TW201921109A - Resist composition and patterning process - Google Patents

Abstract

A resist composition is provided comprising a base polymer containing an iodized polymer, and an acid generator containing a sulfonium salt and/or iodonium salt of iodized benzene ring-containing fluorosulfonic acid. When processed by lithography, the resist composition exhibits a high sensitivity, low LWR and improved CDU independent of whether it is of positive tone or negativc tone.

Description

Photoresist material and pattern forming method

The present invention relates to a photoresist material comprising: a polymer containing a repeating unit with iodine; and an acid generator containing a sulfonium salt or a sulfonium salt of fluorosulfonic acid with iodine, and a pattern using the photoresist material Formation method.

With the high integration and high speed of LSI, the miniaturization of pattern rules is rapidly progressing. In particular, logic devices used in smartphones and the like are driving miniaturization, and multiple-exposure (multi-patterned lithography) processing using ArF lithography has been used for mass production of logic devices at the 10nm node.

Subsequent lithography at the 7nm node and 5nm node has clearly seen the problems of high cost caused by multiple exposures and overlapping accuracy in multiple exposures. It is expected that extreme ultraviolet (EUV) lithography will reduce the number of exposures.

EUV with a wavelength of 13.5nm is shorter than ArF lithography with a wavelength of 193nm, the wavelength is shorter than 1/10, so the contrast of light is high, and high resolution can be expected. EUV has a short wavelength and high energy density, so a small amount of photons will sensitize the acid generator. The number of photons in the EUV exposure is said to be 1/14 of the ArF exposure. In EUV exposure, the phenomenon that the line edge roughness (LWR) and hole size uniformity (CDU) deteriorate due to photon variation is considered a problem.

In order to reduce the variation of photons, some people have proposed to increase the absorption of the photoresist and increase the number of photons absorbed into the photoresist.

A styrene-based resin substituted with a halogen atom has been studied before (Patent Document 1). In particular, among the halogen atoms, the iodine atom has a high absorption for EUV light having a wavelength of 13.5 nm. Therefore, proposals have been made in recent years to use a resin having an iodine atom as an EUV photoresist material (Patent Documents 2 and 3). However, if iodine atoms are contained, the number of absorbed photons will increase and it will become a high sensitivity. It is reported that the iodinated styrene is only 14% of hydroxystyrene in the acid generation efficiency of EUV exposure (Non-Patent Document 1).
[Prior technical literature]
[Patent Literature]

[Patent Document 1] Japanese Unexamined Patent Publication No. 5-204157
[Patent Document 2] Japanese Patent Laid-Open No. 2015-161823
[Patent Document 3] International Publication No. 2013/024777
[Non-patent literature]

[Non-Patent Document 1] Jpn. J. Appl. Physics Vol. 46, No. 7, pp. L142-L144, 2007

(Problems to be Solved by the Invention)

It is hoped to develop a photoresist material with high sensitivity and capable of reducing the LWR and hole pattern CDU among chemically amplified photoresist using acid as a catalyst.

In view of the foregoing, the present invention aims to provide a photoresist material in which both the positive type photoresist material and the negative type photoresist material are highly sensitive and the LWR and CDU are small, and a pattern forming method using the photoresist material.
(The way to solve the problem)

The inventors of the present case have made intensive research in order to achieve the foregoing objects, and as a result, they found that a photoresist material containing a polymer containing an iodine atom and an acid generator containing a sulfonium salt and / or a sulfonium salt of a fluorinated sulfonic acid containing an iodized benzene ring was obtained. It is high and LWR and CDU are small, which can be used as a photoresist material with a wide tolerance, which completes the present invention.

Therefore, the present invention provides the following photoresist materials and pattern forming methods.
A photoresist material comprising: a base polymer, a polymer containing an iodine atom; and an acid generator, a sulfonium salt and / or a sulfonium salt of a fluorosulfonic acid containing an iodized benzene ring.
2. The photoresist material according to 1., wherein the phosphonium salt and phosphonium salt of the iodized benzene ring-containing fluorosulfonic acid are each a phosphonium salt represented by the following formula (A-1) and a formula (A-2) Osmium salt
[Chemical 1]
In the formula, L ¹ is a single bond, an ether bond, or an ester bond, or an alkyl group having 1 to 6 carbon atoms that may also contain an ether bond or an ester bond; R ¹ is a hydroxyl group, a carboxyl group, a fluorine atom, a chlorine atom, or a bromine atom. Or an amine group, or a fluorine atom, a chlorine atom, a bromine atom, a hydroxyl group, an amine group, or an alkoxy group having 1 to 10 carbon atoms, an alkyl group having 1 to 20 carbon atoms, or an alkoxy group having 1 to 20 carbon atoms , An alkoxycarbonyl group having 2 to 10 carbon atoms, a fluorenyl group having 2 to 20 carbon atoms or an alkylsulfonyloxy group having 1 to 20 carbon atoms, or -NR ⁸ -C (= O) -R ⁹ or -NR ⁸ -C (= O) -OR ⁹ , R ⁸ is a hydrogen atom, or may contain a halogen atom, a hydroxyl group, an alkoxy group having 1 to 6 carbon atoms, a fluorenyl group having 2 to 6 carbon atoms, or 2 carbon atoms A alkoxy group of 6 to 6 carbons having an alkyl group of 1 to 6, R ⁹ is an alkyl group having 1 to 16 carbons, an alkenyl group having 2 to 16 carbons, or an aryl group having 6 to 12 carbons, and may also contain Halogen atom, hydroxyl group, alkoxy group having 1 to 6 carbon atoms, fluorenyl group having 2 to 6 carbon atoms, or fluorenyl group having 2 to 6 carbon atoms;
R ² is a single bond or a divalent linking group having 1 to 20 carbons when p is 1, and a trivalent or tetravalent linking group having 1 to 20 carbons when p is 2 or 3. The linking group may also contain Oxygen, sulfur or nitrogen atoms;
Rf ¹ to Rf ⁴ are each independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group, but at least one of these is a fluorine atom or a trifluoromethyl group; and Rf ¹ and Rf ² may be combined to form a carbonyl group. ;
R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷ are each independently a monovalent hydrocarbon group having 1 to 20 carbon atoms which may also contain a hetero atom; and any of R ³ , R ⁴ and R ⁵ is also Can be bonded to each other and form a ring with the sulfur atoms to which they are bonded;
p is an integer conforming to 1 ≦ p ≦ 3; q and r are integers conforming to 1 ≦ q ≦ 5, 0 ≦ r ≦ 3, and 1 ≦ q + r ≦ 5.
3. The photoresist material according to 1. or 2., wherein the iodine atom-containing polymer contains a repeating unit represented by the following formula (a1) or (a2);
[Chemical 2]
In the formula, R ^{A is} each independently a hydrogen atom or a methyl group; R ²¹ is a single bond or a methylene group; R ²² is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms; X ¹ is a single bond, an ether bond, Ester bond, amido bond, -C (= O) -OR ^23- , phenylene, -Ph-C (= O) -OR ^24- , or -Ph-R ²⁵ -OC (= O) -R ²⁶ -, Ph is a phenylene group; R ²³ is an alkylene group having 1 to 10 carbon atoms, and may also contain an ether bond or an ester bond; R ²⁴ , R ²⁵ and R ²⁶ are each independently a single bond, or a linear or Branched alkyl groups having 1 to 6 carbon atoms; m and n are integers conforming to 1 ≦ m ≦ 5, 0 ≦ n ≦ 4, and 1 ≦ m + n ≦ 5.
4. The photoresist material according to 3., wherein n is an integer from 1 to 3.
5. The photoresist material according to any one of 1. to 4. further containing an organic solvent.
6. The photoresist material according to any one of 1. to 5, wherein the polymer containing an iodine atom further comprises a repeating unit represented by the following formula (b1) or a repeating unit represented by the following formula (b2);
[Chemical 3]
In the formula, R ^{A is} each independently a hydrogen atom or a methyl group; Y ¹ is a single bond, phenylene or naphthyl group, or a linking group having 1 to 12 carbon atoms containing an ester bond or a lactone ring; Y ² is Single bond or ester bond; R ³¹ and R ³² are each independently an acid labile group; R ³³ is a fluorine atom, a trifluoromethyl group, a cyano group, an alkyl group having 1 to 6 carbons, and an alkyl group having 1 to 6 carbons Oxygen group, fluorenyl group with 2 to 7 carbon atoms, fluorenyl group with 2 to 7 carbon atoms, or alkoxycarbonyl group with 2 to 7 carbon atoms; R ³⁴ is a single bond or alkylene group with 1 to 6 carbon atoms And a part of its carbon atom may be replaced by an ether bond or an ester bond; t is 1 or 2, and s is an integer of 0 to 4, but 1 ≦ t + s ≦ 5.
7. The photoresist material according to 6., further comprising a dissolution inhibitor.
8. The photoresist material of 6. or 7. is a chemically amplified positive photoresist material.
9. The photoresist material according to any one of 1. to 4., wherein the polymer containing an iodine atom does not contain an acid labile group.
10. The photoresist material according to 9., further comprising a crosslinking agent.
11. The photoresist material according to 9. or 10. is a chemically amplified negative photoresist material.
12. The photoresist material according to any one of 1. to 11., further comprising a quencher.
13. The photoresist material according to any one of 1. to 12., further comprising a surfactant.
14. The photoresist material according to any one of 1. to 13, wherein the polymer containing an iodine atom further contains at least one selected from the repeating units represented by the following formulae (g1) to (g3);
[Chemical 4]
In the formula, R ^{A is} each independently a hydrogen atom or a methyl group;
Z ¹ is a single bond, phenylene, -OZ ^12- , or -C (= O) -Z ¹¹ -Z ^12- , Z ¹¹ is -O- or -NH-, and Z ¹² is a carbon number of 1 to 6 An alkylene or an alkenyl group having 2 to 6 carbon atoms or an phenylene group may also contain a carbonyl group, an ester bond, an ether bond, or a hydroxyl group;
Z ² is a single ^{bond, -Z 21 -C (= O)} -O -, - Z 21 -O- or ^{-Z 21 -OC (= O) -} , Z 21 is an alkylene group having a carbon number of 1 to 12, May also contain carbonyl, ester or ether bonds;
A is a hydrogen atom or a trifluoromethyl group;
Z ³ is a single bond, methylene, ethylene, phenyl, fluorinated phenyl, -OZ ³² -or -C (= O) -Z ³¹ -Z ^32- , and Z ³¹ is -O- or -NH-, Z ³² is an alkylene group having 1 to 6 carbon atoms, a phenylene group, a fluorinated phenylene group, a phenylene group substituted with a trifluoromethyl group, or an alkenyl group having 2 to 6 carbon atoms, also May contain carbonyl, ester, ether or hydroxyl groups;
R ⁴¹ to R ⁴⁸ are each independently a monovalent hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom; and may be any of R ⁴³ , R ⁴⁴ and R ⁴⁵ , or R ⁴⁶ , R ⁴⁷ and Any of R ⁴⁸ is bonded to each other and forms a ring with the sulfur atom to which they are bonded;
Q ^- represents a non-nucleophilic counter ion.
15. A pattern forming method, comprising the following steps:
The photoresist material according to any one of 1. to 14. is coated on a substrate and subjected to heat treatment to form a photoresist film; the photoresist film is exposed with high-energy rays; and the exposed light is exposed using a developing solution The resist film is developed.
16. The pattern forming method according to 15., wherein the high-energy ray is an ArF excimer laser having a wavelength of 193 nm or a KrF excimer laser having a wavelength of 248 nm.
17. The pattern forming method according to 15., wherein the high-energy rays are electron beams or extreme ultraviolet rays having a wavelength of 3 to 15 nm.
(Effect of the invention)

In addition to the addition of a polymer containing iodine atoms and a photoresist material containing an acid generator of fluorosulfonic acid containing iodized benzene ring, the molecular weight of iodine is large, so it has the characteristics of small acid diffusion. In addition, the absorption of iodine in EUV at a wavelength of 13.5nm is very large. Therefore, secondary electrons are generated from iodine during exposure. Compared with the addition of iodine-containing polymers, which generates fluorosulfonic acid without iodine, When the agent is used, the sensitivity is higher. Thereby, a high-sensitivity, low-LWR, and low-CDU photoresist material can be constructed.

[Photoresistive material]
The photoresist material of the present invention comprises: a polymer containing an iodine atom; and a sulfonium salt or a sulfonium salt of a fluorosulfonic acid containing an iodized benzene ring (they are sometimes collectively referred to as an onium fluorosulfonium-containing fluorosulfonate) Salt) acid generator. The aforementioned sulfonium salt and sulfonium salt are acid generators that generate fluorinated sulfonic acid containing an iodized benzene ring by irradiation with light. In the photoresist material of the present invention, an acid generator that generates a different sulfonic acid, phosphonium imine, or methylated acid may be added, or it may be combined with a combination type acid generator that is bonded to the base polymer. .

Illumination of a sulfonic acid salt of a fluorosulfonic acid containing an iodized benzene ring with a sulfonic acid or a sulfonic acid salt of a carboxylic acid that is weaker than the fluorinated salt of a sulfonic acid or a carboxylic acid that produces a weaker iodized benzene ring will produce a fluorinated sulfonic acid containing an iodized benzene ring. Weaker sulfonic acid or carboxylic acid. Since the acid generator is not completely decomposed, an undecomposed acid generator may exist in the vicinity. Here, if fluorinated sulfonic acid containing iodized benzene ring, and sulfonic acid of weaker acid and phosphonium salt of carboxylic acid coexist, fluorinated sulfonic acid containing iodized benzene ring, sulfonic acid and carboxylic acid with weak acid will occur. Ion exchange between sulfonium salts of acids to generate sulfonium salts of fluorosulfonic acids containing iodinated benzene rings and release weak acids of sulfonic acids and carboxylic acids. The reason is that the fluorosulfonate containing the iodized benzene ring, which has a higher strength in terms of acid, is more stable. On the other hand, even if the sulfonium salt of fluorosulfonic acid containing iodinated benzene ring and the weak acid sulfonic acid and carboxylic acid are present, ion exchange does not occur. This ion exchange due to the order of acid strength is not only the case of sulfonium salts, but also occurs in the case of sulfonium salts. When an acid generator of fluorosulfonic acid is combined, a weak acid sulfonium salt and a sulfonium salt function as a quencher. In addition, the absorption of iodine in EUV with a wavelength of 13.5 nm is extremely large, so secondary electrons occur during exposure, and the energy of the secondary electrons is shifted to the acid generator, which promotes decomposition, thereby increasing sensitivity. In particular, when the substitution number of iodine is 3 or more, the effect is high.

In order to improve LWR, it is effective to suppress the aggregation system of a polymer and an acid generator. In order to suppress the aggregation of the polymer, it is effective to reduce the difference between hydrophobicity and hydrophilicity, reduce the glass transition point (Tg), and decrease the molecular weight of the polymer. Specifically, it is effective to reduce the difference in polarity between the hydrophobic acid-labile group and the hydrophilic adhesive group, and to reduce the Tg by using a tight adhesive group such as a monocyclic lactone. In order to suppress the aggregation of the acid generator, it is effective to introduce a substituent into the cation part of triphenylphosphonium. In particular, with respect to the methacrylate polymer for ArF formed by an alicyclic protecting group and an adhesive group of a lactone, triphenylsulfonium formed only by an aromatic group is a heterostructure, and compatibility is low. The substituent introduced into triphenylphosphonium is considered to be the same alicyclic group or lactone as the user of the base polymer. The phosphonium salt is hydrophilic, so when a lactone is introduced, the hydrophilicity becomes too high, the compatibility with the polymer is reduced, and the phosphonium salt is agglomerated. The introduction of a hydrophobic alkyl group can make the phosphonium salt uniformly dispersed in the photoresist film. In International Publication No. 2011/048919, a method is proposed in which an alkyl group is introduced into a sulfonium salt that generates fluorinated sulfoimino acid at the α-position to make LWR better.

The aforementioned onium fluorosulfonate salt containing iodized benzene ring has a small atomic amount of iodine introduced into the anion part, so the diffusion is small, and the compatibility with the polymer with iodine is also high, so the dispersibility is excellent. CDU improves.

The improvement effect of LWR and CDU caused by the above-mentioned fluorosulfonic acid salt containing iodized benzene ring is effective in positive pattern formation, negative pattern formation, and negative pattern formation in organic solvent development.

[Fluorosulfonic acid phosphonium salt and phosphonium salt containing iodinated benzene ring]
The phosphonium salt and phosphonium salt of the fluorosulfonic acid containing an iodinated benzene ring are each represented by the following formulae (A-1) and (A-2).
[Chemical 5]

In the formulae (A-1) and (A-2), L ¹ is a single bond, an ether bond, or an ester bond, or an alkylene group having 1 to 6 carbon atoms that may contain an ether bond or an ester bond. The said alkylene group may be any of linear, branched, and cyclic.

R ¹ is a hydroxyl group, a carboxyl group, a fluorine atom, a chlorine atom, a bromine atom, or an amine group, or may contain a fluorine atom, a chlorine atom, a bromine atom, a hydroxyl group, an amine group, or an alkoxy group having 1 to 10 carbon atoms. Alkyl group of 20 to 20, alkoxy group of 1 to 20 carbon, alkoxycarbonyl of 2 to 10 carbon, fluorenyloxy of 2 to 20 carbon or alkylsulfonyloxy of 1 to 20 carbon Or -NR ⁸ -C (= O) -R ⁹ or -NR ⁸ -C (= O) -OR ⁹ , R ⁸ is a hydrogen atom, or may contain a halogen atom, a hydroxyl group, and an alkane having 1 to 6 carbon atoms. Oxygen, fluorenyl group with 2 to 6 carbon atoms, or alkoxyl group with 2 to 6 carbon atoms, alkyl group with 1 to 6 carbon atoms, R ⁹ is an alkyl group with 1 to 16 carbon atoms, and alkenyl group with 2 to 16 carbon atoms Or an aryl group having 6 to 12 carbon atoms may contain a halogen atom, a hydroxyl group, an alkoxy group having 1 to 6 carbon atoms, a fluorenyl group having 2 to 6 carbon atoms, or a fluorenyl group having 2 to 6 carbon atoms. The alkyl, alkoxy, alkoxycarbonyl, fluorenyl, fluorenyl, and alkenyl may be any of linear, branched, and cyclic.

Among these, R ^{1 is} preferably a hydroxyl group, -NR ⁸ -C (= O) -R ⁹ , a fluorine atom, a chlorine atom, a bromine atom, a methyl group, or a methoxy group.

R ² is a single bond or a divalent linking group having 1 to 20 carbons when p is 1, and a trivalent or tetravalent linking group having 1 to 20 carbons when p is 2 or 3. The linking group may also contain Oxygen, sulfur, or nitrogen.

Rf ¹ to Rf ⁴ are each independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group, but at least one of them is a fluorine atom or a trifluoromethyl group. 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.

R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷ are each independently a monovalent hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom. In addition, any of R ³ , R ^4, and R ⁵ may be bonded to each other and form a ring together with the sulfur atom to which they are bonded. The monovalent hydrocarbon group may be any of linear, branched, and cyclic, and specific examples thereof include an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, and an alkyl group having 2 to 12 carbon atoms. Alkynyl, aryl having 6 to 20 carbons, aralkyl having 7 to 12 carbons, and the like. In addition, part or all of the hydrogen atoms of these groups may be substituted with a hydroxyl group, a carboxyl group, a halogen atom, a cyano group, a sulfonylamino group, a nitro group, a mercapto group, a sultone group, a sulfone group, or a sulfonium-containing salt As a base, a part of the carbon atoms of these groups may be substituted with an ether bond, an ester bond, a carbonyl group, a carbonate group, or a sulfonate bond.

p is an integer satisfying 1 ≦ p ≦ 3. q and r are integers conforming to 1 ≦ q ≦ 5, 0 ≦ r ≦ 3, and 1 ≦ q + r ≦ 5. q is an integer satisfying 1 ≦ q ≦ 3, and 2 or 3 is more desirable. r is preferably an integer satisfying 0 ≦ r ≦ 2.

The cation of the sulfonium salt represented by the formula (A-1) is preferably the following formula (A-3) or (A-4), and the cation of the sulfonium salt represented by the formula (A-2) is preferably the following formula (A-5) is preferred.
[Chemical 6]

In the formula, R ¹¹ to R ¹⁸ are each independently a monovalent hydrocarbon group having 1 to 14 carbon atoms. The aforementioned monovalent hydrocarbon group is preferably an alkyl group having 1 to 14 carbon atoms, an alkenyl group having 2 to 14 carbon atoms, an aryl group having 6 to 14 carbon atoms, an aralkyl group having 7 to 14 carbon atoms, a hydroxyl group, a carboxyl group, a halogen atom, Cyano, amidino, nitro, sultone, fluorenyl, or sulfonium-containing groups. In addition, part or all of the hydrogen atoms of the aforementioned monovalent hydrocarbon group may be substituted with a hydroxyl group, a carboxyl group, a halogen atom, a cyano group, a fluorenylamino group, a nitro group, a sultone group, a fluorenyl group, or a sulfonium salt-containing group. A part of the carbon atom of the group may be substituted with an ether bond, an ester bond, a carbonyl group, a carbonate group, or a sulfonate bond. L ² is a single bond, a methylene group, an ether bond, a thioether bond, or a carbonyl group. a to h are each independently an integer of 0 to 5.

Examples of the cation of the phosphonium salt represented by the formula (A-1) include, but are not limited to, the following.
[Chemical 7]

[Chemical 8]

[Chemical 9]

[Chemical 10]

[Chemical 11]

[Chemical 12]

[Chemical 13]

[Chemical 14]

[Chemical 15]

[Chemical 16]

Examples of the cation of the phosphonium salt represented by the formula (A-2) include, but are not limited to, the following.
[Chem. 17]

Examples of the anions of the phosphonium salt represented by the formula (A-1) and the phosphonium salt represented by the formula (A-2) include, but are not limited to, the following.

[Chemical 18]

[Chemical 19]

[Chemical 20]

[Chemical 21]

[Chemical 22]

[Chemical 23]

[Chemical 24]

[Chemical 25]

[Chem. 26]

[Chemical 27]

[Chemical 28]

[Chem. 29]

[Hua 30]

[Chemical 31]

[Chemical 32]

[Chemical 33]

[Chem 34]

[Chem. 35]

[Chemical 36]

[Chem. 37]

[Chemical 38]

[Chemical 39]

[Chemical 40]

As a method for synthesizing the sulfonium salt represented by the formula (A-1) and the sulfonium salt represented by the formula (A-2), sulfonium salts which are weaker in acid than fluorinated sulfonic acid containing iodinated benzyloxy or Method of sulfonium salt for ion exchange. Examples of acids which are weaker than fluorinated sulfonic acids bonded to benzene substituted with iodine include hydrochloric acid and carbonic acid. It can also be synthesized by ion exchange with sodium salt, ammonium salt and phosphonium chloride or phosphonium chloride of benzene-bonded fluorinated sulfonic acid substituted with iodine.

In the photoresist material of the present invention, the content of the onium fluorosulfonate salt containing the iodized benzene ring is preferably 0.01 to 1,000 parts by mass with respect to 100 parts by mass of the base polymer described later, and considering the sensitivity and the effect of inhibiting acid diffusion. Ideal, 0.05 ~ 500 parts by mass is more ideal. The aforementioned iodine benzene ring-containing fluorosulfonate salts may be used singly or in combination of two or more kinds.

[Base polymer]
The base polymer contained in the photoresist material of the present invention includes a polymer having an iodine atom (hereinafter also referred to as polymer A). The polymer A preferably contains a repeating unit represented by the following formula (a1) (hereinafter also referred to as repeating unit a1.) Or a repeating unit represented by the following formula (a2) (hereinafter also referred to as repeating unit a2.).
[Chemical 41]

In the formula, R ^{A is} each independently a hydrogen atom or a methyl group. R ²¹ is a single bond or a methylene group. R ²² is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. The aforementioned alkyl group is preferably a linear or branched one. X ¹ is a single bond, an ether bond, an ester bond, an amidine bond, -C (= O) -OR ^23- , phenylene, -Ph-C (= O) -OR ^24- , or -Ph-R ²⁵ -OC (= O) -R ^26- , and Ph is phenylene. R ²³ is an alkylene group having 1 to 10 carbon atoms, and may be linear, branched, or cyclic, and may include an ether bond or an ester bond. R ²⁴ , R ²⁵ and R ²⁶ are each independently a single bond or a linear or branched alkylene group having 1 to 6 carbon atoms.

m and n are integers conforming to 1 ≦ m ≦ 5, 0 ≦ n ≦ 4, and 1 ≦ m + n ≦ 5. If a hydroxyl group is present, the generation efficiency of secondary electrons is high, and the sensitivity is higher. Therefore, n should preferably be an integer that satisfies 1 ≦ n ≦ 3. m should preferably be an integer satisfying 1 ≦ m ≦ 3.

Examples of the monomer to which the repeating unit a1 is given include, but are not limited to, the following. In the following formula, R ^{A is the} same as described above.
[Chemical 42]

[Chemical 43]

[Chemical 44]

[Chemical 45]

Examples of the monomer to which the repeating unit a2 is given include, but are not limited to, the following. In the following formula, R ^{A is the} same as described above.
[Chemical 46]

The repeating units a1 and a2 may be used alone or in combination of two or more.

When the photoresist material of the present invention is a positive type, it is preferable that the polymer A further contains a repeating unit containing an acid-labile group. As the repeating unit containing an acid labile group, a repeating unit represented by the following formula (b1) (hereinafter also referred to as repeating unit b1) or a repeating unit represented by the formula (b2) (hereinafter also referred to as repeating unit b2) is preferred. Better. In addition, when the photoresist material of the present invention is a negative type, it is preferable that the polymer A does not contain an acid-labile repeating unit.
[Chemical 47]

In the formula, R ^{A is} each independently a hydrogen atom or a methyl group. Y ¹ is a single bond, phenylene or naphthyl, or a linking group having 1 to 12 carbon atoms containing an ester bond or a lactone ring. Y ² is a single bond or an ester bond. R ³¹ and R ³² are each independently an acid-labile group. R ³³ is a fluorine atom, a trifluoromethyl group, a cyano group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a fluorenyl group having 2 to 7 carbon atoms, or a fluorene group having 2 to 7 carbon atoms Or an alkoxycarbonyl group having 2 to 7 carbon atoms. R ³⁴ is a single bond or an alkylene group having 1 to 6 carbon atoms, and a part of carbon atoms thereof may be replaced with an ether bond or an ester bond. t is 1 or 2, s is an integer from 0 to 4, but 1 ≦ t + s ≦ 5. The alkyl group, alkoxy group, fluorenyl group, fluorenyl group, and alkoxycarbonyl group may be any of linear, branched, and cyclic groups. Further, it is preferable that the alkylene group having 1 to 6 carbon atoms is linear or branched.

Examples of the monomer to which the repeating unit b1 is given include, but are not limited to, the following. In the following formula, R ^A and R ^{31 are the} same as described above.
[Chemical 48]

Examples of the monomers that give the repeating unit b2 include, but are not limited to, the following. In the following formula, R ^A and R ^{32 are the} same as described above.
[Chemical 49]

The acid-labile groups represented by R ³¹ and R ³² in the repeating units b1 and b2 are described in, for example, Japanese Patent Application Laid-Open No. 2013-80033 and Japanese Patent Application Laid-Open No. 2013-83821.

Typical examples of the acid-labile group include those represented by the following formulae (AL-1) to (AL-3).
[Chemical 50]

In the formulae (AL-1) and (AL-2), R ^L1 and R ^L2 are monovalent hydrocarbon groups, and may include hetero atoms such as an oxygen atom, a sulfur atom, a nitrogen atom, and a fluorine atom. The monovalent hydrocarbon group may be any of linear, branched, and cyclic groups. An alkyl group having 1 to 40 carbon atoms is preferable, and an alkyl group having 1 to 20 carbon atoms is more preferable. In the formula (AL-1), x 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 each independently a hydrogen atom or a monovalent hydrocarbon group, and may include a hetero atom such as an oxygen atom, a sulfur atom, a nitrogen atom, or a fluorine atom. The monovalent hydrocarbon group may be any of linear, branched, and cyclic, and an alkyl group having 1 to 20 carbon atoms is preferred. In addition, any one of R ^L2 , R ^L3, and R ^L4 may be bonded to each other and form a ring having 3 to 20 carbon atoms together with the carbon atom or carbon atom and oxygen atom to which they are bonded. The aforementioned ring is preferably a ring having 4 to 16 carbon atoms, and an alicyclic ring is particularly preferred.

In the formula (AL-3), R ^L5 , R ^L6, and R ^L7 are each independently a monovalent hydrocarbon group, and may include a hetero atom such as an oxygen atom, a sulfur atom, a nitrogen atom, and a fluorine atom. The monovalent hydrocarbon group may be any of linear, branched, and cyclic, and an alkyl group having 1 to 20 carbon atoms is preferred. In addition, any one of R ^L5 , R ^L6, and R ^L7 may be bonded to each other and form a ring having 3 to 20 carbon atoms together with the carbon atoms to which they are bonded. The aforementioned ring is preferably a ring having 4 to 16 carbon atoms, and an alicyclic ring is particularly preferred.

The polymer A may further contain a repeating unit c containing a phenolic hydroxyl group as an adhesive group. The repeating unit c may be used alone or in combination of two or more.

Examples of the monomer to which the repeating unit c is given are as follows, but are not limited thereto. In the following formula, R ^{A is the} same as described above.
[Chemical 51]

The polymer A may further contain a repeating unit d containing a hydroxyl group, a carboxyl group, a lactone ring, an ether bond, an ester bond, a carbonyl group, or a cyano group other than the phenolic hydroxyl group as another adhesive group. The repeating unit d may be used alone or in combination of two or more.

Examples of the monomers that give the repeating unit d include, but are not limited to, the following. In the following formula, R ^{A is the} same as described above.
[Chemical 52]

[Chem 53]

[Chem. 54]

[Chem 55]

[Chemical] 56

[Chemical] 57

[Chemical] 58

[Chemical 59]

The polymer A may further contain a repeating unit e derived from indene, benzofuran, benzothiophene, vinylnaphthalene, coumarin, coumarin, norbornadiene, or derivatives thereof. The repeating unit e may be used alone or in combination of two or more.

Examples of the monomers that give the repeating unit e include, but are not limited to, the following.
[Chemical 60]

The polymer A may further contain a repeating unit f derived from styrene, vinylnaphthalene, vinylanthracene, vinylfluorene, methylenedihydroindene, vinylpyridine, or vinylcarbazole. The repeating unit f may be used alone or in combination of two or more.

The polymer A may further contain a repeating unit g derived from a polymerizable olefin-containing onium salt. Japanese Patent Application Laid-Open No. 2005-84365 proposes a sulfonium salt and a sulfonium salt containing a polymerizable olefin that generates a specific sulfonic acid. Japanese Patent Laid-Open No. 2006-178317 proposes a sulfonium salt in which a sulfonic acid is directly bonded to a main chain.

Examples of an ideal repeating unit g include a repeating unit (hereinafter also referred to as repeating unit g1) represented by the following formula (g1), a repeating unit (hereinafter also referred to as repeating unit g2) represented by the following formula (g2), and the following A repeating unit represented by formula (g3) (hereinafter also referred to as repeating unit g3.). The repeating units g1 to g3 may be used alone or in combination of two or more.
[Chem. 61]

In the formula, R ^{A is} each independently a hydrogen atom or a methyl group. Z ¹ is a single bond, phenylene, -OZ ^12- , or -C (= O) -Z ¹¹ -Z ^12- , Z ¹¹ is -O- or -NH-, and Z ¹² is a carbon number of 1 to 6 An alkylene group or an alkenyl group having 2 to 6 carbon atoms or an phenylene group may contain a carbonyl group, an ester bond, an ether bond, or a hydroxyl group. Z ² is a single ^{bond, -Z 21 -C (= O)} -O -, - Z 21 -O- or ^{-Z 21 -OC (= O) -} , Z 21 is an alkylene group having a carbon number of 1 to 12, It may contain a carbonyl group, an ester bond, or an ether bond. A is a hydrogen atom or a trifluoromethyl group. Z ³ is a single bond, methylene, ethylene, phenyl, fluorinated phenyl, -OZ ³² -or -C (= O) -Z ³¹ -Z ^32- , and Z ³¹ is -O- or -NH-, Z ³² is an alkylene group having 1 to 6 carbon atoms, a phenylene group, a fluorinated phenylene group, a phenylene group substituted with a trifluoromethyl group, or an alkenyl group having 2 to 6 carbon atoms, also It may contain a carbonyl group, an ester bond, an ether bond, or a hydroxyl group.

In the formulae (g1) to (g3), R ⁴¹ to R ⁴⁸ are each independently a monovalent hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom. In addition, any of R ⁴³ , R ^44, and R ⁴⁵ or any of R ⁴⁶ , R ^47, and R ⁴⁸ may be bonded to each other and form a ring together with the sulfur atom to which they are bonded. The sulfonium cations in the formulae (g2) and (g3) are preferably those represented by the aforementioned formula (A-3) or (A-4), and specific examples thereof can be exemplified by the sulfonium cations in the formula (A-1). The former are the same.

In the formula (g1), Q ^- is relatively non-nucleophilic ion. Examples of the non-nucleophilic counter ion include halide ions such as chloride ions and bromide ions, fluoroalkyl sulfonates such as trifluoromethanesulfonate, 1,1,1-trifluoroethanesulfonate, and nonafluorobutanesulfonate. , Toluenesulfonate, benzenesulfonate, 4-fluorobenzenesulfonate, arylsulfonate such as 1,2,3,4,5-pentafluorobenzenesulfonate, alkylsulfonate such as methanesulfonate, butanesulfonate, Bis (trifluoromethylsulfonyl) sulfonium imine, bis (perfluoroethylsulfonyl) sulfonium imine, bis (perfluorobutylsulfonyl) sulfonium imine, etc. Methylate acids such as fluoromethylsulfonyl) methylate and ginseng (perfluoroethylsulfonyl) methylate.

Examples of the non-nucleophilic counter ion include a sulfonic acid group substituted by fluorine at the α position represented by the following general formula (K-1), and a sulfonic acid group substituted by fluorine at the α and β positions represented by the following general formula (K-2). Acid radicals and so on.
[Chem 62]

In the formula (K-1), R ⁵¹ is a hydrogen atom, a linear, branched, or cyclic alkyl group having 1 to 20 carbon atoms or an alkenyl group having 2 to 20 carbon atoms or an aromatic group having 6 to 20 carbon atoms The group may contain an ether bond, an ester bond, a carbonyl group, a lactone ring or a fluorine atom.

In the formula (K-2), R ⁵² is a hydrogen atom, a linear, branched, or cyclic alkyl group having 1 to 30 carbon atoms, a fluorenyl group having 2 to 20 carbon atoms, or an alkenyl group having 2 to 20 carbon atoms. Or an aryl or aryloxy group having 6 to 20 carbon atoms may also contain an ether bond, an ester bond, a carbonyl group, or a lactone ring.

Examples of the monomer to which the repeating unit g1 is given include, but are not limited to, the following. In the following formula, R ^A and Q ^{-are the} same as described above.
[Chem 63]

Examples of the monomers that give the repeating unit g2 include, but are not limited to, the following. In the following formula, R ^{A is the} same as described above.
[Chemical 64]

[Chem. 65]

[Chemical 66]

[Chemical 67]

[Chemical 68]

Examples of the monomer to which the repeating unit g3 is given include, but are not limited to, the following. In the following formula, R ^{A is the} same as described above.
[Chemical 69]

[Chemical 70]

By reducing the acid diffusion by bonding the acid generator to the polymer main chain, it is possible to prevent a decrease in resolution due to the blurring of the acid diffusion. Moreover, the edge roughness can be improved by uniformly dispersing the acid generator.

Polymer A for positive photoresist materials contains repeating units a1 or a2 containing iodine atoms, and also contains repeating units b1 or b2 containing acid labile groups. In this case, the content ratios of the repeating units a1, a2, b1, b2, c, d, e, f, and g are 0 ≦ a1 <1.0, 0 ≦ a2 <1.0, 0 <a1 + a2 <1.0, 0 ≦ b1 <1.0 , 0 ≦ b2 <1.0, 0 <b1 + b2 <1.0, 0 ≦ c ≦ 0.9, 0 ≦ d ≦ 0.9, 0 ≦ e ≦ 0.8, 0 ≦ f ≦ 0.8, and 0 ≦ g ≦ 0.5, and 0 ≦ a1 ≦ 0.9, 0 ≦ a2 ≦ 0.9, 0.1 ≦ a1 + a2 ≦ 0.9, 0 ≦ b1 ≦ 0.9, 0 ≦ b2 ≦ 0.9, 0.1 ≦ b1 + b2 ≦ 0.9, 0 ≦ c ≦ 0.8, 0 ≦ d ≦ 0.8, 0 ≦ e ≦ 0.7, 0 ≦ f ≦ 0.7 and 0 ≦ g ≦ 0.4, 0 ≦ a1 ≦ 0.8, 0 ≦ a2 ≦ 0.8, 0.1 ≦ a1 + a2 ≦ 0.8, 0 ≦ b1 ≦ 0.8, 0 ≦ b2 ≦ 0.8, 0.1 ≦ b1 + b2 ≦ 0.8 0 ≦ c ≦ 0.75, 0 ≦ d ≦ 0.75, 0 ≦ e ≦ 0.6, 0 ≦ f ≦ 0.6, and 0 ≦ g ≦ 0.3 are more preferable. When the repeating unit g is at least one selected from the repeating units g1 to g3, g = g1 + g2 ++ g3. In addition, a1 + a2 + b1 + b2 + c + d + e + f + g = 1.0.

On the other hand, polymer A for negative photoresist does not necessarily require an acid labile group. Examples of such a base polymer include repeating units a1 or a2 containing iodine atoms and repeating unit c, and further include repeating units d, e, f, and / or g as necessary. The content ratio of these repeating units is 0 ≦ a1 <1.0, 0 ≦ a2 <1.0, 0 <a1 + a2 <1.0, 0 <c <1.0, 0 ≦ d ≦ 0.9, 0 ≦ e ≦ 0.8, 0 ≦ f ≦ 0.8, And 0 ≦ g ≦ 0.5, 0 ≦ a1 ≦ 0.8, 0 ≦ a2 ≦ 0.8, 0.1 ≦ a1 + a2 ≦ 0.8, 0.2 ≦ c ≦ 0.9, 0 ≦ d ≦ 0.8, 0 ≦ e ≦ 0.7, 0 ≦ f ≦ 0.7 And 0 ≦ g ≦ 0.4, 0 ≦ a1 ≦ 0.7, 0 ≦ a2 ≦ 0.7, 0.2 ≦ a1 + a2 ≦ 0.7, 0.3 ≦ c ≦ 0.8, 0 ≦ d ≦ 0.75, 0 ≦ e ≦ 0.6, 0 ≦ f ≦ 0.6 and 0 ≦ g ≦ 0.3 are more preferable. When the repeating unit g is selected from at least one of the repeating units g1 to g3, g = g1 + g2 ++ g3. In addition, a1 + a2 + c + d + e + f + g = 1.0.

In order to synthesize the polymer A, for example, a monomer giving the repeating unit may be added to an organic solvent, a radical polymerization initiator may be added, and heating polymerization may be performed.

Examples of organic solvents used in the polymerization include toluene, benzene, tetrahydrofuran, diethyl ether, and diethyl ether. Alkanes, etc. Examples of the polymerization initiator include 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis (2,4-dimethylvaleronitrile), and dimethyl-2,2-azo Nitros (2-methylpropionate), benzamidine peroxide, lauryl peroxide, etc. The reaction temperature is preferably 50 to 80 ° C, and the reaction time is preferably 2 to 100 hours, and more preferably 5 to 20 hours.

When copolymerizing a monomer containing a hydroxyl group, the hydroxyl group may be replaced with an acetoxy group such as ethoxyethoxy group which is easily deprotected by an acid during polymerization. After the polymerization, a weak acid and water may be used for deprotection. Substituted by amidino, methylamidino, trimethylacetamido and the like, and subjected to alkaline hydrolysis after polymerization.

When hydroxystyrene and hydroxyvinylnaphthalene are copolymerized, hydroxystyrene and hydroxyvinylnaphthalene may be replaced with ethoxylated styrene and ethoxylated vinylnaphthalene. Acetyloxy is deprotected to become a hydroxystyrene unit and a hydroxyvinylnaphthalene unit.

The alkali used in the alkali hydrolysis may be ammonia water, triethylamine, or the like. The reaction temperature is preferably -20 to 100 ° C, more preferably 0 to 60 ° C, and the reaction time is preferably 0.2 to 100 hours, and more preferably 0.5 to 20 hours.

For polymer A, the polystyrene-equivalent weight average molecular weight (Mw) measured by gel permeation chromatography (GPC) using tetrahydrofuran (THF) as a solvent is preferably 1,000 to 500,000, and more preferably 2,000 to 30,000. When Mw is the said range, heat resistance and alkali solubility will be favorable.

In addition, if the molecular weight distribution (Mw / Mn) of the polymer A is wide, there may be foreign matter on the pattern after the exposure or the shape of the pattern may deteriorate due to the presence of a polymer having a low molecular weight and a high molecular weight. As the pattern is regularly refined, the effects of Mw and molecular weight distribution tend to increase. Therefore, in order to suit the photoresist material used for the fine pattern size, the molecular weight distribution of the aforementioned base polymer is 1.0 to 2.0, especially a narrow dispersion of 1.0 to 1.5 is preferred. .

The base polymer may contain two or more polymers A having different composition ratios, Mw, and molecular weight distributions. In addition, as long as the effect of the present invention is not impaired, a polymer different from the polymer A may be contained, but it is preferable not to contain a polymer.

[Other ingredients]
An organic solvent, an acid generator and a surfactant other than the above-mentioned iodine benzene ring-containing fluorosulfonate salt are used in the photoresist material containing the iodine-benzene ring-containing fluorosulfonate salt and the base polymer. The dissolution inhibitor and cross-linking agent are appropriately combined and blended according to the purpose to form a positive type photoresist material and a negative type photoresist material. In the exposure part, because of the catalyst reaction, the dissolution rate of the developer to the base solution will be accelerated. Therefore, it can become a very high-sensitivity positive photoresist material and negative photoresist material. In this case, the photoresist film has high dissolution contrast and resolvability, has exposure margin, excellent processing adaptability, good pattern shape after exposure, and can especially suppress acid diffusion, so the density difference is small, so it is practical It is very effective as a photoresist material for super LSI. In particular, if it is made of a chemically-amplified positive-type photoresist material using an acid catalyst reaction, the sensitivity can be higher, and each characteristic is more excellent, which is extremely useful.

Examples of the organic solvent include ketones such as cyclohexanone, cyclopentanone, methyl-2-n-pentanone, and 3-methoxy groups described in paragraphs [0144] to [0145] of Japanese Patent Application Laid-Open No. 2008-111103. Alcohols such as butanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, propylene glycol monomethyl ether, ethylene glycol mono Ethers such as methyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, propylene glycol dimethyl ether, dimethyl glycol dimethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, ethyl lactate, pyruvate Ethyl acetate, butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, tertiary butyl acetate, tertiary butyl propionate, propylene glycol monotertiary butyl ether acetate, etc. Esters, lactones such as γ-butyrolactone, and mixed solvents of these. These solvents can be used alone or in combination of two or more.

In the photoresist material of the present invention, the content of the organic solvent is preferably 100 to 10,000 parts by mass relative to 100 parts by mass of the base polymer, and more preferably 200 to 8,000 parts by mass.

The photoresist material of the present invention may contain an acid generator (hereinafter also referred to as another acid generator) other than the aforementioned onium fluorosulfonate containing iodide benzene ring, as long as the effect of the present invention is not impaired. Other acid generators include compounds (photoacid generators) that generate acid by sensing active light or radiation. The component of the photoacid generator may be any compound that produces acid due to high-energy radiation, and is preferably an acid generator that generates a sulfonic acid, amidinic acid, or a methylated acid. The ideal photoacid generators include sulfonium salts, sulfonium salts, sulfonyldiazomethane, N-sulfonyloxyfluorenimine, oxime-O-sulfonate type acid generators, and the like. Specific examples of the acid generator are described in paragraphs [0122] to [0142] of Japanese Patent Application Laid-Open No. 2008-111103. Other acid generators can be used individually by 1 type or in combination of 2 or more types. The content of the other acid generator is preferably 0 to 200 parts by mass, and more preferably 0.1 to 100 parts by mass based on 100 parts by mass of the base polymer.

Examples of the surfactant include those described in paragraphs [0165] to [0166] of Japanese Patent Application Laid-Open No. 2008-111103. By adding a surfactant, the coating property of the photoresist material can be further improved or controlled. The surfactant can be used singly or in combination of two or more kinds. In the photoresist material of the present invention, the content of the aforementioned surfactant is preferably 0.0001 to 10 parts by mass relative to 100 parts by mass of the base polymer.

In the case of a positive photoresist material, by dissolving a dissolution inhibitor, the dissolution speed difference between the exposed portion and the unexposed portion can be further increased, and the resolution can be further improved. In the case of a negative-type photoresist material, by adding a cross-linking agent, the dissolution rate of the exposed portion is reduced, and a negative pattern can be obtained.

Examples of the dissolution inhibitor include a molecular weight of preferably 100 to 1,000, more preferably 150 to 800, and a hydrogen atom of the phenolic hydroxyl group of a compound containing two or more phenolic hydroxyl groups in the molecule. It is said that the hydrogen atom of the carboxyl group of the compound having an acid-labile group or a compound containing a carboxyl group in the ratio of 0 to 100 mol% is substituted with an average of 50 to 100 mol% as a whole. It is an acid-labile compound. Specifically, bisphenol A, phenol, phenol phenolphthalein, cresol novolac, naphthalene carboxylic acid, adamantane carboxylic acid, a hydroxyl group of cholic acid, a compound in which a hydrogen atom of a carboxyl group is substituted with an acid labile group, etc. For example, those described in paragraphs [0155] to [0178] of Japanese Patent Application Laid-Open No. 2008-122932.

When the photoresist material of the present invention is a positive type photoresist material, the content of the dissolution inhibitor is preferably 0 to 50 parts by mass, and more preferably 5 to 40 parts by mass relative to 100 parts by mass of the base polymer. The said dissolution inhibitor can be used individually by 1 type or in combination of 2 or more types.

Examples of the cross-linking agent include epoxy compounds, melamine compounds, guanamine compounds, glycoluril compounds or urea compounds, isocyanates substituted with at least one group selected from methylol, alkoxymethyl, and methyloxymethyl. Compounds, azide compounds, compounds containing double bonds such as allyl ether groups, and the like. They can be used as additives or can be introduced into the polymer side chain as a pendant group. Moreover, a hydroxyl-containing compound can also be used as a crosslinking agent. The crosslinking agent may be used singly or in combination of two or more kinds.

Examples of the epoxy compound include (2,3-epoxypropyl) isocyanurate, trimethylolmethane triglycidyl ether, trimethylolpropane triglycidyl ether, and trihydroxyethylethyl Alkane triglycidyl ether and the like.

Examples of the melamine compound include hexamethylolmelamine, hexamethoxymethylmelamine, a compound obtained by methoxymethylating 1 to 6 methylol groups of hexamethylolmelamine, a mixture thereof, or hexamethylol A compound obtained by methylation of 1 to 6 methylol groups of oxyethyl melamine, hexamethyloxymethyl melamine, hexamethylol melamine, or a mixture thereof.

Examples of the guanamine compounds include tetramethylolguanamine, tetramethoxymethylguanamine, compounds obtained by methoxymethylation of 1 to 4 methylol groups of tetramethylolguanamine, or Mixtures thereof, tetramethoxyethylguanamine, tetramethoxyguanamine, compounds obtained by methylation of 1 to 4 methylol groups of tetramethylolguanamine, or a mixture thereof.

Examples of glycoluril compounds include 1 to 4 methylol groups of tetramethylol glycoluril, tetramethoxyglycol urea, tetramethoxymethyl glycoluril, and tetramethylol glycoluril through methoxymethylation. The obtained compound, a mixture thereof, a compound obtained by methylating 1 to 4 hydroxymethyl groups of tetramethylol glycoluril, or a mixture thereof. Examples of the urea compound include tetramethylolurea, tetramethoxymethylurea, a compound obtained by methoxymethylating one to four methylol groups of tetramethylolurea, or a mixture thereof, tetramethylol Methoxyethylurea and the like.

Examples of the isocyanate compound include a tolyl diisocyanate, a diphenylmethane diisocyanate, a hexamethylene diisocyanate, and a cyclohexane diisocyanate.

Examples of the azide compound include 1,1'-biphenyl-4,4'-bisazide, 4,4'-methylene biazide, 4,4'-oxybisazide, and the like.

Examples of the eneether group-containing compound include ethylene glycol divinyl ether, triethylene glycol divinyl ether, 1,2-propylene glycol divinyl ether, 1,4-butanediol divinyl ether, and tetramethylene diethylene glycol. Alcohol divinyl ether, neopentyl glycol divinyl ether, trimethylolpropane trivinyl ether, hexanediol divinyl ether, 1,4-cyclohexanediol divinyl ether, neopentyl tetraol trivinyl ether, Neopentaerythritol tetravinyl ether, sorbitol tetravinyl ether, sorbitol pentavinyl ether, trimethylolpropane trivinyl ether, and the like.

When the photoresist material of the present invention is a negative type photoresist material, the content of the crosslinking agent is preferably 0.1 to 50 parts by mass, and more preferably 1 to 40 parts by mass relative to 100 parts by mass of the base polymer.

In the photoresist material of the present invention, a quencher may be blended. Examples of the quencher include conventional basic compounds. Conventional basic compounds include grades 1, 2, and 3 aliphatic amines, mixed amines, aromatic amines, heterocyclic amines, nitrogen-containing compounds with a carboxyl group, and nitrogen-containing compounds with a sulfonyl group. Compounds, nitrogen-containing compounds having a hydroxyl group, nitrogen-containing compounds having a hydroxyphenyl group, alcoholic nitrogen-containing compounds, amidines, amidines, carbamates, and the like. In particular, the primary, secondary, and tertiary amine compounds described in paragraphs [0146] to [0164] of Japanese Patent Application Laid-Open No. 2008-111103 include a hydroxyl group, an ether bond, an ester bond, a lactone ring, a cyano group, and a sulfonic acid. An amine compound having an ester bond or a urethane group-containing compound described in Japanese Patent No. 3790649 is preferred. By adding such a basic compound, for example, the diffusion rate of the acid in the photoresist film can be further suppressed, or the shape can be corrected.

Examples of the quencher include onium salts such as sulfonium salts, sulfonium salts, and ammonium salts of α-position unfluorinated sulfonic acids and carboxylic acids described in Japanese Patent Application Laid-Open No. 2008-158339. The α-fluorinated sulfonic acid, sulfamic acid, or methylated acid is necessary to deprotect the acid labile group of the carboxylic acid ester, but by exchanging with the salt of the α-unfluorinated onium salt, it will Unfluorinated sulfonic acid or carboxylic acid in alpha position is released. The unfluorinated sulfonic acid and carboxylic acid in the alpha position do not cause a deprotection reaction, so they act as quenchers.

It is also preferable to use an onium carboxylate salt represented by the following formula (1) as a quencher.
[Chemical 71]

In the formula (1), R ¹⁰¹ is a monovalent hydrocarbon group having 1 to 40 carbon atoms which may contain a hetero atom. The monovalent hydrocarbon group may be any of linear, branched, and cyclic. Specific examples include an alkyl group having 1 to 40 carbon atoms, an alkenyl group having 2 to 40 carbon atoms, and 2 to 40 carbon atoms. Alkynyl, aryl having 6 to 40 carbons, aralkyl having 7 to 40 carbons, and the like. In addition, part or all of the hydrogen atoms of these groups may be substituted with a hydroxyl group, a carboxyl group, a halogen atom, a cyano group, a fluorenylamino group, a nitro group, a thiol group, a sultone group, a fluorenyl group, or a sulfonium salt-containing group. A part of the carbon atoms of the isopropyl group may also be substituted with an ether bond, an ester bond, a carbonyl group, a carbonate group, or a sulfonate bond.

In the formula (1), M _A ⁺ represents an onium cation. Examples of the onium cation include a sulfonium cation, a sulfonium cation, and an ammonium cation. The sulfonium cation represented by the formula (A-3) or (A-4) or the sulfonium cation represented by the formula (A-5) is preferred.

The anion part of the said carboxylate is preferably represented by the following formula (2).
[Chemical 72]

In formula (2), R ¹⁰² and R ¹⁰³ are each independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group. R ¹⁰⁴ is a hydrogen atom, a hydroxyl group, or a monovalent hydrocarbon group having 1 to 35 carbon atoms which may contain a hetero atom. The aforementioned monovalent hydrocarbon group may be any of linear, branched, and cyclic, and specific examples thereof include an alkyl group having 1 to 35 carbon atoms, an alkenyl group having 2 to 35 carbon atoms, and 2 to 35 carbon atoms. Alkynyl, aryl having 6 to 35 carbons, aralkyl having 7 to 35 carbons, and the like. In addition, part or all of the hydrogen atoms of these groups may be substituted with a hydroxyl group, a carboxyl group, a halogen atom, a cyano group, a fluorenylamino group, a nitro group, a thiol group, a sultone group, a fluorenyl group, or a sulfonium-containing group. A part of the carbon atoms of the isopropyl group may also be substituted with an ether bond, an ester bond, a carbonyl group, a carbonate group, or a sulfonate bond.

The quencher may be a polymer-type quencher described in Japanese Patent Application Laid-Open No. 2008-239918. By aligning the photoresist surface after coating, the rectangularity of the photoresist after the pattern is improved. The polymer type quenching agent also has the effect of preventing the film loss of the pattern and the rounding of the top of the pattern when the protective film for the exposure is applied.

In the photoresist material of the present invention, the content of the quencher is preferably 0 to 5 parts by mass relative to 100 parts by mass of the base polymer, and more preferably 0 to 4 parts by mass. The quencher may be used singly or in combination of two or more kinds.

The photoresist material of the present invention may be blended with a water repellent enhancer for better water repellency on the photoresist surface after spin coating. The water repellent enhancer can be used in immersion lithography without top coating. The water repellent enhancer is preferably a polymer compound containing a fluorinated alkyl group, a polymer compound containing a specific structure of 1,1,1,3,3,3-hexafluoro-2-propanol residue, etc., Japan Illustrative examples such as JP 2007-297590 and JP 2008-111103 are more desirable. The aforementioned water repellent enhancer needs to be dissolved in an organic solvent developer. The aforementioned specific water-repellent enhancer having 1,1,1,3,3,3-hexafluoro-2-propanol residues has good solubility in a developing solution. As for the water repellent enhancer, a polymer compound containing a repeating unit of an amine group and an amine salt can prevent the acid in the PEB from evaporating and prevent poor opening of the pore pattern after development. The water repellent enhancer may be used alone or in combination of two or more. In the photoresist material of the present invention, the content of the water repellent enhancer is preferably 0 to 20 parts by mass, and more preferably 0.5 to 10 parts by mass relative to 100 parts by mass of the base polymer.

Acetyl alcohols can also be blended into the photoresist material of the present invention. Examples of the acetylene alcohols include those described in paragraphs [0179] to [0182] of Japanese Patent Application Laid-Open No. 2008-122932. In the photoresist material of the present invention, the content of acetylene alcohols is preferably 0 to 5 parts by mass relative to 100 parts by mass of the base polymer.

[Pattern forming method]
When the photoresist material of the present invention is used in the manufacture of various integrated circuits, a well-known lithography technique can be used.

For example, the positive photoresist material of the present invention is applied to a substrate (Si, SiO) for manufacturing integrated circuits by a suitable coating method such as spin coating, roll coating, flow coating, dip coating, spray coating, and doctor blade coating. _{2, SiN, SiON, TiN,} WSi, BPSG, SOG, organic antireflective film, etc.) or a mask for producing the circuit board (Cr, CrO, CrON, MoSi 2, SiO 2 , etc.) the coated film thickness 0.01 ~ 2.0 μm. It is preferably pre-baked on a hot plate under conditions of 60 to 150 ° C. for 10 seconds to 30 minutes, and more preferably at 80 to 120 ° C. for 30 seconds to 20 minutes. Secondly, the target pattern is exposed through a predetermined mask or directly using high-energy rays such as ultraviolet rays, extreme ultraviolet rays, EB, EUV, X-rays, soft X-rays, excimer lasers, gamma rays, synchrotron radiation, and the like. It is appropriate to perform exposure so that the exposure amount is about 1 to 200 mJ / cm ² , especially about 10 to 100 mJ / cm ² , or about 0.1 to 100 μC / cm ² , and particularly preferably about 0.5 to 50 μC / cm ² . Then, the PEB is preferably performed on the hot plate under the conditions of 60 to 150 ° C, 10 seconds to 30 minutes, and more preferably 80 to 120 ° C, 30 seconds to 20 minutes.

In addition, 0.1 to 10% by mass, preferably 2 to 5% by mass of tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide (TEAH), tetrapropylammonium hydroxide (TPAH), tetrabutylammonium The developing solution of alkali aqueous solution such as basic ammonium hydroxide (TBAH) is performed for 3 seconds to 3 minutes according to conventional methods such as dip method, puddle method, and spray method, and preferably 5 seconds to 2 It develops in minutes, thereby dissolving the irradiated portion in the developing solution and not dissolving the unexposed portion, and forming the intended positive pattern on the substrate. The case of negative photoresist is the opposite of the case of positive photoresist, that is, the lighted part is not dissolved in the developing solution, and the unexposed part is dissolved. In addition, the photoresist material of the present invention is particularly suitable for utilizing the fine patterning of KrF excimer laser, ArF excimer laser, EB, EUV, X-ray, soft X-ray, γ-ray, and synchrotron radiation in high-energy rays. .

It is also possible to use a positive-type photoresist material containing a base polymer containing an acid-labile group to perform negative development using organic solvent development to obtain a negative pattern. Examples of the developer used in this case include 2-octanone, 2-nonanone, 2-heptanone, 3-heptanone, 4-heptanone, 2-hexanone, 3-hexanone, diisobutanone, methyl Cyclohexanone, acetophenone, methylacetophenone, propyl acetate, butyl acetate, isobutyl acetate, pentyl acetate, butenyl acetate, isoamyl acetate, propyl formate, butyl formate, formic acid Isobutyl, amyl formate, isoamyl formate, methyl valerate, methyl pentenoate, methyl crotonic acid, ethyl crotonic acid, methyl propionate, ethyl propionate, 3-ethoxypropyl Ethyl acetate, methyl lactate, ethyl lactate, propyl lactate, butyl lactate, isobutyl lactate, amyl lactate, isoamyl lactate, methyl 2-hydroxyisobutyrate, ethyl 2-hydroxyisobutyrate Ester, methyl benzoate, ethyl benzoate, phenyl acetate, benzyl acetate, phenyl methyl acetate, benzyl formate, phenyl ethyl formate, methyl 3-phenylpropionate, benzyl propionate, Ethyl phenylacetate, 2-phenylethyl acetate, and the like. These organic solvents may be used alone or in combination of two or more.

Rinse at the end of development. The eluent is preferably a solvent that is miscible with the developing solution and does not dissolve the photoresist film. Such a solvent is preferably an alcohol having 3 to 10 carbons, an ether compound having 8 to 12 carbons, an alkane having 6 to 12 carbons, an olefin, an alkyne, or an aromatic solvent.

Specific examples of the alcohol having 3 to 10 carbon atoms include n-propanol, isopropanol, 1-butanol, 2-butanol, isobutanol, third butanol, 1-pentanol, 2-pentanol, 3-pentyl alcohol, tertiary 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-pentanol, 2-methyl-2-pentanol, 2-methyl-3-pentanol, 3-methyl-1 -Pentyl alcohol, 3-methyl-2-pentanol, 3-methyl-3-pentanol, 4-methyl-1-pentanol, 4-methyl-2-pentanol, 4-methyl-3 -Pentyl alcohol, cyclohexanol, 1-octanol and the like.

The ether compound having 8 to 12 carbon atoms can be selected from the group consisting of di-n-butyl ether, di-isobutyl ether, di-second butyl ether, di-n-pentyl ether, di-isopentyl ether, di-second pentyl ether, di-third pentyl ether, One or more solvents in di-n-hexyl ether.

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

Examples of the aromatic solvent include toluene, xylene, ethylbenzene, cumene, third butylbenzene, and mesitylene.

By rinsing, the collapse of the photoresist pattern and the occurrence of defects can be reduced. In addition, leaching is not necessary, and the amount of solvent used can be reduced by not performing leaching.

Shrinking can also be performed by using the heat flow, RELACS technology, or DSA technology to make the hole pattern and trench pattern after development. The shrinkage agent is coated on the hole pattern, and the cross-linking of the shrinkage agent occurs on the surface of the photoresist by the diffusion of the acid catalyst from the photoresist layer in the baking, and the shrinkage agent adheres to the sidewall of the hole pattern. The baking temperature is preferably 70 to 180 ° C, more preferably 80 to 170 ° C, and the time is preferably 10 to 300 seconds. The excess shrinkage agent is removed to reduce the hole pattern.
[Example]

The present invention will be specifically described by the following synthesis examples, examples, and comparative examples, but the present invention is not limited to the following examples.

The structures of the acid generators PAG1 to PAG21 used in the photoresist material are as follows. PAG1 ~ PAG21 are synthesized by ion exchange of ammonium salt of fluorosulfonic acid containing iodized benzene ring given the following anion, and osmium chloride or rhenium chloride given the following cation.

[Chemical 73]

[Chemical 74]

[Chemical 75]

[Synthesis example] Synthesis of base polymers (Polymers 1-9, Comparative Polymers 1, 2) The monomers were combined and copolymerized in a THF solvent, precipitated into methanol, and washed repeatedly with hexane. Isolate and dry to obtain a base polymer (Polymers 1-9, Comparative Polymers 1, 2) with the composition shown below. The composition of the obtained base polymer was confirmed by ¹ H-NMR, and Mw and the degree of dispersion (Mw / Mn) were confirmed by GPC (solvent: THF, standard: polystyrene).

[Chemical 76]

[Chemical 77]

[Chem. 78]

[Chemical 79]

[Examples and Comparative Examples]
The components shown in Tables 1 and 2 were dissolved in a solution in which 100 ppm of 3M Corporation's FC-4430 solvent was dissolved in a solvent, and filtered through a 0.2 μm filter to prepare a photoresist material.

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

Comparative acid generator: Compare PAG1 and 2 (refer to the following structural formula)
[Chemical 80]

Quenching agent 1, 2 (refer to the following structural formula)
[Chem. 81]

[EUV exposure evaluation]
[Examples 1 to 29, Comparative Examples 1 to 4]
Each photoresist material shown in Tables 1 and 2 was spin-coated on a silicon coating made of Shin-Etsu Chemical Industry Co., Ltd. having a film thickness of 20 nm, containing a spin-coated hard mask SHB-A940 (the content of silicon was 43% by mass). The Si substrate was pre-baked at 105 ° C for 60 seconds using a hot plate to prepare a photoresist film with a thickness of 60 nm. It was exposed using ASML's EUV scanning exposure machine NXE3300 (NA0.33, σ0.9 / 0.6, quadrupole illumination, mask on the wafer with a hole pattern with a pitch of 46nm and a + 20% deviation), and exposed it on a hot plate PEB was performed at the temperatures described in Tables 1 and 60 for 60 seconds, and developed with a 2.38% by mass TMAH aqueous solution for 30 seconds. Positive photoresist patterns (hole patterns with a size of 23 nm) were formed in Examples 1 to 28 and Comparative Examples 1 to 3. In Example 29 and Comparative Example 4, a negative photoresist pattern (a dot pattern with a size of 23 nm) was formed.
Using a length measurement SEM (CG5000) manufactured by Hitachi Advanced Technology Co., Ltd., measure the exposure when a hole or dot is formed at 23 nm, define it as the sensitivity, and determine the size of 50 holes or dots at this time, and find the CDU (size variation 3σ).
The results are shown in Tables 1 and 2.

【Table 1】

【Table 2】

According to the results of Tables 1 and 2, the photoresist material of the present invention containing a polymer containing an iodine atom and an onium fluorosulfonate containing an iodized benzene ring as an acid generator has high sensitivity and good CDU.

Claims (17)

A photoresist material comprises: a base polymer, a polymer containing an iodine atom; and an acid generator, a sulfonium salt and / or a sulfonium salt of a fluorosulfonic acid containing an iodized benzene ring. For example, the photoresist material in the scope of application for patent No. 1 wherein the phosphonium salt and phosphonium salt of the fluorosulfonic acid containing iodinated benzene ring are each a phosphonium salt represented by the following formula (A-1) and the following formula (A-2 ) Represented by phosphonium salt; [化 82] In the formula, L ¹ is a single bond, an ether bond or an ester bond, or an alkyl group having 1 to 6 carbon atoms which may also contain an ether bond or an ester bond; R ¹ is a hydroxyl group, a carboxyl group, a fluorine atom, a chlorine atom, or a bromine atom. Or an amine group, or a fluorine atom, a chlorine atom, a bromine atom, a hydroxyl group, an amine group, or an alkoxy group having 1 to 10 carbon atoms, an alkyl group having 1 to 20 carbon atoms, or an alkoxy group having 1 to 20 carbon atoms , An alkoxycarbonyl group having 2 to 10 carbon atoms, a fluorenyl group having 2 to 20 carbon atoms or an alkylsulfonyloxy group having 1 to 20 carbon atoms, or -NR ⁸ -C (= O) -R ⁹ or -NR ⁸ -C (= O) -OR ⁹ , R ⁸ is a hydrogen atom, or may contain a halogen atom, a hydroxyl group, an alkoxy group having 1 to 6 carbon atoms, a fluorenyl group having 2 to 6 carbon atoms, or 2 carbon atoms A alkoxy group of 6 to 6 carbons having an alkyl group of 1 to 6, R ⁹ is an alkyl group having 1 to 16 carbons, an alkenyl group having 2 to 16 carbons, or an aryl group having 6 to 12 carbons, and may also contain Halogen atom, hydroxyl group, alkoxy group with 1 to 6 carbon atoms, fluorenyl group with 2 to 6 carbon atoms, or fluorenyl group with 2 to 6 carbon atoms; R ² is a single bond or 1 to 6 carbon atoms when p is 1 The divalent linking group of 20 is a trivalent or tetravalent linking group having 1 to 20 carbon atoms when p is 2 or 3. The linking group may also contain an oxygen atom, a sulfur atom, or a nitrogen atom; each of Rf ¹ to Rf ⁴ Independently hydrogen atom, fluorine Atom or trifluoromethyl, but at least one of these is a fluorine atom or trifluoromethyl; Rf ¹ and Rf ² may also be combined to form a carbonyl group; R ³ , R ⁴ , R ⁵ , R ⁶ and R ^{7 is} independently a monovalent hydrocarbon group having 1 to 20 carbon atoms which may also contain a hetero atom; and any of R ³ , R ^4, and R ⁵ may be bonded to each other and the sulfur to which they are bonded The atoms together form a ring; p is an integer that conforms to 1 ≦ p ≦ 3; q and r are integers that conform to 1 ≦ q ≦ 5, 0 ≦ r ≦ 3, and 1 ≦ q + r ≦ 5. For example, the photoresist material of the scope of application for the patent item 1 or 2, wherein the polymer containing iodine atom contains a repeating unit represented by the following formula (a1) or (a2); In the formula, R ^{A is} each independently a hydrogen atom or a methyl group; R ²¹ is a single bond or a methylene group; R ²² is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms; X ¹ is a single bond, an ether bond, Ester bond, amido bond, -C (= O) -OR ^23- , phenylene, -Ph-C (= O) -OR ^24- , or -Ph-R ²⁵ -OC (= O) -R ²⁶ -, Ph is a phenylene group; R ²³ is an alkylene group having 1 to 10 carbon atoms, and may also contain an ether bond or an ester bond; R ²⁴ , R ²⁵ and R ²⁶ are each independently a single bond, or a linear or Branched alkyl groups having 1 to 6 carbon atoms; m and n are integers conforming to 1 ≦ m ≦ 5, 0 ≦ n ≦ 4, and 1 ≦ m + n ≦ 5. For example, the photoresist material of item 3 of the patent application range, wherein n is an integer from 1 to 3. For example, the photoresist material in the first or second patent application range contains an organic solvent. For example, the photoresist material according to item 1 or 2 of the patent application scope, wherein the polymer containing an iodine atom further contains a repeating unit represented by the following formula (b1) or a repeating unit represented by the following formula (b2); In the formula, R ^{A is} each independently a hydrogen atom or a methyl group; Y ¹ is a single bond, phenylene or naphthyl group, or a linking group having 1 to 12 carbon atoms containing an ester bond or a lactone ring; Y ² is Single bond or ester bond; R ³¹ and R ³² are each independently an acid labile group; R ³³ is a fluorine atom, a trifluoromethyl group, a cyano group, an alkyl group having 1 to 6 carbons, and an alkyl group having 1 to 6 carbons Oxygen group, fluorenyl group with 2 to 7 carbon atoms, fluorenyl group with 2 to 7 carbon atoms, or alkoxycarbonyl group with 2 to 7 carbon atoms; R ³⁴ is a single bond or alkylene group with 1 to 6 carbon atoms And a part of its carbon atom may be replaced by an ether bond or an ester bond; t is 1 or 2, and s is an integer of 0 to 4, but 1 ≦ t + s ≦ 5. For example, the photoresist material in the patent application No. 6 contains a dissolution inhibitor. For example, the photoresist material in the patent application No. 6 is a chemically amplified positive photoresist material. For example, the photoresist material according to the first or second aspect of the patent application, wherein the polymer containing iodine atoms does not contain acid labile groups. For example, the photoresist material in item 9 of the patent application scope further contains a crosslinking agent. For example, the photoresist material in the scope of patent application No. 9 is a chemically amplified negative photoresist material. For example, the photoresist material in the scope of patent application No. 1 or 2 contains a quencher. For example, the photoresist material in the scope of patent application No. 1 or 2 further contains a surfactant. For example, the photoresist material according to item 1 or 2 of the patent application scope, wherein the polymer containing iodine atom further contains at least one kind selected from the repeating units represented by the following formulae (g1) to (g3); [化 85] In the formula, R ^{A is} each independently a hydrogen atom or a methyl group; Z ¹ is a single bond, phenylene, -OZ ^12- , or -C (= O) -Z ¹¹ -Z ^12- , and Z ¹¹ is -O -Or -NH-, Z ¹² is an alkylene group having 1 to 6 carbon atoms, or an alkenyl group having 2 to 6 carbon atoms, or phenylene group, and may also contain a carbonyl group, an ester bond, an ether bond, or a hydroxyl group; Z ² is Single bond, -Z ²¹ -C (= O) -O-, -Z ²¹ -O- or -Z ²¹ -OC (= O)-, Z ²¹ is an alkylene group having 1 to 12 carbon atoms, and may contain Carbonyl, ester or ether bond; A is a hydrogen atom or a trifluoromethyl group; Z ³ is a single bond, methylene, ethylidene, phenylene, fluorinated phenylene, -OZ ³² -or -C ( = O) -Z ³¹ -Z ^32- , Z ³¹ is -O- or -NH-, Z ³² is alkylene, phenylene, fluorinated phenylene, trifluoromethyl Substituted phenyl groups or alkenyl groups having 2 to 6 carbon atoms may also contain carbonyl groups, ester bonds, ether bonds, or hydroxyl groups; R ⁴¹ to R ⁴⁸ are each independently a carbon number 1 to 20 that may also contain hetero atoms. A monovalent hydrocarbon group; or any one of R ⁴³ , R ⁴⁴ and R ⁴⁵ or any of R ⁴⁶ , R ⁴⁷ and R ⁴⁸ may be bonded to each other and the sulfur atom to which they are bonded together form a ring; Q ^- represents a non-nucleophilic relative ion A pattern forming method includes the following steps: Applying the photoresist material according to any of claims 1 to 14 on the substrate and applying heat treatment to form a photoresist film; exposing the photoresist film with high-energy rays; and using a developing solution to The exposed photoresist film is developed. For example, the pattern forming method according to item 15 of the application, wherein the high-energy ray is an ArF excimer laser having a wavelength of 193 nm or a KrF excimer laser having a wavelength of 248 nm. For example, the pattern forming method according to item 15 of the application, wherein the high-energy rays are electron beams or extreme ultraviolet rays having a wavelength of 3 to 15 nm.