JP5776615B2 - Pattern formation method - Google Patents

Description

  The present invention relates to a pattern forming method that can be applied onto a resist pattern after development, and the size of the resist pattern can be effectively reduced by baking and development.

  In recent years, with the higher integration and higher speed of LSIs, there is a demand for finer pattern rules. In light exposure currently used as a general-purpose technology, the intrinsic resolution limit derived from the wavelength of the light source In order to overcome this problem, microfabrication in which double patterning is combined with ArF excimer laser immersion lithography is performed. As a double patterning method, there is a litho-etch litho-etching (LELE) method in which an exposed pattern is transferred to a hard mask of a substrate by etching, a second exposure is performed at a position shifted by a half pitch, and the hard mask is processed. It is done. This method has a problem of causing a positional deviation between two exposures. On the other hand, the SADP method of transferring to a resist pattern hard mask and forming a film on both side walls of the hard mask, thereby doubling the pattern, can reduce the problem of misalignment because only one exposure is required. In order to simplify the process, a SADP method has been proposed in which a silicon oxide film is formed not on the side wall of the hard mask but on the side wall of the resist pattern after development, thereby doubling the pattern.

  In order to form a line and space 1: 1 pattern doubled by the SADP method, it is necessary to make the width of the resist pattern 1 and the space 3. If a 1: 3 pattern is formed by overexposure using a line-and-space 1: 1 mask, or if a 1: 3 pattern is formed using a line-and-space 1: 3 mask, focus is adjusted from the best focus. The line width of the portion exposed by shifting becomes narrower and the focus margin becomes narrower. In the line and space pattern, a dimension with a line and space width of 1: 1 can provide the widest focus margin. Therefore, a slimming process is required in which a 1: 1 pattern is formed by exposure and development, and then the line is narrowed by an additional process, and various slimming processes and materials have been proposed. A method of slimming by dry etching mixed with oxygen gas, a method of slimming with ozone water (Patent Document 1: Japanese Patent Application Laid-Open No. 2004-63490), an acid-added solution is applied, and an acid is added with an alkaline developer after baking. A method of slimming by removing the solution (Patent Document 2: Japanese Patent Application Laid-Open No. 2010-267880) has been proposed. The slimming method using a solution containing an acid utilizes a deprotection reaction of a positive resist film, but it is difficult to control the diffusion distance of the acid from the solution containing the acid to the resist pattern.

JP 2004-63490 A JP 2010-267880 A

As described above, it is difficult to control the slimming amount because the acid diffusion cannot be controlled in the method of applying the acid added solution on the resist pattern.
An object of the present invention is to provide a slimming material that controls the slimming amount and does not deteriorate edge roughness and shape after slimming, and a pattern forming method using the slimming material.

（式中、Ｒ ¹ 、Ｒ ³ は同一又は異種の水素原子又はメチル基を示す。ｍは１又は２である。ｍが１の場合、Ｘ ¹ は単結合又は２価の有機基であり、ｍが２の場合、Ｘ ¹ は３価の有機基である。Ｘ ² は単結合又は２価の有機基である。Ｘ ¹ 、Ｘ ² が２価の有機基の場合、フェニレン基、−Ｒ ⁴ −Ｃ（＝Ｏ）−Ｏ−Ｒ ⁵ −、−Ｒ ⁴ −Ｏ−Ｒ ⁵ −、又は−Ｒ ⁴ −Ｃ（＝Ｏ）−ＮＨ−Ｒ ⁵ −を表し、Ｒ ⁴ は同一又は異種の単結合、又は炭素数６〜１０のアリーレン基、Ｒ ⁵ は同一又は異種の単結合、又は炭素数１〜１０の直鎖状、分岐状、環状又は有橋環式のアルキレン基、炭素数６〜１０のアリーレン基又は炭素数２〜１０のアルケニレン基であり、エーテル基、エステル基、又はフッ素原子を有していてもよい。Ｘ ¹ が３価の有機基の場合、フェニレン基から水素原子が１個脱離した基、又は−Ｒ ⁴ −Ｃ（＝Ｏ）−Ｏ−Ｒ ^5’ −、−Ｒ ⁴ −Ｏ−Ｒ ^5’ −、又は−Ｒ ⁴ −Ｃ（＝Ｏ）−ＮＨ−Ｒ ^5’ −で示される基であり、Ｒ ⁴ は上記の通り、Ｒ ^5’ はＲ ⁵ から水素原子が１個脱離した基を示す。Ｒ ² は水素原子、フッ素原子、メチル基、トリフルオロメチル基、ジフルオロメチル基であり、又はＸ ¹ と結合して炭素数１〜６の環を形成していてもよく、環の中にフッ素原子、エーテル基を有していてもよい。ａ１、ａ２は０＜ａ１＜１．０、０＜ａ２＜１．０、０．５≦ａ１＋ａ２≦１．０の範囲である。）
〔２〕
式（１）で示される高分子化合物を含む溶液が、炭素数８〜１２のエーテル化合物を溶剤とする〔１〕に記載のパターン形成方法。
〔３〕
炭素数８〜１２のエーテル化合物が、ジ−ｎ−ブチルエーテル、ジ−イソブチルエーテル、ジ−ｓｅｃ−ブチルエーテル、ジ−ｎ−ペンチルエーテル、ジイソペンチルエーテル、ジ−ｓｅｃ−ペンチルエーテル、ジ−ｔｅｒｔ−アミルエーテル、ジ−ｎ−ヘキシルエーテルから選ばれる１種以上であることを特徴とする〔２〕に記載のパターン形成方法。
〔４〕
上記エーテル化合物に、炭素数４〜１０の高級アルコールを０．１〜９０質量％混合することを特徴とする〔２〕又は〔３〕に記載のパターン形成方法。
〔５〕
炭素数４〜１０の高級アルコールが、１−ブチルアルコール、２−ブチルアルコール、イソブチルアルコール、ｔｅｒｔ−ブチルアルコール、１−ペンタノール、２−ペンタノール、３−ペンタノール、ｔｅｒｔ−アミルアルコール、ネオペンチルアルコール、２−メチル−１−ブタノール、３−メチル−１−ブタノール、３−メチル−３−ペンタノール、シクロペンタノール、１−ヘキサノール、２−ヘキサノール、３−ヘキサノール、２，３−ジメチル−２−ブタノール、３，３−ジメチル−１−ブタノール、３，３−ジメチル−２−ブタノール、２−エチル−１−ブタノール、２−メチル−１−ペンタノール、２−メチル−２−ペンタノール、２−メチル−３−ペンタノール、３−メチル−１−ペンタノール、３−メチル−２−ペンタノール、３−メチル−３−ペンタノール、４−メチル−１−ペンタノール、４−メチル−２−ペンタノール、４−メチル−３−ペンタノール、シクロヘキサノール、１−オクタノールから選ばれる１種以上であることを特徴とする〔４〕に記載のパターン形成方法。
〔６〕
下記一般式（１）で示される高分子化合物を含有することを特徴とするレジストパターンのスリミング材料。

（式中、Ｒ¹、Ｒ³は同一又は異種の水素原子又はメチル基を示す。ｍは１又は２である。ｍが１の場合、Ｘ¹は単結合又は２価の有機基であり、ｍが２の場合、Ｘ¹は３価の有機基である。Ｘ²は単結合又は２価の有機基である。Ｘ¹、Ｘ²が２価の有機基の場合、フェニレン基、−Ｒ⁴−Ｃ（＝Ｏ）−Ｏ−Ｒ⁵−、−Ｒ⁴−Ｏ−Ｒ⁵−、又は−Ｒ⁴−Ｃ（＝Ｏ）−ＮＨ−Ｒ⁵−を表し、Ｒ⁴は同一又は異種の単結合、又は炭素数６〜１０のアリーレン基、Ｒ⁵は同一又は異種の単結合、又は炭素数１〜１０の直鎖状、分岐状、環状又は有橋環式のアルキレン基、炭素数６〜１０のアリーレン基又は炭素数２〜１０のアルケニレン基であり、エーテル基、エステル基、又はフッ素原子を有していてもよい。Ｘ¹が３価の有機基の場合、フェニレン基から水素原子が１個脱離した基、又は−Ｒ⁴−Ｃ（＝Ｏ）−Ｏ−Ｒ^5’−、−Ｒ⁴−Ｏ−Ｒ^5’−、又は−Ｒ⁴−Ｃ（＝Ｏ）−ＮＨ−Ｒ^5’−で示される基であり、Ｒ⁴は上記の通り、Ｒ^5’はＲ⁵から水素原子が１個脱離した基を示す。Ｒ²は水素原子、フッ素原子、メチル基、トリフルオロメチル基、ジフルオロメチル基であり、又はＸ¹と結合して炭素数１〜６の環を形成していてもよく、環の中にフッ素原子、エーテル基を有していてもよい。ａ１、ａ２は０＜ａ１＜１．０、０＜ａ２＜１．０、０．５≦ａ１＋ａ２≦１．０の範囲である。）
〔７〕
式（１）で示される高分子化合物を炭素数８〜１２のエーテル化合物に溶解してなる〔６〕に記載のスリミング材料。
〔８〕
炭素数８〜１２のエーテル化合物が、ジ−ｎ−ブチルエーテル、ジ−イソブチルエーテル、ジ−ｓｅｃ−ブチルエーテル、ジ−ｎ−ペンチルエーテル、ジイソペンチルエーテル、ジ−ｓｅｃ−ペンチルエーテル、ジ−ｔｅｒｔ−アミルエーテル、ジ−ｎ−ヘキシルエーテルから選ばれる１種以上であることを特徴とする〔７〕に記載のスリミング材料。
〔９〕
上記エーテル化合物に、炭素数４〜１０の高級アルコールを０．１〜９０質量％混合することを特徴とする〔７〕又は〔８〕に記載のスリミング材料。
〔１０〕
炭素数４〜１０の高級アルコールが、１−ブチルアルコール、２−ブチルアルコール、イソブチルアルコール、ｔｅｒｔ−ブチルアルコール、１−ペンタノール、２−ペンタノール、３−ペンタノール、ｔｅｒｔ−アミルアルコール、ネオペンチルアルコール、２−メチル−１−ブタノール、３−メチル−１−ブタノール、３−メチル−３−ペンタノール、シクロペンタノール、１−ヘキサノール、２−ヘキサノール、３−ヘキサノール、２，３−ジメチル−２−ブタノール、３，３−ジメチル−１−ブタノール、３，３−ジメチル−２−ブタノール、２−エチル−１−ブタノール、２−メチル−１−ペンタノール、２−メチル−２−ペンタノール、２−メチル−３−ペンタノール、３−メチル−１−ペンタノール、３−メチル−２−ペンタノール、３−メチル−３−ペンタノール、４−メチル−１−ペンタノール、４−メチル−２−ペンタノール、４−メチル−３−ペンタノール、シクロヘキサノール、１−オクタノールから選ばれる１種以上であることを特徴とする〔９〕に記載のスリミング材料。 In order to solve the above-mentioned problems, it has been found that according to the present invention, the pattern forming method shown below and the slimming material used therefor are effective.
Accordingly, the present invention provides the following pattern forming method and a slimming material used therefor.
[1]
Film exposure of chemically amplified positive resist composition polymer compound improves the alkali solubility and the base resin by an acid, and bake (PEB), on the resist pattern after the development with an alkali aqueous represented by the following general formula (1 The solution containing a polymer compound having a sulfonic acid residue represented by ) is applied, baked, developed with alkaline water, the polymer compound having the sulfonic acid residue is removed, and the resist pattern is thinned. The pattern formation method characterized by the above-mentioned.

(In the formula, R ¹ and R ³ represent the same or different hydrogen atoms or methyl groups . M is 1 or 2. When m is 1, X ¹ is a single bond or a divalent organic group. When m is 2, X ¹ is a trivalent organic group, X ² is a single bond or a divalent organic group, and when X ¹ and X ² are divalent organic groups, a phenylene group, —R ⁴ —C (═O) —O—R ⁵ —, —R ⁴ —O—R ⁵ —, or —R ⁴ —C (═O) —NH—R ⁵ —, wherein R ⁴ is the same or different. A single bond or an arylene group having 6 to 10 carbon atoms, R ⁵ is the same or different single bond, or a linear, branched, cyclic or bridged alkylene group having 1 to 10 carbon atoms, carbon number 6 An arylene group having from 1 to 10 carbon atoms or an alkenylene group having from 2 to 10 carbon atoms, which may have an ether group, an ester group, or a fluorine atom, and when X ¹ is a trivalent organic group, A group in which one hydrogen atom is eliminated from the group, or —R ⁴ —C (═O) —O—R ^{5 ′} —, —R ⁴ —O—R ^{5 ′} —, or —R ⁴ —C (═O ) -NH-R 5 ^'- is a group represented by, R ⁴ is above the street, R ^5' is .R ² in which a group having a hydrogen atom released one de from R ⁵ represents a hydrogen atom, a fluorine atom, It may be a methyl group, a trifluoromethyl group or a difluoromethyl group, or may be bonded to X ¹ to form a ring having 1 to 6 carbon atoms, and has a fluorine atom or an ether group in the ring. A1 and a2 are in the range of 0 <a1 <1.0, 0 <a2 <1.0, 0.5 ≦ a1 + a2 ≦ 1.0.)
[ 2 ]
The solution containing the polymer compound Ru shown in equation (1) The pattern forming method according to an ether compound having 8 to 12 carbon atoms and a solvent (1).
[ 3 ]
The ether compound having 8 to 12 carbon atoms is di-n-butyl ether, di-isobutyl ether, di-sec-butyl ether, di-n-pentyl ether, diisopentyl ether, di-sec-pentyl ether, di-tert- The pattern forming method as described in [ 2 ], which is at least one selected from amyl ether and di-n-hexyl ether.
[ 4 ]
The pattern formation method as described in [ 2 ] or [ 3 ], wherein 0.1 to 90% by mass of a higher alcohol having 4 to 10 carbon atoms is mixed with the ether compound.
[ 5 ]
A higher alcohol having 4 to 10 carbon atoms is 1-butyl alcohol, 2-butyl alcohol, isobutyl alcohol, tert-butyl alcohol, 1-pentanol, 2-pentanol, 3-pentanol, tert-amyl alcohol, neopentyl. Alcohol, 2-methyl-1-butanol, 3-methyl-1-butanol, 3-methyl-3-pentanol, cyclopentanol, 1-hexanol, 2-hexanol, 3-hexanol, 2,3-dimethyl-2 -Butanol, 3,3-dimethyl-1-butanol, 3,3-dimethyl-2-butanol, 2-ethyl-1-butanol, 2-methyl-1-pentanol, 2-methyl-2-pentanol, 2 -Methyl-3-pentanol, 3-methyl-1-pentanol, 3-methyl-2-pentanol Selected from the group consisting of benzene, 3-methyl-3-pentanol, 4-methyl-1-pentanol, 4-methyl-2-pentanol, 4-methyl-3-pentanol, cyclohexanol and 1-octanol It is above, The pattern formation method as described in [ 4 ] characterized by the above-mentioned.
[ 6 ]
A resist pattern slimming material comprising a polymer compound represented by the following general formula (1):

(In the formula, R ¹ and R ³ represent the same or different hydrogen atoms or methyl groups. M is 1 or 2. When m is 1, X ¹ is a single bond or a divalent organic group. When m is 2, X ¹ is a trivalent organic group, X ² is a single bond or a divalent organic group, and when X ¹ and X ² are divalent organic groups, a phenylene group, —R ⁴ —C (═O) —O—R ⁵ —, —R ⁴ —O—R ⁵ —, or —R ⁴ —C (═O) —NH—R ⁵ —, wherein R ⁴ is the same or different. A single bond or an arylene group having 6 to 10 carbon atoms, R ⁵ is the same or different single bond, or a linear, branched, cyclic or bridged alkylene group having 1 to 10 carbon atoms, carbon number 6 An arylene group having from 1 to 10 carbon atoms or an alkenylene group having from 2 to 10 carbon atoms, which may have an ether group, an ester group, or a fluorine atom, and when X ¹ is a trivalent organic group, A group in which one hydrogen atom is eliminated from the group, or —R ⁴ —C (═O) —O—R ^{5 ′} —, —R ⁴ —O—R ^{5 ′} —, or —R ⁴ —C (═O ) -NH-R 5 ^'- is a group represented by, R ⁴ is above the street, R ^5' is .R ² in which a group having a hydrogen atom released one de from R ⁵ represents a hydrogen atom, a fluorine atom, It may be a methyl group, a trifluoromethyl group or a difluoromethyl group, or may be bonded to X ¹ to form a ring having 1 to 6 carbon atoms, and has a fluorine atom or an ether group in the ring. A1 and a2 are in the range of 0 <a1 <1.0, 0 <a2 <1.0, 0.5 ≦ a1 + a2 ≦ 1.0.)
[ 7 ]
The slimming material according to [ 6 ], wherein the polymer compound represented by formula (1) is dissolved in an ether compound having 8 to 12 carbon atoms.
[ 8 ]
The ether compound having 8 to 12 carbon atoms is di-n-butyl ether, di-isobutyl ether, di-sec-butyl ether, di-n-pentyl ether, diisopentyl ether, di-sec-pentyl ether, di-tert- [ 7 ] The slimming material according to [ 7 ], which is at least one selected from amyl ether and di-n-hexyl ether.
[ 9 ]
The slimming material according to [ 7 ] or [ 8 ], wherein 0.1 to 90% by mass of a higher alcohol having 4 to 10 carbon atoms is mixed with the ether compound.
[ 10 ]
A higher alcohol having 4 to 10 carbon atoms is 1-butyl alcohol, 2-butyl alcohol, isobutyl alcohol, tert-butyl alcohol, 1-pentanol, 2-pentanol, 3-pentanol, tert-amyl alcohol, neopentyl. Alcohol, 2-methyl-1-butanol, 3-methyl-1-butanol, 3-methyl-3-pentanol, cyclopentanol, 1-hexanol, 2-hexanol, 3-hexanol, 2,3-dimethyl-2 -Butanol, 3,3-dimethyl-1-butanol, 3,3-dimethyl-2-butanol, 2-ethyl-1-butanol, 2-methyl-1-pentanol, 2-methyl-2-pentanol, 2 -Methyl-3-pentanol, 3-methyl-1-pentanol, 3-methyl-2-pentanol Selected from the group consisting of benzene, 3-methyl-3-pentanol, 4-methyl-1-pentanol, 4-methyl-2-pentanol, 4-methyl-3-pentanol, cyclohexanol and 1-octanol The slimming material according to [ 9 ], which is as described above.

  According to the present invention, a polymer compound having a sulfonic acid residue, particularly a polymer compound having a repeating unit having a sulfonic acid residue and a repeating unit having a 2,2,2-trifluoro-1-hydroxyethyl group Is applied to the resist pattern after development, and the excess material is peeled off by baking and development to reduce the size of the resist pattern with good dimensional control. it can.

The pattern formation method (slimming method) according to the present invention will be described. (A) is a cross-sectional view of a state in which a photoresist film is formed on a substrate through a hard mask, (B) is an exposure of the photoresist film, (C) is a cross-sectional view in a state where a slimming material is applied, and (D) is a cross-sectional view in a state where the resist pattern is slimmed by baking, developing, removing the slimming material.

  The present inventors have intensively studied a slimming material capable of efficiently reducing a resist pattern after development and a slimming method using the same.

  That is, as a result of various investigations, the present inventors have a polymer compound having a sulfonic acid residue, particularly a repeating unit having a sulfonic acid residue, and a 2,2,2-trifluoro-1-hydroxyethyl group. A material in which a polymer compound having a repeating unit is dissolved in an ether solvent having 8 to 12 carbon atoms is applied on the resist pattern after development, and the excess material is peeled off by baking and development. The present invention has been completed by finding that the size can be reduced with good dimensional control.

  As the polymer compound constituting the main component of the slimming material used in the pattern forming method according to the present invention, one having a repeating unit having a sulfonic acid residue is used, preferably a sulfone represented by the following general formula (1). It has a repeating unit having an acid residue and a repeating unit having a 2,2,2-trifluoro-1-hydroxyethyl group.

（式中、Ｒ¹、Ｒ³は同一又は異種の水素原子又はメチル基を示す。ｍは１又は２である。ｍが１の場合、Ｘ¹は単結合又は２価の有機基であり、ｍが２の場合、Ｘ¹は３価の有機基である。Ｘ²は単結合又は２価の有機基である。Ｘ¹、Ｘ²が２価の有機基の場合、フェニレン基、−Ｒ⁴−Ｃ（＝Ｏ）−Ｏ−Ｒ⁵−、−Ｒ⁴−Ｏ−Ｒ⁵−、又は−Ｒ⁴−Ｃ（＝Ｏ）−ＮＨ−Ｒ⁵−を表し、Ｒ⁴は同一又は異種の単結合、又は炭素数６〜１０のアリーレン基、Ｒ⁵は同一又は異種の単結合、又は炭素数１〜１０の直鎖状、分岐状、環状又は有橋環式のアルキレン基、炭素数６〜１０のアリーレン基又は炭素数２〜１０のアルケニレン基であり、エーテル基、エステル基、又はフッ素原子を有していてもよい。Ｘ¹が３価の有機基の場合、フェニレン基から水素原子が１個脱離した基、又は−Ｒ⁴−Ｃ（＝Ｏ）−Ｏ−Ｒ^5'−、−Ｒ⁴−Ｏ−Ｒ^5'−、又は−Ｒ⁴−Ｃ（＝Ｏ）−ＮＨ−Ｒ^5'−で示される基であり、Ｒ⁴は上記の通り、Ｒ^5'はＲ⁵から水素原子が１個脱離した基を示す。Ｒ²は水素原子、フッ素原子、メチル基、トリフルオロメチル基、ジフルオロメチル基であり、又はＸ¹と結合して炭素数１〜６の環を形成していてもよく、環の中にフッ素原子、エーテル基を有していてもよい。ａ１、ａ２は０＜ａ１＜１．０、０＜ａ２＜１．０、０．５≦ａ１＋ａ２≦１．０の範囲である。）

(In the formula, R ¹ and R ³ represent the same or different hydrogen atoms or methyl groups. M is 1 or 2. When m is 1, X ¹ is a single bond or a divalent organic group. When m is 2, X ¹ is a trivalent organic group, X ² is a single bond or a divalent organic group, and when X ¹ and X ² are divalent organic groups, a phenylene group, —R ⁴ —C (═O) —O—R ⁵ —, —R ⁴ —O—R ⁵ —, or —R ⁴ —C (═O) —NH—R ⁵ —, wherein R ⁴ is the same or different. A single bond or an arylene group having 6 to 10 carbon atoms, R ⁵ is the same or different single bond, or a linear, branched, cyclic or bridged alkylene group having 1 to 10 carbon atoms, carbon number 6 An arylene group having from 1 to 10 carbon atoms or an alkenylene group having from 2 to 10 carbon atoms, which may have an ether group, an ester group, or a fluorine atom, and when X ¹ is a trivalent organic group, A group in which one hydrogen atom is eliminated from the group, or —R ⁴ —C (═O) —O—R ^{5 ′} —, —R ⁴ —O—R ^{5 ′} —, or —R ⁴ —C (═O ) -NH-R 5 ^'- is a group represented by, R ⁴ is above the street, R ^5' is .R ² in which a group having a hydrogen atom released one de from R ⁵ represents a hydrogen atom, a fluorine atom, It may be a methyl group, a trifluoromethyl group or a difluoromethyl group, or may be bonded to X ¹ to form a ring having 1 to 6 carbon atoms, and has a fluorine atom or an ether group in the ring. A1 and a2 are in the range of 0 <a1 <1.0, 0 <a2 <1.0, 0.5 ≦ a1 + a2 ≦ 1.0.)

Monomers for obtaining the repeating units a1 and a2 represented by the above formula (1) are represented by the following general formulas Ma1 and Ma2. Here, R ^{1 to} R ³ , m, X ¹ and X ² are the same as described above.

Ma1 is specifically exemplified below.

Ma2 is specifically exemplified below.

  The polymer compound for the slimming material has, in addition to the repeating units a1 and a2, styrenes, vinylnaphthalenes, vinylanthracenes, acenaphthylenes, and aromatic esters for the purpose of controlling acid diffusion as necessary. Repeating units b such as (meth) acrylates and (meth) acrylates having a cyclic alkyl group ester having 6 to 20 carbon atoms can also be copolymerized. These monomers may have a substituted or unsubstituted hydroxy group.

  The repeating units a1, a2, and b are 0 <a1 <1.0, 0 <a2 <1.0, 0.5 ≦ a1 + a2 ≦ 1.0, 0 ≦ b ≦ 0.5, preferably 0.1 ≦ a1 ≦ 0.99, 0.01 ≦ a2 ≦ 0.5, 0.6 ≦ a1 + a2 ≦ 1.0, 0 ≦ b ≦ 0.4, more preferably 0.2 ≦ a1 ≦ 0.98, 0.02. ≦ a2 ≦ 0.4, 0.7 ≦ a1 + a2 ≦ 1.0, and 0 ≦ b ≦ 0.3. Note that a1 + a2 + b = 1.

  On the other hand, the base polymer of the resist material used for pattern formation of the present invention is a polymer compound whose alkali solubility is improved by an acid, and has a repeating unit in which a carboxyl group and / or a phenolic hydroxyl group is substituted with an acid labile group. In particular, it is preferable to have a carboxyl group substituted with an acid labile group. As the repeating unit having a carboxyl group substituted with an acid labile group, for example, in JP 2012-37867 A, a repeating unit in which a phenolic hydroxyl group is substituted with an acid labile group in [0035] to [0075] Are described in [0087]. Furthermore, an adhesive group selected from a hydroxyl group, a lactone ring, an ether group, an ester group, a carbonyl group, and a cyano group described in [0076] to [0084] in JP 2012-37867 A, [0085] ], Indene, acenaphthylene, chromones, coumarins, norbornadiene, styrenes, vinylnaphthalenes, vinylanthracenes, vinylpyrenes, methyleneindanes described in [0088], You may copolymerize the acid generator of the onium salt which has the polymerizable olefin as described in [0089]-[0091].

  The polymer compound serving as a base polymer for the slimming material and resist material used in the pattern forming method of the present invention has a polystyrene-reduced weight average molecular weight of 1,000 to 500,000, particularly 2 by gel permeation chromatography (GPC). It is preferable that it is 3,000-30,000. If the weight average molecular weight is too small, the slimming material may increase the acid diffusion distance and the slimming amount may be too large to control. In the case of resist material, the diffusion distance of the acid generated from the PAG becomes too large. The image quality may be reduced. If the molecular weight is too large, slimming materials may have reduced alkali solubility and may cause scum after development.In the case of resist materials, undissolved residue may occur in the space, resulting in bridging defects. There is a case where the skirting phenomenon is likely to occur.

Furthermore, in the high molecular compound used as the base polymer of the slimming material and resist material used in the pattern forming method of the present invention, when the molecular weight distribution (Mw / Mn) is wide, low molecular weight or high molecular weight polymers exist. After exposure, foreign matter may be seen on the pattern or the shape of the pattern may deteriorate. Therefore, since the influence of such molecular weight and molecular weight distribution tends to increase as the pattern rule becomes finer, in order to obtain a resist material suitably used for fine pattern dimensions, the multi-component copolymer to be used is obtained. The molecular weight distribution is preferably from 1.0 to 2.0, particularly preferably from 1.0 to 1.5 and narrow dispersion.
It is also possible to blend two or more polymers having different composition ratios, molecular weight distributions, and molecular weights.

  In order to synthesize these polymer compounds, one method is to obtain repeating units a1 and a2 of the polymer compound for the slimming material and a repeating unit having an acid labile group and a repeating unit of the adhesive group for the resist material. There is a method in which a monomer having an unsaturated bond and a monomer for other purposes are added to a radical initiator in an organic solvent and subjected to heat polymerization, whereby a polymer compound can be obtained. Examples of the organic solvent used at the time of polymerization include toluene, benzene, tetrahydrofuran, diethyl ether, dioxane and the like. As polymerization initiators, 2,2′-azobisisobutyronitrile (AIBN), 2,2′-azobis (2,4-dimethylvaleronitrile), dimethyl 2,2-azobis (2-methylpropionate) ), Benzoyl peroxide, lauroyl peroxide and the like, and preferably polymerized by heating to 50 to 80 ° C. The reaction time is 2 to 100 hours, preferably 5 to 20 hours. As the acid labile group, those introduced into the monomer may be used as they are, or the acid labile group may be once removed by an acid catalyst and then protected or partially protected.

  The slimming material used in the pattern forming method of the present invention can contain an organic solvent, and if necessary, a salt, a basic compound, and a surfactant. As the organic solvent, an ether compound having 8 to 12 carbon atoms is used. The ether compound having 8 to 12 carbon atoms is characterized by not dissolving the resist pattern. When an ester or ketone solvent that can be used as a resist material is used, the slimming material and the resist pattern are mixed when the slimming material is applied onto the resist pattern, and the resist pattern is dissolved after development. In order to prevent this, an ether compound having 8 to 12 carbon atoms that does not dissolve the polymer compound for the resist material is preferably used as a mixing material. Specific examples of the ether compound having 8 to 12 carbon atoms include di-n-butyl ether, di-isobutyl ether, di-sec-butyl ether, di-n-pentyl ether, diisopentyl ether, di-sec-pentyl ether, Examples thereof include di-tert-amyl ether and di-n-hexyl ether, and one or two or more mixed solvents thereof can be used.

  Next, examples of the solvent that does not dissolve the resist polymer compound include higher alcohols having 4 to 10 carbon atoms. Although higher alcohols having 4 to 10 carbon atoms are not as much as ether compounds having 8 to 12 carbon atoms, they have the feature of not dissolving the resist polymer compound. However, when only a higher alcohol having 4 to 10 carbon atoms is used as a solvent, not only the mixing amount of the resist pattern and the slimming material is increased and the slimming amount is increased, but also the height of the resist pattern is reduced. Have the disadvantages. However, higher alcohols having 4 to 10 carbon atoms are more excellent in solubility of polymer compounds having polar repeating units such as sulfonic acid residues than ether compounds having 8 to 12 carbon atoms. Therefore, as a solvent for the slimming material, from the viewpoint of preventing mixing with the resist pattern and ensuring the solubility of the polymer compound for slimming, an ether compound having 8 to 12 carbon atoms and a small amount of 4 to 10 carbon atoms are used. Most preferably, alcohol is mixed.

  Examples of the higher alcohol having 4 to 10 carbon atoms include 1-butyl alcohol, 2-butyl alcohol, isobutyl alcohol, tert-butyl alcohol, 1-pentanol, 2-pentanol, 3-pentanol, tert-amyl alcohol, neo Pentyl alcohol, 2-methyl-1-butanol, 3-methyl-1-butanol, 3-methyl-3-pentanol, cyclopentanol, 1-hexanol, 2-hexanol, 3-hexanol, 2,3-dimethyl- 2-butanol, 3,3-dimethyl-1-butanol, 3,3-dimethyl-2-butanol, 2-ethyl-1-butanol, 2-methyl-1-pentanol, 2-methyl-2-pentanol, 2-methyl-3-pentanol, 3-methyl-1-pentanol, 3-methyl-2- Examples include butanol, 3-methyl-3-pentanol, 4-methyl-1-pentanol, 4-methyl-2-pentanol, 4-methyl-3-pentanol, cyclohexanol, and 1-octanol. These 1 type, or 2 or more types of mixed solvents can be used.

In this case, the mixing ratio of the ether compound having 8 to 12 carbon atoms and the higher alcohol having 4 to 10 carbon atoms is preferably 0.1 to 90% by mass, more preferably 1 to 80% by mass for the higher alcohol.
Moreover, it is preferable that the usage-amount of the said solvent is 100-100,000 mass parts with respect to 100 mass parts of polymer compounds for slimming materials, especially 200-50,000 mass parts.

  Examples of salts that can be added as a slimming material according to the present invention include ammonium salts in addition to sulfonium salts and iodonium salts added to resist materials. Basic compounds similar to those added to resist materials are the same primary, secondary, and tertiary aliphatic amines, mixed amines, aromatic amines, heterocyclic amines, and nitrogen-containing nitrogen groups Examples thereof include a compound, a nitrogen-containing compound having a sulfonyl group, a nitrogen-containing compound having a hydroxyl group, a nitrogen-containing compound having a hydroxyphenyl group, an alcoholic nitrogen-containing compound, an amide derivative, and an imide derivative. The slimming amount can be controlled by adding the salt or the basic compound. As the surfactant, the same material as the resist material can be added.

  In this case, 0 to 50 parts by mass of the salt, 0 to 30 parts by mass of the basic compound, and 0 to 30% of the surfactant with respect to 100 parts by mass of the polymer compound for slimming material. It is preferable that it is 10 mass parts, especially 0-5 mass parts. In addition, when mix | blending, it is preferable to set it as 0.1 mass part or more, respectively.

  The resist material used in the pattern forming method of the present invention includes an organic solvent, a compound that generates an acid in response to high energy rays (acid generator), a dissolution controller, a basic compound, a surfactant, if necessary. It can contain acetylene alcohols and other components.

  The resist material used in the pattern forming method of the present invention may contain an acid generator particularly for functioning as a chemically amplified positive resist material. For example, a compound that generates an acid in response to actinic rays or radiation (light (Acid generator) may be contained. In this case, the compounding amount of the photoacid generator is preferably 0.5 to 30 parts by mass, particularly 1 to 20 parts by mass with respect to 100 parts by mass of the base resin. The component of the photoacid generator may be any compound that generates an acid upon irradiation with high energy rays. Suitable photoacid generators include sulfonium salts, iodonium salts, sulfonyldiazomethane, N-sulfonyloxyimide, oxime-O-sulfonate type acid generators, and the like. These can be used alone or in admixture of two or more. Examples of the acid generated from the acid generator include sulfonic acid, imide acid, and methide acid. Of these, a sulfonic acid having a fluorinated α-position is most commonly used. However, in the case where the acid labile group is an acetal group that is easily deprotected, the α-position is not necessarily fluorinated. In the case where a repeating unit of an acid generator is copolymerized as a base polymer, an additive type acid generator is not necessarily essential.

  Specific examples of the organic solvent include ketones such as cyclohexanone and methyl-2-n-amyl ketone described in paragraphs [0144] to [0145] of JP-A-2008-111103, 3-methoxybutanol, 3-methyl- Alcohols such as 3-methoxybutanol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, propylene glycol monomethyl ether, ethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, propylene glycol dimethyl ether , Ethers such as diethylene glycol dimethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, ethyl lactate, pyruvic acid Esters such as chill, butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, tert-butyl acetate, tert-butyl propionate, propylene glycol mono tert-butyl ether acetate, lactones such as γ-butyrolactone, and the like The mixed solvent is mentioned. When using an acetal-based acid labile group, a high-boiling alcohol solvent such as diethylene glycol, propylene glycol, glycerin, 1,4-butanediol, 1, to accelerate the deprotection reaction of the acetal group 3-butanediol and the like can also be added.

Examples of the basic compound include primary, secondary, and tertiary amine compounds described in paragraphs [0146] to [0164] of JP-A-2008-111103, particularly hydroxy groups, ether groups, ester groups, and lactone rings. And an amine compound having a cyano group or a sulfonic acid ester group, or a compound having a carbamate group described in Japanese Patent No. 3790649.
Further, a sulfonic acid which is not fluorinated at the α-position described in JP 2008-158339 A, a sulfonium salt, an iodonium salt, and an ammonium salt of a carboxylic acid described in Japanese Patent No. 3991462 and Japanese Patent No. 426803. Etc. can also be used together as a quencher.

  When the acid labile group is an acetal group that is particularly sensitive to acids, the acid for removing the protecting group may not necessarily be sulfonic acid, imide acid, or methide acid fluorinated at the α-position. In some cases, the deprotection reaction may proceed even in a sulfonic acid in which the α-position is not fluorinated. Since the onium salt of sulfonic acid cannot be used as the quencher at this time, it is preferable to use the onium salt of imidic acid of the present invention alone in such a case.

  The surfactants are paragraphs [0165] to [0166] of JP-A-2008-111103, the dissolution control agents are paragraphs [0155] to [0178] of JP-A-2008-122932, and the acetylene alcohols are JP-A-2008-. Those described in paragraphs [0179] to [0182] of No. 122932 can be used.

  A polymer compound for improving the water repellency of the resist surface after spin coating can also be added. This additive can be used in immersion lithography without a topcoat. Such an additive has a 1,1,1,3,3,3-hexafluoro-2-propanol residue having a specific structure, and is exemplified in JP-A-2007-297590 and JP-A-2008-111103. Has been. The water repellency improver added to the resist material must be dissolved in the organic solvent of the developer. The above-mentioned water repellent improver having a specific 1,1,1,3,3,3-hexafluoro-2-propanol residue has good solubility in a developer. As a water-repellent additive, a polymer compound copolymerized with amino groups or amine salts as a repeating unit has a high effect of preventing the evaporation of an acid in PEB and preventing a defective opening of a hole pattern after development. The addition amount of the water repellency improver is 0.1 to 20 parts by mass, preferably 0.5 to 10 parts by mass with respect to 100 parts by mass of the base resin of the resist material.

In addition, it is preferable that the compounding quantity of an organic solvent shall be 100-10,000 mass parts with respect to 100 mass parts of base resins, especially 300-8,000 mass parts. Moreover, it is preferable that the compounding quantity of a basic compound shall be 0.0001-30 mass parts with respect to 100 mass parts of base resins, especially 0.001-20 mass parts.
Moreover, the compounding quantity of a dissolution control agent, surfactant, and acetylene alcohol can be suitably selected according to the compounding purpose.

  The pattern slimming method according to the present invention is as shown in FIG. 1, and a photoresist film 40 made of a chemically amplified positive resist material is formed on a substrate 20 to be processed on a substrate 10 through a hard mask layer 30 as necessary. (A). Next, the resist film 40 is exposed and developed by a conventional method to form a resist pattern 50 (B), and a slimming material 60 is applied thereon (C). Next, baking is performed, and acid is diffused from the slimming material film 60 to the resist pattern 50 by the heat. As a result, a deprotection reaction is caused in the polymer compound (base polymer) of the resist pattern, and the slimming material film 60 is removed by development to dissolve the resist pattern 50 in the region where the deprotection reaction has occurred. Thin.

In this case, a silicon substrate is generally used as the substrate. Examples of the substrate to be processed include SiO ₂ , SiN, SiON, SiOC, p-Si, α-Si, TiN, WSi, BPSG, SOG, Cr, CrO, CrON, MoSi, a low dielectric film, and an etching stopper film thereof. . As the hard mask, SiO ₂ , SiN, SiON, p-Si, or the like is used as the hard mask. Instead of the hard mask, an underlayer film made of a carbon film and a silicon-containing intermediate film may be laid, or an organic antireflection film may be laid between the hard mask and the photoresist film.

  In the present invention, a resist film made of a positive resist material is formed on the substrate to be processed directly or through the intermediate intervening layer. The resist film has a thickness of 10 to 1,000 nm, particularly 20 to 500 nm. Preferably there is. This resist film is heated (pre-baked) before exposure, and as this condition, it is preferable to carry out at 50 to 180 ° C., particularly 60 to 150 ° C. for 10 to 300 seconds, particularly 15 to 200 seconds.

  Next, exposure is performed. Here, the exposure is most preferably 193 nm exposure using a high energy beam having a wavelength of 140 to 250 nm, and among these, ArF excimer laser. The exposure may be a dry atmosphere in the air or a nitrogen stream, or may be immersion exposure in water. In ArF immersion lithography, pure water or a liquid such as alkane having a refractive index of 1 or more and a highly transparent liquid at the exposure wavelength is used as an immersion solvent. In immersion lithography, pure water or other liquid is inserted between a pre-baked resist film and a projection lens. As a result, a lens with an NA of 1.0 or more can be designed, and a finer pattern can be formed. Immersion lithography is an important technique for extending the life of ArF lithography to the 45 nm node. In the case of immersion exposure, pure water rinsing (post-soak) after exposure to remove the water droplet residue remaining on the resist film may be performed, and elution from the resist film is prevented, and the surface lubricity of the film is prevented. In order to increase the thickness, a protective film may be formed on the resist film after pre-baking. As a resist protective film used in immersion lithography, for example, a polymer compound having a 1,1,1,3,3,3-hexafluoro-2-propanol residue that is insoluble in water and dissolved in an alkaline developer is used. A base and a material dissolved in an alcohol solvent having 4 to 10 carbon atoms, an ether solvent having 8 to 12 carbon atoms, and a mixed solvent thereof is preferable. After forming the photoresist film, pure water rinsing (post-soak) may be performed to extract acid generators from the film surface or to wash out particles, or to remove water remaining on the film after exposure. Rinse (post-soak) may be performed.

It is preferable to expose so that the exposure amount in exposure is about 1 to 200 mJ / cm ² , preferably about 10 to 100 mJ / cm ² . Next, post-exposure baking (PEB) is performed on a hot plate at 50 to 150 ° C. for 1 to 5 minutes, preferably 60 to 120 ° C. for 1 to 3 minutes.

  Further, 0.1 to 5% by weight, preferably 2 to 3% by weight, using an aqueous developer such as tetramethylammonium hydroxide (TMAH) for 0.1 to 3 minutes, preferably 0.5 to 2 minutes. The target pattern is formed on the substrate by development by a conventional method such as a dip method, a paddle method, or a spray method.

  The slimming material according to the present invention is applied onto the developed resist pattern. After application, baking is performed at 40 to 150 ° C. for 5 to 300 seconds. In addition to evaporating the solvent by baking, acid diffusion from the slimming material to the resist pattern and deprotection reaction are performed. The thickness of the slimming material is 1 to 100 nm, preferably 1.5 to 50 nm.

  Peeling of the slimming material can be performed with an alkali developer, an ether solvent having 8 to 12 carbon atoms, an alcohol solvent having 4 to 10 carbon atoms, and a mixed solvent thereof. Peeling with an alkali developer is preferably used. It is done. As the alkaline developer, the same one as used for forming the resist pattern can be used.

EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated concretely, this invention is not restrict | limited to the following Example etc. In addition, a weight average molecular weight (Mw) shows the polystyrene conversion weight average molecular weight by GPC.
[Synthesis example]
As a polymer compound to be added to the slimming material, each monomer is combined and subjected to a copolymerization reaction in a tetrahydrofuran solvent, crystallized in methanol, further washed with hexane, isolated and dried, and shown below. The high molecular compound (Polymer 1-11, comparative polymer 1) of the composition was obtained. The composition of the obtained polymer compound was confirmed by ¹ H-NMR, and the molecular weight and dispersity were confirmed by gel permeation chromatography.

Polymer 1
Molecular weight (Mw) = 9,100
Dispersity (Mw / Mn) = 1.81

Polymer 2
Molecular weight (Mw) = 9,100
Dispersity (Mw / Mn) = 1.89

Polymer 3
Molecular weight (Mw) = 6,100
Dispersity (Mw / Mn) = 1.56

Polymer 4
Molecular weight (Mw) = 9,400
Dispersity (Mw / Mn) = 1.94

Polymer 5
Molecular weight (Mw) = 7,200
Dispersity (Mw / Mn) = 1.64

Polymer 6
Molecular weight (Mw) = 7,100
Dispersity (Mw / Mn) = 1.71

Polymer 7
Molecular weight (Mw) = 9,900
Dispersity (Mw / Mn) = 1.97

Polymer 8
Molecular weight (Mw) = 7,000
Dispersity (Mw / Mn) = 1.70

Polymer 9
Molecular weight (Mw) = 8,800
Dispersity (Mw / Mn) = 1.79

Polymer 10
Molecular weight (Mw) = 8,800
Dispersity (Mw / Mn) = 1.79

Polymer 11
Molecular weight (Mw) = 8,800
Dispersity (Mw / Mn) = 1.79

Comparative polymer 1
Molecular weight (Mw) = 7,800
Dispersity (Mw / Mn) = 1.68

撥水性ポリマー１
分子量（Ｍｗ）＝７，８００
分散度（Ｍｗ／Ｍｎ）＝１．５５

Resist polymer 1
Molecular weight (Mw) = 7,500
Dispersity (Mw / Mn) = 1.61

Water repellent polymer 1
Molecular weight (Mw) = 7,800
Dispersity (Mw / Mn) = 1.55

[Examples 1 to 16, Comparative Examples 1 and 2]
The polymer compound synthesized above (Polymer 1 to 11, Comparative Polymer 1), an acid generator, a sulfonium salt, an additive such as a water repellent polymer, and a solvent are mixed and filtered through a 0.2 μm Teflon filter A prepared solution was prepared.

Each composition in the following table is as follows.
Acid generator: PAG1 (see structural formula below)

Sulfonium salt 1, sulfonium salt 2, amine quencher 1 (see the structural formula below)

Preparation of positive resist material A 0.2 μm solution containing 100 ppm of surfactant FC-4430 manufactured by Sumitomo 3M Co., Ltd. dissolved in the composition shown in Table 2 below using the above-described polymer compound (resist polymer 1). A resist solution was prepared by filtering through a size filter.

有機溶剤：ＰＧＭＥＡ（プロピレングリコールモノメチルエーテルアセテート）

Organic solvent: PGMEA (propylene glycol monomethyl ether acetate)

ArF exposure patterning evaluation Table 2 A resist material prepared with the composition shown in Table 2 was formed on a silicon wafer with a spin-on carbon film ODL-50 (carbon content of 80% by mass) manufactured by Shin-Etsu Chemical Co., Ltd. having a silicon content of 200 nm. A spin-on hard mask SHB-A940 (silicon content 43% by mass) was spin-coated on a substrate for a trilayer process having a film thickness of 35 nm, and baked at 100 ° C. for 60 seconds using a hot plate. The thickness of the resist film was 100 nm. Using an ArF excimer laser immersion scanner (manufactured by Nikon Corporation, NSR-610C, NA 1.30, σ 0.98 / 0.78, dipole aperture 20 degrees, azimuthally polarized illumination, 6% halftone phase shift mask) Exposure is performed while changing the exposure amount, and after exposure, baking is performed at 90 ° C. for 60 seconds (PEB), and paddle development is performed for 30 seconds with a 2.38 mass% tetramethylammonium hydroxide aqueous solution, and a 45 nm 1: 1 line and space pattern. The slimming material shown in Table 1 was applied onto the developed resist pattern, baked at the temperature shown in Table 3, and paddle developed for 30 seconds with a 2.38 mass% aqueous tetramethylammonium hydroxide solution. The pattern and dimensions of the 45 nm line after development and after slimming were reduced. Jirafunesu was measured by measuring SEM ((Ltd.) Hitachi CG-4000). Table 3 shows the results.

  The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has substantially the same configuration as the technical idea described in the claims of the present invention, and any device that exhibits the same function and effect is the present invention. It is included in the technical scope of the invention.

DESCRIPTION OF SYMBOLS 10 Substrate 20 Substrate 30 Hard mask layer 40 Photoresist film 50 Resist pattern 60 Slimming material film

Claims (10)

Film exposure of chemically amplified positive resist composition polymer compound improves the alkali solubility and the base resin by an acid, and bake (PEB), on the resist pattern after the development with an alkali aqueous represented by the following general formula (1 The solution containing a polymer compound having a sulfonic acid residue represented by ) is applied, baked, developed with alkaline water, the polymer compound having the sulfonic acid residue is removed, and the resist pattern is thinned. The pattern formation method characterized by the above-mentioned.

(In the formula, R ¹ and R ³ represent the same or different hydrogen atoms or methyl groups . M is 1 or 2. When m is 1, X ¹ is a single bond or a divalent organic group. When m is 2, X ¹ is a trivalent organic group, X ² is a single bond or a divalent organic group, and when X ¹ and X ² are divalent organic groups, a phenylene group, —R ⁴ —C (═O) —O—R ⁵ —, —R ⁴ —O—R ⁵ —, or —R ⁴ —C (═O) —NH—R ⁵ —, wherein R ⁴ is the same or different. A single bond or an arylene group having 6 to 10 carbon atoms, R ⁵ is the same or different single bond, or a linear, branched, cyclic or bridged alkylene group having 1 to 10 carbon atoms, carbon number 6 Or an arylene group having from 1 to 10 carbon atoms or an alkenylene group having from 2 to 10 carbon atoms, which may have an ether group, an ester group, or a fluorine atom, and when X ¹ is a trivalent organic group, phenylene A group in which one hydrogen atom is eliminated from the group, or —R ⁴ —C (═O) —O—R ^{5 ′} —, —R ⁴ —O—R ^{5 ′} —, or —R ⁴ —C (═O ) -NH-R 5 ^'- is a group represented by, R ⁴ is above the street, R ^5' is .R ² in which a group having a hydrogen atom released one de from R ⁵ represents a hydrogen atom, a fluorine atom, It may be a methyl group, a trifluoromethyl group or a difluoromethyl group, or may be bonded to X ¹ to form a ring having 1 to 6 carbon atoms, and has a fluorine atom or an ether group in the ring. A1 and a2 are in the range of 0 <a1 <1.0, 0 <a2 <1.0, 0.5 ≦ a1 + a2 ≦ 1.0.) The solution containing the polymer compound Ru shown in equation (1) The pattern forming method according to claim 1 to an ether compound having 8 to 12 carbon atoms and a solvent. The ether compound having 8 to 12 carbon atoms is di-n-butyl ether, di-isobutyl ether, di-sec-butyl ether, di-n-pentyl ether, diisopentyl ether, di-sec-pentyl ether, di-tert- The pattern forming method according to claim 2 , wherein the pattern forming method is one or more selected from amyl ether and di-n-hexyl ether. The above ether compound, a pattern forming method according to claim 2 or 3 characterized by mixing 0.1 to 90 wt% of the higher alcohol having 4 to 10 carbon atoms. A higher alcohol having 4 to 10 carbon atoms is 1-butyl alcohol, 2-butyl alcohol, isobutyl alcohol, tert-butyl alcohol, 1-pentanol, 2-pentanol, 3-pentanol, tert-amyl alcohol, neopentyl. Alcohol, 2-methyl-1-butanol, 3-methyl-1-butanol, 3-methyl-3-pentanol, cyclopentanol, 1-hexanol, 2-hexanol, 3-hexanol, 2,3-dimethyl-2 -Butanol, 3,3-dimethyl-1-butanol, 3,3-dimethyl-2-butanol, 2-ethyl-1-butanol, 2-methyl-1-pentanol, 2-methyl-2-pentanol, 2 -Methyl-3-pentanol, 3-methyl-1-pentanol, 3-methyl-2-pentanol Selected from the group consisting of benzene, 3-methyl-3-pentanol, 4-methyl-1-pentanol, 4-methyl-2-pentanol, 4-methyl-3-pentanol, cyclohexanol and 1-octanol The pattern forming method according to claim 4, which is as described above. A resist pattern slimming material comprising a polymer compound represented by the following general formula (1):

(In the formula, R ¹ and R ³ represent the same or different hydrogen atoms or methyl groups. M is 1 or 2. When m is 1, X ¹ is a single bond or a divalent organic group. When m is 2, X ¹ is a trivalent organic group, X ² is a single bond or a divalent organic group, and when X ¹ and X ² are divalent organic groups, a phenylene group, —R ⁴ —C (═O) —O—R ⁵ —, —R ⁴ —O—R ⁵ —, or —R ⁴ —C (═O) —NH—R ⁵ —, wherein R ⁴ is the same or different. A single bond or an arylene group having 6 to 10 carbon atoms, R ⁵ is the same or different single bond, or a linear, branched, cyclic or bridged alkylene group having 1 to 10 carbon atoms, carbon number 6 An arylene group having from 1 to 10 carbon atoms or an alkenylene group having from 2 to 10 carbon atoms, which may have an ether group, an ester group, or a fluorine atom, and when X ¹ is a trivalent organic group, A group in which one hydrogen atom is eliminated from the group, or —R ⁴ —C (═O) —O—R ^{5 ′} —, —R ⁴ —O—R ^{5 ′} —, or —R ⁴ —C (═O ) -NH-R 5 ^'- is a group represented by, R ⁴ is above the street, R ^5' is .R ² in which a group having a hydrogen atom released one de from R ⁵ represents a hydrogen atom, a fluorine atom, It may be a methyl group, a trifluoromethyl group or a difluoromethyl group, or may be bonded to X ¹ to form a ring having 1 to 6 carbon atoms, and has a fluorine atom or an ether group in the ring. A1 and a2 are in the range of 0 <a1 <1.0, 0 <a2 <1.0, 0.5 ≦ a1 + a2 ≦ 1.0.) The slimming material according to claim 6 , wherein the polymer compound represented by the formula (1) is dissolved in an ether compound having 8 to 12 carbon atoms. The ether compound having 8 to 12 carbon atoms is di-n-butyl ether, di-isobutyl ether, di-sec-butyl ether, di-n-pentyl ether, diisopentyl ether, di-sec-pentyl ether, di-tert- The slimming material according to claim 7 , wherein the slimming material is at least one selected from amyl ether and di-n-hexyl ether. The slimming material according to claim 7 or 8 , wherein 0.1 to 90% by mass of a higher alcohol having 4 to 10 carbon atoms is mixed with the ether compound. A higher alcohol having 4 to 10 carbon atoms is 1-butyl alcohol, 2-butyl alcohol, isobutyl alcohol, tert-butyl alcohol, 1-pentanol, 2-pentanol, 3-pentanol, tert-amyl alcohol, neopentyl. Alcohol, 2-methyl-1-butanol, 3-methyl-1-butanol, 3-methyl-3-pentanol, cyclopentanol, 1-hexanol, 2-hexanol, 3-hexanol, 2,3-dimethyl-2 -Butanol, 3,3-dimethyl-1-butanol, 3,3-dimethyl-2-butanol, 2-ethyl-1-butanol, 2-methyl-1-pentanol, 2-methyl-2-pentanol, 2 -Methyl-3-pentanol, 3-methyl-1-pentanol, 3-methyl-2-pentanol Selected from the group consisting of benzene, 3-methyl-3-pentanol, 4-methyl-1-pentanol, 4-methyl-2-pentanol, 4-methyl-3-pentanol, cyclohexanol and 1-octanol It is the above, The slimming material of Claim 9 characterized by the above-mentioned.

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