₂ ) _b C (CF ₃ ) _c (R ⁴ ) _d (OR ¹¹ S (O) ₂ F), b, c, d and R ⁴ is basically the same as those in to ^{Q 1} in the above formula (2), R ¹¹ and R ^12, the equation (25) ~ (27) R 11 and R ¹² basically in The same as above.

Since the fluorine-containing polymer (B) of the present invention has a monomer unit obtained by cyclopolymerization of the fluorine-containing diene (2), the main chain has an aliphatic ring structure and the side chain has a functional group. It becomes a fluorine-containing polymer, has high chemical stability and heat resistance, and has high transparency in a wide wavelength range, especially transparency to far ultraviolet rays such as KrF and ArF excimer lasers and vacuum ultraviolet rays such as F ₂ excimer lasers. become. In addition, since the fluorine-containing polymer (B) of the present invention has at least one substituent selected from the group consisting of a carboxy group, a sulfo group and a sulfonyl fluoride group as an acidic group, a chemically amplified resist substrate is used. It is excellent in the effect of suppressing the PED effect seen when left in the atmosphere after drawing, and can be suitably used for high-precision pattern production. Furthermore, since the fluoropolymer (B) of the present invention is insoluble in the immersion solvent (water) and dissolves in the developer, the resist film is used as a resist protective film in immersion lithography. It becomes possible to protect from the immersion solvent, and the removal process of the protective film alone becomes unnecessary.

<Fluoropolymer (C-1)>
The fluorine-containing polymer (C-1) of the present invention has a monomer unit obtained by cyclopolymerizing the fluorine-containing diene (3) and a monomer unit obtained by polymerizing the monomer (5). It is a fluorine-containing polymer.

The fluorinated diene (3) is cyclized and polymerized under relatively mild conditions to obtain a cyclized polymer having a hydroxyl group as a ring side chain. This cyclopolymerization is considered to produce the following monomer units (m) to (r) from the results of spectroscopic analysis and the like. Incidentally, (m) in ~ (r), R ² is the same as R ² in the formula (3).
Specifically, it is considered that a cyclized polymer having a monomer unit (m) or a monomer unit (n) is obtained from the fluorine-containing diene (1) when n in the above formula (3) is 0. It is considered that a cyclized polymer having a monomer unit (o), a monomer unit (p) or a monomer unit (q) is obtained from the fluorine-containing diene (1) when n = 1. From the fluorine-containing diene (1) in this case, it is considered that a cyclized polymer having the monomer unit (r) is obtained.

The monomer (5) is polymerized under relatively mild conditions to obtain a polymer having as a side chain at least one substituent selected from the group consisting of a carboxy group, a sulfo group and a sulfonyl fluoride group. By this polymerization, for example, CH ₂ ═CHC (O) OH, CH ₂ ═C (CH ₃ ) C (O) OH, CH ₂ ═CFC (O) OH exemplified as the compound represented by the above formula (23). When is used as a monomer, the following monomer units (i) to (iii) are considered to be generated from the results of spectroscopic analysis and the like.

  In the present invention, the fluorine-containing polymer (C-1) includes a monomer unit obtained by cyclopolymerizing the fluorine-containing diene (3), and a monomer unit obtained by polymerizing the monomer (5). If it is a polymer which has this, it will not specifically limit, In the range which does not impair the characteristic, you may have the other monomer unit mentioned above similarly to a fluorine-containing polymer (A) other than the said monomer unit. In the fluorine-containing polymer (C-1) of the present invention, the proportion of other monomer units is preferably 50 mol% or less, particularly preferably 15 mol% or less.

  Therefore, the fluorine-containing polymer (C-1) of the present invention comprises the fluorine-containing diene (3) and the monomer (5) as shown in the production method according to the second aspect of the present invention described later. It is preferable that it is a polymer obtained by copolymerizing. The fluorine-containing polymer (C-1) of the present invention has monomer units obtained by cyclopolymerizing the fluorine-containing dienes (1), (2) and (4) and the monomer (6). It may be.

The fluorine-containing polymer (C-1) of the present invention has a monomer unit obtained by cyclopolymerizing the fluorine-containing diene (3) and a monomer unit obtained by polymerizing the monomer (5). Fluorine-containing polymer having an aliphatic ring structure in the main chain and a functional group in the side chain, having high chemical stability and heat resistance, and high transparency in a wide wavelength range, especially KrF, ArF excimer laser It will have a transparency to vacuum ultraviolet rays such as far ultraviolet or F ₂ excimer laser and the like. Moreover, since the fluoropolymer (C-1) of the present invention has at least one substituent selected from the group consisting of a carboxy group, a sulfo group and a sulfonyl fluoride group as an acidic group, a chemically amplified resist It is excellent in the effect of suppressing the PED effect seen when the substrate is left in the atmosphere after drawing, and can be suitably used for high-precision pattern manufacturing. Furthermore, since the fluoropolymer (C-1) of the present invention is insoluble in the immersion solvent (water) and dissolves in the developer, the resist film is used when used as a resist protective film in immersion lithography. Can be protected from the immersion solvent, eliminating the need for a step of removing the protective film alone.

<Fluoropolymer (C-2)>
The fluorine-containing polymer (C-2) of the present invention has a monomer unit obtained by cyclopolymerizing the fluorine-containing diene (3) and a monomer unit obtained by polymerizing the monomer (6). It is a fluorine-containing polymer.

  The fluorinated diene (3) is cyclized and polymerized under relatively mild conditions to obtain a cyclized polymer having a hydroxyl group as a ring side chain. This cyclopolymerization is considered to produce the monomer units (m) to (r) described above from the results of spectroscopic analysis and the like as described in the fluoropolymer (C-1).

The monomer (6) is polymerized under relatively mild conditions, and a polymer having an alkoxycarbonyl group (C (O) OR ⁵ , R ⁵ represents an alkyl group having 6 or less carbon atoms) as a side chain is obtained. can get. This polymerization, for example, the equation _{(24) CF 2 = CF-} C exemplified as compounds represented by _{(O) OCH 3, CF 2} = CF-C (O) OCH 2 CH 3, CF 2 = CF- When OCF ₂ CF ₂ CF ₂ C (O) OCH ₃ is used as a monomer, the following monomer units (iv) to (vi) are considered to be generated from the results of spectroscopic analysis and the like.

  In the present invention, the fluorine-containing polymer (C-2) includes a monomer unit obtained by cyclopolymerizing the fluorine-containing diene (3), and a monomer unit obtained by polymerizing the monomer (6). If it is a polymer which has this, it will not specifically limit, In the range which does not impair the characteristic, you may have the other monomer unit mentioned above similarly to a fluorine-containing polymer (A) other than the said monomer unit. In the fluorine-containing polymer (C-2) of the present invention, the proportion of other monomer units is preferably 50 mol% or less, particularly preferably 15 mol% or less.

  Therefore, the fluorinated polymer (C-2) of the present invention comprises the fluorinated diene (3) and the monomer (6) as shown in the production method according to the second aspect of the present invention described later. It is preferable that it is a polymer obtained by copolymerizing. The fluorine-containing polymer (C-2) of the present invention has monomer units obtained by cyclopolymerizing the fluorine-containing dienes (1), (2) and (4) and the monomer (5). It may be.

Since the fluorine-containing polymer (C-2) of the present invention has a monomer unit obtained by cyclopolymerizing the fluorine-containing diene (3) and a monomer unit obtained by polymerizing the monomer (6). Fluorine-containing polymer having an aliphatic ring structure in the main chain and a functional group in the side chain, high chemical stability and heat resistance, and high transparency in a wide wavelength range, especially KrF, ArF excimer laser It will have a transparency to vacuum ultraviolet rays such as far ultraviolet or F ₂ excimer laser and the like. In addition, the fluorine-containing polymer (C-2) of the present invention has an alkoxycarbonyl group (C (O) OR ⁵ , R ⁵ represents an alkyl group having 6 or less carbon atoms) as an acidic group. It is excellent in the effect of suppressing the PED effect observed when the amplification resist substrate is left in the atmosphere after drawing, and can be suitably used for high-precision pattern manufacturing. Furthermore, since the fluoropolymer (C-2) of the present invention is insoluble in the immersion solvent (water) and dissolves in the developer, the resist film is used when used as a resist protective film in immersion lithography. Can be protected from the immersion solvent, eliminating the need for a step of removing the protective film alone.

<Fluoropolymer (D-1)>
The fluorine-containing polymer (D-1) of the present invention has a monomer unit obtained by cyclopolymerizing the fluorine-containing diene (4) and a monomer unit obtained by polymerizing the monomer (5). It is a fluorine-containing polymer.

The fluorinated diene (4) is cyclized and polymerized under relatively mild conditions to obtain a cyclized polymer having a hydroxyl group as a ring side chain. This cyclopolymerization is considered to produce the following monomer units (s) to (x) from the results of spectroscopic analysis and the like. Incidentally, (s) in ~ (x), Q ² is the same as Q ² in the formula (4).
Specifically, it is considered that a cyclized polymer having a monomer unit (s) or a monomer unit (t) is obtained from the fluorine-containing diene (4) in the case where n is 0 in the above formula (4). It is considered that a cyclized polymer having a monomer unit (u), a monomer unit (v) or a monomer unit (w) can be obtained from the fluorine-containing diene (4) in the case where n = 1. From the fluorine-containing diene (4) in this case, it is considered that a cyclized polymer having the monomer unit (x) is obtained.

The monomer (5) is polymerized under relatively mild conditions to obtain a polymer having as a side chain at least one substituent selected from the group consisting of a carboxy group, a sulfo group and a sulfonyl fluoride group. By this polymerization, as described in the fluoropolymer (C-1), for example, CH ₂ ═CHC (O) OH, CH ₂ ═C (CH ₃ ) exemplified as the compound represented by the formula (23). ) When C (O) OH, CH ₂ = CFC (O) OH is used as a monomer, the monomer units (i) to (iii) described above are generated from the results of spectroscopic analysis and the like. Conceivable.

  In the present invention, the fluorine-containing polymer (D-1) includes a monomer unit obtained by cyclopolymerizing the fluorine-containing diene (4), and a monomer unit obtained by polymerizing the monomer (5). If it is a polymer which has this, it will not specifically limit, In the range which does not impair the characteristic, you may have the other monomer unit mentioned above similarly to a fluorine-containing polymer (A) other than the said monomer unit. In the fluorine-containing polymer (D-1) of the present invention, the proportion of other monomer units is preferably 50 mol% or less, particularly preferably 15 mol% or less.

  Therefore, the fluorinated polymer (D-1) of the present invention comprises the fluorinated diene (4) and the monomer (5) as shown in the production method according to the second aspect of the present invention described later. It is preferable that it is a polymer obtained by copolymerizing. Moreover, the fluorine-containing polymer (D-1) of the present invention may have a monomer unit obtained by cyclopolymerizing the fluorine-containing dienes (1) to (3) and the monomer (6). .

The fluorine-containing polymer (D-1) of the present invention has a monomer unit obtained by cyclopolymerizing the fluorine-containing diene (4) and a monomer unit obtained by polymerizing the monomer (5). Fluorine-containing polymer having an aliphatic ring structure in the main chain and a functional group in the side chain, high chemical stability and heat resistance, and high transparency in a wide wavelength range, especially KrF, ArF excimer laser It will have a transparency to vacuum ultraviolet rays such as far ultraviolet or F ₂ excimer laser and the like. Moreover, since the fluorine-containing polymer (D-1) of the present invention has at least one substituent selected from the group consisting of a carboxy group, a sulfo group and a sulfonyl fluoride group as an acidic group, a chemically amplified resist It is excellent in the effect of suppressing the PED effect seen when the substrate is left in the atmosphere after drawing, and can be suitably used for high-precision pattern manufacturing. Furthermore, since the fluoropolymer (D-1) of the present invention is insoluble in the immersion solvent (water) and dissolves in the developer, the resist film is used when used as a resist protective film in immersion lithography. Can be protected from the immersion solvent, eliminating the need for a step of removing the protective film alone.

<Fluoropolymer (D-2)>
The fluorine-containing polymer (D-2) of the present invention has a monomer unit obtained by cyclopolymerizing the fluorine-containing diene (4) and a monomer unit obtained by polymerizing the monomer (6). It is a fluorine-containing polymer.

  The fluorinated diene (4) is cyclized and polymerized under relatively mild conditions to obtain a cyclized polymer having a hydroxyl group as a ring side chain. As described in the fluoropolymer (D-1), the cyclopolymerization is considered to generate the monomer units (s) to (x) described above from the results of spectroscopic analysis and the like.

The monomer (6) is polymerized under relatively mild conditions, and a polymer having an alkoxycarbonyl group (C (O) OR ⁵ , R ⁵ represents an alkyl group having 6 or less carbon atoms) as a side chain is obtained. can get. By this polymerization, as described in the fluoropolymer (C-2), for example, CF ₂ ═CF—C (O) OCH ₃ , CF ₂ ═CF exemplified as the compound represented by the formula (24). When —C (O) OCH ₂ CH ₃ , CF ₂ ═CF—OCF ₂ CF ₂ CF ₂ C (O) OCH ₃ is used as a monomer, the above-described ( It is considered that monomer units of iv) to (vi) are formed.

  In the present invention, the fluorine-containing polymer (D-2) includes a monomer unit obtained by cyclopolymerizing the fluorine-containing diene (4), and a monomer unit obtained by polymerizing the monomer (6). If it is a polymer which has this, it will not specifically limit, In the range which does not impair the characteristic, you may have the other monomer unit mentioned above similarly to a fluorine-containing polymer (A) other than the said monomer unit. In the fluorine-containing polymer (D-2) of the present invention, the proportion of other monomer units is preferably 50 mol% or less, particularly preferably 15 mol% or less.

  Therefore, the fluorine-containing polymer (D-2) of the present invention includes the fluorine-containing diene (4) and the monomer (6) as shown in the production method according to the second aspect of the present invention described later. It is preferable that it is a polymer obtained by copolymerizing. Moreover, the fluorine-containing polymer (D-2) of the present invention may have a monomer unit obtained by cyclopolymerizing the fluorine-containing dienes (1) to (3) and the monomer (5). .

Since the fluorine-containing polymer (D-2) of the present invention has a monomer unit obtained by cyclopolymerizing the fluorine-containing diene (4) and a monomer unit obtained by polymerizing the monomer (6). Fluorine-containing polymer having an aliphatic ring structure in the main chain and a functional group in the side chain, high chemical stability and heat resistance, and high transparency in a wide wavelength range, especially KrF, ArF excimer laser It will have a transparency to vacuum ultraviolet rays such as far ultraviolet or F ₂ excimer laser and the like. In addition, since the fluorine-containing polymer (D-2) of the present invention has an alkoxycarbonyl group (C (O) OR ⁵ , R ⁵ represents an alkyl group having 6 or less carbon atoms) as an acidic group, it has chemical properties. It is excellent in the effect of suppressing the PED effect observed when the amplification resist substrate is left in the atmosphere after drawing, and can be suitably used for high-precision pattern manufacturing. Furthermore, since the fluoropolymer (D-2) of the present invention is insoluble in an immersion solvent (water) and dissolves in a developing solution, when used as a resist protective film in immersion lithography, a resist film Can be protected from the immersion solvent, eliminating the need for a step of removing the protective film alone.

  The molecular weight of the fluoropolymer according to the first aspect of the present invention is appropriately selected depending on the application. For example, when used as a resist protective film composition according to the third aspect of the present invention to be described later, it is necessary that it can be uniformly dissolved in an organic solvent and can be uniformly applied on the resist. The number average molecular weight in terms of polystyrene is suitably 1,000 to 100,000, preferably 2,000 to 20,000. It is preferable that the number average molecular weight is in this range because it can be uniformly dissolved in an organic solvent that does not dissolve the resist film described later.

The production method of the fluoropolymer according to the second aspect of the present invention is the fluoropolymer (A), (B), (C-1), (C-2), (D-1) and (D-). 2) a method for obtaining each of the above, specifically,
The production method of the fluoropolymer for obtaining the fluoropolymer (A) includes a production method comprising a polymerization step of cyclopolymerizing the fluorodiene (1) to produce a polymer; the fluorodiene (3) A polymerization step for producing a polymer by cyclopolymerization, and an introduction step for introducing at least one substituent selected from the group consisting of a carboxy group, a sulfo group and a sulfonyl fluoride group into the polymer. Production method: Production method comprising a polymerization step of cyclopolymerizing the fluorine-containing diene represented by the above formulas (25) to (27) to produce a polymer, and a hydrolysis step of hydrolyzing the polymer And the like.
The production method of the fluoropolymer for obtaining the fluoropolymer (B) is a production method comprising a polymerization step of cyclopolymerizing the fluorodiene (2) to produce a polymer; the fluorodiene (4) A polymerization step for producing a polymer by cyclopolymerization, and an introduction step for introducing at least one substituent selected from the group consisting of a carboxy group, a sulfo group and a sulfonyl fluoride group into the polymer. Production method; production method comprising a polymerization step of cyclopolymerizing the fluorine-containing diene represented by the above formula (28) to produce a polymer, and a hydrolysis step of hydrolyzing the polymer; It is done.
The fluoropolymer production method for obtaining the fluoropolymer (C-1) comprises a copolymerization step in which the fluorodiene (3) and the monomer (5) are cyclopolymerized (copolymerized). The production method of the fluoropolymer for obtaining the fluoropolymer (C-2) is cyclopolymerization (copolymerization) of the fluorodiene (3) and the monomer (6). The production method comprises a copolymerization step.
The fluoropolymer production method for obtaining the fluoropolymer (D-1) comprises a copolymerization step in which the fluorodiene (4) and the monomer (5) are cyclopolymerized (copolymerized). The production method of the fluoropolymer for obtaining the fluoropolymer (D-2) is cyclopolymerization (copolymerization) of the fluorodiene (4) and the monomer (6). The production method comprises a copolymerization step.
Hereinafter, the fluorine-containing polymer (C) simply refers to the fluorine-containing polymers (C-1) and (C-2), and the fluorine-containing polymer (D) refers to the fluorine-containing polymer (D-1) and (D-2) shall be indicated.

  In the present invention, in the case of “cyclopolymerization”, two or more fluorine-containing dienes are used in addition to the cyclopolymerization of one type of fluorine-containing diene (1) to (4) to obtain a homopolymer. (1) is cyclopolymerized (copolymerized) to obtain a copolymer, and two or more fluorine-containing dienes (2) are cyclopolymerized (copolymerized) to obtain a copolymer. To obtain a copolymer by cyclopolymerization (copolymerization) of the fluorine-containing diene (3), and to obtain a copolymer by cyclopolymerization (copolymerization) of two or more fluorine-containing dienes (4) And cyclopolymerizing (copolymerizing) any one of the fluorine-containing dienes (1) to (4) with the above-mentioned other monomer to obtain a copolymer having other monomer units as repeating units. .

In the present invention, the polymerization step and the copolymerization step are performed in the presence of a polymerization initiation source.
The polymerization initiation source is not particularly limited as long as the polymerization reaction proceeds radically, and for example, a radical generator, light, ionizing radiation, or the like can be used. Of these, it is preferable to use a radical generator.
Examples of the radical generator include peroxides, azo compounds, persulfates, and the like, and the following peroxides are preferable.
_{· C 6 H 5 -C (O} ) O-OC (O) -C 6 H 5
_{· C 6 F 5 -C (O} ) O-OC (O) -C 6 F 5
_{· C 3 F 7 -C (O} ) O-OC (O) -C 3 F 7
_{· (CH 3) 3 C-} C (O) O-OC (O) -C (CH 3) 3
_{· (CH 3) 2 CH-} C (O) O-OC (O) -CH (CH 3) 2
_{· (CH 3) 3 C-} C 6 H 10 -C (O) O-OC (O) -C 6 H 10 -C (CH 3) 3
(CH ₃ ) ₃ C—O—C (O) O—OC (O) —O—C (CH ₃ ) _{3
· (CH 3) 2 CH-} OC (O) O-OC (O) -O-CH (CH 3) 2
_{· (CH 3) 3 C-} C 6 H 10 -O-C (O) O-OC (O) -O-C 6 H 10 -C (CH 3) 3
Here, C ₆ H ₅ represents a phenyl group, C ₆ F ₅ represents a pentafluorophenyl group, and C ₆ H ₁₀ represents a cyclohexylene group.

  Moreover, in this invention, the polymerization method in the said polymerization process and the said copolymerization process is not specifically limited, The fluorine-containing diene (1)-(4) used according to the fluorine-containing polymer obtained, monomer (5 ) And (6) and so-called bulk polymerization in which other monomers are subjected to polymerization as they are; in fluorinated hydrocarbons, chlorinated hydrocarbons, fluorinated chlorinated hydrocarbons, alcohols, hydrocarbons and other organic solvents capable of dissolving or dispersing them Examples include solution polymerization performed; 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 the aqueous medium.

Furthermore, in this invention, the organic solvent used as needed for the superposition | polymerization in the said superposition | polymerization process and the said copolymerization process is not limited to 1 type, You may use the mixed solvent by a multiple types of organic solvent.
Specifically, aliphatic hydrocarbons such as pentane, hexane, and heptane; hydrocarbon alcohols such as methanol, ethanol, n-propanol, isopropanol, and t-butanol; acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and the like Hydrocarbon ketones; hydrocarbon ethers such as dimethyl ether, diethyl ether, methyl ethyl ether, methyl t-butyl ether, diethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether; cyclic aliphatic hydrocarbons such as tetrahydrofuran and 1,4-dioxane Ethers; nitriles such as acetonitrile; methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, t-butyl acetate, methyl propionate, Hydrocarbon esters such as ethyl lopionate; aromatic hydrocarbons such as toluene and xylene; chlorinated hydrocarbons such as methylene chloride, chloroform and carbon tetrachloride; R-113, R-113a, R-141b, R Fluorocarbons such as -225ca and R-225cb; 1,1,1,2,2,3,3,4,4,5,5,6,6-tridecafluorohexane, 1,1, Fluorinated hydrocarbons such as 1,2,2,3,3,4,4-nonafluorohexane; fluorinated hydrocarbon ethers such as methyl 2,2,3,3-tetrafluoroethyl ether; 2,2-trifluoroethanol, 1,1,1,3,3,3-hexafluoroisopropanol, 2,2,3,3-tetrafluoropropanol, 2,2,3,3,4,4,5 5-octafluoropentanol What fluorinated hydrocarbon alcohols; and the like.

Further, in the present invention, the temperature and pressure at which the polymerization is carried out in the polymerization step and the copolymerization step are not particularly limited, and are appropriately set in consideration of various factors such as the boiling point of the monomer, the heating source, and the removal of the polymerization heat. It is desirable.
Specifically, the polymerization temperature can be set to a suitable temperature between 0 to 200 ° C., and is preferably set to a temperature of about room temperature to about 100 ° C. which is a practically suitable range. Further, the polymerization pressure may be under reduced pressure or under pressure, and is preferably set to about atmospheric pressure to about 100 atmosphere, which is a practically suitable range, and is set to about atmospheric pressure to about 10 atmosphere. More preferably.

In the present invention, the introduction step is a step of introducing at least one substituent selected from the group consisting of a carboxy group, a sulfo group and a sulfonyl fluoride group into the polymer obtained by the polymerization step.
In the present invention, the introduction step introduces a precursor of at least one substituent selected from the group consisting of a carboxy group, a sulfo group and a sulfonyl fluoride group into the polymer obtained by the polymerization step. The process of converting into this substituent later is also included. Specifically, the hydroxyl group in the polymer obtained by the above polymerization step is Na-chlorinated, then a carboxylate compound having a leaving group such as a halide or methanesulfonyl group (for example, ethyl bromoacetate), sulfone, etc. By reacting with an acid ester compound or a compound containing a sulfonyl fluoride group, a precursor of a carboxy group, a sulfo group and a sulfonyl fluoride group is introduced, and then hydrolyzed to form a carboxy group, a sulfo group and a sulfonyl fluoride group. Examples of the conversion method are illustrated.

  The resist protective film composition according to the third aspect of the present invention (hereinafter simply referred to as “the protective film composition of the present invention”) includes any one of the fluoropolymers (A) to (D) and a solvent (E ).

In the present invention, the solvent (E) is not particularly limited as long as it dissolves any of the fluorine-containing polymers (A) to (D) to be contained together as a composition.
Examples of such a solvent (E) include alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol, 1-butanol, 2-butanol, 1-pentanol, 2-pentanol, ethylene glycol, and 1,2-propanediol. Ketones such as acetone, methyl isobutyl ketone and cyclohexanone; Acetic esters such as ethyl acetate and butyl acetate; Aromatic hydrocarbons such as toluene and xylene; Glycol monoalkyl such as propylene glycol monomethyl ether and propylene glycol monoethyl ether Ethers; glycol monoalkyl ether esters such as propylene glycol monomethyl ether acetate and carbitol acetate; fluorocarbons, hydrofluorocarbons, hydrocarbons Fluorocarbons such as fluorocarbons; perfluoro ethers, fluoro alcohols, fluorine-based solvents such as fluoro ketones; and the like, may be used those either alone, or in combination of two or more. A mixture of water and a water-soluble organic solvent can also be used.
In the present invention, since the resist protective film formed from the resist protective film composition is formed on the top of the resist film by a spin coating method or the like, the solvent (E) does not substantially dissolve the resist film. A solvent is preferred. Of these, alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol, 1-butanol, 2-butanol, 1-pentanol, 2-pentanol, ethylene glycol and 1,2-propanediol are particularly preferable.

  The proportion of each component in the resist protective film composition of the present invention is usually 100 to 4000 parts by mass of the solvent (E) with respect to any 100 parts by mass of the fluoropolymers (A) to (D). The solvent (E) is preferably contained in an amount of 500 to 2000 parts by mass with respect to any 100 parts by mass of the fluoropolymers (A) to (D).

The resist protective film composition of the present invention is preferably used after each component is uniformly mixed and then filtered through a 0.1 to 2 μm filter.
A resist protective film is formed by applying and drying the resist protective film composition of the present invention on a resist film 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 through a mask on which a pattern is drawn on the formed resist protective film, and then development processing is performed to remove the resist protective film and form a resist film pattern.

  In addition, the resist protective film composition of the present invention is preferably used in an immersion lithography process used to improve resolution, and the fluorine-containing polymer constituting the resist protective film composition is insoluble in water. It is most preferable to be used in an immersion lithography process using water as an immersion liquid because it is soluble in a developer (for example, an aqueous solution of TMAH (tetramethylammonium hydroxide)).

In the present invention, as the light to be irradiated, specifically, for example, ultraviolet rays such as g-line having a wavelength of 436 nm, i-line having a wavelength of 365 nm, KrF excimer laser having a wavelength of 248 nm, ArF excimer laser having a wavelength of 193 nm, wavelength of 157 nm And far ultraviolet rays such as F ₂ excimer laser and vacuum ultraviolet rays.
The resist protective film composition of the present invention is a resist protective film 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. is there.

  The photoresist pattern forming method according to the fourth aspect of the present invention includes a resist layer forming step of forming a resist layer on the surface of a substrate, and the above-described present invention on the resist layer formed in the resist layer forming step. A resist protective film forming step of forming a resist protective film using the protective film composition, and exposing the substrate on which the resist protective film is formed (after the resist protective film forming step) by an immersion lithography method, A photoresist pattern forming method comprising: a treatment step of alkali development.

  Here, the resist layer forming step is not particularly limited as long as it is a conventionally known forming step. For example, after applying a known resist material on a substrate such as a silicon wafer with a spinner or the like, pre-baking (PAB treatment) is performed. And the like.

  Next, the resist protective film forming step is not particularly limited as long as the protective film composition of the present invention is used in a conventionally known forming step. For example, on the resist layer formed by the resist layer forming step, Examples include a step of applying the protective film composition of the present invention with a spinner and the like, followed by baking or heat drying.

Next, the processing step is not particularly limited as long as it is an exposure process and an alkali development process used in a conventionally known immersion lithography method.
Specifically, first, the substrate after forming the resist protective film is selectively exposed through a desired mask pattern in a state where the substrate is immersed in an inert water (immersion liquid) such as pure water or deionized water. After the exposure is completed, the substrate is taken out of the immersion liquid, and the immersion liquid is removed from the substrate. Next, a step of performing post-exposure baking on the exposed substrate (resist film) and developing with an alkali developer composed of an alkaline aqueous solution is exemplified. And the resist pattern by which the resist film was patterned by the shape according to a mask pattern by drying in the said process process is obtained.
In the present invention, the light used for exposure in the immersion lithography method is not particularly limited, and the above-described ultraviolet rays, far ultraviolet rays, and vacuum ultraviolet rays can be used as the irradiation light.

  In such a photoresist pattern forming method, since the resist protective film is formed using the protective film composition of the present invention, the dissolution of the acid generator and the like from the resist layer into the immersion medium is suppressed, and the fine pattern is fine. A photoresist pattern can be formed.

Next, although the Example of this invention is described concretely, this invention is not limited to these.
Abbreviations used in the following examples are as follows.
THF: tetrahydrofuran. PSt: polystyrene. R225: Dichloropentafluoropropane (solvent). PFB: perfluorobutyryl peroxide. IPP: diisopropyl peroxydicarbonate.

Synthesis Example 1 Synthesis of CF ₂ ═CFCF ₂ C (CF ₃ ) (OH) CH ₂ CH═CH ₂ 108 g of CF ₂ ClCFClCF ₂ C (O) CF ₃ and 500 ml of dehydrated THF were placed in a ₂ L glass reactor. And cooled to 0 ° C. A solution obtained by diluting 200 ml of a 2M THF solution of CH ₂ ═CHCH ₂ MgCl with 200 ml of dehydrated THF was added dropwise over about 5.5 hours under a nitrogen atmosphere. After completion of the dropwise addition, the mixture was stirred at 0 ° C. for 30 minutes and at room temperature for 17 hours, and 200 ml of 2N hydrochloric acid was further added dropwise. Then, 200 ml of water and 300 ml of diethyl ether were added and separated to obtain a diethyl ether layer 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 placed in a 500 ml glass reactor, and zinc was activated with iodine. Then heated to 100 ° C., a material obtained by diluting with dioxane 50ml of 84g of the above-synthesized _{CF 2 ClCFClCF 2 C (CF 3} ) (OH) CH 2 CH = CH 2, was added dropwise over 1.5 hours. 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: hereinafter referred to as “monomer 1-1”). .

(Synthesis Example ₂₎ In the _{CF 2 = CFCF 2 C (CF} 3) (OH) Synthesis Example 1 of CH = CH _2, by using a CH ₂ = CHMgCl instead of _{CH 2 = CHCH 2 MgCl, CF} 2 = CFCF ₂ C (CF ₃ ) (OH) CH═CH ₂ (hereinafter referred to as “monomer 1-2”) was obtained.

(Synthesis Example _{3) CF 2 = CFCF 2 C} (CF 3) (OH) CH 2 CH 2 CH = in Synthesis Example 1 of _{CH 2, CH 2 = CHCH 2} CH 2 MgCl instead of CH ₂ = CHCH ₂ MgCl Was used to obtain CF ₂ ═CFCF ₂ C (CF ₃ ) (OH) CH ₂ CH ₂ CH═CH ₂ (hereinafter referred to as “Monomer 1-3”).

(Synthesis Example _{4) CF 2 = CFCH 2 CH} (C (CF 3) 2 OH) CH 2 CH = 500g of CF ₂ ClCFClI glass reactor synthesis 1L of CH ₂ and _{CH 2 = CHC (CF 3)} 2 OH Of 344 g and 32.6 g of BPO were added and heated at 95 ° C. for 71 hours. The reaction crude liquid was distilled under reduced pressure to obtain 544 g of CF ₂ ClCFClCH ₂ CHI (C (CF ₃ ) ₂ OH) (55-58 ° C./0.2 kPa).
In a 5 L glass reactor, 344 g of CF ₂ ClCFClCH ₂ CHI (C (CF ₃ ) ₂ OH) synthesized above and 1.7 L of dehydrated THF were placed, and cooled to −70 ° C. There, the CH ₂ = CHCH ₂ MgCl a 2M-THF solution 1.8L, was added dropwise over 4 hours. After completion of the dropwise addition, the temperature was raised to 0 ° C. and stirred for 16 hours, and then 1.6 L of a saturated aqueous ammonium chloride solution was added and the temperature was raised to room temperature. The reaction solution was separated, the organic layer was concentrated with an evaporator, and then distilled under reduced pressure to obtain 287 g of CF ₂ ClCFClCH ₂ CH (C (CF ₃ ) ₂ OH) CH ₂ CH═CH ₂ (62-66 ° C./0 .2 kPa).
Next, 97 g of zinc and 300 g of water were placed in a 1 L glass reactor and heated to 90 ° C. _{There, CF 2 ClCFClCH 2 CH (C} (CF 3) 2 OH) synthesized above was added dropwise to 287g of CH ₂ CH = CH _2, was stirred for 24 hours. To the reaction solution, 70 mL of hydrochloric acid was added dropwise, stirred for 2 hours, filtered and separated, and distilled under reduced pressure to give 115 g of CF ₂ ═CFCH ₂ CH (C (CF ₃ ) ₂ OH) CH ₂ CH═CH ₂ ( 53-54 ° C./1 kPa, hereinafter referred to as “monomer 2-1”).

In (Synthesis Example _{5) CF 2 = CFCH 2 CH} (C (CF 3) 2 OH) CH = Synthesis Example 4 of CH _2, by using a CH ₂ = CHMgCl instead of CH ₂ = CHCH ₂ MgCl, CF ₂ = CFCH ₂ CH (C (CF ₃ ) ₂ OH) CH═CH ₂ (hereinafter referred to as “monomer 2-2”) can be obtained.

(Synthesis Example _{6) CF 2 = CFCH 2 CH} (C (CF 3) 2 OH) CH 2 CH 2 CH = in Synthesis Example 4 of CH _2, CH ₂ = CHCH ₂ to MgCl instead of CH ₂ = CHCH ₂ CH By using ₂ MgCl, CF ₂ ═CFCH ₂ CH (C (CF ₃ ) ₂ OH) CH ₂ CH ₂ CH═CH ₂ (hereinafter referred to as “monomer 2-3”) can be obtained.

Synthesis Example 7 Synthesis of CF ₂ ═CFCH ₂ CH (CH ₂ C (CF ₃ ) ₂ OH) CH ₂ CH═CH _{2 In} a 200 mL glass reactor, 118 g of CF ₂ ClCFClI and 1.1 g of AIBN were placed. And heated to 75 ° C. There _{CH 2 = CHCH 2 C (CF} 3) the 75.8g of ₂ OCH ₂ OCH ₃ was added dropwise over 1 hour, and stirred for 7 hours After completion of the dropwise addition 75 ° C.. Next, distillation under reduced pressure yielded 144 g of CF ₂ ClCFClCH ₂ CHI (CH ₂ C (CF ₃ ) ₂ OCH ₂ OCH ₃ ) (80-85 ° C./0.16 kPa).
A 2 L glass reactor was charged with 144 g of CF ₂ ClCFClCH ₂ CHI (CH ₂ C (CF ₃ ) ₂ OCH ₂ OCH ₃ ) synthesized above and 550 mL of dehydrated THF, and cooled to −75 ° C. Thereto, 220 ml of a 2M THF solution of CH ₂ = CHCH ₂ MgCl was added dropwise over 2 hours. After completion of the dropwise addition, the mixture was stirred at -75 ° C for 3 hours, 400 mL of a saturated aqueous ammonium chloride solution was added, and the temperature was raised to room temperature. The reaction solution was separated, the organic layer was concentrated with an evaporator, and then distilled under reduced pressure to obtain 66.3 g of CF ₂ ClCFClCH ₂ CH (CH ₂ C (CF ₃ ) ₂ OCH ₂ OCH ₃ ) CH ₂ CH═CH ₂ ( 54-56 ° C./0.08 kPa).
_{Then, CF 2 ClCFClCH 2 CH (CH} 2 C (CF 3) 2 OCH 2 OCH 3) synthesized above glass reactor 500mL put CH ₂ CH = CH ₂ of 66.3g and 200mL of methanol, the catalyst An amount of concentrated hydrochloric acid was added and heated at 60 ° C. for 19 hours. Thereafter, the reaction solution was cooled to room temperature, and 30 mL of water was added for liquid separation. The organic layer obtained by the liquid separation was further washed with 150 ml of water to obtain 63 g of a crude liquid.
A 200 mL glass reactor was then charged with 30 g of zinc, 78 g of dioxane and 22 g of water and heated to 85 ° C. Thereto, 63 g of the above crude liquid was added dropwise and stirred for 24 hours. Thereafter, the reaction solution was filtered and diluted hydrochloric acid was added for liquid separation. The organic layer was washed with saturated saline and distilled under reduced pressure to obtain 23.6 g of CF ₂ ═CFCH ₂ CH (CH ₂ C (CF ₃ ) ₂ OH) CH ₂ CH═CH ₂ (54-56 ° C./0.5 kPa). Hereafter referred to as “monomer 3-1”).

(Synthesis Example 8) CF ₂ = CFCH ₂ CH in _{(CH 2 C (CF 3)} 2 OH) CH = Synthesis Example 4 of _{CH 2, CH 2 = CHC (} CF 3) CH 2 = CHCH instead of ₂ OH _{By using 2} C (CF ₃ ) ₂ OH and CH ₂ ═CHMgCl instead of CH ₂ ═CHCH ₂ MgCl, CF ₂ ═CFCH ₂ CH (CH ₂ C (CF ₃ ) ₂ OH) CH═CH ₂ ( Hereinafter, “monomer 3-2”) can be obtained.

Synthesis Example 9 Synthesis of CF ₂ ═CFCH ₂ CH (CH ₂ C (CF ₃ ) ₂ OH) CH ₂ CH ₂ CH═CH _{2 In} Synthesis Example 4, instead of CH ₂ ═CHC (CF ₃ ) ₂ OH _{CH 2 = CHCH 2 C (CF} 3) a ₂ OH, CH ₂ = CHCH ₂ to MgCl instead of by the use of _{CH 2 = CHCH 2 CH 2 MgCl} , CF 2 = CFCH 2 CH (CH 2 C (CF 3) ₂ OH) CH ₂ CH ₂ CH═CH ₃ (hereinafter referred to as “monomer 3-3”) can be obtained.

(Synthesis Example 10)
172 g of monomer 1-1 obtained in Synthesis Example 1 and 46.3 g of ethyl acetate were charged into a 500 ml four-necked flask, and 5.14 g of IPP was added as a polymerization initiator. The system was frozen and degassed, sealed, and polymerized at 40 ° C. for 19.5 hours. After the polymerization, the reaction solution was dropped into hexane to reprecipitate the polymer, followed by vacuum drying at 140 ° C. for 20 hours. As a result, 0.9 g of an amorphous polymer having a fluorine-containing ring structure in the main chain (hereinafter referred to as “polymer X-1”) was obtained.
PSt conversion molecular weight measured by GPC using THF of the obtained polymer X-1 as a solvent was number average molecular weight (Mn) 5,300, weight average molecular weight (Mw) 12,500, and Mw / Mn = 2.37. Moreover, Tg measured by the differential scanning calorimetry (DSC) was 149 degreeC, and it was a white powder form at room temperature.
The obtained polymer X-1 is soluble in acetone, THF, ethyl acetate, methanol, 2-perfluorohexylethanol, and in R225, perfluoro (2-butyltetrahydrofuran), perfluoro-n-octane. It was insoluble.

(Synthesis Example 11)
4 g of monomer 2-1 obtained in Synthesis Example 4 and 2.2 g of ethyl acetate were charged into a glass pressure-resistant reactor having an internal volume of 30 mL, and 6.23 g of 3 wt% R225 solution of PFB was added as a polymerization initiator. After the system was frozen and degassed, it was sealed and polymerized in a constant temperature shaking tank (20 ° C.) for 41 hours. After the polymerization, the reaction solution was dropped into hexane to reprecipitate the polymer, followed by vacuum drying at 90 ° C. for 21 hours. As a result, 1.33 g of an amorphous polymer (hereinafter referred to as “polymer Y-1”) having a fluorine-containing ring structure in the main chain was obtained.
PSt conversion molecular weight measured by GPC using THF of the obtained polymer Y-1 as a solvent is number average molecular weight (Mn) 15,600, weight average molecular weight (Mw) 25,100, and Mw / Mn = 1.61. Moreover, Tg measured by the differential scanning calorimetry (DSC) was 118 degreeC, and it was a white powdery polymer at room temperature.
The obtained polymer Y-1 was soluble in acetone, THF, methanol, and R225.

(Synthesis Example 12)
In Synthesis Example 11, by using the monomer 3-1 obtained in Synthesis Example 7 instead of the monomer 2-1, a white powdery amorphous polymer having a monomer unit having a fluorine-containing aliphatic ring structure in the main chain ( Hereinafter, “polymer Z-1” was obtained.
When the molecular weight of the obtained polymer Z-1 was measured by GPC (THF solvent), in terms of PSt, the number average molecular weight (Mn) was 7,600, and the weight average molecular weight (Mw) was 15,000. The molecular weight distribution (Mw / Mn) was 1.99. The glass transition temperature measured by differential scanning calorimetry (DSC) was 99 ° C.

Example 1
6.0 g of the polymer X-1 obtained in Synthesis Example 10 and 120 g 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 (3.18 g of methanol was added to 0.35 g of sodium hydroxide and dissolved in advance) was stirred at room temperature overnight. After the solvent was distilled off, 150 g of dehydrated THF and 1.48 g of ethyl bromoacetate were added and stirred vigorously. After a while, the solution gradually became cloudy. Stirring was continued for several days at room temperature, and the reaction solution was transferred to 100 ml of saturated aqueous sodium bicarbonate. After adding 100 g of diethyl ether and shaking, the lower layer was removed, and the upper layer was dried over 20 g of anhydrous magnesium sulfate. The solution was filtered with filter paper, the solvent was distilled off to about half volume, and the solution was dropped into hexane to reprecipitate the polymer, followed by vacuum drying at 90 ° C. for 18 hours. As a result, 4.33 g of a thin brown white powdery amorphous polymer was obtained.

The peak of CF ₃ group of ¹⁹ F-NMR of the obtained polymer (CF ₃ in which a hydroxyl group on the same carbon is blocked: δ = −70 to −74 ppm <reference: CFCl ₃ >, the hydroxyl group is not blocked) The protection ratio calculated by CF ₃ : δ = −75 ppm to −79 ppm <reference: CFCl ₃ >) was 15%. The protection rate was calculated by the following formula.
(Peak area of CF ₃ groups in the monomer units having a protective ratio = (blocked hydroxyl group) / ((a peak area) + (block of CF ₃ groups in the monomer units having a blocked hydroxyl group CF ₃ group peak area in the monomer unit having a non-hydroxyl group)) × 100)

Next, 0.5 g of the obtained polymer was dissolved in 8.5 g of methanol and stirred with a magnetic stirrer. When the polymer was completely dissolved, a sodium hydroxide methanol solution (1.48 g of methanol was added to 0.15 g of sodium hydroxide and dissolved in advance) was stirred for 20 hours at room temperature. Hydrochloric acid was added thereto to form an acid form, which was dropped into pure water to reprecipitate the polymer, filtered and dried, and then redissolved in ethyl acetate. Then, after dripping in hexane and reprecipitating a polymer, it vacuum-dried at 70 degreeC for 15 hours. As a result, 0.2 g of an amorphous polymer (hereinafter referred to as “polymer 1A”) in the form of a light brown white powder was obtained. ^{From 1} H-NMR, ethyl group peaks of ethyl ester (CH ₃ : δ = 1.1 ppm to 1.4 ppm <reference: CFCl ₃ >, —OCH ₂ —: δ = 4.0 ppm to 4.3 ppm <reference: The disappearance of CFCl ₃ >) was confirmed.

(Example 2)
In Example 1, instead of the polymer X-1, the reaction is performed in the same manner as in Example 1 except that the polymer Y-1 obtained in Synthesis Example 11 is used, and the main chain has a fluorinated ring structure. An amorphous polymer (hereinafter referred to as “polymer 1B”) can be obtained.

(Example 3)
1.15 g of monomer 1-1 obtained in Synthesis Example 1, 1.53 g of CF ₂ ═CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ SO ₃ H and 10.00 g of ethyl acetate and a glass pressure-resistant reactor having an internal volume of 30 mL And 0.192 g of IPP is added as a polymerization initiator. After the system is frozen and degassed, the tube is sealed and polymerized in a constant temperature shaking tank (40 ° C.) for 18 hours. After the polymerization, the reaction solution is dropped into hexane to reprecipitate the polymer, followed by vacuum drying at 90 ° C. for 24 hours. As a result, 0.86 g of an amorphous polymer having a fluorine-containing ring structure in the main chain (hereinafter referred to as “polymer 1C”) was obtained. The PSt equivalent molecular weight measured by GPC using THF as a solvent is a number average molecular weight (Mn) 15,800, a weight average molecular weight (Mw) 27,600, and Mw / Mn = 1.76.
From the measurement by differential scanning calorimetry (DSC), the obtained polymer 1C has a Tg of 140 ° C. and is a white powder polymer at room temperature. ^The polymer composition calculated by ¹⁹ F-NMR and ¹ H-NMR measurements is as follows: repeating unit consisting of monomer 1-1 / CF ₂ ═CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ SO ₃ H repeating unit = 91 / 9 mol%.
The obtained polymer 1C is soluble in acetone, THF, ethyl acetate, and methanol, and insoluble in R225, perfluoro (2-butyltetrahydrofuran), and perfluoro-n-octane.

Example 4
2.29 g of monomer 1-1 obtained in Synthesis Example 1; 0.38 g of CF ₂ = CFOCF ₂ CF ₂ CF ₂ C (O) OH; 2.79 g of 1,4-dioxane; and 2.49 g of ethyl acetate. A glass pressure-resistant reactor having an internal volume of 30 mL was charged, and 0.122 g of IPP was added as a polymerization initiator. After the system was frozen and degassed, the tube was sealed and polymerized in a constant temperature shaking tank (40 ° C.) for 18 hours. After the polymerization, the reaction solution was dropped into hexane to reprecipitate the polymer, followed by vacuum drying at 90 ° C. for 24 hours. As a result, 1.90 g of an amorphous polymer having a fluorine-containing ring structure in the main chain (hereinafter referred to as “polymer 2C”) was obtained. The PSt equivalent molecular weight measured by GPC using THF as a solvent was a number average molecular weight (Mn) of 5000, a weight average molecular weight (Mw) of 11400, and Mw / Mn = 2.28.
When measured by differential scanning calorimetry (DSC), the polymer 2C obtained had a Tg of 123 ° C. and was a white powder polymer at room temperature. ^The polymer composition calculated by ¹⁹ F-NMR and ¹ H-NMR measurements was as follows: repeating unit consisting of monomer 1-1 / CF ₂ = repeating unit consisting of CFOCF ₂ CF ₂ CF ₂ C (O) OH = 89/11 mol %Met.
The obtained polymer 2C was soluble in acetone, THF, ethyl acetate, and methanol, and insoluble in R225, perfluoro (2-butyltetrahydrofuran), and perfluoro-n-octane.

(Example 5)
17.23 g of a monomer 1-1 obtained in Synthesis Example 1, CF ₂ ═CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ SO ₂ F4.06 g, and 74.02 g of ethyl acetate are pressure resistant reaction made of glass having an internal volume of 150 mL. The vessel was charged and 1.82 g of IPP was added as a polymerization initiator. After the system was frozen and degassed, the tube was sealed and polymerized in a constant temperature shaking tank (40 ° C.) for 18 hours. After the polymerization, the reaction solution was dropped into hexane to reprecipitate the polymer, followed by vacuum drying at 90 ° C. for 24 hours. As a result, 15.03 g of an amorphous polymer having a fluorine-containing ring structure in the main chain (hereinafter referred to as “polymer 3C”) was obtained. The PSt equivalent molecular weight measured by GPC using THF as a solvent was a number average molecular weight (Mn) 19300, a weight average molecular weight (Mw) 47800, and Mw / Mn = 2.12.
When measured by differential scanning calorimetry (DSC), the obtained polymer 3C had a Tg of 151 ° C. and was a white powder polymer at room temperature. ^The polymer composition calculated by ¹⁹ F-NMR and ¹ H-NMR measurements was as follows: repeating unit consisting of monomer 1-1 / CF ₂ ═CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ SO ₂ F repeating unit = 98 / 2 mol%.
The obtained polymer 3C was soluble in acetone, THF, ethyl acetate, and methanol, and insoluble in R225, perfluoro (2-butyltetrahydrofuran), and perfluoro-n-octane.

(Example 6)
15 mL of the monomer 1-1 obtained in Synthesis Example 1, 0.46 g of CH ₂ ═C (CH ₃ ) C (O) OH, 9.98 g of 1,4-dioxane, and 42.4 g of ethyl acetate were added to a volume of 100 mL. Were added to a glass pressure-resistant reactor, and 1.358 g of IPP was added as a polymerization initiator. After the system was frozen and degassed, it was sealed and polymerized in a constant temperature shaking tank (40 ° C.) for 20 hours. After the polymerization, the reaction solution was concentrated to 25 g with an evaporator, and 100 g of methanol was added to obtain a uniform solution. Thereafter, 200 g of hexane was added and the mixture was allowed to stand after stirring. After standing, it was separated into a hexane layer and a methanol layer. The methanol layer was concentrated to dryness and vacuum dried at 90 ° C. for 24 hours. As a result, 11.5 g of an amorphous polymer having a fluorine-containing ring structure in the main chain (hereinafter referred to as “polymer 4C”) was obtained. The PSt equivalent molecular weight measured by GPC using THF as a solvent was a number average molecular weight (Mn) of 2200, a weight average molecular weight (Mw) of 6800, and Mw / Mn = 3.01.
The resulting polymer 4C was a white powder at room temperature. ^The polymer composition calculated by ¹⁹ F-NMR and ¹ H-NMR measurements and infrared spectroscopy is the repeating unit consisting of monomer 1-1 / CH ₂ ═C (CH ₃ ) C (O) OH repeating unit = It was 90/10 mol%.
The obtained polymer 4C was soluble in acetone, THF, ethyl acetate, and methanol, and insoluble in R225, perfluoro (2-butyltetrahydrofuran), and perfluoro-n-octane.

(Example 7)
2.30g and _{CF 2 = CFOCF 2 CF 2 CF} 2 C (O) OCH 3 0.40g and pressure resistant reactor made of glass having an inner volume of 30mL of ethyl acetate 5.30g of monomer 1-1 obtained in Synthesis Example 1 Then, 0.126 g of IPP was added as a polymerization initiator. After the system was frozen and degassed, the tube was sealed and polymerized in a constant temperature shaking tank (40 ° C.) for 18 hours. After the polymerization, the reaction solution was dropped into hexane to reprecipitate the polymer, followed by vacuum drying at 90 ° C. for 24 hours. As a result, 1.97 g of an amorphous polymer having a fluorine-containing ring structure in the main chain (hereinafter referred to as “polymer 5C”) was obtained. The PSt equivalent molecular weight measured by GPC using THF as a solvent was a number average molecular weight (Mn) 18300, a weight average molecular weight (Mw) 51000, and Mw / Mn = 2.79.
When measured by differential scanning calorimetry (DSC), the obtained polymer 5C had a Tg of 150 ° C. and was a white powder polymer at room temperature. ^The polymer composition calculated by ¹⁹ F-NMR and ¹ H-NMR measurements was as follows: repeating unit consisting of monomer 1-1 / CF ₂ ═CFOCF ₂ CF ₂ CF ₂ C (O) OCH ₃ repeating unit = 96/4 Mol%.
The obtained polymer 5C was soluble in acetone, THF, ethyl acetate, and methanol, and insoluble in R225, perfluoro (2-butyltetrahydrofuran), and perfluoro-n-octane.

(Example 8)
1.5 g of monomer 2-1 obtained in Synthesis Example 4, 0.42 g of 5-norbornene-2-carboxylic acid (hereinafter referred to as “monomer 4”) and 3.56 g of butyl acetate were made of glass having an internal volume of 30 mL. The pressure resistant reactor was charged, and 0.55 g of IPP was added as a polymerization initiator. After the system was frozen and degassed, the tube was sealed and polymerized in a constant temperature shaking tank (40 ° C.) for 18 hours. After the polymerization, the reaction solution was dropped into hexane to reprecipitate the polymer, followed by vacuum drying at 80 ° C. for 24 hours. As a result, 1.1 g of an amorphous polymer having a fluorine-containing ring structure in the main chain (hereinafter referred to as “polymer 1D”) was obtained. The PSt equivalent molecular weight measured by GPC using THF as a solvent was a number average molecular weight (Mn) 2100, a weight average molecular weight (Mw) 3000, and Mw / Mn = 1.43.
When measured by differential scanning calorimetry (DSC), the obtained polymer 1D had a Tg of 135 ° C. and was a white powder polymer at room temperature. ^The polymer composition calculated by ¹⁹ F-NMR and ¹ H-NMR measurements was: repeating unit consisting of monomer 2-1 / repeating unit consisting of monomer 4 = 80/20 mol%.
The obtained polymer 1D was soluble in acetone, THF, ethyl acetate, and methanol, and insoluble in R225, perfluoro (2-butyltetrahydrofuran), and perfluoro-n-octane.

Example 9
In Example 7, the same reaction as in Example 7 was carried out except that the monomer 2-1 obtained in Synthesis Example 4 was used instead of the monomer 1-1, and an amorphous having a fluorinated ring structure in the main chain A polymer (hereinafter referred to as “polymer 2D”) can be obtained.

(Examples 10 to 13)
1.0 g of each of the polymers 2C to 5C obtained in Examples 4 to 7 was dissolved in 9.0 g of propylene glycol monomethyl ether acetate and filtered using a PTFE filter having a pore size of 0.2 μm, and a resist protective film A composition was prepared.
Subsequently, each obtained resist protective film composition was spin-coated on the CaF ₂ substrate, and after the coating, heat treatment was performed at 90 ° C. for 2 minutes to form a resist protective film having a thickness shown in Table 1 below. The light transmittance of the resist protective film thus obtained is shown in Table 1. Thus, it was found that the transmittance of the obtained resist protective film with respect to an ArF excimer laser with a wavelength of 193 nm and an F ₂ excimer laser with a wavelength of 157 nm was excellent.

(Examples 14 to 16)
1.0 g of each of polymers 2C, 4C and 5C obtained in Example 4, Example 6 and Example 7 was dissolved in 9.0 g of propylene glycol monomethyl ether acetate, and a PTFE filter having a pore size of 0.2 μm was prepared. And filtered to produce a resist protective film composition.
Next, each obtained resist protective film composition is spin-coated on a silicon substrate treated with hexamethyldisilazane, and after the coating, it is heat-treated at 90 ° C. for 2 minutes to form a resist protective film having a thickness of 0.15 μm. Formed. The contact angle of the resist protective film thus obtained with respect to water was measured. The results are shown in Table 2. Thereby, it turned out that the protective film which consists of a resist protective film composition containing polymer 2C, 4C, 5C has a moderate contact angle (70 degree-90 degree | times).

(Examples 17 to 19)
The resist protective film on the silicon substrate prepared in Examples 14 to 16 was immersed in water and an alkali developer for 30 seconds. Then, it dried for 90 seconds at 110 degreeC, and the presence or absence of the melt | dissolution in water and an alkali developing solution was confirmed visually. The results are shown in Table 3. Thus, it was found that all of the obtained resist protective films were insoluble in water and soluble in an alkaline developer.

(Examples 20 to 22)
The refractive index with respect to the light of 193 nm of the resist protective film on the silicon substrate prepared in Examples 14 to 16 was measured using a spectroscopic ellipsometer (M2000D) manufactured by JA Woollam. The results are shown in Table 4. As a result, the refractive index with respect to 193 nm of the obtained resist protective film is larger than the refractive index (1.44) with respect to 193 nm of water, and even when the immersion medium is water, it may be useful as a protective film. I understood.

Claims (14)

A fluorine-containing polymer having a monomer unit obtained by cyclopolymerizing a fluorine-containing diene represented by the following formula (1).
_{CF 2 = CFCF 2 C (CF} 3) (OR 1) - (CH 2) n CR 2 = CHR 3 ··· (1)
(In the formula, R ¹ represents an organic group having 20 or less carbon atoms having at least one substituent selected from the group consisting of a carboxy group, a sulfo group and a sulfonyl fluoride group, and R ² and R ³ are respectively Independently represents a hydrogen atom or an alkyl group having 12 or less carbon atoms, n is an integer of 0 to 2.) A fluorine-containing polymer having a monomer unit obtained by cyclopolymerizing a fluorine-containing diene represented by the following formula (2).
^{_{CF 2 = CFCH 2 CHQ 1 -}} (CH 2) n CR 2 = CHR 3 ··· (2)
(In the formula, R ² and R ³ each independently represent a hydrogen atom or an alkyl group having 12 or less carbon atoms, and Q ¹ represents (CH ₂ ) _b C (CF ₃ ) _c (R ⁴ ) _d OR ¹ (b Is an integer of 0 to 3, c and d are integers of 0 to 2 satisfying c + d = 2, R ⁴ is a hydrogen atom, a fluorine atom or a methyl group, R ¹ is a carboxy group, a sulfo group and a sulfonyl group An organic group having 20 or less carbon atoms having at least one substituent selected from the group consisting of fluoride groups.), N is an integer of 0 to 2.) Monomer units obtained by cyclopolymerizing a fluorine-containing diene represented by the following formula (3);
A monomer unit obtained by polymerizing a monomer having at least one substituent selected from the group consisting of a carboxy group, a sulfo group and a sulfonyl fluoride group and a carbon-carbon double bond;
A fluorine-containing polymer.
_{CF 2 = CFCF 2 C (CF} 3) (OH) - (CH 2) n CR 2 = CHR 3 ··· (3)
(In the formula, R ² and R ³ each independently represents a hydrogen atom or an alkyl group having 12 or less carbon atoms. N is an integer of 0 to 2.) Monomer units obtained by cyclopolymerizing a fluorine-containing diene represented by the following formula (3);
Obtained by polymerizing a monomer having an alkoxycarbonyl group (C (O) OR ⁵ , R ⁵ represents an alkyl group having 6 or less carbon atoms) and a carbon-carbon double bond substituted with a fluorine atom. Monomer units;
A fluorine-containing polymer.
_{CF 2 = CFCF 2 C (CF} 3) (OH) - (CH 2) n CR 2 = CHR 3 ··· (3)
(In the formula, R ² and R ³ each independently represents a hydrogen atom or an alkyl group having 12 or less carbon atoms. N is an integer of 0 to 2.) A monomer unit obtained by cyclopolymerizing a fluorine-containing diene represented by the following formula (4);
A monomer unit obtained by polymerizing a monomer having at least one substituent selected from the group consisting of a carboxy group, a sulfo group and a sulfonyl fluoride group and a carbon-carbon double bond;
A fluorine-containing polymer.
^{_{CF 2 = CFCH 2 CHQ 2 -}} (CH 2) n CR 2 = CHR 3 ··· (4)
(In the formula, R ² and R ³ each independently represent a hydrogen atom or an alkyl group having 12 or less carbon atoms, and Q ² is (CH ₂ ) _b C (CF ₃ ) _c (R ⁴ ) _d OH (b is N is an integer of 0 to 3, c and d are integers of 0 to 2 satisfying c + d = 2, and R ⁴ is a hydrogen atom, a fluorine atom or a methyl group. .) A monomer unit obtained by cyclopolymerizing a fluorine-containing diene represented by the following formula (4);
Obtained by polymerizing a monomer having an alkoxycarbonyl group (C (O) OR ⁵ , R ⁵ represents an alkyl group having 6 or less carbon atoms) and a carbon-carbon double bond substituted with a fluorine atom. Monomer units;
A fluorine-containing polymer.
^{_{CF 2 = CFCH 2 CHQ 2 -}} (CH 2) n CR 2 = CHR 3 ··· (4)
(In the formula, R ² and R ³ each independently represent a hydrogen atom or an alkyl group having 12 or less carbon atoms, and Q ² is (CH ₂ ) _b C (CF ₃ ) _c (R ⁴ ) _d OH (b is N is an integer of 0 to 3, c and d are integers of 0 to 2 satisfying c + d = 2, and R ⁴ is a hydrogen atom, a fluorine atom or a methyl group. .) A polymerization step of cyclopolymerizing a fluorine-containing diene represented by the following formula (3) to form a polymer; and at least one selected from the group consisting of a carboxy group, a sulfo group and a sulfonyl fluoride group in the polymer A process for producing a fluoropolymer according to claim 1, comprising an introduction step of introducing one substituent.
_{CF 2 = CFCF 2 C (CF} 3) (OH) - (CH 2) n CR 2 = CHR 3 ··· (3)
(In the formula, R ² and R ³ each independently represents a hydrogen atom or an alkyl group having 12 or less carbon atoms. N is an integer of 0 to 2.) A polymerization step of cyclopolymerizing a fluorine-containing diene represented by the following formula (4) to form a polymer, and at least one selected from the group consisting of a carboxy group, a sulfo group and a sulfonyl fluoride group in the polymer; A method for producing a fluoropolymer according to claim 2, further comprising an introduction step of introducing one substituent.
^{_{CF 2 = CFCH 2 CHQ 2 -}} (CH 2) n CR 2 = CHR 3 ··· (4)
(In the formula, R ² and R ³ each independently represent a hydrogen atom or an alkyl group having 12 or less carbon atoms, and Q ² is (CH ₂ ) _b C (CF ₃ ) _c (R ⁴ ) _d OH (b is N is an integer of 0 to 3, c and d are integers of 0 to 2 satisfying c + d = 2, and R ⁴ is a hydrogen atom, a fluorine atom or a methyl group. .) A monomer having a fluorine-containing diene represented by the following formula (3), at least one substituent selected from the group consisting of a carboxy group, a sulfo group and a sulfonyl fluoride group, and a carbon-carbon double bond; The manufacturing method of the fluorine-containing polymer which obtains the fluorine-containing polymer of Claim 3 which comprises the copolymerization process of copolymerizing these.
_{CF 2 = CFCF 2 C (CF} 3) (OH) - (CH 2) n CR 2 = CHR 3 ··· (3)
(In the formula, R ² and R ³ each independently represents a hydrogen atom or an alkyl group having 12 or less carbon atoms. N is an integer of 0 to 2.) Fluorine-containing diene represented by the following formula (3), an alkoxycarbonyl group (C (O) OR ⁵ , R ⁵ represents an alkyl group having 6 or less carbon atoms), and a carbon-carbon 2 substituted with a fluorine atom. The manufacturing method of the fluorine-containing polymer which obtains the fluorine-containing polymer of Claim 4 which comprises the copolymerization process of copolymerizing the monomer which has a heavy bond.
_{CF 2 = CFCF 2 C (CF} 3) (OH) - (CH 2) n CR 2 = CHR 3 ··· (3)
(In the formula, R ² and R ³ each independently represents a hydrogen atom or an alkyl group having 12 or less carbon atoms. N is an integer of 0 to 2.) A monomer having a fluorine-containing diene represented by the following formula (4), at least one substituent selected from the group consisting of a carboxy group, a sulfo group and a sulfonyl fluoride group, and a carbon-carbon double bond; The manufacturing method of the fluorine-containing polymer which obtains the fluorine-containing polymer of Claim 5 which comprises the copolymerization process of copolymerizing these.
^{_{CF 2 = CFCH 2 CHQ 2 -}} (CH 2) n CR 2 = CHR 3 ··· (4)
(In the formula, R ² and R ³ each independently represent a hydrogen atom or an alkyl group having 12 or less carbon atoms, and Q ² is (CH ₂ ) _b C (CF ₃ ) _c (R ⁴ ) _d OH (b is N is an integer of 0 to 3, c and d are integers of 0 to 2 satisfying c + d = 2, and R ⁴ is a hydrogen atom, a fluorine atom or a methyl group. .) Fluorine-containing diene represented by the following formula (4), an alkoxycarbonyl group (C (O) OR ⁵ , R ⁵ represents an alkyl group having 6 or less carbon atoms), and a carbon-carbon disubstituted with a fluorine atom. The manufacturing method of the fluorine-containing polymer which obtains the fluorine-containing polymer of Claim 6 which comprises the copolymerization process of copolymerizing the monomer which has a heavy bond.
^{_{CF 2 = CFCH 2 CHQ 2 -}} (CH 2) n CR 2 = CHR 3 ··· (4)
(In the formula, R ² and R ³ each independently represent a hydrogen atom or an alkyl group having 12 or less carbon atoms, and Q ² is (CH ₂ ) _b C (CF ₃ ) _c (R ⁴ ) _d OH (b is N is an integer of 0 to 3, c and d are integers of 0 to 2 satisfying c + d = 2, and R ⁴ is a hydrogen atom, a fluorine atom or a methyl group. .)   A resist protective film composition comprising the fluorine-containing polymer according to claim 1 and a solvent for dissolving the fluorine-containing polymer. A resist layer forming step of forming a resist layer on the surface of the substrate;
A resist protective film forming step of forming a resist protective film on the resist layer using the resist protective film composition according to claim 13;
A step of exposing the substrate on which the resist protective film has been formed by an immersion lithography method and performing alkali development;
A photoresist pattern forming method comprising: