JP2022019350A - Resist material and pattern forming method - Google Patents

Abstract

To provide a resist material which has high sensitivity and hardly causes nanobridges, pattern collapse and residues even when being positive or negative, and to provide a pattern forming method using the same.SOLUTION: The resist material contains: an ammonium salt- and fluorine atom-containing polymer which contains a repeating unit AU having an ammonium salt structure of a sulfonamide compound having a benzene ring substituted with an iodine atom and at least one selected from a repeating unit FU-1 having a trifluoromethyl alcohol group optionally substituted with an acid-labile group and a repeating unit FU-2 having a fluorinated hydrocarbyl group; and a base polymer.SELECTED DRAWING: None

Description

The present invention relates to a resist material and a pattern forming method.

With the increasing integration and speed of LSI, the miniaturization of pattern rules is rapidly progressing. In particular, the expansion of the logic memory market due to the spread of smartphones is driving miniaturization. As a state-of-the-art miniaturization technology, mass production of 10 nm node devices by double patterning of ArF immersion lithography is being carried out, and mass production of 7 nm nodes by double patterning is also beginning to occur in the next generation. Extreme ultraviolet (EUV) lithography is a candidate for the next-generation 5 nm node.

EUV lithography has the problem that defects contained in a total of 80 layers of Mo and Si mask blanks are transferred, and there is little decrease in light intensity and there is no high-intensity pellicle that is not likely to be damaged during exposure. There is a problem that particles in the exposure machine adhere to the mask, and there is an urgent need to reduce defects. Further, in EUV lithography, since less than half of the pattern size formed by the conventional ArF immersion lithography is formed, the probability of occurrence of defects increases, and more advanced defect control is required.

Here, in a resist material for ArF immersion lithography, an additive which is a fluorine atom-containing polymer which is oriented toward the surface of a resist film to improve water repellency has been proposed (Patent Document 1). It has a 1,1,1,1,3,3,3-hexafluoro-2-propanol (HFA) group, which improves the solubility of the alkaline developer on the resist film surface and causes bridges to be generated on the resist surface. It has the effect of reducing defects.

Furthermore, it has been shown that the addition of a polymer containing a repeating unit having an HFA group and a rigid repeating unit having an aromatic group can reduce the outgas generated from the resist film during EUV exposure (Patent Documents). 2, 3). It has been shown that the modification of the resist film surface has the potential to reduce pattern defects and suppress the generation of outgas.

A resist material using a base polymer containing an iodine atom has been proposed (Patent Documents 4 and 5). Iodine atom absorbs EUV extremely much, and it is expected that the sensitivity will be increased by the sensitizing effect. However, the iodine atom has low solubility in an alkaline developer, and when it is introduced into a base polymer, the dissolution rate in the alkaline developer decreases, resulting in lower sensitivity or the space portion of the resist pattern. Residues may have formed.

Materials containing an amino group or an ammonium salt in a fluorine atom-containing polymer that is oriented toward the surface of a resist film to improve water repellency have been proposed (Patent Documents 6 and 7). As a result, the diffusion of acid on the surface of the resist film is suppressed, and the rectangularity of the resist pattern after development is improved. However, since the absorption of EUV is not so high, the sensitizing effect by this is limited.

Japanese Unexamined Patent Publication No. 2007-297590 Japanese Unexamined Patent Publication No. 2014-67014 Japanese Unexamined Patent Publication No. 2014-67012 Japanese Unexamined Patent Publication No. 2015-161823 Japanese Unexamined Patent Publication No. 2019-1997 Japanese Unexamined Patent Publication No. 2009-31767 Japanese Unexamined Patent Publication No. 2008-239918

In a chemically amplified resist material catalyzed by an acid, it is desired to develop a resist material that can reduce nanobridges and pattern collapse of line patterns, have no residue in the space portion, and can improve sensitivity. There is.

The present invention has been made in view of the above circumstances, and is highly sensitive regardless of whether it is a positive type or a negative type, a resist material that is less likely to cause nanobridges, pattern collapse and residues, and pattern formation using the same. The purpose is to provide a method.

As a result of diligent studies to achieve the above object, the present inventor has been substituted with a repeating unit having an ammonium salt structure of a sulfonamide compound having a benzene ring substituted with an iodine atom and an acid unstable group. By adding a polymer containing at least one selected from a repeating unit having a trifluoromethyl alcohol group and a repeating unit having a fluorinated hydrocarbyl group (hereinafter, also referred to as an ammonium salt and a fluorine atom-containing polymer). To obtain a resist material that prevents the occurrence of nanobridges and pattern collapse, has a wide process margin, has excellent edge roughness (LWR) of line patterns and dimensional uniformity (CDU) of hole patterns, and does not generate residues in the space portion. We found that we could do it, and completed the present invention.

（式中、ｍ¹は、１～５の整数である。ｍ²は、０～３の整数である。ｎ¹は、１又は２である。ｎ²は、０＜ｎ²／ｎ¹≦１を満たす正数である。ｎ³は、１又は２である。ｎ⁴は、１又は２である。
Ｒ^Aは、それぞれ独立に、水素原子又はメチル基である。
Ｘ^1Aは、単結合、フェニレン基、エステル結合又はアミド結合である。
Ｘ^1Bは、単結合又は炭素数１～２０の(ｎ¹＋１)価の炭化水素基であり、該炭化水素基は、エーテル結合、カルボニル基、エステル結合、アミド結合、スルトン環、ラクタム環、カーボネート結合、ハロゲン原子、ヒドロキシ基又はカルボキシ基を含んでいてもよい。
Ｘ^1Cは、単結合、エーテル結合、カルボニル基、エステル結合、アミド結合、カーボネート結合又は炭素数１～２０のヒドロカルビレン基であり、該ヒドロカルビレン基は、エーテル結合、カルボニル基、エステル結合、アミド結合、スルトン環、ラクタム環、カーボネート結合、ハロゲン原子、ヒドロキシ基又はカルボキシ基を含んでいてもよい。
Ｘ^2Aは、単結合、フェニレン基、－Ｏ－、－Ｃ(＝Ｏ)－Ｏ－又は－Ｃ(＝Ｏ)－ＮＨ－である。
Ｘ^2Bは、炭素数１～１２の(ｎ⁴＋１)価の飽和炭化水素基又は(ｎ⁴＋１)価の芳香族炭化水素基であり、フッ素原子、ヒドロキシ基、エステル結合又はエーテル結合を含んでいてもよい。
Ｘ³は、単結合、フェニレン基、－Ｏ－、－Ｃ(＝Ｏ)－Ｏ－Ｘ³¹－Ｘ³²－又は－Ｃ(＝Ｏ)－ＮＨ－Ｘ³¹－Ｘ³²－である。Ｘ³¹は、単結合又は炭素数１～４のアルカンジイル基である。Ｘ³²は、単結合、エステル結合、エーテル結合又はスルホンアミド結合である。
Ｒ¹、Ｒ²及びＲ³は、それぞれ独立に、水素原子、炭素数１～１２のアルキル基、炭素数２～１２のアルケニル基、炭素数６～１２のアリール基又は炭素数７～１２のアラルキル基である。また、Ｒ¹とＲ²と又はＲ¹とＸ^1Bとが、互いに結合してこれらが結合する窒素原子と共に環を形成してもよく、該環の中に酸素原子、硫黄原子、窒素原子又は二重結合を含んでいてもよい。
Ｒ⁴は、ヒドロキシ基、ハロゲン原子で置換されていてもよい炭素数１～６の飽和ヒドロカルビル基、ハロゲン原子で置換されていてもよい炭素数１～６の飽和ヒドロカルビルオキシ基、ホルミル基、ハロゲン原子で置換されていてもよい炭素数２～７の飽和ヒドロカルビルカルボニル基、ハロゲン原子で置換されていてもよい炭素数２～７の飽和ヒドロカルビルカルボニルオキシ基、ハロゲン原子で置換されていてもよい炭素数１～４の飽和ヒドロカルビルスルホニルオキシ基、炭素数６～１０のアリール基、フッ素原子、塩素原子、ニトロ基、シアノ基、又は－Ｎ(Ｒ^4A)(Ｒ^4B)、－Ｎ(Ｒ^4C)－Ｃ(＝Ｏ)－Ｒ^4D若しくは－Ｎ(Ｒ^4C)－Ｃ(＝Ｏ)－Ｏ－Ｒ^4Dである。Ｒ^4A及びＲ^4Bは、それぞれ独立に、水素原子又は炭素数１～６の飽和ヒドロカルビル基である。Ｒ^4Cは、水素原子又は炭素数１～６の飽和ヒドロカルビル基である。Ｒ^4Dは、炭素数１～６の飽和ヒドロカルビル基、炭素数２～８の不飽和脂肪族ヒドロカルビル基、炭素数６～１４のアリール基又は炭素数７～１５のアラルキル基である。
Ｒ⁵は、炭素数１～１０の(ｎ³＋１)価の炭化水素基であり、エステル結合、エーテル結合又はカルボニル基を含んでいてもよい。
Ｒ⁶は、炭素数１～１０の飽和ヒドロカルビル基又は炭素数６～１０のアリール基であり、該飽和ヒドロカルビル基は、フッ素原子、塩素原子、臭素原子又はヨウ素原子で置換されていてもよく、該アリール基は、フッ素原子、塩素原子、臭素原子、ヨウ素原子又は炭素数１～１０の飽和ヒドロカルビル基で置換されていてもよい。
Ｒ⁷は、単結合、エステル結合又は炭素数１～１２の飽和ヒドロカルビレン基であり、該飽和ヒドロカルビレン基の水素原子の一部又は全部がフッ素原子で置換されていてもよく、該飽和ヒドロカルビレン基の炭素原子の一部がエステル結合又はエーテル結合で置換されていてもよい。
Ｒ⁸は、水素原子、フッ素原子、メチル基、トリフルオロメチル基又はジフルオロメチル基である。Ｒ⁷とＲ⁸とは、互いに結合してこれらが結合する炭素原子と共に環を形成してもよく、該環の中にエーテル結合、フッ素原子又はトリフルオロメチル基を含んでいてもよい。
Ｒ⁹は、水素原子又は酸不安定基である。
Ｒ¹⁰は、少なくとも１個のフッ素原子で置換された炭素数１～２０のヒドロカルビル基であり、その炭素原子の一部が、エステル結合又はエーテル結合で置換されていてもよい。）
３．前記アンモニウム塩及びフッ素原子含有ポリマーを、ベースポリマー１００質量部に対し、０.１～２０質量部含む１又は２のレジスト材料。
４．更に、スルホン酸、イミド酸又はメチド酸を発生する酸発生剤を含む１～３のいずれかのレジスト材料。
５．更に、有機溶剤を含む１～４のいずれかのレジスト材料。
６．前記ベースポリマーが、下記式（ａ１）で表される繰り返し単位又は下記式（ａ２）で表される繰り返し単位を含むものである１～５のいずれかのレジスト材料。

（式中、Ｒ^Aは、それぞれ独立に、水素原子又はメチル基である。
Ｒ¹¹及びＲ¹²は、それぞれ独立に、酸不安定基である。
Ｒ¹³は、フッ素原子、トリフルオロメチル基、炭素数１～５の飽和ヒドロカルビル基又は炭素数１～５の飽和ヒドロカルビルオキシ基である。
Ｙ¹は、単結合、フェニレン基若しくはナフチレン基、又はエステル結合及びラクトン環から選ばれる少なくとも１種を含む炭素数１～１２の２価の連結基である。
Ｙ²は、単結合又はエステル結合である。
ａは、０～４の整数である。）
７．化学増幅ポジ型レジスト材料である６のレジスト材料。
８．前記ベースポリマーが、酸不安定基を含まないものである１～５のいずれかのレジスト材料。
９．化学増幅ネガ型レジスト材料である８のレジスト材料。
１０．前記ベースポリマーが、下記式（ｆ１）～（ｆ３）のいずれかで表される繰り返し単位を含む１～９のいずれかのポジ型レジスト材料。

（式中、Ｒ^Aは、それぞれ独立に、水素原子又はメチル基である。
Ｚ¹は、単結合、炭素数１～６の脂肪族ヒドロカルビレン基、フェニレン基、ナフチレン基若しくはこれらを組み合わせて得られる炭素数７～１８の基、又は－Ｏ－Ｚ¹¹－、－Ｃ(＝Ｏ)－Ｏ－Ｚ¹¹－若しくは－Ｃ(＝Ｏ)－ＮＨ－Ｚ¹¹－である。Ｚ¹¹は、炭素数１～６の脂肪族ヒドロカルビレン基、フェニレン基、ナフチレン基又はこれらを組み合わせて得られる炭素数７～１８の基であり、カルボニル基、エステル結合、エーテル結合又はヒドロキシ基を含んでいてもよい。
Ｚ²は、単結合又はエステル結合である。
Ｚ³は、単結合、－Ｚ³¹－Ｃ(＝Ｏ)－Ｏ－、－Ｚ³¹－Ｏ－又は－Ｚ³¹－Ｏ－Ｃ(＝Ｏ)－である。Ｚ³¹は、炭素数１～１２のヒドロカルビレン基、フェニレン基又はこれらを組み合わせて得られる炭素数７～１８の基であり、カルボニル基、エステル結合、エーテル結合、ヨウ素原子又は臭素原子を含んでいてもよい。
Ｚ⁴は、メチレン基、２,２,２－トリフルオロ－１,１－エタンジイル基又はカルボニル基である。
Ｚ⁵は、単結合、メチレン基、エチレン基、フェニレン基、フッ素化フェニレン基、トリフルオロメチル基で置換されたフェニレン基、－Ｏ－Ｚ⁵¹－、－Ｃ(＝Ｏ)－Ｏ－Ｚ⁵¹－又は－Ｃ(＝Ｏ)－ＮＨ－Ｚ⁵¹－である。Ｚ⁵¹は、炭素数１～６の脂肪族ヒドロカルビレン基、フェニレン基、フッ素化フェニレン基又はトリフルオロメチル基で置換されたフェニレン基であり、カルボニル基、エステル結合、エーテル結合又はヒドロキシ基を含んでいてもよい。
Ｒ²¹～Ｒ²⁸は、それぞれ独立に、ハロゲン原子、又はヘテロ原子を含んでいてもよい炭素数１～２０のヒドロカルビル基である。また、Ｒ²³とＲ²⁴と又はＲ²⁶とＲ²⁷とが、互いに結合してこれらが結合する硫黄原子と共に環を形成していてもよい。
Ｍ^-は、非求核性対向イオンである。）
１１．更に、界面活性剤を含む１～１０のいずれかのレジスト材料。
１２．１～１１のいずれかのレジスト材料を用いて基板上にレジスト膜を形成する工程と、前記レジスト膜を高エネルギー線で露光する工程と、前記露光したレジスト膜を、現像液を用いて現像する工程とを含むパターン形成方法。
１３．前記高エネルギー線が、波長１９３ｎｍのＡｒＦエキシマレーザー光又は波長２４８ｎｍのＫｒＦエキシマレーザー光である１２のパターン形成方法。
１４．前記高エネルギー線が、電子線（ＥＢ）又は波長３～１５ｎｍのＥＵＶである１２のパターン形成方法。 That is, the present invention provides the following resist material and pattern forming method.
1. 1. A repeating unit AU having an ammonium salt structure of a sulfonamide compound having a benzene ring substituted with an iodine atom, a repeating unit FU-1 having a trifluoromethyl alcohol group optionally substituted with an acid unstable group, and fluorination. A resist material containing an ammonium salt and a fluorine atom-containing polymer containing at least one selected from the repeating unit FU-2 having a hydrocarbyl group, and a base polymer.
2. 2. The repeating unit AU is represented by the following formula (AU), the repeating unit FU-1 is represented by the following formula (FU-1), and the repeating unit FU-2 is represented by the following formula (FU-2). 1) Resist material represented by).

(In the equation, m ¹ is an integer of 1 to 5. m ² is an integer of 0 to 3. n ¹ is 1 or 2. n ² is 0 <n ² / n ¹ ≦. A positive number satisfying 1. n ³ is 1 or 2. n ⁴ is 1 or 2.
^RA is independently a hydrogen atom or a methyl group.
X ^1A is a single bond, phenylene group, ester bond or amide bond.
X ^1B is a single-bonded or (n ¹ + 1) -valent hydrocarbon group having 1 to 20 carbon atoms, and the hydrocarbon group is an ether bond, a carbonyl group, an ester bond, an amide bond, a sulton ring, a lactam ring, and the like. It may contain a carbonate bond, a halogen atom, a hydroxy group or a carboxy group.
X ^1C is a single bond, an ether bond, a carbonyl group, an ester bond, an amide bond, a carbonate bond or a hydrocarbylene group having 1 to 20 carbon atoms, and the hydrocarbylene group is an ether bond, a carbonyl group or an ester bond. , Amide bond, sulton ring, lactam ring, carbonate bond, halogen atom, hydroxy group or carboxy group may be contained.
X ^2A is a single bond, a phenylene group, -O-, -C (= O) -O- or -C (= O) -NH-.
X ^2B is a (n ⁴ + 1) -valent saturated hydrocarbon group or (n ⁴ + 1) -valent aromatic hydrocarbon group having 1 to 12 carbon atoms and contains a fluorine atom, a hydroxy group, an ester bond or an ether bond. You may be.
X ³ is a single bond, a phenylene group, -O-, -C (= O) -O-X ³¹ -X ^32- or -C (= O) -NH-X ³¹ -X ^32- . X ³¹ is a single bond or an alkanediyl group having 1 to 4 carbon atoms. X ³² is a single bond, ester bond, ether bond or sulfone amide bond.
R ¹ , R ² and R ³ independently have a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms or 7 to 12 carbon atoms. It is an Aralkill group. Further, R ¹ and R ² or R ¹ and X ^{1 B} may be bonded to each other to form a ring together with the nitrogen atom to which they are bonded, and an oxygen atom, a sulfur atom, a nitrogen atom or a ring may be formed in the ring. It may contain a double bond.
R ⁴ is a hydroxy group, a saturated hydrocarbyl group having 1 to 6 carbon atoms which may be substituted with a halogen atom, a saturated hydrocarbyloxy group having 1 to 6 carbon atoms which may be substituted with a halogen atom, a formyl group, and a halogen. Saturated hydrocarbylcarbonyl group having 2 to 7 carbon atoms which may be substituted with an atom, saturated hydrocarbylcarbonyloxy group having 2 to 7 carbon atoms which may be substituted with a halogen atom, carbon which may be substituted with a halogen atom. Saturated hydrocarbylsulfonyloxy group of number 1 to 4, aryl group of 6 to 10 carbon atoms, fluorine atom, chlorine atom, nitro group, cyano group, or -N (R ^4A ) (R ^4B ), -N (R ^4C ) -C (= O) -R ^4D or -N (R ^4C ) -C (= O) -OR ^4D . R ^4A and R ^4B are independently hydrogen atoms or saturated hydrocarbyl groups having 1 to 6 carbon atoms. R ^4C is a hydrogen atom or a saturated hydrocarbyl group having 1 to 6 carbon atoms. R ^4D is a saturated hydrocarbyl group having 1 to 6 carbon atoms, an unsaturated aliphatic hydrocarbyl group having 2 to 8 carbon atoms, an aryl group having 6 to 14 carbon atoms or an aralkyl group having 7 to 15 carbon atoms.
R ⁵ is a (n ³ + 1) -valent hydrocarbon group having 1 to 10 carbon atoms and may contain an ester bond, an ether bond or a carbonyl group.
R ⁶ is a saturated hydrocarbyl group having 1 to 10 carbon atoms or an aryl group having 6 to 10 carbon atoms, and the saturated hydrocarbyl group may be substituted with a fluorine atom, a chlorine atom, a bromine atom or an iodine atom. The aryl group may be substituted with a fluorine atom, a chlorine atom, a bromine atom, an iodine atom or a saturated hydrocarbyl group having 1 to 10 carbon atoms.
R ⁷ is a saturated hydrocarbylene group having a single bond, an ester bond or 1 to 12 carbon atoms, and a part or all of the hydrogen atom of the saturated hydrocarbylene group may be substituted with a fluorine atom. A part of the carbon atom of the saturated hydrocarbylene group may be substituted with an ester bond or an ether bond.
R ⁸ is a hydrogen atom, a fluorine atom, a methyl group, a trifluoromethyl group or a difluoromethyl group. R ⁷ and R ⁸ may be bonded to each other to form a ring together with the carbon atom to which they are bonded, and the ring may contain an ether bond, a fluorine atom or a trifluoromethyl group.
R ⁹ is a hydrogen atom or an acid unstable group.
R ¹⁰ is a hydrocarbyl group having 1 to 20 carbon atoms substituted with at least one fluorine atom, and a part of the carbon atom may be substituted with an ester bond or an ether bond. )
3. 3. A resist material containing 0.1 to 20 parts by mass of the ammonium salt and a fluorine atom-containing polymer with respect to 100 parts by mass of the base polymer.
4. The resist material according to any one of 1 to 3, further comprising an acid generator that generates sulfonic acid, imidic acid or methidoic acid.
5. Further, any of 1 to 4 resist materials containing an organic solvent.
6. The resist material according to any one of 1 to 5, wherein the base polymer contains a repeating unit represented by the following formula (a1) or a repeating unit represented by the following formula (a2).

(In the formula, ^RA is a hydrogen atom or a methyl group, respectively.
R ¹¹ and R ¹² are each independently an acid unstable group.
R ¹³ is a fluorine atom, a trifluoromethyl group, a saturated hydrocarbyl group having 1 to 5 carbon atoms or a saturated hydrocarbylviloxy group having 1 to 5 carbon atoms.
Y ¹ is a divalent linking group having 1 to 12 carbon atoms containing at least one selected from a single bond, a phenylene group or a naphthylene group, or an ester bond and a lactone ring.
Y ² is a single bond or an ester bond.
a is an integer of 0 to 4. )
7. 6 resist materials which are chemically amplified positive resist materials.
8. The resist material according to any one of 1 to 5, wherein the base polymer does not contain an acid unstable group.
9. 8 resist materials which are chemically amplified negative resist materials.
10. The positive resist material according to any one of 1 to 9, wherein the base polymer contains a repeating unit represented by any of the following formulas (f1) to (f3).

(In the formula, ^RA is a hydrogen atom or a methyl group, respectively.
Z ¹ is a single bond, an aliphatic hydrocarbylene group having 1 to 6 carbon atoms, a phenylene group, a naphthylene group, or a group having 7 to 18 carbon atoms obtained by combining them, or -O-Z ^11- , -C. (= O) -O-Z ¹¹ -or -C (= O) -NH-Z ^11- . Z ¹¹ is an aliphatic hydrocarbylene group having 1 to 6 carbon atoms, a phenylene group, a naphthylene group or a group having 7 to 18 carbon atoms obtained by combining them, and is a carbonyl group, an ester bond, an ether bond or a hydroxy group. May include.
Z ² is a single bond or an ester bond.
Z ³ is a single bond, -Z ³¹ -C (= O) -O-, -Z ³¹ -O- or -Z ³¹ -OC (= O)-. Z ³¹ is a hydrocarbylene group having 1 to 12 carbon atoms, a phenylene group, or a group having 7 to 18 carbon atoms obtained by combining them, and contains a carbonyl group, an ester bond, an ether bond, an iodine atom or a bromine atom. You may be.
Z ⁴ is a methylene group, 2,2,2-trifluoro-1,1-ethandyl group or a carbonyl group.
Z ⁵ is a single bond, a methylene group, an ethylene group, a phenylene group, a fluorinated phenylene group, a phenylene group substituted with a trifluoromethyl group, -O-Z ^{51-, -C (= O) -O-Z 51 . -Or} -C (= O) -NH-Z 51-. Z ⁵¹ is a phenylene group substituted with an aliphatic hydrocarbylene group, a phenylene group, a fluorinated phenylene group or a trifluoromethyl group having 1 to 6 carbon atoms, and has a carbonyl group, an ester bond, an ether bond or a hydroxy group. It may be included.
R ²¹ to R ²⁸ are hydrocarbyl groups having 1 to 20 carbon atoms which may independently contain a halogen atom or a hetero atom. Further, R ²³ and R ²⁴ or R ²⁶ and R ²⁷ may be bonded to each other to form a ring together with the sulfur atom to which they are bonded.
M ^- is a non-nucleophilic opposed ion. )
11. Further, any of 1 to 10 resist materials containing a surfactant.
A step of forming a resist film on a substrate using any of 12.1 to 11 and a step of exposing the resist film with high energy rays, and a step of exposing the exposed resist film with a developing solution. A pattern forming method including a step of developing.
13. A method for forming a pattern 12 in which the high energy ray is an ArF excimer laser light having a wavelength of 193 nm or a KrF excimer laser light having a wavelength of 248 nm.
14. A method for forming a pattern 12 in which the high energy ray is an electron beam (EB) or EUV having a wavelength of 3 to 15 nm.

The ammonium salt and fluorine atom-containing polymer is a polymer-type quencher having high solubility in an alkaline developer. Since the polymer also contains a repeating unit having a fluorine atom, the polymer is oriented on the surface of the resist film after forming the resist film using the resist material containing the polymer and the base polymer. This increases the absorption of exposure light on the resist film surface by iodine atoms, exerts a sensitizing effect, and at the same time controls acid diffusion near the resist film surface layer, preventing acid evaporation from the resist film surface layer. As a result, the rectangularity of the resist pattern after development is enhanced, and the LWR of the line pattern and the CDU of the hole pattern when observed from the sky are improved. Further, the solubility of the resist film surface in the alkaline developer is improved, and bridge defects and pattern collapse after pattern formation are reduced.

[Resist material]
The resist material of the present invention contains an ammonium salt, a fluorine atom-containing polymer, and a base polymer.

[Ammonium salt and fluorine atom-containing polymer]
The ammonium salt and the fluorine atom-containing polymer have a repeating unit AU having an ammonium salt structure of a sulfonamide compound having a benzene ring substituted with an iodine atom, and a trifluoromethyl alcohol group which may be substituted with an acid unstable group. It contains at least one selected from the repeating unit FU-1 having a fluorinated hydrocarbyl group and the repeating unit FU-2 having a fluorinated hydrocarbyl group.

The repeating unit AU preferably has the ammonium salt structure as a pendant group, and particularly preferably one represented by the following formula (AU).

In equation (AU), m ¹ is an integer from 1 to 5. m ² is an integer from 0 to 3. n ¹ is 1 or 2. n ² is a positive number satisfying 0 <n ² / n ¹ ≦ 1. n ³ is 1 or 2. n ⁴ is 1 or 2.

In formula (AU), ^RA is independently a hydrogen atom or a methyl group.

In formula (AU), X ^1A is a single bond, phenylene group, ester bond or amide bond. X ^1B is a single-bonded or (n ¹ + 1) -valent hydrocarbon group having 1 to 20 carbon atoms, and the hydrocarbon group is an ether bond, a carbonyl group, an ester bond, an amide bond, a sulton ring, a lactam ring, and the like. It may contain a carbonate bond, a halogen atom, a hydroxy group or a carboxy group.

The (n ¹ + 1) -valent hydrocarbon group having 1 to 20 carbon atoms represented by X ^1B is derived from an aliphatic hydrocarbon having 1 to 20 carbon atoms or an aromatic hydrocarbon having 6 to 20 carbon atoms (n ¹ + 1). ) A group obtained by desorption of hydrogen atoms, which may be linear, branched or cyclic. Specific examples thereof include methane, ethane, propane, butane, pentane, hexane, heptan, octane, nonane, decane, undecane, dodecane, cyclopropane, cyclobutane, cyclopentane, cyclohexane, methylcyclopentane, ethylcyclopentane, and methylcyclohexane. , Ethylcyclohexane, 1-propylcyclohexane, isopropylcyclohexane, norbornan, adamantan, methylnorbornan, ethylnorbornan, methyladamantan, ethyladamantan, tetrahydrodicyclopentadiene, etc. (n ¹ + 1) from saturated hydrocarbons having 1 to 20 carbon atoms. Group obtained by desorption of hydrogen atom of (n ¹ + 1) from aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, 1-propylbenzene, isopropylbenzene and naphthalene. Group; A group obtained by combining these can be mentioned.

In the formula (AU), X ^1C is a single bond, an ether bond, a carbonyl group, an ester bond, an amide bond, a carbonate bond or a hydrocarbylene group having 1 to 20 carbon atoms, and the hydrocarbylene group is an ether bond. , A carbonyl group, an ester bond, an amide bond, a sulton ring, a lactam ring, a carbonate bond, a halogen atom, a hydroxy group or a carboxy group.

In the formula (AU), R ¹ , R ² and R ³ are independently a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms or an aryl group having 6 to 12 carbon atoms. It is an aralkyl group having 7 to 12 carbon atoms. Further, R ¹ and R ² or R ¹ and X ^{1 B} may be bonded to each other to form a ring together with the nitrogen atom to which they are bonded, and an oxygen atom, a sulfur atom, a nitrogen atom or a ring may be formed in the ring. It may contain a double bond. At this time, the ring is preferably a ring having 3 to 12 carbon atoms.

The alkyl group having 1 to 12 carbon atoms represented by R ¹ , R ² and R ³ may be linear, branched or cyclic, and specific examples thereof include a methyl group, an ethyl group and n-propyl. Group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, n -Decil group, n-dodecyl group and the like can be mentioned. Examples of the alkenyl group having 2 to 12 carbon atoms represented by R ¹ , R ² and R ³ include a vinyl group, a 1-propenyl group, a 2-propenyl group, a butenyl group, a hexenyl group and the like. Examples of the aryl group having 6 to 12 carbon atoms represented by R ¹ , R ² and R ³ include a phenyl group, a tolyl group, a xylyl group, a 1-naphthyl group, a 2-naphthyl group and the like. Examples of the aralkyl group having 7 to 12 carbon atoms represented by R ¹ , R ² and R ³ include a benzyl group and the like.

In the formula (AU), R ⁴ is a hydroxy group, a saturated hydrocarbyl group having 1 to 6 carbon atoms which may be substituted with a halogen atom, and a saturated hydrocarbyloxy having 1 to 6 carbon atoms which may be substituted with a halogen atom. A group, a formyl group, a saturated hydrocarbylcarbonyl group having 2 to 7 carbon atoms which may be substituted with a halogen atom, a saturated hydrocarbylcarbonyloxy group having 2 to 7 carbon atoms which may be substituted with a halogen atom, and a halogen atom substituted. A saturated hydrocarbylsulfonyloxy group having 1 to 4 carbon atoms, an aryl group having 6 to 10 carbon atoms, a fluorine atom, a chlorine atom, a nitro group, a cyano group, or -N (R ^4A ) (R ^4B ), which may be used. -N (R ^4C ) -C (= O) -R ^4D or -N (R ^4C ) -C (= O) -OR ^4D . R ^4A and R ^4B are independently hydrogen atoms or saturated hydrocarbyl groups having 1 to 6 carbon atoms. R ^4C is a hydrogen atom or a saturated hydrocarbyl group having 1 to 6 carbon atoms. R ^4D is a saturated hydrocarbyl group having 1 to 6 carbon atoms, an unsaturated aliphatic hydrocarbyl group having 2 to 8 carbon atoms, an aryl group having 6 to 14 carbon atoms or an aralkyl group having 7 to 15 carbon atoms.

The saturated hydrocarbyl group having 1 to 6 carbon atoms represented by R ⁴ , R ^4A to R ^4D may be linear, branched or cyclic, and specific examples thereof include a methyl group, an ethyl group and n-. Alkyl groups with 1 to 6 carbon atoms such as propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, n-hexyl group; cyclopropyl group, cyclobutyl group , Cycloalkyl group having 3 to 6 carbon atoms such as cyclopentyl group and cyclohexyl group. The saturated hydrocarbyl part of the saturated hydrocarbyloxy group having 1 to 6 carbon atoms, the saturated hydrocarbylcarbonyl group having 2 to 7 carbon atoms and the saturated hydrocarbylcarbonyloxy group having 2 to 7 carbon atoms represented by ^R4 is the saturated hydrocarbyl group described above. Examples of the saturated hydrocarbyl portion of the saturated hydrocarbylsulfonyloxy group having 1 to 4 carbon atoms include those having 1 to 4 carbon atoms among the above-mentioned specific examples of the saturated hydrocarbyl group. Will be. Examples of the aryl group having 6 to 10 carbon atoms represented by R ⁴ include a phenyl group and a naphthyl group.

In formula (AU), R ⁵ is a (n ³ + 1) -valent hydrocarbon group having 1 to 10 carbon atoms and may contain an ester bond, an ether bond or a carbonyl group. The (n ³ + 1) -valent hydrocarbon group having 1 to 10 carbon atoms has (n ³ + 1) hydrogen atoms from an aliphatic hydrocarbon having 1 to 20 carbon atoms or an aromatic hydrocarbon having 6 to 20 carbon atoms. Is a group obtained by desorption of, and may be linear, branched, or cyclic. Specific examples thereof include methane, ethane, propane, butane, pentane, hexane, heptan, octane, nonane, decane, cyclopropane, cyclobutane, cyclopentane, cyclohexane, methylcyclopentane, ethylcyclopentane, methylcyclohexane, and ethylcyclohexane. A group obtained by desorbing (n ³ + 1) hydrogen atoms from saturated hydrocarbons having 1 to 20 carbon atoms such as 1-propylcyclohexane, isopropylcyclohexane, norbornan, adamantan, methylnorbornan, ethylnorbornan, and tetrahydrodicyclopentadiene. A group obtained by desorbing (n ³ + 1) hydrogen atoms from aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, 1-propylbenzene, isopropylbenzene, and naphthalene; a group obtained by combining these. Can be mentioned.

In the formula (AU), R ⁶ is a saturated hydrocarbyl group having 1 to 10 carbon atoms or an aryl group having 6 to 10 carbon atoms, and the saturated hydrocarbyl group is substituted with a fluorine atom, a chlorine atom, a bromine atom or an iodine atom. The aryl group may be substituted with a fluorine atom, a chlorine atom, a bromine atom, an iodine atom or a saturated hydrocarbyl group having 1 to 10 carbon atoms. The saturated hydrocarbyl group having 1 to 10 carbon atoms may be linear, branched or cyclic, and specific examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group and an n-butyl group. Isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group and the like have 1 to 10 carbon atoms. Alkyl group: Cyclic saturated hydrocarbyl group having 3 to 10 carbon atoms such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, norbornyl group and adamantyl group. Examples of the aryl group having 6 to 10 carbon atoms include a phenyl group and a naphthyl group.

Examples of the cation of the monomer giving the repeating unit AU include, but are not limited to, those shown below. In the following formula, ^RA is the same as described above.

Examples of the anion of the monomer that gives the repeating unit AU include, but are not limited to, those shown below.

The monomer giving the repeating unit AU is a polymerizable ammonium salt type monomer. The ammonium salt type monomer is a monomer which is an amine compound having a structure in which one hydrogen atom bonded to a nitrogen atom of the cation of the repeating unit is desorbed, and a sulfonamide compound having a benzene ring substituted with an iodine atom. It can be obtained by the neutralization reaction of.

The repeating unit AU is formed by carrying out a polymerization reaction using the ammonium salt type monomer, and is obtained by carrying out a polymerization reaction using the monomer which is an amine compound to synthesize a polymer, and then obtaining a reaction solution or a reaction solution obtained. It may be formed by adding a sulfonamide compound having a benzene ring substituted with an iodine atom to a solution containing the purified polymer and carrying out a neutralization reaction. At this time, it is ideal for the effect of the present invention that the neutralization reaction is carried out in an amount such that the substance amount ratio (molar ratio) of the amino group of the amine compound and the carboxylic acid is 1: 1. However, the sulfonamide compound may be excessive or small with respect to the amino group.

As the repeating units FU-1 and FU-2, those represented by the following formulas (FU-1) and (FU-2) are preferable.

In formula (FU-1), n ⁴ is 1 or 2.

In formulas (FU-1) and (FU-2), ^RA is independently a hydrogen atom or a methyl group, respectively.

In formula (FU-1), X ^2A is a single bond, phenylene group, -O-, -C (= O) -O- or -C (= O) -NH-. X ^2B is a (n ⁴ + 1) -valent saturated hydrocarbon group or (n ⁴ + 1) -valent aromatic hydrocarbon group having 1 to 12 carbon atoms and contains a fluorine atom, a hydroxy group, an ester bond or an ether bond. You may be.

The (n ⁴ + 1) -valent saturated hydrocarbon group having 1 to 12 carbon atoms represented by X ^2B may be linear, branched, or cyclic, and specific examples thereof include methane, ethane, and propane. Butane, pentane, hexane, heptane, octane, nonane, decane, undecane, dodecane, cyclopropane, cyclobutane, cyclopentane, cyclohexane, methylcyclopentane, ethylcyclopentane, methylcyclohexane, ethylcyclohexane, 1-propylcyclohexane, isopropylcyclohexane, Examples thereof include groups obtained by desorbing (n ⁴ + 1) hydrogen atoms from saturated hydrocarbons such as norbornan, adamantan, methylnorbornan, ethylnorbornan, methyladamantan, ethyladamantan, and tetrahydrodicyclopentadiene. The (n ⁴ + 1) -valent aromatic hydrocarbon group represented by X ^2B includes aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, 1-propylbenzene, isopropylbenzene and naphthalene (n ⁴ + 1). Examples thereof include groups obtained by desorption of individual hydrogen atoms.

In formula (FU-2), X ³ is a single bond, phenylene group, -O-, -C (= O) -O-X ³¹ -X ³² -or -C (= O) -NH-X ^31- X ^32- . X ³¹ is a single bond or an alkanediyl group having 1 to 4 carbon atoms. X ³² is a single bond, ester bond, ether bond or sulfone amide bond. Examples of the alkanediyl group having 1 to 4 carbon atoms include a methanediyl group, an ethane-1,1-diyl group, an ethane-1,2-diyl group, a propane-1,1-diyl group, and a propane-1,2-diyl group. Group, Propane-1,3-Diyl Group, Propane-2,2-Diyl Group, Butane-1,1-Diyl Group, Butane-1,2-Diyl Group, Butane-1,3-Diyl Group, Butane-2 , 3-Diyl group, butane-1,4-Diyl group, 1,1-dimethylethane-1,2-Diyl group and the like.

In formula (FU-1), R ⁷ is a single bond, an ester bond or a saturated hydrocarbylene group having 1 to 12 carbon atoms, and a part or all of the hydrogen atoms of the saturated hydrocarbylene group are fluorine atoms. It may be substituted, and a part of the carbon atom of the saturated hydrocarbylene group may be substituted with an ester bond or an ether bond. The saturated hydrocarbylene group may be linear, branched or cyclic.

In formula (FU-1), R ⁸ is a hydrogen atom, a fluorine atom, a methyl group, a trifluoromethyl group or a difluoromethyl group. R ⁷ and R ⁸ may be bonded to each other to form a ring together with the carbon atom to which they are bonded, and the ring may contain an ether bond, a fluorine atom or a trifluoromethyl group.

In formula (FU-1), R ⁹ is a hydrogen atom or an acid unstable group. Specific examples of the acid unstable group will be described later.

In the formula (FU-2), R ¹⁰ is a hydrocarbyl group having 1 to 20 carbon atoms substituted with at least one fluorine atom, and a part of the carbon atom is substituted with an ester bond or an ether bond. You may. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched or cyclic. Specific examples thereof include the same as those exemplified in the description of R ¹⁰¹ to R ¹⁰⁵ in the formulas (1-1) and (1-2) described later. Of these, a saturated hydrocarbyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms and the like are preferable.

Examples of the monomer giving the repeating unit FU-1 include, but are not limited to, those shown below. In the following formula, ^RA and R ⁹ are the same as described above.

Examples of the monomer giving the repeating unit FU-2 include, but are not limited to, those shown below. In the following formula, ^RA is the same as described above.

The ammonium salt and the fluorine atom-containing polymer contain at least one selected from the repeating units FU-1 and FU-2, so that the efficiency of orientation to the resist film surface is enhanced after the resist film is formed.

The ammonium salt and fluorine atom-containing polymer may contain repeating units that function as acid generators, in addition to the repeating units AU, FU-1 and FU-2. Examples of such a repeating unit include a repeating unit represented by any of the formulas (f1) to (f3) described later.

The content ratios of the repeating units AU, FU-1 and FU-2 are 0 <AU <1.0, 0 ≦ (FU-1) <1.0, 0 ≦ (FU-2) <1.0 and 0 <. (FU-1) + (FU-2) <1.0 is preferable, 0.001 ≤ AU ≤ 0.7, 0 ≤ (FU-1) ≤ 0.95, 0 ≤ (FU-2) ≤ 0. 95 and 0.1 ≦ (FU-1) ＋ (FU-2) ≦ 0.99 are more preferable, 0.01 ≦ AU ≦ 0.5, 0 ≦ (FU-1) ≦ 0.8, 0 ≦ ( FU-2) ≤ 0.8 and 0.2 ≤ (FU-1) + (FU-2) ≤ 0.98 are more preferable. Further, the ammonium salt and the fluorine atom-containing polymer may contain other repeating units as long as the effects of the present invention are not impaired (that is, AU + (FU-1) + (FU-2) = 1). Is preferable.

The weight average molecular weight (Mw) of the ammonium salt and the fluorine atom-containing polymer is preferably 1,000 to 1,000,000, more preferably 2,000 to 100,000. The molecular weight distribution (Mw / Mn) is preferably 1.0 to 3.0. In addition, Mw and Mn are polystyrene-equivalent measured values by gel permeation chromatography (GPC) using tetrahydrofuran (THF) as a solvent.

The ammonium salt and the fluorine atom-containing polymer are oriented on the surface of the resist film to improve the solubility of the resist film surface in an alkaline developer. This can prevent bridge defects and pattern collapse of the pattern.

In the resist material of the present invention, the content of the ammonium salt and the fluorine atom-containing polymer is preferably 0.001 to 20 parts by mass with respect to 100 parts by mass of the base polymer described later, from the viewpoint of sensitivity and acid diffusion suppressing effect. .01 to 10 parts by mass is more preferable.

[Base polymer]
In the case of a positive resist material, the base polymer contained in the resist material of the present invention contains a repeating unit containing an acid unstable group. The repeating unit containing an acid unstable group is a repeating unit represented by the following formula (a1) (hereinafter, also referred to as a repeating unit a1) or a repeating unit represented by the following formula (a2) (hereinafter, repeating unit a2). Also referred to as) is preferable.

In formulas (a1) and (a2), ^RA is independently a hydrogen atom or a methyl group, respectively. R ¹¹ and R ¹² are each independently an acid unstable group. When the base polymer contains both the repeating unit a1 and the repeating unit a2, R ¹¹ and R ¹² may be the same as or different from each other. R ¹³ is a fluorine atom, a trifluoromethyl group, a saturated hydrocarbyl group having 1 to 5 carbon atoms or a saturated hydrocarbylviloxy group having 1 to 5 carbon atoms. Y ¹ is a divalent linking group having 1 to 12 carbon atoms containing at least one selected from a single bond, a phenylene group or a naphthylene group, or an ester bond and a lactone ring. Y ² is a single bond or an ester bond. a is an integer of 0 to 4.

Examples of the monomer giving the repeating unit a1 include, but are not limited to, those shown below. In the following formula, ^RA and R ¹¹ are the same as described above.

Examples of the monomer that gives the repeating unit a2 include, but are not limited to, those shown below. In the following formula, ^RA and R ¹² are the same as described above.

The acid unstable group represented by R ⁷ in the formula (FU-1), the acid unstable group represented by R ¹¹ in the formula (a1), and the acid non-acidic group represented by R ¹² in the formula (a 2). Examples of the stable group include those described in JP-A-2013-80033 and JP-A-2013-83821.

（式中、破線は、結合手である。） Typically, the acid unstable group includes those represented by the following formulas (AL-1) to (AL-3).

(In the formula, the broken line is the bond.)

In the formulas (AL-1) and (AL-2), ^RL1 and ^RL2 are independently hydrocarbyl groups having 1 to 40 carbon atoms, and are heteroatoms such as oxygen atom, sulfur atom, nitrogen atom, and fluorine atom. It may contain an atom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched or cyclic. As the hydrocarbyl group, a saturated hydrocarbyl group having 1 to 40 carbon atoms is preferable, and a saturated hydrocarbyl group having 1 to 20 carbon atoms is more preferable.

In the formula (AL-1), b is an integer of 0 to 10, and an integer of 1 to 5 is preferable.

In the formula (AL-2), R ^L3 and R ^L4 are independently hydrogen atoms or hydrocarbyl groups having 1 to 20 carbon atoms, and contain heteroatoms such as oxygen atom, sulfur atom, nitrogen atom, and fluorine atom. You may be. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched or cyclic. As the hydrocarbyl group, a saturated hydrocarbyl group having 1 to 20 carbon atoms is preferable. Further, any two of R ^L2 , R ^L3 and R ^L4 may be bonded to each other to form a ring having 3 to 20 carbon atoms together with a carbon atom or a carbon atom and an oxygen atom to which they are bonded. As the ring, a ring having 4 to 16 carbon atoms is preferable, and an alicyclic ring is particularly preferable.

In the formula (AL-3), ^RL5 , ^RL6 and ^RL7 are independently hydrocarbyl groups having 1 to 20 carbon atoms and contain heteroatoms such as oxygen atom, sulfur atom, nitrogen atom and fluorine atom. You may be. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched or cyclic. As the hydrocarbyl group, a saturated hydrocarbyl group having 1 to 20 carbon atoms is preferable. Further, any two of ^RL5 , ^RL6 and ^RL7 may be bonded to each other to form a ring having 3 to 20 carbon atoms together with the carbon atom to which they are bonded. As the ring, a ring having 4 to 16 carbon atoms is preferable, and an alicyclic ring is particularly preferable.

The base polymer may contain a repeating unit b containing a phenolic hydroxy group as an adhesive group. Examples of the monomer that gives the repeating unit b include, but are not limited to, those shown below. In the following formula, ^RA is the same as described above.

The base polymer has a hydroxy group other than the phenolic hydroxy group, a lactone ring, a sultone ring, an ether bond, an ester bond, a sulfonic acid ester bond, a carbonyl group, a sulfonyl group, a cyano group or a carboxy group as other adhesive groups. The repeating unit c to be included may be included. Examples of the monomer giving the repeating unit c include, but are not limited to, those shown below. In the following formula, ^RA is the same as described above.

The base polymer may contain a repeating unit d derived from indene, benzofuran, benzothiophene, acenaphthylene, chromone, coumarin, norbornadiene or derivatives thereof. Examples of the monomer that gives the repeating unit d include, but are not limited to, those shown below.

The base polymer may contain a repeating unit e derived from styrene, vinylnaphthalene, vinylanthracene, vinylpyrene, methyleneindane, vinylpyridine or vinylcarbazole.

The base polymer may contain a repeating unit f derived from an onium salt containing a polymerizable unsaturated bond. The preferred repeating unit f is a repeating unit represented by the following formula (f1) (hereinafter, also referred to as a repeating unit f1) and a repeating unit represented by the following formula (f2) (hereinafter, also referred to as a repeating unit f2). And a repeating unit represented by the following formula (f3) (hereinafter, also referred to as a repeating unit f3) can be mentioned. The repeating units f1 to f3 may be used alone or in combination of two or more.

In the formulas (f1) to (f3), ^RA is independently a hydrogen atom or a methyl group. Z ¹ is a single bond, an aliphatic hydrocarbylene group having 1 to 6 carbon atoms, a phenylene group, a naphthylene group, or a group having 7 to 18 carbon atoms obtained by combining them, or -O-Z ^11- , -C. (= O) -O-Z ¹¹ -or -C (= O) -NH-Z ^11- . Z ¹¹ is an aliphatic hydrocarbylene group having 1 to 6 carbon atoms, a phenylene group, a naphthylene group or a group having 7 to 18 carbon atoms obtained by combining them, and is a carbonyl group, an ester bond, an ether bond or a hydroxy group. May include. Z ² is a single bond or an ester bond. Z ³ is a single bond, -Z ³¹ -C (= O) -O-, -Z ³¹ -O- or -Z ³¹ -OC (= O)-. Z ³¹ is a hydrocarbylene group having 1 to 12 carbon atoms, a phenylene group, or a group having 7 to 18 carbon atoms obtained by combining them, and contains a carbonyl group, an ester bond, an ether bond, an iodine atom or a bromine atom. You may be. Z ⁴ is a methylene group, 2,2,2-trifluoro-1,1-ethandyl group or a carbonyl group. Z ⁵ is a single bond, a methylene group, an ethylene group, a phenylene group, a fluorinated phenylene group, a phenylene group substituted with a trifluoromethyl group, -O-Z ^{51-, -C (= O) -O-Z 51 . -Or} -C (= O) -NH-Z 51-. Z ⁵¹ is a phenylene group substituted with an aliphatic hydrocarbylene group, a phenylene group, a fluorinated phenylene group or a trifluoromethyl group having 1 to 6 carbon atoms, and has a carbonyl group, an ester bond, an ether bond or a hydroxy group. It may be included.

In the formulas (f1) to (f3), R ²¹ to R ²⁸ are hydrocarbyl groups having 1 to 20 carbon atoms which may independently contain a halogen atom or a hetero atom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched or cyclic. Specific examples thereof include the same as those exemplified in the description of R ¹⁰¹ to R ¹⁰⁵ in the formulas (1-1) and (1-2) described later. Further, R ²³ and R ²⁴ or R ²⁶ and R ²⁷ may be bonded to each other to form a ring together with the sulfur atom to which they are bonded. At this time, the ring is the same as that exemplified as a ring that can be formed together with the sulfur atom to which R ¹⁰¹ and R ¹⁰² are bonded in the description of the formula (1-1) described later. Can be mentioned.

In formula (f1), M- is a non ^- nucleophilic counter ion. Examples of the non-nucleophilic counter ion include halide ions such as chloride ion and bromide ion; fluoroalkyl sulfonate ions such as triflate ion, 1,1,1-trifluoroethanesulfonate ion and nonafluorobutane sulfonate ion; Aryl sulfonate ions such as tosylate ion, benzene sulfonate ion, 4-fluorobenzene sulfonate ion, 1,2,3,4,5-pentafluorobenzene sulfonate ion; alkyl sulfonate ion such as mesylate ion, butane sulfonate ion; bis (Trifluoromethylsulfonyl) imide ion, bis (perfluoroethylsulfonyl) imide ion, bis (perfluorobutylsulfonyl) imide ion and other imide ions; tris (trifluoromethylsulfonyl) methide ion, tris (perfluoroethylsulfonyl) methide ion and the like Can be mentioned.

As another example of the non-nucleophilic opposed ion, a sulfonic acid ion in which the α-position represented by the following formula (f1-1) is replaced with a fluorine atom, and the α-position represented by the following formula (f1-2) Is substituted with a fluorine atom, and the β-position is substituted with a trifluoromethyl group.

In the formula (f1-1), R ³¹ is a hydrogen atom or a hydrocarbyl group having 1 to 20 carbon atoms, and the hydrocarbyl group may contain an ether bond, an ester bond, a carbonyl group, a lactone ring or a fluorine atom. good. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched or cyclic. Specific examples thereof include the same hydrocarbyl groups represented by R ¹¹¹ in the formula (1A'), which will be described later.

In the formula (f1-2), R ³² is a hydrogen atom, a hydrocarbyl group having 1 to 30 carbon atoms or a hydrocarbylcarbonyl group having 2 to 30 carbon atoms, and the hydrocarbyl group and the hydrocarbylcarbonyl group are an ether bond or an ester bond. , A carbonyl group or a lactone ring may be included. The hydrocarbyl moiety of the hydrocarbyl group and the hydrocarbylcarbonyl group may be saturated or unsaturated, and may be linear, branched or cyclic. Specific examples thereof include the same hydrocarbyl groups represented by R ¹¹¹ in the formula (1A'), which will be described later.

Examples of the cation of the monomer giving the repeating unit f1 include, but are not limited to, those shown below. In the following formula, ^RA is the same as described above.

Examples of the cation of the monomer giving the repeating unit f2 or f3 include those similar to those exemplified as the cation of the sulfonium salt represented by the formula (1-1) described later.

Examples of the anion of the monomer giving the repeating unit f2 include, but are not limited to, those shown below. In the following formula, ^RA is the same as described above.

Examples of the anion of the monomer giving the repeating unit f3 include, but are not limited to, those shown below. In the following formula, ^RA is the same as described above.

By binding an acid generator to the polymer main chain, acid diffusion can be reduced and deterioration of resolution due to blurring of acid diffusion can be prevented. In addition, LWR and CDU are improved by uniformly dispersing the acid generator. When a base polymer containing the repeating unit f (that is, a polymer bound type acid generator) is used, the addition of the additive type acid generator described later may be omitted.

The base polymer for positive resist materials requires a repeating unit a1 or a2 containing an acid unstable group. In this case, the content ratios of the repeating units a1, a2, b, c, d, e and f are 0≤a1 <1.0, 0≤a2 <1.0, 0 <a1 + a2 <1.0, 0≤b. ≤0.9, 0≤c≤0.9, 0≤d≤0.8, 0≤e≤0.8 and 0≤f≤0.5 are preferred, 0≤a1≤0.9, 0≤a2 ≦ 0.9, 0.1 ≦ a1 + a2 ≦ 0.9, 0 ≦ b ≦ 0.8, 0 ≦ c ≦ 0.8, 0 ≦ d ≦ 0.7, 0 ≦ e ≦ 0.7 and 0 ≦ f ≤0.4 is more preferable, 0≤a1≤0.8, 0≤a2≤0.8, 0.1≤a1 + a2≤0.8, 0≤b≤0.75, 0≤c≤0.75, 0 ≦ d ≦ 0.6, 0 ≦ e ≦ 0.6 and 0 ≦ f ≦ 0.3 are more preferable. When the repeating unit f is at least one selected from the repeating units f1 to f3, f = f1 + f2 + f3. Further, a1 + a2 + b + c + d + e + f = 1.0.

On the other hand, the base polymer for negative resist materials does not necessarily require an acid unstable group. Examples of such a base polymer include a repeating unit b and, if necessary, a repeating unit c, d, e and / or f. The content ratio of these repeating units is preferably 0 <b ≦ 1.0, 0 ≦ c ≦ 0.9, 0 ≦ d ≦ 0.8, 0 ≦ e ≦ 0.8, and 0 ≦ f ≦ 0.5. , 0.2 ≦ b ≦ 1.0, 0 ≦ c ≦ 0.8, 0 ≦ d ≦ 0.7, 0 ≦ e ≦ 0.7 and 0 ≦ f ≦ 0.4, more preferably 0.3 ≦ More preferably, b ≦ 1.0, 0 ≦ c ≦ 0.75, 0 ≦ d ≦ 0.6, 0 ≦ e ≦ 0.6 and 0 ≦ f ≦ 0.3. When the repeating unit f is at least one selected from the repeating units f1 to f3, f = f1 + f2 + f3. Further, b + c + d + e + f = 1.0.

In order to synthesize the base polymer, for example, the above-mentioned monomer giving a repeating unit may be heated by adding a radical polymerization initiator in an organic solvent to carry out the polymerization.

Examples of the organic solvent used in the polymerization include toluene, benzene, THF, diethyl ether, dioxane and the like. As the polymerization initiator, 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis (2,4-dimethylvaleronitrile), dimethyl 2,2-azobis (2-methylpropionate). ), Benzoyl peroxide, lauroyl peroxide and the like. The temperature at the time of polymerization is preferably 50 to 80 ° C. The reaction time is preferably 2 to 100 hours, more preferably 5 to 20 hours.

When copolymerizing a monomer containing a hydroxy group, the hydroxy group may be replaced with an acetal group which is easily deprotected with an acid such as an ethoxyethoxy group at the time of polymerization, and deprotection may be carried out with a weak acid and water after the polymerization. Alkaline hydrolysis may be carried out after polymerization by substituting with an acetyl group, a formyl group, a pivaloyl group or the like.

When copolymerizing hydroxystyrene or hydroxyvinylnaphthalene, acetoxystyrene or acetoxyvinylnaphthalene is used instead of hydroxystyrene or hydroxyvinylnaphthalene, and after polymerization, the acetoxy group is deprotected by the alkaline hydrolysis to deprotect hydroxystyrene or hydroxyvinyl. It may be naphthalene.

As the base for alkaline hydrolysis, aqueous ammonia, triethylamine and the like can be used. The reaction temperature is preferably −20 to 100 ° C., more preferably 0 to 60 ° C. The reaction time is preferably 0.2 to 100 hours, more preferably 0.5 to 20 hours.

The base polymer has a Mw of preferably 1,000 to 500,000, more preferably 2,000 to 30,000. When Mw is in the above range, the heat resistance of the resist film and the solubility in an alkaline developer are good.

Further, when Mw / Mn is wide in the base polymer, since a polymer having a low molecular weight or a high molecular weight is present, foreign matter may be seen on the pattern or the shape of the pattern may be deteriorated after exposure. As the pattern rule becomes finer, the influence of Mw and Mw / Mn tends to increase. Therefore, in order to obtain a resist material suitable for fine pattern dimensions, the Mw / Mn of the base polymer is 1.0. It is preferable that the dispersion is as narrow as 2.0, particularly 1.0 to 1.5.

The base polymer may contain two or more polymers having different composition ratios, Mw, and Mw / Mn.

[Acid generator]
The resist material of the present invention may contain an acid generator that generates a strong acid (hereinafter, also referred to as an additive-type acid generator). The strong acid here means a compound having sufficient acidity to cause a deprotection reaction of the acid unstable group of the base polymer in the case of a chemically amplified positive type resist material, and is used as a chemically amplified negative type resist. In the case of a material, it means a compound having sufficient acidity to cause a polarity change reaction or a cross-linking reaction due to an acid. By including such an acid generator, the resist material of the present invention can function as a chemically amplified positive resist material or a chemically amplified negative resist material.

Examples of the acid generator include compounds that generate an acid in response to active light rays or radiation (photoacid generator). The photoacid generator may be any compound that generates an acid by irradiation with high energy rays, but a compound that generates a sulfonic acid, an imide acid or a methidoic acid is preferable. Suitable photoacid generators include sulfonium salts, iodonium salts, sulfonyldiazomethanes, N-sulfonyloxyimides, oxime-O-sulfonate type acid generators and the like. Specific examples of the photoacid generator include those described in paragraphs [0122] to [0142] of JP-A-2008-11103.

Further, as the photoacid generator, a sulfonium salt represented by the following formula (1-1) and an iodonium salt represented by the following formula (1-2) can also be preferably used.

In the formulas (1-1) and (1-2), R ¹⁰¹ to R ¹⁰⁵ are hydrocarbyl groups having 1 to 20 carbon atoms which may independently contain a halogen atom or a hetero atom.

Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like.

The hydrocarbyl group having 1 to 20 carbon atoms represented by R ¹⁰¹ to R ¹⁰⁵ may be saturated or unsaturated, and may be linear, branched or cyclic. Specific examples thereof include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, n-hexyl group and n-. Alkyl groups having 1 to 20 carbon atoms such as octyl group, n-nonyl group, n-decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, heptadecyl group, octadecyl group, nonadecil group and icosyl group; Cyclic saturated hydrocarbyl group having 3 to 20 carbon atoms such as cyclopropyl group, cyclopentyl group, cyclohexyl group, cyclopropylmethyl group, 4-methylcyclohexyl group, cyclohexylmethyl group, norbornyl group, adamantyl group; vinyl group, propenyl group, Alkenyl groups such as butenyl group and hexenyl group; alkynyl groups having 2 to 20 carbon atoms such as ethynyl group, propynyl group and butyl group; cyclic unsaturated aliphatic hydrocarbyl having 3 to 20 carbon atoms such as cyclohexenyl group and norbornenyl group. Group; phenyl group, methylphenyl group, ethylphenyl group, n-propylphenyl group, isopropylphenyl group, n-butylphenyl group, isobutylphenyl group, sec-butylphenyl group, tert-butylphenyl group, naphthyl group, methylnaphthyl Group, ethylnaphthyl group, n-propylnaphthyl group, isopropylnaphthyl group, n-butylnaphthyl group, isobutylnaphthyl group, sec-butylnaphthyl group, tert-butylnaphthyl group and other aryl groups having 6 to 20 carbon atoms; benzyl group , An aralkyl group having 7 to 20 carbon atoms such as a phenethyl group; a group obtained by combining these groups and the like can be mentioned.

Further, a part or all of the hydrogen atoms of these groups may be substituted with heteroatom-containing groups such as oxygen atom, sulfur atom, nitrogen atom and halogen atom, and a part of carbon atoms of these groups may be substituted. , Oxygen atom, sulfur atom, nitrogen atom and the like may be substituted with a hetero atom-containing group, and as a result, a hydroxy group, a cyano group, a nitro group, a carbonyl group, an ether bond, an ester bond, a sulfonic acid ester bond, a carbonate. It may contain a bond, a lactone ring, a sulton ring, a carboxylic acid anhydride, a haloalkyl group and the like.

（式中、破線は、Ｒ¹⁰³との結合手である。） Further, R ¹⁰¹ and R ¹⁰² may be bonded to each other to form a ring together with the sulfur atom to which they are bonded. At this time, the ring having the following structure is preferable.

(In the formula, the broken line is the bond with R ^103. )

Examples of the cation of the sulfonium salt represented by the formula (1-1) include, but are not limited to, those shown below.

Examples of the cation of the iodonium salt represented by the formula (1-2) include, but are not limited to, those shown below.

In the formulas (1-1) and (1-2), Xa ^- is an anion selected from the following formulas (1A) to (1D).

In the formula (1A), R ^fa is a hydrocarbyl group having 1 to 40 carbon atoms which may contain a fluorine atom or a hetero atom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched or cyclic. Specific examples thereof include the same as those exemplified as the hydrocarbyl group represented by ^R111 of the formula (1A') described later.

As the anion represented by the formula (1A), the anion represented by the following formula (1A') is preferable.

In formula (1A'), ^RHF is a hydrogen atom or a trifluoromethyl group, preferably a trifluoromethyl group. R ¹¹¹ is a hydrocarbyl group having 1 to 38 carbon atoms which may contain a heteroatom. As the hetero atom, an oxygen atom, a nitrogen atom, a sulfur atom, a halogen atom and the like are preferable, and an oxygen atom is more preferable. The hydrocarbyl group is particularly preferably one having 6 to 30 carbon atoms from the viewpoint of obtaining high resolution in fine pattern formation.

The hydrocarbyl group represented by R ¹¹¹ may be saturated or unsaturated, and may be linear, branched or cyclic. Specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a neopentyl group, a hexyl group, a heptyl group and a 2-ethylhexyl group. , Nonyl group, undecyl group, tridecyl group, pentadecyl group, heptadecyl group, icosanyl group and other alkyl groups having 1 to 38 carbon atoms; cyclopentyl group, cyclohexyl group, 1-adamantyl group, 2-adamantyl group, 1-adamantylmethyl group , Norbornyl group, Norbornylmethyl group, Tricyclodecanyl group, Tetracyclododecanyl group, Tetracyclododecanylmethyl group, Dicyclohexylmethyl group and other cyclic saturated hydrocarbyl groups having 3 to 38 carbon atoms; allyl group, 3 -Unsaturated aliphatic hydrocarbyl group having 2 to 38 carbon atoms such as cyclohexenyl group; aryl group having 6 to 38 carbon atoms such as phenyl group, 1-naphthyl group and 2-naphthyl group; benzyl group, diphenylmethyl group and the like. An aralkyl group having 7 to 38 carbon atoms; a group obtained by combining these groups and the like can be mentioned.

Further, a part or all of the hydrogen atoms of these groups may be substituted with heteroatom-containing groups such as oxygen atom, sulfur atom, nitrogen atom and halogen atom, and a part of carbon atoms of these groups may be substituted. , Oxygen atom, sulfur atom, nitrogen atom and the like may be substituted with a hetero atom-containing group, and as a result, a hydroxy group, a cyano group, a carbonyl group, an ether bond, an ester bond, a sulfonic acid ester bond, a carbonate bond, a lactone. It may contain a ring, a sulton ring, a carboxylic acid anhydride, a haloalkyl group and the like. Hydrocarbyl groups containing a hetero atom include a tetrahydrofuryl group, a methoxymethyl group, an ethoxymethyl group, a methylthiomethyl group, an acetamidemethyl group, a trifluoroethyl group, a (2-methoxyethoxy) methyl group, an acetoxymethyl group and a 2-carboxy group. Examples thereof include a -1-cyclohexyl group, a 2-oxopropyl group, a 4-oxo-1-adamantyl group, a 3-oxocyclohexyl group and the like.

Regarding the synthesis of a sulfonium salt containing an anion represented by the formula (1A'), JP-A-2007-145977, JP-A-2008-106045, JP-A-2009-7327, and JP-A-2009-258695 And so on. Further, the sulfonium salts described in JP-A-2010-215608, JP-A-2012-41320, JP-A-2012-106986, JP-A-2012-153644 and the like are also preferably used.

Examples of the anion represented by the formula (1A) include the same as those exemplified as the anion represented by the formula (1A) in JP-A-2018-197853.

In the formula (1B), R ^fb1 and R ^fb2 are hydrocarbyl groups having 1 to 40 carbon atoms which may independently contain a fluorine atom or a hetero atom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched or cyclic. Specific examples thereof include the same as those exemplified as the hydrocarbyl group represented by R ¹¹¹ in the formula (1A'). R ^fb1 and R ^fb2 are preferably a fluorine atom or a linear fluorinated alkyl group having 1 to 4 carbon atoms. Further, R ^fb1 and R ^fb2 may be bonded to each other to form a ring together with a group (-CF ₂ -SO ₂ -N ^--- SO ₂ -CF _2- ) to which they are bonded, and at this time, R may be formed. The group obtained by bonding ^fb1 and R ^fb2 to each other is preferably a fluorinated ethylene group or a fluorinated propylene group.

In the formula (1C), R ^fc1 , R ^fc2 and R ^fc3 are hydrocarbyl groups having 1 to 40 carbon atoms which may independently contain a fluorine atom or a heteroatom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched or cyclic. Specific examples thereof include the same as those exemplified as the hydrocarbyl group represented by R ¹¹¹ in the formula (1A'). R ^fc1 , R ^fc2 and R ^fc3 are preferably a fluorine atom or a linear fluorinated alkyl group having 1 to 4 carbon atoms. Further, R ^fc1 and R ^fc2 may be bonded to each other to form a ring together with a group (-CF ₂ -SO ₂ -C ^--- SO ₂ -CF _2- ) to which they are bonded, and at this time, R may be formed. The group obtained by bonding ^fc1 and R ^fc2 to each other is preferably a fluorinated ethylene group or a fluorinated propylene group.

In formula (1D), R ^fd is a hydrocarbyl group having 1 to 40 carbon atoms which may contain a heteroatom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched or cyclic. Specific examples thereof include the same as those exemplified as the hydrocarbyl group represented by R ¹¹¹ in the formula (1A').

The synthesis of a sulfonium salt containing an anion represented by the formula (1D) is described in detail in JP-A-2010-215608 and JP-A-2014-133723.

Examples of the anion represented by the formula (1D) include the same as those exemplified as the anion represented by the formula (1D) in JP-A-2018-197853.

The photoacid generator containing an anion represented by the formula (1D) does not have a fluorine atom at the α-position of the sulfo group, but has two trifluoromethyl groups at the β-position. Due to this, it has sufficient acidity to cleave the acid unstable groups in the base polymer. Therefore, it can be used as a photoacid generator.

As the photoacid generator, those represented by the following formula (2) can also be preferably used.

In the formula (2), R ²⁰¹ and R ²⁰² are hydrocarbyl groups having 1 to 30 carbon atoms which may independently contain a halogen atom or a hetero atom, respectively. R ²⁰³ is a hydrocarbylene group having 1 to 30 carbon atoms which may contain a heteroatom. Further, any two of R ²⁰¹ , R ²⁰² and R ²⁰³ may be bonded to each other to form a ring together with the sulfur atom to which they are bonded. At this time, examples of the ring include those similar to those exemplified as the ring that can be formed together with the sulfur atom to which R ¹⁰¹ and R ¹⁰² are bonded in the description of the formula (1-1). ..

The hydrocarbyl group represented by R ²⁰¹ and R ²⁰² may be saturated or unsaturated, and may be linear, branched or cyclic. Specific examples thereof include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, tert-pentyl group, n-hexyl group and n-. Alkyl groups having 1 to 30 carbon atoms such as octyl group, 2-ethylhexyl group, n-nonyl group, n-decyl group; cyclopentyl group, cyclohexyl group, cyclopentylmethyl group, cyclopentylethyl group, cyclopentylbutyl group, cyclohexylmethyl group, Cyclic saturated hydrocarbyl group having 3 to 30 carbon atoms such as cyclohexylethyl group, cyclohexylbutyl group, norbornyl group, oxanorbornyl group, tricyclo [5.2.1.10 ^2,6 ] decanyl group, adamantyl group; phenyl Group, methylphenyl group, ethylphenyl group, n-propylphenyl group, isopropylphenyl group, n-butylphenyl group, isobutylphenyl group, sec-butylphenyl group, tert-butylphenyl group, naphthyl group, methylnaphthyl group, ethyl An aryl group having 6 to 30 carbon atoms such as a naphthyl group, an n-propylnaphthyl group, an isopropylnaphthyl group, an n-butylnaphthyl group, an isobutylnaphthyl group, a sec-butylnaphthyl group, a tert-butylnaphthyl group, and an anthracenyl group; Examples thereof include groups obtained in combination. Further, a part or all of the hydrogen atoms of these groups may be substituted with heteroatom-containing groups such as oxygen atom, sulfur atom, nitrogen atom and halogen atom, and a part of carbon atoms of these groups may be substituted. , Oxygen atom, sulfur atom, nitrogen atom and the like may be substituted with a hetero atom-containing group, and as a result, a hydroxy group, a cyano group, a carbonyl group, an ether bond, an ester bond, a sulfonic acid ester bond, a carbonate bond, a lactone. It may contain a ring, a sulton ring, a carboxylic acid anhydride, a haloalkyl group and the like.

The hydrocarbylene group represented by R ²⁰³ may be saturated or unsaturated, and may be linear, branched or cyclic. Specific examples thereof include a methanediyl group, an ethane-1,1-diyl group, an ethane-1,2-diyl group, a propane-1,3-diyl group, a butane-1,4-diyl group, and a pentane-1,5. -Diyl group, hexane-1,6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonan-1,9-diyl group, decane-1,10-diyl group, undecane -1,11-diyl group, dodecane-1,12-diyl group, tridecane-1,13-diyl group, tetradecane-1,14-diyl group, pentadecane-1,15-diyl group, hexadecane-1,16- Alcandiyl group having 1 to 30 carbon atoms such as diyl group and heptadecane-1,17-diyl group; cyclically saturated group having 3 to 30 carbon atoms such as cyclopentanediyl group, cyclohexanediyl group, norbornandyl group and adamantandiyl group. Hydrocarbylene group; phenylene group, methylphenylene group, ethylphenylene group, n-propylphenylene group, isopropylphenylene group, n-butylphenylene group, isobutylphenylene group, sec-butylphenylene group, tert-butylphenylene group, naphthylene group. , Methylnaphthylene group, ethylnaphthylene group, n-propylnaphthylene group, isopropylnaphthylene group, n-butylnaphthylene group, isobutylnaphthylene group, sec-butylnaphthylene group, tert-butylnaphthylene group and other arylene groups having 6 to 30 carbon atoms. An example is a group obtained by combining these. Further, a part or all of the hydrogen atoms of these groups may be substituted with heteroatom-containing groups such as oxygen atom, sulfur atom, nitrogen atom and halogen atom, and a part of carbon atoms of these groups may be substituted. , Oxygen atom, sulfur atom, nitrogen atom and the like may be substituted with a hetero atom-containing group, and as a result, a hydroxy group, a cyano group, a carbonyl group, an ether bond, an ester bond, a sulfonic acid ester bond, a carbonate bond, a lactone. It may contain a ring, a sulton ring, a carboxylic acid anhydride, a haloalkyl group and the like. As the hetero atom, an oxygen atom is preferable.

In formula (2), ^LA is a hydrocarbylene group having 1 to 20 carbon atoms which may contain a single bond, an ether bond, or a heteroatom. The hydrocarbylene group may be saturated or unsaturated, and may be linear, branched or cyclic. Specific examples thereof include the same as those exemplified as the hydrocarbylene group represented by R ²⁰³ .

In formula (2), X ^A , X ^B , X ^C and X ^D are independently hydrogen atoms, fluorine atoms or trifluoromethyl groups, respectively. However, at least one of X ^A , X ^B , X ^C and X ^D is a fluorine atom or a trifluoromethyl group.

In equation (2), k is an integer of 0 to 3.

As the photoacid generator represented by the formula (2), the one represented by the following formula (2') is preferable.

In equation (2'), ^LA is the same as above. R ^HF is a hydrogen atom or a trifluoromethyl group, preferably a trifluoromethyl group. Each of R ³⁰¹ , R ³⁰² and R ³⁰³ is a hydrocarbyl group having 1 to 20 carbon atoms which may independently contain a hydrogen atom or a hetero atom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched or cyclic. Specific examples thereof include the same as those exemplified as the hydrocarbyl group represented by R ¹¹¹ in the formula (1A'). x and y are independently integers of 0 to 5, and z is an integer of 0 to 4.

Examples of the photoacid generator represented by the formula (2) include those similar to those exemplified as the photoacid generator represented by the formula (2) of JP-A-2017-026980.

Among the photoacid generators, those containing an anion represented by the formula (1A') or (1D) are particularly preferable because they have small acid diffusion and excellent solubility in a solvent. Further, the one represented by the formula (2') has extremely small acid diffusion and is particularly preferable.

As the photoacid generator, a sulfonium salt or an iodonium salt containing an anion having an aromatic ring substituted with an iodine atom or a bromine atom can also be used. Examples of such a salt include those represented by the following formula (3-1) or (3-2).

In the equations (3-1) and (3-2), p is an integer satisfying 1 ≦ p ≦ 3. q and r are integers that satisfy 1 ≦ q ≦ 5, 0 ≦ r ≦ 3 and 1 ≦ q + r ≦ 5. q is preferably an integer satisfying 1 ≦ q ≦ 3, and more preferably 2 or 3. r is preferably an integer satisfying 0 ≦ r ≦ 2.

In formulas (3-1) and (3-2), ^XBI is an iodine atom or a bromine atom, and when p and / or q is 2 or more, they may be the same or different from each other.

In formulas (3-1) and (3-2), L ¹ is a saturated hydrocarbylene group having 1 to 6 carbon atoms which may contain a single bond, an ether bond or an ester bond, or an ether bond or an ester bond. Is. The saturated hydrocarbylene group may be linear, branched or cyclic.

In formulas (3-1) and (3-2), L ² is a single bond or a divalent linking group having 1 to 20 carbon atoms when p is 1, and carbon when p is 2 or 3. It is a linking group having a (p + 1) valence of several 1 to 20, and the linking group may contain an oxygen atom, a sulfur atom or a nitrogen atom.

In formulas (3-1) and (3-2), ^R401 is a hydroxy group, a carboxy group, a fluorine atom, a chlorine atom, a bromine atom or an amino group, or a fluorine atom, a chlorine atom, a bromine atom, a hydroxy group, and an amino. A saturated hydrocarbyl group having 1 to 20 carbon atoms, a saturated hydrocarbyl oxy group having 1 to 20 carbon atoms, a saturated hydrocarbyl carbonyl group having 2 to 20 carbon atoms, and a saturated hydrocarbyl carbonyl group having 2 to 10 carbon atoms, which may contain a group or an ether bond. Hydrocarbyloxycarbonyl group, saturated hydrocarbylcarbonyloxy group with 2 to 20 carbon atoms or saturated hydrocarbyloxycarbonyl group with 1 to 20 carbon atoms, or -N (R ^401A ) (R ^401B ), -N (R ^401C ) -C ( = O) -R ^401D or -N (R ^401C ) -C (= O) ^{-OR 401D} . R ^401A and R ^401B are independently hydrogen atoms or saturated hydrocarbyl groups having 1 to 6 carbon atoms. R ^401C is a hydrogen atom or a saturated hydrocarbyl group having 1 to 6 carbon atoms, a halogen atom, a hydroxy group, a saturated hydrocarbyloxy group having 1 to 6 carbon atoms, a saturated hydrocarbylcarbonyl group having 2 to 6 carbon atoms or a saturated hydrocarbyl group having 2 carbon atoms. It may contain up to 6 saturated hydrocarbylcarbonyloxy groups. R ^401D is an aliphatic hydrocarbyl group having 1 to 16 carbon atoms, an aryl group having 6 to 14 carbon atoms or an aralkyl group having 7 to 15 carbon atoms, and has a halogen atom, a hydroxy group, and a saturated hydrocarbyloxy group having 1 to 6 carbon atoms. It may contain a group, a saturated hydrocarbylcarbonyl group having 2 to 6 carbon atoms or a saturated hydrocarbylcarbonyloxy group having 2 to 6 carbon atoms. The aliphatic hydrocarbyl group may be saturated or unsaturated, and may be linear, branched or cyclic. The saturated hydrocarbyl group, saturated hydrocarbyloxy group, saturated hydrocarbyloxycarbonyl group, saturated hydrocarbylcarbonyl group and saturated hydrocarbylcarbonyloxy group may be linear, branched or cyclic. When p and / or r is 2 or more, each R ⁴⁰¹ may be the same as or different from each other.

Of these, R ⁴⁰¹ includes hydroxy groups, -N (R ^401C ) -C (= O) -R ^401D , -N (R ^401C ) -C (= O) ^{-OR 401D} , fluorine atoms, and chlorine. Atoms, bromine atoms, methyl groups, methoxy groups and the like are preferable.

In formulas (3-1) and (3-2), Rf ¹ to Rf ⁴ are independently hydrogen atoms, fluorine atoms or trifluoromethyl groups, but at least one of them is a fluorine atom or trifluoromethyl group. It is a fluoromethyl group. Further, Rf ¹ and Rf 2 may be combined to form a carbonyl group. In particular, it is preferable that both Rf ³ and Rf ⁴ are fluorine atoms.

In formulas (3-1) and (3-2), R ⁴⁰² to R ⁴⁰⁶ are hydrocarbyl groups having 1 to 20 carbon atoms which may independently contain a halogen atom or a hetero atom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched or cyclic. Specific examples thereof include those similar to those exemplified as the hydrocarbyl group represented by R ¹⁰¹ to R ¹⁰⁵ in the description of the formulas (1-1) and (1-2). Further, a part or all of the hydrogen atoms of these groups may be substituted with a hydroxy group, a carboxy group, a halogen atom, a cyano group, a nitro group, a mercapto group, a sulton group, a sulfone group or a sulfonium salt-containing group. , Some of the carbon atoms of these groups may be substituted with ether bonds, ester bonds, carbonyl groups, amide bonds, carbonate bonds or sulfonic acid ester bonds. Further, R ⁴⁰² and R ⁴⁰³ may be bonded to each other to form a ring together with the sulfur atom to which they are bonded. At this time, examples of the ring include the same ring as that exemplified as a ring in which R ¹⁰¹ and R ¹⁰² are bonded to each other and can be formed together with the sulfur atom to which they are bonded in the description of the formula (1-1). ..

Examples of the cation of the sulfonium salt represented by the formula (3-1) include the same as those exemplified as the cation of the sulfonium salt represented by the formula (1-1). Further, as the cation of the iodonium salt represented by the formula (3-2), the same as those exemplified as the cation of the iodonium salt represented by the formula (1-2) can be mentioned.

Examples of the onium salt anion represented by the formula (3-1) or (3-2) include, but are not limited to, those shown below. In the following formula, X ^BI is the same as described above.

In the resist material of the present invention, the content of the additive-type acid generator is preferably 0.1 to 50 parts by mass, more preferably 1 to 40 parts by mass with respect to 100 parts by mass of the base polymer. The resist material of the present invention can function as a chemically amplified resist material when the base polymer contains a repeating unit f and / or contains an additive-type acid generator.

[Organic solvent]
The resist material of the present invention may contain an organic solvent. The organic solvent is not particularly limited as long as each component described above and each component described later can be dissolved. Examples of the organic solvent include ketones such as cyclohexanone, cyclopentanone, methyl-2-n-pentylketone and 2-heptanone described in paragraphs [0144] to [0145] of JP-A-2008-111103; 3 -Alcohols such as methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, diacetone alcohol; propylene glycol monomethyl ether, ethylene glycol monomethyl ether, propylene glycol mono Ethers such as ethyl ether, ethylene glycol monoethyl ether, propylene glycol dimethyl ether, diethylene glycol dimethyl ether; propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, ethyl lactate, ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, Esters such as ethyl 3-ethoxypropionate, tert-butyl acetate, tert-butyl propionate, propylene glycol mono tert-butyl ether acetate and the like; lactones such as γ-butyrolactone and the like can be mentioned.

In the resist material of the present invention, the content of the organic solvent is preferably 100 to 10,000 parts by mass, more preferably 200 to 8,000 parts by mass with respect to 100 parts by mass of the base polymer. The organic solvent can be used alone or in combination of two or more.

[Other ingredients]
In addition to the above-mentioned components, a quencher other than the ammonium salt and the fluorine atom-containing polymer (hereinafter, also referred to as other quenchers), a surfactant, a dissolution inhibitor, a cross-linking agent, etc. are appropriately combined according to the purpose. By blending to form a positive resist material and a negative resist material, the dissolution rate of the base polymer in the developing solution is accelerated by a catalytic reaction in the exposed part, so that the positive resist material and the negative type with extremely high sensitivity are formed. It can be a resist material. In this case, the resolution contrast and resolution of the resist film are high, there is an exposure margin, the process adaptability is excellent, the pattern shape after exposure is good, and acid diffusion can be suppressed in particular, so that the difference in coarseness and density is small. From these facts, it is highly practical and can be very effective as a resist material for VLSI.

Examples of the other quenching include conventional basic compounds. Conventional basic compounds include primary, secondary and tertiary aliphatic amines, mixed amines, aromatic amines, heterocyclic amines, nitrogen-containing compounds having a carboxy group, and sulfonyl groups. Examples thereof include a nitrogen-containing compound having a hydroxy group, a nitrogen-containing compound having a hydroxyphenyl group, an alcoholic nitrogen-containing compound, amides, imides, and carbamate. In particular, primary, secondary and tertiary amine compounds described in paragraphs [0146] to [0164] of JP-A-2008-111103, particularly hydroxy groups, ether bonds, ester bonds, lactone rings, and the like. A cyano group, an amine compound having a sulfonic acid ester bond, a compound having a carbamate group described in Japanese Patent No. 3790649, and the like are preferable. By adding such a basic compound, for example, the diffusion rate of the acid in the resist membrane can be further suppressed or the shape can be corrected.

As another example of the other quench, the amine compound having an aromatic group substituted with an iodine atom described in JP-A-2020-0227297 can be mentioned. This has a sensitizing effect due to the large absorption of EUV, and has a high acid diffusion control effect due to the large molecular weight.

As another example of the other quench, the onium salt such as a sulfonium salt, an iodonium salt, an ammonium salt, etc. of a sulfonic acid and a carboxylic acid whose α-position is not fluorinated described in JP-A-2008-158339 can be mentioned. Be done. Sulphonic acid, imidoic acid or methidoic acid with fluorinated α-position is required to deprotect the acid unstable groups of carboxylic acid esters, but salt exchange with onium salts with non-fluorinated α-position. Releases a sulfonic acid or carboxylic acid whose α-position is not fluorinated. Sulfonic acids and carboxylic acids whose α-position is not fluorinated do not undergo a deprotection reaction and therefore function as a quencher.

Examples of such a quencher include a compound represented by the following formula (4) (onium salt of a sulfonic acid whose α-position is not fluorinated) and a compound represented by the following formula (5) (carboxylic acid). Onium salt).

In the formula (4), R ⁵⁰¹ is a hydrocarbyl group having 1 to 40 carbon atoms which may contain a hydrogen atom or a hetero atom, and the hydrogen atom bonded to the α-position carbon atom of the sulfo group is a fluorine atom. Or, those substituted with a fluoroalkyl group are excluded.

The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched or cyclic. Specific examples thereof include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, tert-pentyl group, n-pentyl group, n-hexyl group and n-. Alkyl groups such as octyl group, 2-ethylhexyl group, n-nonyl group, n-decyl group; cyclopentyl group, cyclohexyl group, cyclopentylmethyl group, cyclopentylethyl group, cyclopentylbutyl group, cyclohexylmethyl group, cyclohexylethyl group, cyclohexylbutyl Cyclic saturated hydrocarbyl group such as group, norbornyl group, tricyclo [5.2.1.0 ^2,6 ] decanyl group, adamantyl group, adamantylmethyl group; vinyl group, allyl group, propenyl group, butenyl group, hexenyl group, etc. Alkenyl group; Cyclic unsaturated aliphatic hydrocarbyl group such as cyclohexenyl group; Phenyl group, naphthyl group, alkylphenyl group (2-methylphenyl group, 3-methylphenyl group, 4-methylphenyl group, 4-ethylphenyl) Group, 4-tert-butylphenyl group, 4-n-butylphenyl group, etc.), Dialkylphenyl group (2,4-dimethylphenyl group, 2,4,6-triisopropylphenyl group, etc.), alkylnaphthyl group (methyl) Aryl groups such as naphthyl group, ethylnaphthyl group, etc.), dialkylnaphthyl groups (dimethylnaphthyl group, diethylnaphthyl group, etc.); heteroaryl groups such as thienyl group; benzyl group, 1-phenylethyl group, 2-phenylethyl group, etc. The Aralkill group of.

Further, a part of the hydrogen atom of these groups may be substituted with a hetero atom-containing group such as an oxygen atom, a sulfur atom, a nitrogen atom and a halogen atom, and a part of the carbon atom of these groups is an oxygen atom. It may be substituted with a hetero atom-containing group such as a sulfur atom or a nitrogen atom, and as a result, a hydroxy group, a cyano group, a carbonyl group, an ether bond, an ester bond, a sulfonic acid ester bond, a carbonate bond, a lactone ring, or a sulton ring. , Carous acid anhydride, haloalkyl group and the like may be contained. Hydrocarbyl groups containing heteroatoms include 4-hydroxyphenyl group, 4-methoxyphenyl group, 3-methoxyphenyl group, 2-methoxyphenyl group, 4-ethoxyphenyl group, 4-tert-butoxyphenyl group and 3-tert. -Alkoxyphenyl group such as butoxyphenyl group; alkoxynaphthyl group such as methoxynaphthyl group, ethoxynaphthyl group, n-propoxynaphthyl group, n-butoxynaphthyl group; dialkoxynaphthyl group such as dimethoxynaphthyl group and diethoxynaphthyl group; An aryloxoalkyl group such as a 2-aryl-2-oxoethyl group such as a 2-phenyl-2-oxoethyl group, a 2- (1-naphthyl) -2-oxoethyl group, and a 2- (2-naphthyl) -2-oxoethyl group. And so on.

In formula (5), R ⁵⁰² is a hydrocarbyl group having 1 to 40 carbon atoms which may contain a heteroatom. Examples of the hydrocarbyl group represented by R ⁵⁰² include the same groups as those exemplified as the hydrocarbyl group represented by R ⁵⁰¹ . Further, as other specific examples, a trifluoromethyl group, a trifluoroethyl group, a 2,2,2-trifluoro-1-methyl-1-hydroxyethyl group, 2,2,2-trifluoro-1- (tri). Fluoromethyl-containing alkyl groups such as fluoromethyl) -1-hydroxyethyl group; fluorine-containing aryl groups such as pentafluorophenyl group and 4-trifluoromethylphenyl group may also be mentioned.

In formulas (4) and (5), Mq ⁺ is an onium cation. As the onium cation, a sulfonium cation, an iodonium cation or an ammonium cation is preferable, and a sulfonium cation or an iodonium cation is more preferable. Examples of the sulfonium cation include those similar to those exemplified as the cation of the sulfonium salt represented by the formula (1-1). In addition, examples of the iodonium cation include those similar to those exemplified as the cation of the iodonium salt represented by the formula (1-2).

As the quencher, a sulfonium salt of an iodinated benzene ring-containing carboxylic acid represented by the following formula (6) can also be preferably used.

In equation (6), x'is an integer from 1 to 5. y'is an integer from 0 to 3. z'is an integer of 1 to 3.

In formula (6), R ⁶⁰¹ may have a hydroxy group, a fluorine atom, a chlorine atom, a bromine atom, an amino group, a nitro group, a cyano group, or a part or all of a hydrogen atom substituted with a halogen atom. Saturated hydrocarbyl group with 1 to 6 carbon atoms, saturated hydrocarbylviroxy group with 1 to 6 carbon atoms, saturated hydrocarbylcarbonyloxy group with 2 to 6 carbon atoms or saturated hydrocarbylbutyloxy group with 1 to 4 carbon atoms, or -N (R). ^601A ) -C (= O) -R ^601B or -N (R ^601A ) -C (= O) ^{-OR 601B} . R ^601A is a hydrogen atom or a saturated hydrocarbyl group having 1 to 6 carbon atoms. R ^601B is a saturated hydrocarbyl group having 1 to 6 carbon atoms or an unsaturated aliphatic hydrocarbyl group having 2 to 8 carbon atoms.

In formula (6), L ¹¹ is a single bond or a (z'+ 1) valent linking group having 1 to 20 carbon atoms, and is an ether bond, a carbonyl group, an ester bond, an amide bond, a sultone ring, a lactam ring, or a carbonate. It may contain a bond, a halogen atom, a hydroxy group or a carboxy group. The saturated hydrocarbyl group, saturated hydrocarbyloxy group, saturated hydrocarbylcarbonyloxy group and saturated hydrocarbylsulfonyloxy group may be linear, branched or cyclic. When y'and / or z'are 2 or more, each R ⁶⁰¹ may be the same as or different from each other.

In formula (6), R ⁶⁰² , R ⁶⁰³ and R ⁶⁰⁴ are hydrocarbyl groups having 1 to 20 carbon atoms which may independently contain a halogen atom or a hetero atom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched or cyclic. Specific examples thereof include the same as those exemplified as the hydrocarbyl groups represented by R ¹⁰¹ to R ¹⁰⁵ in the formulas (1-1) and (1-2). Further, a part or all of the hydrogen atoms of these groups may be substituted with a hydroxy group, a carboxy group, a halogen atom, an oxo group, a cyano group, a nitro group, a sulton group, a sulfone group or a sulfonium salt-containing group. , Some of the carbon atoms of these groups may be substituted with ether bonds, ester bonds, carbonyl groups, amide bonds, carbonate bonds or sulfonic acid ester bonds. Further, R ⁶⁰² and R ⁶⁰³ may be bonded to each other to form a ring together with the sulfur atom to which they are bonded.

Specific examples of the compound represented by the formula (6) include those described in JP-A-2017-219836. This is also highly absorbed, has a high sensitizing effect, and has a high acid diffusion control effect.

As another example of the other quencher, the polymer type quencher described in JP-A-2008-239918 can be mentioned. This enhances the rectangularity of the resist after the pattern by orienting it on the surface of the resist film after the resist material is applied. The polymer-type quencher also has the effect of preventing the film loss of the pattern and the rounding of the pattern top when the protective film for immersion exposure is applied.

When the resist material of the present invention contains other quenchers, the content thereof is preferably 0 to 5 parts by mass, more preferably 0 to 4 parts by mass with respect to 100 parts by mass of the base polymer. The other quenchers can be used alone or in combination of two or more.

Examples of the surfactant include those described in paragraphs [0165] to [0166] of JP-A-2008-111103. By adding a surfactant, the coatability of the resist material can be further improved or controlled. When the resist material of the present invention contains the surfactant, the content thereof is preferably 0.0001 to 10 parts by mass with respect to 100 parts by mass of the base polymer. The surfactant can be used alone or in combination of two or more.

When the resist material of the present invention is of the positive type, the difference in dissolution rate between the exposed portion and the unexposed portion can be further increased by adding a dissolution inhibitor, and the resolution can be further improved. .. As the dissolution inhibitor, the hydrogen atom of the phenolic hydroxy group of the compound having a molecular weight of preferably 100 to 1,000, more preferably 150 to 800 and containing two or more phenolic hydroxy groups in the molecule is acid. A compound substituted with an unstable group at a ratio of 0 to 100 mol% as a whole, or a compound containing a carboxy group in the molecule, the hydrogen atom of the carboxy group is replaced with an acid unstable group at an average ratio of 50 to 100 mol% as a whole. Examples thereof include compounds substituted with. Specific examples thereof include bisphenol A, trisphenol, phenolphthaline, cresol novolac, naphthalenecarboxylic acid, adamantancarboxylic acid, hydroxy group of cholic acid, and compounds in which the hydrogen atom of the carboxy group is replaced with an acid unstable group. For example, it is described in paragraphs [0155] to [0178] of JP-A-2008-122932.

When the resist material of the present invention is a positive resist material and contains the dissolution inhibitor, the content thereof is preferably 0 to 50 parts by mass, more preferably 5 to 40 parts by mass with respect to 100 parts by mass of the base polymer. .. The dissolution inhibitor may be used alone or in combination of two or more.

On the other hand, when the resist material of the present invention is a negative type, a negative pattern can be obtained by reducing the dissolution rate of the exposed portion by adding a cross-linking agent. The cross-linking agent includes an epoxy compound, a melamine compound, a guanamine compound, a glycoluryl compound or a urea compound, an isocyanate compound, and an azido compound substituted with at least one group selected from a methylol group, an alkoxymethyl group and an acyloxymethyl group. , Compounds containing a double bond such as an alkenyloxy group, and the like. These may be used as additives or may be introduced as pendant groups in the polymer side chains. Further, a compound containing a hydroxy group can also be used as a cross-linking agent.

Examples of the epoxy compound include tris (2,3-epoxypropyl) isocyanate, trimethylolmethane triglycidyl ether, trimethylolpropane triglycidyl ether, and trimethylolethane triglycidyl ether.

Examples of the melamine compound include a compound in which 1 to 6 methylol groups of hexamethylol melamine, hexamethoxymethyl melamine, and hexamethylol melamine are methoxymethylated or a mixture thereof, hexamethoxyethyl melamine, hexaacyloxymethyl melamine, and hexamethylol melamine. Examples thereof include a compound in which 1 to 6 methylol groups of the above are acyloxymethylated, or a mixture thereof.

Examples of the guanamine compound include a compound in which 1 to 4 methylol groups of tetramethylol guanamine, tetramethoxymethyl guanamine, and tetramethylol guanamine are methoxymethylated or a mixture thereof, and one of tetramethoxyethyl guanamine, tetraacyloxyguanamine, and tetramethylol guanamine. Examples thereof include a compound in which up to 4 methylol groups are acyloxymethylated, or a mixture thereof.

Examples of the glycol uryl compound include tetramethylol glycol uryl, tetramethoxyglycol uryl, tetramethoxymethyl glycol uryl, and a compound in which 1 to 4 of the methylol groups of tetramethylol glycol uryl are methoxymethylated or a mixture thereof, and methylol of tetramethylol glycol uril. Examples thereof include a compound in which 1 to 4 groups are acyloxymethylated or a mixture thereof. Examples of the urea compound include tetramethylol urea, tetramethoxymethylurea, a compound in which 1 to 4 methylol groups of tetramethylol urea are methoxymethylated, or a mixture thereof, and tetramethoxyethylurea.

Examples of the isocyanate compound include tolylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, cyclohexane diisocyanate and the like.

Examples of the azide compound include 1,1'-biphenyl-4,4'-bis azide, 4,4'-methylidene bis azide, and 4,4'-oxybis azide.

Examples of the compound containing an alkenyloxy group include ethylene glycol divinyl ether, triethylene glycol divinyl ether, 1,2-propanediol divinyl ether, 1,4-butanediol divinyl ether, tetramethylene glycol divinyl ether, and neopentyl glycol divinyl ether. Examples thereof include trimethylol propanetrivinyl ether, hexanediol divinyl ether, 1,4-cyclohexanediol divinyl ether, pentaerythritol trivinyl ether, pentaerythritol tetravinyl ether, sorbitol tetravinyl ether, sorbitol pentavinyl ether, and trimethylolpropanetrivinyl ether.

When the resist material of the present invention is a negative resist material and contains a cross-linking agent, the content thereof is preferably 0.1 to 50 parts by mass, more preferably 1 to 40 parts by mass with respect to 100 parts by mass of the base polymer. .. The cross-linking agent can be used alone or in combination of two or more.

Acetylene alcohols can also be added to the resist material of the present invention. Examples of the acetylene alcohols include those described in paragraphs [0179] to [0182] of JP-A-2008-122932. When the resist material of the present invention contains acetylene alcohols, the content thereof is preferably 0 to 5 parts by mass with respect to 100 parts by mass of the base polymer. The acetylene alcohols may be used alone or in combination of two or more.

[Pattern formation method]
When the resist material of the present invention is used for manufacturing various integrated circuits, known lithography techniques can be applied. For example, as a pattern forming method, a step of forming a resist film on a substrate using the above-mentioned resist material, a step of exposing the resist film with high energy rays, and a step of exposing the exposed resist film with a developing solution are used. Examples thereof include a method including a step of developing.

First, the resist material of the present invention is applied to a substrate for manufacturing an integrated circuit (Si, SiO ₂ , SiN, SiON, TiN, WSi, BPSG, SOG, an organic antireflection film, etc.) or a substrate for manufacturing a mask circuit (Cr, CrO). , CrON, MoSi ₂ , SiO ₂ etc.) by an appropriate coating method such as spin coating, roll coating, flow coating, dip coating, spray coating, doctor coating, etc. so that the coating film thickness is 0.01 to 2 μm. do. This is prebaked on a hot plate at preferably 60 to 150 ° C. for 10 seconds to 30 minutes, more preferably 80 to 120 ° C. for 30 seconds to 20 minutes to form a resist film.

The resist film is then exposed using high energy rays. Examples of the high energy rays include ultraviolet rays, far ultraviolet rays, EB, EUV having a wavelength of 3 to 15 nm, X-rays, soft X-rays, excimer laser light, γ-rays, synchrotron radiation and the like. When ultraviolet rays, far ultraviolet rays, EUV, X-rays, soft X-rays, excimer laser light, γ-rays, synchrotron radiation, etc. are used as the high-energy rays, a mask for directly or forming a desired pattern is used. Irradiation is performed so that the exposure amount is preferably about 1 to 200 mJ / cm ² , and more preferably about 10 to 100 mJ / cm ² . When EB is used as a high energy ray, a mask for directly or forming a target pattern is used with an exposure amount of preferably about 0.1 to 100 μC / cm ² , more preferably about 0.5 to 50 μC / cm ² . Draw using. The resist material of the present invention is particularly suitable for fine patterning by KrF excimer laser light, ArF excimer laser light, EB, EUV, X-ray, soft X-ray, γ-ray, and synchrotron radiation among high-energy rays. It is particularly suitable for fine patterning by EB or EUV.

After exposure, post-exposure baking (PEB) may be performed on a hot plate or in an oven, preferably at 60 to 150 ° C. for 10 seconds to 30 minutes, more preferably at 80 to 120 ° C. for 30 seconds to 20 minutes.

After exposure or PEB, 0.1 to 10% by mass, preferably 2 to 5% by mass of alkalis such as tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide, tetrapropylammonium hydroxide, and tetrabutylammonium hydroxide. Using an aqueous developer, develop a resist film exposed by a conventional method such as a dip method, a puddle method, or a spray method for 3 seconds to 3 minutes, preferably 5 seconds to 2 minutes. As a result, the desired pattern is formed. In the case of the positive resist material, the portion irradiated with light is dissolved in the developing solution, the portion not exposed is not dissolved, and the desired positive pattern is formed on the substrate. In the case of the negative resist material, the opposite is true of the positive resist material, that is, the light-irradiated portion is insoluble in the developer and the unexposed portion is dissolved.

Negative development to obtain a negative pattern by organic solvent development can also be performed using a positive resist material containing a base polymer containing an acid unstable group. The developing solution used at this time is 2-octanone, 2-nonanone, 2-heptanone, 3-heptanone, 4-heptanone, 2-hexanone, 3-hexanone, diisobutylketone, methylcyclohexanone, acetophenone, methylacetphenone, propyl acetate. , Butyl acetate, Isobutyl acetate, Pentyl acetate, Butenyl acetate, Isopentyl acetate, propyl formate, Butyl formate, Isobutyl formate, Pentyl formate, Isopentyl formate, Methyl valerate, Methyl pentate, Methyl crotonate, Ethyl crotonate, Methyl propionate , Ethyl propionate, ethyl 3-ethoxypropionate, methyl lactate, ethyl lactate, propyl lactate, butyl lactate, isobutyl lactate, pentyl lactate, isopentyl lactate, methyl 2-hydroxyisobutyrate, ethyl 2-hydroxyisobutyrate, methyl benzoate , Ethyl benzoate, phenyl acetate, benzyl acetate, methyl phenylacetate, benzyl formate, phenylethyl formate, methyl 3-phenylpropionate, benzyl propionate, ethyl phenylacetate, 2-phenylethyl acetate and the like. These organic solvents can be used alone or in admixture of two or more.

Rinse at the end of development. As the rinsing solution, a solvent that is miscible with the developing solution and does not dissolve the resist film is preferable. As such a solvent, an alcohol having 3 to 10 carbon atoms, an ether compound having 8 to 12 carbon atoms, an alkane having 6 to 12 carbon atoms, an alkene, an alkyne, and an aromatic solvent are preferably used.

Specifically, examples of the alcohol having 3 to 10 carbon atoms include n-propyl alcohol, isopropyl alcohol, 1-butyl alcohol, 2-butyl alcohol, isobutyl alcohol, tert-butyl alcohol, 1-pentanol and 2-pentanol. 3-Pentanol, tert-pentyl 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-pen Tanol, 2-methyl-2-pentanol, 2-methyl-3-pentanol, 3-methyl-1-pentanol, 3-methyl-2-pentanol, 3-methyl-3-pentanol, 4-methyl Examples thereof include -1-pentanol, 4-methyl-2-pentanol, 4-methyl-3-pentanol, cyclohexanol, 1-octanol and the like.

Examples of the ether compound having 8 to 12 carbon atoms include di-n-butyl ether, diisobutyl ether, di-sec-butyl ether, di-n-pentyl ether, diisopentyl ether, di-sec-pentyl ether, and di-tert-pentyl. Examples thereof include ether and di-n-hexyl ether.

Examples of alkanes having 6 to 12 carbon atoms include hexane, heptane, octane, nonane, decane, undecane, dodecane, methylcyclopentane, dimethylcyclopentane, cyclohexane, methylcyclohexane, dimethylcyclohexane, cycloheptane, cyclooctane, cyclononane and the like. Be done. Examples of the alkene having 6 to 12 carbon atoms include hexene, heptene, octene, cyclohexene, methylcyclohexene, dimethylcyclohexene, cycloheptene, cyclooctene and the like. Examples of the alkyne having 6 to 12 carbon atoms include hexyne, heptyne, octyne and the like.

Examples of the aromatic solvent include toluene, xylene, ethylbenzene, isopropylbenzene, tert-butylbenzene, mesitylene and the like.

By rinsing, it is possible to reduce the occurrence of the resist pattern collapse and defects. In addition, rinsing is not always essential, and the amount of solvent used can be reduced by not rinsing.

The developed hole pattern or trench pattern can also be shrunk by thermal flow, RELACS technology or DSA technology. A shrink agent is applied onto the hole pattern, and the diffusion of the acid catalyst from the resist layer in the bake causes cross-linking of the shrink agent on the surface of the resist, and the shrink agent adheres to the side wall of the hole pattern. The bake temperature is preferably 70 to 180 ° C., more preferably 80 to 170 ° C., and the bake time is preferably 10 to 300 seconds, removing excess shrink agent and reducing the hole pattern.

Hereinafter, the present invention will be specifically described with reference to synthetic examples, comparative synthetic examples, examples and comparative examples, but the present invention is not limited to the following examples.

[1] Monomer synthesis [Synthesis Examples 1-1 to 1-12, Comparative Synthesis Example 1-1]
2- (Dimethylamino) ethyl methacrylate and N-[(trifluoromethyl) sulfonyl] -2,3,5-triiodobenzamide are mixed at a ratio of 1: 1 (molar ratio) to obtain the monomer M-1. rice field. Similarly, a monomer containing a nitrogen atom is mixed with a sulfonamide compound having a benzene ring substituted with an iodine atom or trifluoroacetic acid for comparative examples, and the monomers M-2 to M-12 and the monomer cM-1 are mixed. Got

[2] Polymer Synthesis The structures of the fluorine atom-containing monomers FM-1 to FM-11 and the PAG monomer PM-1 used in the synthesis of the polymer are shown below.

[Synthesis Example 2-1] Synthesis of Polymer AP-1 To a 2L flask, 7.8 g of M-1 and 26.5 g of FM-1 and 60 g of THF as a solvent were added. The reaction vessel was cooled to −70 ° C. under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated 3 times. After raising the temperature to room temperature, 1.2 g of AIBN was added as a polymerization initiator, the temperature was raised to 60 ° C., and the mixture was reacted for 15 hours. This reaction solution was added to 1 L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60 ° C. to obtain polymer AP-1. The composition of AP-1 was confirmed by ¹³ C-NMR and ¹ H-NMR, and Mw and Mw / Mn were confirmed by GPC.

[Synthesis Example 2-2] Synthesis of Polymer AP-2 In a 2L flask, 7.8 g of M-1 and 20.8 g of FM-1 and methacrylic acid 3,3,4,4,5,5,6,6 6.6 g of 6-nonafluorohexyl and 60 g of THF as a solvent were added. The reaction vessel was cooled to −70 ° C. under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated 3 times. After raising the temperature to room temperature, 1.2 g of AIBN was added as a polymerization initiator, the temperature was raised to 60 ° C., and the mixture was reacted for 15 hours. This reaction solution was added to 1 L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60 ° C. to obtain a polymer AP-2. The composition of AP-2 was confirmed by ¹³ C-NMR and ¹ H-NMR, and Mw and Mw / Mn were confirmed by GPC.

[Synthesis Example 2-3] Synthesis of Polymer AP-3 In a 2L flask, 8.6 g of M-2, 20.8 g of FM-1, 6.0 g of methacrylic acid 1H, 1H, 5H-octafluoropentyl and a solvent. As a result, 60 g of THF was added. The reaction vessel was cooled to −70 ° C. under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated 3 times. After raising the temperature to room temperature, 1.2 g of AIBN was added as a polymerization initiator, the temperature was raised to 60 ° C., and the mixture was reacted for 15 hours. This reaction solution was added to 1 L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60 ° C. to obtain a polymer AP-3. The composition of AP-3 was confirmed by ¹³ C-NMR and ¹ H-NMR, and Mw and Mw / Mn were confirmed by GPC.

[Synthesis Example 2-4] Synthesis of Polymer AP-4 In a 2L flask, 7.3 g of M-3, 34.0 g of FM-2, 6.0 g of methacrylic acid 1H, 1H, 5H-octafluoropentyl and a solvent. As a result, 60 g of THF was added. The reaction vessel was cooled to −70 ° C. under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated 3 times. After raising the temperature to room temperature, 1.2 g of AIBN was added as a polymerization initiator, the temperature was raised to 60 ° C., and the mixture was reacted for 15 hours. This reaction solution was added to 1 L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60 ° C. to obtain a polymer AP-4. The composition of AP-4 was confirmed by ¹³ C-NMR and ¹ H-NMR, and Mw and Mw / Mn were confirmed by GPC.

[Synthesis Example 2-5] Synthesis of Polymer AP-5 In a 2L flask, 7.9 g of M-4, 24.0 g of FM-3, and 1,1,1,1,3,3,3-hexafluoroisopropyl methacrylate. 7.1 g and 60 g of THF as a solvent were added. The reaction vessel was cooled to −70 ° C. under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated 3 times. After raising the temperature to room temperature, 1.2 g of AIBN was added as a polymerization initiator, the temperature was raised to 60 ° C., and the mixture was reacted for 15 hours. This reaction solution was added to 1 L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60 ° C. to obtain a polymer AP-5. The composition of AP-5 was confirmed by ¹³ C-NMR and ¹ H-NMR, and Mw and Mw / Mn were confirmed by GPC.

[Synthesis Example 2-6] Synthesis of Polymer AP-6 In a 2L flask, 7.0 g of M-5, 18.0 g of FM-4, and 1,1,1,1,3,3,3-hexafluoroisopropyl methacrylate. 7.1 g and 60 g of THF as a solvent were added. The reaction vessel was cooled to −70 ° C. under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated 3 times. After raising the temperature to room temperature, 1.2 g of AIBN was added as a polymerization initiator, the temperature was raised to 60 ° C., and the mixture was reacted for 15 hours. This reaction solution was added to 1 L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60 ° C. to obtain a polymer AP-6. The composition of AP-6 was confirmed by ¹³ C-NMR and ¹ H-NMR, and Mw and Mw / Mn were confirmed by GPC.

[Synthesis Example 2-7] Synthesis of Polymer AP-7 7.0 g of M-6, 26.5 g of FM-5 and 60 g of THF as a solvent were added to a 2 L flask. The reaction vessel was cooled to −70 ° C. under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated 3 times. After raising the temperature to room temperature, 1.2 g of AIBN was added as a polymerization initiator, the temperature was raised to 60 ° C., and the mixture was reacted for 15 hours. This reaction solution was added to 1 L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60 ° C. to obtain a polymer AP-7. The composition of AP-7 was confirmed by ¹³ C-NMR and ¹ H-NMR, and Mw and Mw / Mn were confirmed by GPC.

[Synthesis Example 2-8] Synthesis of Polymer AP-8 To a 2L flask, 7.3 g of M-7, 43.0 g of FM-6 and 60 g of THF as a solvent were added. The reaction vessel was cooled to −70 ° C. under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated 3 times. After raising the temperature to room temperature, 1.2 g of AIBN was added as a polymerization initiator, the temperature was raised to 60 ° C., and the mixture was reacted for 15 hours. This reaction solution was added to 1 L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60 ° C. to obtain a polymer AP-8. The composition of AP-8 was confirmed by ¹³ C-NMR and ¹ H-NMR, and Mw and Mw / Mn were confirmed by GPC.

[Synthesis Example 2-9] Synthesis of Polymer AP-9 In a 2L flask, 8.1 g of M-8, 15.7 g of FM-7, 9.0 g of methacrylic acid 1H, 1H, 5H-octafluoropentyl and a solvent. As a result, 60 g of THF was added. The reaction vessel was cooled to −70 ° C. under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated 3 times. After raising the temperature to room temperature, 1.2 g of AIBN was added as a polymerization initiator, the temperature was raised to 60 ° C., and the mixture was reacted for 15 hours. This reaction solution was added to 1 L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60 ° C. to obtain a polymer AP-9. The composition of AP-9 was confirmed by ¹³ C-NMR and ¹ H-NMR, and Mw and Mw / Mn were confirmed by GPC.

[Synthesis Example 2-10] Synthesis of Polymer AP-10 In a 2L flask, 8.4 g of M-9, 19.7 g of FM-8, 9.0 g of methacrylic acid 1H, 1H, 5H-octafluoropentyl and a solvent. As a result, 60 g of THF was added. The reaction vessel was cooled to −70 ° C. under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated 3 times. After raising the temperature to room temperature, 1.2 g of AIBN was added as a polymerization initiator, the temperature was raised to 60 ° C., and the mixture was reacted for 15 hours. This reaction solution was added to 1 L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60 ° C. to obtain a polymer AP-10. The composition of AP-10 was confirmed by ¹³ C-NMR and ¹ H-NMR, and Mw and Mw / Mn were confirmed by GPC.

[Synthesis Example 2-11] Synthesis of Polymer AP-11 In a 2L flask, 6.1 g of M-10, 20.7 g of FM-8, 9.0 g of methacrylic acid 1H, 1H, 5H-octafluoropentyl and a solvent. As a result, 60 g of THF was added. The reaction vessel was cooled to −70 ° C. under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated 3 times. After raising the temperature to room temperature, 1.2 g of AIBN was added as a polymerization initiator, the temperature was raised to 60 ° C., and the mixture was reacted for 15 hours. This reaction solution was added to 1 L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60 ° C. to obtain a polymer AP-11. The composition of AP-11 was confirmed by ¹³ C-NMR and ¹ H-NMR, and Mw and Mw / Mn were confirmed by GPC.

[Synthesis Example 2-12] Synthesis of Polymer AP-12 In a 2L flask, 6.4 g of M-11, 19.7 g of FM-8, 9.0 g of methacrylic acid 1H, 1H, 5H-octafluoropentyl and a solvent. As a result, 60 g of THF was added. The reaction vessel was cooled to −70 ° C. under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated 3 times. After raising the temperature to room temperature, 1.2 g of AIBN was added as a polymerization initiator, the temperature was raised to 60 ° C., and the mixture was reacted for 15 hours. This reaction solution was added to 1 L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60 ° C. to obtain a polymer AP-12. The composition of AP-12 was confirmed by ¹³ C-NMR and ¹ H-NMR, and Mw and Mw / Mn were confirmed by GPC.

[Synthesis Example 2-13] Synthesis of Polymer AP-13 In a 2L flask, 8.8 g of M-12, 19.7 g of FM-8, 9.0 g of methacrylic acid 1H, 1H, 5H-octafluoropentyl and a solvent. As a result, 60 g of THF was added. The reaction vessel was cooled to −70 ° C. under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated 3 times. After raising the temperature to room temperature, 1.2 g of AIBN was added as a polymerization initiator, the temperature was raised to 60 ° C., and the mixture was reacted for 15 hours. This reaction solution was added to 1 L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60 ° C. to obtain a polymer AP-13. The composition of AP-13 was confirmed by ¹³ C-NMR and ¹ H-NMR, and Mw and Mw / Mn were confirmed by GPC.

[Synthesis Example 2-14] Synthesis of Polymer AP-14 In a 2L flask, 7.8 g of M-1, 11.9 g of FM-9, 9.8 g of FM-8, and 1H, 1H, 5H-octa of methacrylic acid. 9.0 g of fluoropentyl and 60 g of THF as a solvent were added. The reaction vessel was cooled to −70 ° C. under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated 3 times. After raising the temperature to room temperature, 1.2 g of AIBN was added as a polymerization initiator, the temperature was raised to 60 ° C., and the mixture was reacted for 15 hours. This reaction solution was added to 1 L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60 ° C. to obtain a polymer AP-14. The composition of AP-14 was confirmed by ¹³ C-NMR and ¹ H-NMR, and Mw and Mw / Mn were confirmed by GPC.

[Synthesis Example 2-15] Synthesis of Polymer AP-15 In a 2L flask, 7.8 g of M-1, 11.7 g of FM-10, 9.8 g of FM-8, and 1H, 1H, 5H-octa of methacrylic acid. 9.0 g of fluoropentyl and 60 g of THF as a solvent were added. The reaction vessel was cooled to −70 ° C. under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated 3 times. After raising the temperature to room temperature, 1.2 g of AIBN was added as a polymerization initiator, the temperature was raised to 60 ° C., and the mixture was reacted for 15 hours. This reaction solution was added to 1 L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60 ° C. to obtain a polymer AP-15. The composition of AP-15 was confirmed by ¹³ C-NMR and ¹ H-NMR, and Mw and Mw / Mn were confirmed by GPC.

[Synthesis Example 2-16] Synthesis of Polymer AP-16 To a 2L flask, 7.9 g of M-4, 24.0 g of FM-3, 13.3 g of FM-11 and 60 g of THF as a solvent were added. The reaction vessel was cooled to −70 ° C. under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated 3 times. After raising the temperature to room temperature, 1.2 g of AIBN was added as a polymerization initiator, the temperature was raised to 60 ° C., and the mixture was reacted for 15 hours. This reaction solution was added to 1 L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60 ° C. to obtain a polymer AP-16. The composition of AP-16 was confirmed by ¹³ C-NMR and ¹ H-NMR, and Mw and Mw / Mn were confirmed by GPC.

[Synthesis Example 2-17] Synthesis of Polymer AP-17 To a 2L flask, 7.8 g of M-1, 26.2 g of FM-8, 7.4 g of PM-1 and 60 g of THF as a solvent were added. The reaction vessel was cooled to −70 ° C. under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated 3 times. After raising the temperature to room temperature, 1.2 g of AIBN was added as a polymerization initiator, the temperature was raised to 60 ° C., and the mixture was reacted for 15 hours. This reaction solution was added to 1 L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60 ° C. to obtain a polymer AP-17. The composition of AP-17 was confirmed by ¹³ C-NMR and ¹ H-NMR, and Mw and Mw / Mn were confirmed by GPC.

[Comparative Synthesis Example 2-1] Synthesis of Comparative Polymer cP-1 40.0 g of FM-2, 6.0 g of methacrylic acid 1H, 1H, 5H-octafluoropentyl and 60 g of THF as a solvent were added to a 2L flask. .. The reaction vessel was cooled to −70 ° C. under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated 3 times. After raising the temperature to room temperature, 1.2 g of AIBN was added as a polymerization initiator, the temperature was raised to 60 ° C., and the mixture was reacted for 15 hours. This reaction solution was added to 1 L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60 ° C. to obtain a comparative polymer cP-1. The composition of cP-1 was confirmed by ¹³ C-NMR and ¹ H-NMR, and Mw and Mw / Mn were confirmed by GPC.

[Comparative Synthesis Example 2-2] Synthesis of Comparative Polymer cP-2 In a 2L flask, 1.6 g of 2- (dimethylamino) ethyl methacrylate, 35.0 g of THF, and 1H, 1H, 5H-octa methacrylate of methacrylic acid are used. 6.0 g of fluoropentyl and 60 g of THF as a solvent were added. The reaction vessel was cooled to −70 ° C. under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated 3 times. After raising the temperature to room temperature, 1.2 g of AIBN was added as a polymerization initiator, the temperature was raised to 60 ° C., and the mixture was reacted for 15 hours. This reaction solution was added to 1 L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60 ° C. to obtain a comparative polymer cP-2. The composition of cP-2 was confirmed by ¹³ C-NMR and ¹ H-NMR, and Mw and Mw / Mn were confirmed by GPC.

[Comparative Synthesis Example 2-3] Synthesis of Comparative Polymer cP-3 2.7 g of cM-1, 35.0 g of FM-2, 6.0 g of methacrylic acid 1H, 1H, 5H-octafluoropentyl in a 2L flask. And 60 g of THF was added as a solvent. The reaction vessel was cooled to −70 ° C. under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated 3 times. After raising the temperature to room temperature, 1.2 g of AIBN was added as a polymerization initiator, the temperature was raised to 60 ° C., and the mixture was reacted for 15 hours. This reaction solution was added to 1 L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60 ° C. to obtain a comparative polymer cP-3. The composition of cP-3 was confirmed by ¹³ C-NMR and ¹ H-NMR, and Mw and Mw / Mn were confirmed by GPC.

[Synthesis Examples 3-1 and 3-2] Synthesis of base polymers BP-1 and BP-2 Copolymerization reaction is carried out in THF which is a solvent by combining each monomer, the reaction solution is put into methanol, and the precipitated solid. Was repeatedly washed with hexane, isolated, and dried to obtain a base polymer (BP-1, BP-2) having the composition shown below. The composition of the obtained base polymer was confirmed by ¹ H-NMR, and Mw and Mw / Mn were confirmed by GPC (solvent: THF, standard: polystyrene).

[3] Preparation of resist material and its evaluation [Examples 1 to 22, Comparative Examples 1 to 5]
(1) Preparation of resist material A solution in which each component is dissolved in a solvent in which 100 ppm of Polyfox PF-636 manufactured by Omniova Co., Ltd. is dissolved as a surfactant with the compositions shown in Tables 1 and 2 is used with a 0.2 μm size filter. The resist material was prepared by filtration. The resist materials of Examples 1 to 21 and Comparative Examples 1 to 4 are of the positive type, and the resist materials of Examples 22 and Comparative Example 5 are of the negative type.

In Tables 1 and 2, each component is as follows.
-Organic solvent: PGMEA (propylene glycol monomethyl ether acetate)
DAA (diacetone alcohol)

-Acid generator: PAG-1 to PAG-4

・ Quencher: Q-1 to Q-4

(2) EUV lithography evaluation Si of each resist material shown in Tables 1 and 2 formed by Shin-Etsu Chemical Industry Co., Ltd. silicon-containing spin-on hard mask SHB-A940 (silicon content is 43% by mass) with a film thickness of 20 nm. A resist film having a film thickness of 40 nm was prepared by spin-coating on a substrate and prebaking at 100 ° C. for 60 seconds using a hot plate. Using ASML's EUV scanner NXE3300 (NA0.33, σ0.9, 90 degree dipole illumination), a positive resist film was exposed to an 18 nm line and space (LS) 1: 1 pattern, and a negative resist film was exposed. Is exposed to a 22 nm LS1: 1 pattern, PEB is carried out on a hot plate at the temperatures shown in Tables 1 and 2 for 60 seconds, and development is carried out with a 2.38 mass% TMAH aqueous solution for 30 seconds, and Examples 1 to 21 are carried out. In Comparative Examples 1 to 4, an LS pattern having a size of 18 nm was obtained, and in Example 22 and Comparative Example 5, an LS pattern having a size of 22 nm was obtained.
Using a length measuring SEM (CG5000) manufactured by Hitachi High-Technologies Corporation, the exposure amount when the LS pattern was formed at 1: 1 was measured and used as the sensitivity, and the LWR at this time was measured. In addition, the window is the value obtained by subtracting the dimension of the thinnest line that does not cause the line to collapse in the area of high exposure from the dimension of the thickest line where a string-like bridge does not occur between the lines in the area with low exposure. did. The results are shown in Tables 1 and 2.

As shown in Tables 1 and 2, the resist material to which the ammonium salt and the fluorine atom-containing polymer was added had high sensitivity, a small LWR, and a wide window.

Claims (14)

A repeating unit AU having an ammonium salt structure of a sulfonamide compound having a benzene ring substituted with an iodine atom, a repeating unit FU-1 having a trifluoromethyl alcohol group optionally substituted with an acid unstable group, and fluorination. A resist material containing an ammonium salt and a fluorine atom-containing polymer containing at least one selected from the repeating unit FU-2 having a hydrocarbyl group, and a base polymer. The repeating unit AU is represented by the following formula (AU), the repeating unit FU-1 is represented by the following formula (FU-1), and the repeating unit FU-2 is represented by the following formula (FU-2). ). The resist material according to claim 1.

(In the equation, m ¹ is an integer of 1 to 5. m ² is an integer of 0 to 3. n ¹ is 1 or 2. n ² is 0 <n ² / n ¹ ≦. A positive number satisfying 1. n ³ is 1 or 2. n ⁴ is 1 or 2.
^RA is independently a hydrogen atom or a methyl group.
X ^1A is a single bond, phenylene group, ester bond or amide bond.
X ^1B is a single-bonded or (n ¹ + 1) -valent hydrocarbon group having 1 to 20 carbon atoms, and the hydrocarbon group is an ether bond, a carbonyl group, an ester bond, an amide bond, a sulton ring, a lactam ring, and the like. It may contain a carbonate bond, a halogen atom, a hydroxy group or a carboxy group.
X ^1C is a single bond, an ether bond, a carbonyl group, an ester bond, an amide bond, a carbonate bond or a hydrocarbylene group having 1 to 20 carbon atoms, and the hydrocarbylene group is an ether bond, a carbonyl group or an ester bond. , Amide bond, sulton ring, lactam ring, carbonate bond, halogen atom, hydroxy group or carboxy group may be contained.
X ^2A is a single bond, a phenylene group, -O-, -C (= O) -O- or -C (= O) -NH-.
X ^2B is a (n ⁴ + 1) -valent saturated hydrocarbon group or (n ⁴ + 1) -valent aromatic hydrocarbon group having 1 to 12 carbon atoms and contains a fluorine atom, a hydroxy group, an ester bond or an ether bond. You may be.
X ³ is a single bond, a phenylene group, -O-, -C (= O) -O-X ³¹ -X ^32- or -C (= O) -NH-X ³¹ -X ^32- . X ³¹ is a single bond or an alkanediyl group having 1 to 4 carbon atoms. X ³² is a single bond, ester bond, ether bond or sulfone amide bond.
R ¹ , R ² and R ³ independently have a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms or 7 to 12 carbon atoms. It is an Aralkill group. Further, R ¹ and R ² or R ¹ and X ^{1 B} may be bonded to each other to form a ring together with the nitrogen atom to which they are bonded, and an oxygen atom, a sulfur atom, a nitrogen atom or a ring may be formed in the ring. It may contain a double bond.
R ⁴ is a hydroxy group, a saturated hydrocarbyl group having 1 to 6 carbon atoms which may be substituted with a halogen atom, a saturated hydrocarbyloxy group having 1 to 6 carbon atoms which may be substituted with a halogen atom, a formyl group, and a halogen. Saturated hydrocarbylcarbonyl group having 2 to 7 carbon atoms which may be substituted with an atom, saturated hydrocarbylcarbonyloxy group having 2 to 7 carbon atoms which may be substituted with a halogen atom, carbon which may be substituted with a halogen atom. Saturated hydrocarbylsulfonyloxy group of number 1 to 4, aryl group of 6 to 10 carbon atoms, fluorine atom, chlorine atom, nitro group, cyano group, or -N (R ^4A ) (R ^4B ), -N (R ^4C ) -C (= O) -R ^4D or -N (R ^4C ) -C (= O) -OR ^4D . R ^4A and R ^4B are independently hydrogen atoms or saturated hydrocarbyl groups having 1 to 6 carbon atoms. R ^4C is a hydrogen atom or a saturated hydrocarbyl group having 1 to 6 carbon atoms. R ^4D is a saturated hydrocarbyl group having 1 to 6 carbon atoms, an unsaturated aliphatic hydrocarbyl group having 2 to 8 carbon atoms, an aryl group having 6 to 14 carbon atoms or an aralkyl group having 7 to 15 carbon atoms.
R ⁵ is a (n ³ + 1) -valent hydrocarbon group having 1 to 10 carbon atoms and may contain an ester bond, an ether bond or a carbonyl group.
R ⁶ is a saturated hydrocarbyl group having 1 to 10 carbon atoms or an aryl group having 6 to 10 carbon atoms, and the saturated hydrocarbyl group may be substituted with a fluorine atom, a chlorine atom, a bromine atom or an iodine atom. The aryl group may be substituted with a fluorine atom, a chlorine atom, a bromine atom, an iodine atom or a saturated hydrocarbyl group having 1 to 10 carbon atoms.
R ⁷ is a saturated hydrocarbylene group having a single bond, an ester bond or 1 to 12 carbon atoms, and a part or all of the hydrogen atom of the saturated hydrocarbylene group may be substituted with a fluorine atom. A part of the carbon atom of the saturated hydrocarbylene group may be substituted with an ester bond or an ether bond.
R ⁸ is a hydrogen atom, a fluorine atom, a methyl group, a trifluoromethyl group or a difluoromethyl group. R ⁷ and R ⁸ may be bonded to each other to form a ring together with the carbon atom to which they are bonded, and the ring may contain an ether bond, a fluorine atom or a trifluoromethyl group.
R ⁹ is a hydrogen atom or an acid unstable group.
R ¹⁰ is a hydrocarbyl group having 1 to 20 carbon atoms substituted with at least one fluorine atom, and a part of the carbon atom may be substituted with an ester bond or an ether bond. ) The resist material according to claim 1 or 2, which contains 0.1 to 20 parts by mass of the ammonium salt and a fluorine atom-containing polymer with respect to 100 parts by mass of the base polymer. The resist material according to any one of claims 1 to 3, further comprising an acid generator that generates sulfonic acid, imic acid or methidoic acid. The resist material according to any one of claims 1 to 4, further comprising an organic solvent. The resist material according to any one of claims 1 to 5, wherein the base polymer contains a repeating unit represented by the following formula (a1) or a repeating unit represented by the following formula (a2).

(In the formula, ^RA is a hydrogen atom or a methyl group, respectively.
R ¹¹ and R ¹² are each independently an acid unstable group.
R ¹³ is a fluorine atom, a trifluoromethyl group, a saturated hydrocarbyl group having 1 to 5 carbon atoms or a saturated hydrocarbylviloxy group having 1 to 5 carbon atoms.
Y ¹ is a divalent linking group having 1 to 12 carbon atoms containing at least one selected from a single bond, a phenylene group or a naphthylene group, or an ester bond and a lactone ring.
Y ² is a single bond or an ester bond.
a is an integer of 0 to 4. ) The resist material according to claim 6, which is a chemically amplified positive resist material. The resist material according to any one of claims 1 to 5, wherein the base polymer does not contain an acid unstable group. The resist material according to claim 8, which is a chemically amplified negative resist material. The positive resist material according to any one of claims 1 to 9, wherein the base polymer contains a repeating unit represented by any of the following formulas (f1) to (f3).

(In the formula, ^RA is a hydrogen atom or a methyl group, respectively.
Z ¹ is a single bond, an aliphatic hydrocarbylene group having 1 to 6 carbon atoms, a phenylene group, a naphthylene group, or a group having 7 to 18 carbon atoms obtained by combining them, or -O-Z ^11- , -C. (= O) -O-Z ¹¹ -or -C (= O) -NH-Z ^11- . Z ¹¹ is an aliphatic hydrocarbylene group having 1 to 6 carbon atoms, a phenylene group, a naphthylene group or a group having 7 to 18 carbon atoms obtained by combining them, and is a carbonyl group, an ester bond, an ether bond or a hydroxy group. May include.
Z ² is a single bond or an ester bond.
Z ³ is a single bond, -Z ³¹ -C (= O) -O-, -Z ³¹ -O- or -Z ³¹ -OC (= O)-. Z ³¹ is a hydrocarbylene group having 1 to 12 carbon atoms, a phenylene group, or a group having 7 to 18 carbon atoms obtained by combining them, and contains a carbonyl group, an ester bond, an ether bond, an iodine atom or a bromine atom. You may be.
Z ⁴ is a methylene group, 2,2,2-trifluoro-1,1-ethandyl group or a carbonyl group.
Z ⁵ is a single bond, a methylene group, an ethylene group, a phenylene group, a fluorinated phenylene group, a phenylene group substituted with a trifluoromethyl group, -O-Z ^{51-, -C (= O) -O-Z 51 . -Or} -C (= O) -NH-Z 51-. Z ⁵¹ is a phenylene group substituted with an aliphatic hydrocarbylene group, a phenylene group, a fluorinated phenylene group or a trifluoromethyl group having 1 to 6 carbon atoms, and has a carbonyl group, an ester bond, an ether bond or a hydroxy group. It may be included.
R ²¹ to R ²⁸ are hydrocarbyl groups having 1 to 20 carbon atoms which may independently contain a halogen atom or a hetero atom. Further, R ²³ and R ²⁴ or R ²⁶ and R ²⁷ may be bonded to each other to form a ring together with the sulfur atom to which they are bonded.
M ^- is a non-nucleophilic opposed ion. ) The resist material according to any one of claims 1 to 10, further comprising a surfactant. A step of forming a resist film on a substrate using the resist material according to any one of claims 1 to 11, a step of exposing the resist film with high energy rays, and a developer of the exposed resist film. A pattern forming method including a step of developing using. The pattern forming method according to claim 12, wherein the high energy ray is an ArF excimer laser light having a wavelength of 193 nm or a KrF excimer laser light having a wavelength of 248 nm. The pattern forming method according to claim 12, wherein the high energy ray is an electron beam or extreme ultraviolet rays having a wavelength of 3 to 15 nm.