JP6468139B2 - Monomer, polymer compound, resist material and pattern forming method - Google Patents

Description

  The present invention relates to a functional material, a monomer useful as a raw material for pharmaceuticals and agricultural chemicals, a polymer compound containing a repeating unit derived from the monomer, a resist material containing the polymer compound, and the resist material. The present invention relates to the pattern forming method used.

  With the high integration and high speed of LSI, pattern rule miniaturization is progressing rapidly. In particular, the expansion of the flash memory market and the increase in storage capacity are leading to miniaturization. As a state-of-the-art miniaturization technology, a film is formed on the side walls on both sides of an ArF lithography pattern, and a double-patterning (SADP) device that forms two patterns with a half line width from one pattern is used for a 20 nm node stage device. Mass production is in progress. As a next-generation 10nm node microfabrication technology, SAQP that repeats SADP twice is a candidate, but it is pointed out that this process of repeating sidewall film formation by CVD and processing by dry etching is very expensive. ing. Extreme ultraviolet (EUV) lithography with a wavelength of 13.5 nm can form patterns with dimensions on the order of 10 nm with a single exposure, but has the problem of low laser power and low productivity. Development of three-dimensional devices such as flash memories stacked in the vertical direction typified by BiCS is being promoted due to the dead end of microfabrication, which is also an expensive process.

  In recent years, organic solvent development has attracted attention again. A negative pattern is formed by organic solvent development using a positive resist material with high resolution. As an ArF resist material for negative tone development using an organic solvent, a conventional positive ArF resist material can be used, and Patent Document 1 discloses a pattern forming method using the same.

  In the method of forming a negative pattern by organic solvent development, a film from which a rigid protective group such as an annular structure having dry etching resistance is removed remains as a negative pattern, so that dry etching resistance is insufficient. For this reason, the big subject remains in the negative pattern formation by organic solvent image development.

  On the other hand, a method for forming a negative pattern by development with an alkaline aqueous solution has been studied. As the resist material used in the above method, a negative-polarity-type resist material having a γ-hydroxycarboxylic acid in the repeating unit of the base resin and forming a lactone ring by heating after exposure (Patent Document 2), alcoholic A negative resist material (Patent Document 3), a α-hydroxyacrylate and a lactone unit (Patent Document 3) using a copolymer containing a hydroxy group-containing (meth) acrylate unit and a fluoroalcohol-containing unit as a base resin. 4) Crosslinker-crosslinking negative resist materials in which α-hydroxyacrylate and various fluoroalcohol units (Patent Documents 5 to 7), mono (meth) acryloyloxypinacol units and fluoroalcohol units (Patent Document 8) are combined. Etc.

  Among these, the one described in Patent Document 1 is a polarity conversion negative resist material that is not a crosslinking reaction, but the γ-hydroxycarboxylic acid unit caused swelling of the pattern after development. On the other hand, those described in Patent Documents 2 to 7 are cross-linked negative resist materials. In the negative pattern formation with an alcoholic hydroxy group or the like and a crosslinking agent, there is a problem that bridging between patterns or pattern collapse is likely to occur due to swelling, but the effect of reducing swelling was confirmed by introduction of fluoroalcohol units. In addition, as a recent example of forming a negative polarity pattern of a polarity change type, a base resin having a polar unit such as a tertiary hydroxy group, a tertiary ether bond, a tertiary ester bond or an acetal bond as a polarity changing group Has been proposed. Among these, by using a polar unit having one tertiary hydroxy group, it has been confirmed that it is difficult to swell after development, but on the other hand, there is a difference in dissolution rate between the unexposed part and the exposed part in the developer. Since it is not sufficient, there is a problem that the bottom of the pattern has a skirt in the line and space pattern, or a so-called tapered shape (Patent Documents 9 to 10, Non-Patent Document 1).

  All of the above-described negative pattern formation methods have achieved certain results in pattern formation on the order of 100 nm, but in pattern formation of 100 nm and smaller, bridges and collapses due to pattern swelling, and the bottom of the pattern bottoms. Etc. are inevitable, and the performance is insufficient. In a negative pattern forming process by organic solvent development that has been intensively studied in recent years, the cost of an organic solvent used for a developer is higher than that of a conventional alkaline developer. From the standpoint of improving etching resistance, a high-resolution negative resist material that has a rigid main chain structure remaining in the film and can be subjected to conventional alkali development is desired.

Japanese Patent No. 4554665 JP 2003-195502 A International Publication No. 2004/074936 Japanese Patent Laid-Open No. 2005-3862 Japanese Patent Laid-Open No. 2005-3863 JP 2006-145775 A JP 2006-317803 A JP 2006-215067 A US Pat. No. 7,300,929 US Pat. No. 7,563,558

Proc. SPIE vol. 5376, p71 (2004)

  In recent years, where the demand for miniaturization is severe, in negative pattern formation by organic solvent development, which is being studied, the negative pattern remaining on the resist film has a lower carbon density than before exposure. Therefore, it is a problem to maintain the resistance in the etching process and the pattern shape after the etching.

  The present invention has been made in view of the above circumstances, and a polymerizable monomer having a substituent whose polarity is changed by the action of an acid, a polymer compound obtained from the monomer, and the polymer compound as a base resin It is an object of the present invention to provide a resist material to be contained and a pattern forming method using the resist material.

  As a result of intensive studies to achieve the above object, the present inventors can easily obtain a monomer represented by the formula (1) described later, and resist a polymer compound obtained from the monomer as a resist. It has been found that by using it as a base resin of a material, it is possible to form a negative pattern insoluble in an alkaline developer having high resolution and excellent etching resistance, and the present invention has been completed.

［式中、Ｒ¹は、水素原子又はメチル基を表す。Ｒ²及びＲ³は、それぞれ独立に、炭素数１〜１０の直鎖状、分岐状又は環状の１価炭化水素基を表し、Ｒ²とＲ³とは、互いに結合してこれらが結合する炭素原子と共に脂環基を形成してもよい。Ｘ¹は、炭素数１〜２０の直鎖状、分岐状又は環状の２価炭化水素基を表し、該２価炭化水素基を構成する−ＣＨ₂−が、−Ｏ−又は−Ｃ(＝Ｏ)−で置換されていてもよい。ｋ ¹は、０又は１を表す。ｋ²は、２〜４の整数を表す。Ｚ ¹ は、下記式で表される基を表す。

（式中、破線は結合手を示す。）］
［２］Ｚ¹が、炭素数３〜２０の環状の脂肪族炭化水素基である［１］の単量体。
［３］下記式（３）で表される繰り返し単位を含むことを特徴とする高分子化合物。

［式中、Ｒ¹は、水素原子又はメチル基を表す。Ｒ²及びＲ³は、それぞれ独立に、炭素数１〜１０の直鎖状、分岐状又は環状の１価炭化水素基を表し、Ｒ²とＲ³とは、互いに結合してこれらが結合する炭素原子と共に脂環基を形成してもよい。Ｘ¹は、炭素数１〜２０の直鎖状、分岐状又は環状の２価炭化水素基を表し、該２価炭化水素基を構成する−ＣＨ₂−が、−Ｏ−又は−Ｃ(＝Ｏ)−で置換されていてもよい。ｋ ¹は、０又は１を表す。ｋ²は、２〜４の整数を表す。Ｚ ¹ は、下記式で表される基を表す。

（式中、破線は結合手を示す。）］
［４］更に、下記式（Ａ）〜（Ｄ）で表される繰り返し単位から選ばれる少なくとも１種を含む［３］の高分子化合物。

（式中、Ｒ¹は前記と同じ。Ｚ^Aは、炭素数１〜２０のフルオロアルコール含有置換基を表す。Ｚ^Bは、炭素数１〜２０のフェノール性ヒドロキシ基含有置換基を表す。Ｚ^Cは、炭素数１〜２０のカルボキシル基含有置換基を表す。Ｚ^Dは、ラクトン骨格、スルトン骨格、カーボネート骨格、環状エーテル骨格、酸無水物骨格、アルコール性ヒドロキシ基、アルコキシカルボニル基、スルホンアミド基又はカルバモイル基を含有する置換基を表す。Ｘ²は、単結合、メチレン基、エチレン基、フェニレン基、フッ素化されたフェニレン基、ナフチレン基、−Ｏ−Ｒ⁰¹−、又は−Ｃ(＝Ｏ)−Ｚ²−Ｒ⁰¹−を表し、Ｚ²は、酸素原子又はＮＨを表し、Ｒ⁰¹は、炭素数１〜６の直鎖状、分岐状若しくは環状のアルキレン基、炭素数２〜６の直鎖状、分岐状若しくは環状のアルケニレン基、フェニレン基、又はナフチレン基を表し、カルボニル基、エステル基、エーテル基又はヒドロキシ基を含んでいてもよい。）
［５］［３］又は［４］の高分子化合物を含むベース樹脂、酸発生剤及び有機溶剤を含有するレジスト材料。
［６］架橋剤を含まない［５］のレジスト材料。
［７］［５］又は［６］のレジスト材料を基板上に塗布してレジスト膜を形成し、加熱処理後に高エネルギー線で前記レジスト膜を露光し、加熱処理後に現像液を用いてパターンを得ることを特徴とするパターン形成方法。
［８］アルカリ現像液を用いて未露光部を溶解させ、露光部が溶解しないネガ型パターンを得る［７］のパターン形成方法。 That is, the present invention provides the following monomer, polymer compound, resist material, and pattern formation method.
[1] A monomer represented by the following formula (1).

[ Wherein, R ¹ represents a hydrogen atom or a methyl group. R ² and R ³ each independently represent a linear, branched or cyclic monovalent hydrocarbon group having 1 to 10 carbon atoms, and R ² and R ³ are bonded to each other. You may form an alicyclic group with a carbon atom. X ¹ represents a linear, branched or cyclic divalent hydrocarbon group having 1 to 20 carbon atoms, and —CH ₂ — constituting the divalent hydrocarbon group is —O— or —C (= Optionally substituted with O)- . k ¹ represents 0 or 1. k ² represents an integer of 2 to 4. Z ¹ represents a group represented by the following formula.

(In the formula, a broken line indicates a bond.)]
[2] The monomer according to [1], wherein Z ¹ is a cyclic aliphatic hydrocarbon group having 3 to 20 carbon atoms.
[3] A polymer compound comprising a repeating unit represented by the following formula (3).

[ Wherein, R ¹ represents a hydrogen atom or a methyl group. R ² and R ³ each independently represent a linear, branched or cyclic monovalent hydrocarbon group having 1 to 10 carbon atoms, and R ² and R ³ are bonded to each other. You may form an alicyclic group with a carbon atom. X ¹ represents a linear, branched or cyclic divalent hydrocarbon group having 1 to 20 carbon atoms, and —CH ₂ — constituting the divalent hydrocarbon group is —O— or —C (= Optionally substituted with O)- . k ¹ represents 0 or 1. k ² represents an integer of 2 to 4. Z ¹ represents a group represented by the following formula.

(In the formula, a broken line indicates a bond.)]
[4] The polymer compound according to [3], further comprising at least one selected from repeating units represented by the following formulas (A) to (D).

(In the formula, R ¹ is the same as described above. Z ^A represents a fluoroalcohol-containing substituent having 1 to 20 carbon atoms. Z ^B represents a phenolic hydroxy group-containing substituent having 1 to 20 carbon atoms. Z ^C represents a carboxyl group-containing substituent having 1 to 20 carbon atoms Z ^D is a lactone skeleton, a sultone skeleton, a carbonate skeleton, a cyclic ether skeleton, an acid anhydride skeleton, an alcoholic hydroxy group, an alkoxycarbonyl group, a sulfonamide X ² represents a single bond, a methylene group, an ethylene group, a phenylene group, a fluorinated phenylene group, a naphthylene group, —O—R ⁰¹ —, or —C (= O) —Z ² —R ⁰¹ —, Z ² represents an oxygen atom or NH, R ⁰¹ represents a linear, branched or cyclic alkylene group having 1 to 6 carbon atoms, or 2 to 6 carbon atoms. Linear, branched Or cyclic alkenylene group, a phenylene group, or a naphthylene group, a carbonyl group, an ester group, which may contain an ether or hydroxyl group.)
[5] A resist material containing a base resin containing the polymer compound of [3] or [4], an acid generator and an organic solvent.
[6] The resist material according to [5], which does not contain a crosslinking agent.
[ 7 ] The resist material of [5] or [6] is applied onto a substrate to form a resist film, the resist film is exposed with high energy rays after heat treatment, and a pattern is formed using a developer after the heat treatment. A pattern forming method characterized in that it is obtained.
[ 8 ] The pattern forming method according to [ 7 ], wherein an unexposed portion is dissolved using an alkali developer to obtain a negative pattern in which the exposed portion is not dissolved.

The monomer of the present invention has excellent transparency to radiation having a wavelength of 500 nm or less, particularly 300 nm or less, such as KrF laser light, ArF laser light, and F ₂ laser light, and has excellent development characteristics. It is very useful as a polymer raw material monomer for producing a base resin of a radiation resist material. When a polymer compound containing a repeating unit derived from the monomer of the present invention is used as a base resin for a resist material, a negative pattern insoluble in an alkaline developer having high resolution and excellent etching resistance can be formed. .

  Hereinafter, the present invention will be described in detail. In the following description, there is an asymmetric carbon depending on the structure represented by the chemical formula, and there may be an enantiomer or a diastereomer. These isomers are represented by the formula. These isomers may be used alone or as a mixture.

[Monomer]
The monomer of the present invention is represented by the following formula (1).

In the formula, R ¹ represents a hydrogen atom or a methyl group. R ² and R ³ each independently represent a linear, branched or cyclic monovalent hydrocarbon group having 1 to 10 carbon atoms, and R ² and R ³ are bonded to each other. You may form an alicyclic group with a carbon atom. X ¹ represents a linear, branched or cyclic divalent hydrocarbon group having 1 to 20 carbon atoms, and —CH ₂ — constituting the divalent hydrocarbon group is —O— or —C (= Optionally substituted with O)-. Z ¹ represents a linear, branched or cyclic aliphatic hydrocarbon group having 1 to 20 carbon atoms, and —CH ₂ — constituting the aliphatic hydrocarbon group is —O— or —C (= Optionally substituted with O)-. k ¹ represents 0 or 1. k ² represents an integer of 2 to 4.

  Examples of the linear, branched or cyclic monovalent hydrocarbon group having 1 to 10 carbon atoms include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, s-butyl group, and t-butyl group. And alkyl groups such as cyclopentyl group, cyclohexyl group, 2-ethylhexyl group, n-octyl group, norbornyl group, tricyclodecanyl group and adamantyl group.

（式中、破線は結合手を示す。） Examples of the linear, branched or cyclic divalent hydrocarbon group having 1 to 20 carbon atoms include, but are not limited to, those shown below.

(In the formula, a broken line indicates a bond.)

（式中、破線は結合手を示す。） Examples of the linear, branched or cyclic aliphatic hydrocarbon group having 1 to 20 carbon atoms include, but are not limited to, those shown below.

(In the formula, a broken line indicates a bond.)

（式中、Ｒ¹〜Ｒ³、Ｘ¹、ｋ¹及びｋ²は前記と同じ。Ｒ⁵及びＲ⁶は、水素原子を表すか、Ｒ⁵及びＲ⁶が互いに結合して、置換基を有していてもよいメチレン基若しくはエチレン基、又は−Ｏ−を形成してもよい。） Among these, Z ^1, preferably a cyclic aliphatic hydrocarbon group having 3 to 20 carbon atoms, particularly those having a cyclohexane ring skeleton (including bridged ring norbornane ring) is preferred. In this case, examples of the monomer of the present invention include, but are not limited to, those represented by the following formula (2).

(In the formula, R ^{1 to} R ³ , X ¹ , k ¹ and k ² are the same as above. R ⁵ and R ⁶ represent a hydrogen atom, or R ⁵ and R ⁶ are bonded to each other to form a substituent. Methylene group or ethylene group which may have, or -O- may be formed.)

Specific examples of the repeating unit derived from the monomer represented by the formula (1) include, but are not limited to, those shown below.

（式中、Ｒ¹〜Ｒ³、Ｘ¹、Ｚ¹、ｋ¹及びｋ²は前記と同じ。Ｒ⁴は、炭素数１〜１０の直鎖状、分岐状又は環状の１価炭化水素基を表す。Ｘ³は、ハロゲン原子、ヒドロキシ基又はアシルオキシ基を表す。Ｍは、Ｌｉ、Ｎａ、Ｋ、ＭｇＸ、又はＺｎＸを表し、Ｘは、ハロゲン原子を表す。） The monomer represented by the formula (1) can be obtained by, for example, the reaction shown in the following scheme A, but is not limited thereto.

(Wherein R ^{1 to} R ³ , X ¹ , Z ¹ , k ¹ and k ² are the same as above. R ⁴ is a linear, branched or cyclic monovalent hydrocarbon group having 1 to 10 carbon atoms. X ³ represents a halogen atom, a hydroxy group, or an acyloxy group, M represents Li, Na, K, MgX, or ZnX, and X represents a halogen atom.)

  The first step is a step of obtaining the polyol compound (6) by an addition reaction between the hydroxy ester compound (4) and the organometallic reagent (5).

The reaction can be carried out according to a conventional method. For example, the hydroxy ester compound (4) is dissolved in an ether solvent such as tetrahydrofuran or diethyl ether, and substituents R ² and R ³ such as Grignard reagents such as methyl magnesium chloride and ethyl magnesium chloride, alkyl lithium reagents such as methyl lithium, etc. A polyol compound (6) having a tertiary alcohol can be obtained by adding an organometallic reagent (5) corresponding to. The amount of the organometallic reagent (5) used is preferably 3.0 to 10.0 moles and more preferably 3.0 to 5.0 moles with respect to 1 mole of the ester group of the hydroxy ester compound (4). When the amount of the organometallic reagent (5) used is less than 3.0 mol, 1 mol of the organometallic reagent (5) is consumed for the hydroxy group of the hydroxy ester compound (4). In some cases, the reaction may not be completed. On the other hand, if the amount exceeds 10.0 mol, the cost may be disadvantageous due to an increase in raw material costs. The reaction can be carried out by cooling or heating, if necessary, but is usually carried out in the range of 0 ° C. to the boiling point of the solvent. The reaction time is preferably about 0.5 to 24 hours, although it is desirable in terms of yield to follow the reaction by gas chromatography (GC) or silica gel thin layer chromatography (TLC) to complete the reaction. The polyol compound (6) can be obtained from the reaction mixture by ordinary aqueous work-up, and can be purified according to conventional methods such as distillation, chromatography, recrystallization and the like if necessary.

  The second step is a step of obtaining the monomer (1) by reacting the esterifying agent (7) with the polyol compound (6).

The reaction can be carried out according to a conventional method. Examples of the esterifying agent (7) include acid chloride (when X ³ is a chlorine atom in formula (7)), carboxylic acid (when X ³ is a hydroxy group in formula (7)), or acid anhydride (formula ( 7) is particularly preferred when X ³ is an acyloxy group. When acid chloride is used, in the absence of solvent or in a solvent such as methylene chloride, acetonitrile, toluene, hexane, etc., polyol compound (6), the corresponding acid chloride such as methacryloyl chloride, triethylamine, pyridine, 4-dimethylaminopyridine, etc. These bases may be added sequentially or simultaneously and cooled or heated as necessary. In the case of using carboxylic acid, the polyol compound (6) and the corresponding carboxylic acid such as methacrylic acid are heated in the presence of an acid catalyst in a solvent such as toluene or hexane, and water generated as necessary is removed from the system. It is better to remove it. Examples of the acid catalyst include inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid and perchloric acid, and organic acids such as p-toluenesulfonic acid and benzenesulfonic acid. When an acid anhydride is used, a polyol compound (6), a corresponding acid anhydride such as methacrylic acid anhydride, triethylamine, pyridine, 4- A base such as dimethylaminopyridine may be added sequentially or simultaneously, and cooled or heated as necessary. The reaction time is preferably about 0.5 to 24 hours, although it is desirable in terms of yield to follow the reaction by gas chromatography (GC) or silica gel thin layer chromatography (TLC) to complete the reaction. The monomer (1) can be obtained from the reaction mixture by ordinary aqueous work-up, and if necessary, it can be purified according to conventional methods such as distillation, chromatography, recrystallization and the like.

（式中、Ｒ¹、Ｒ⁵、Ｒ⁶、Ｘ¹、Ｘ³及びｋ¹は前記と同じ。Ｒ⁷は、水素原子又はアシル基を表す。） As a specific example of the method for producing the monomer represented by the formula (2), a method for obtaining the monomer (2-1) in the case where R ² and R ³ are both methyl groups and k ² is 2. Is shown in Scheme B below.

(In the formula, R ¹ , R ⁵ , R ⁶ , X ¹ , X ³ and k ¹ are the same as described above. R ⁷ represents a hydrogen atom or an acyl group.)

The first step is a step of obtaining a triol compound (9) by reacting a Grignard reagent with the lactone compound (8). The triol compound (9) having a tertiary alcohol can be obtained by dissolving the lactone compound (8) in an ether solvent such as tetrahydrofuran or diethyl ether and adding methylmagnesium chloride. The amount of methylmagnesium chloride used is preferably 3.0 to 10.0 moles, more preferably 3.0 to 5.0 moles relative to the lactone compound (8). If the amount of methylmagnesium chloride used is less than 3.0 mol, 1 to 2 mol of methylmagnesium chloride is consumed in the substituent —OR ⁷ of the lactone compound (8), and the addition reaction to the lactone is not completed. In some cases, if it exceeds 10.0 moles, it may be disadvantageous in terms of cost due to an increase in raw material costs. The reaction can be carried out by cooling or heating, if necessary, but is usually carried out in the range of 0 ° C. to the boiling point of the solvent. The reaction time is preferably about 0.5 to 24 hours, although it is desirable in terms of yield to follow the reaction by gas chromatography (GC) or silica gel thin layer chromatography (TLC) to complete the reaction. The triol compound (9) can be obtained from the reaction mixture by ordinary aqueous work-up, and if necessary, can be purified according to conventional methods such as distillation, chromatography, recrystallization and the like.

  The second step is a step of obtaining the monomer (2-1) by reacting the esterifying agent (7) with the triol compound (9). The reaction conditions are the same as the reaction of the polyol compound (6) and the esterifying agent (7).

（式中、Ｒ¹、Ｒ²、Ｒ³、Ｘ¹、Ｚ¹、ｋ¹及びｋ²は前記と同じ。） [Polymer compound]
The polymer compound of the present invention contains a repeating unit represented by the following formula (3), and the repeating unit is derived from a monomer represented by the formula (1).

(In the formula, R ¹ , R ² , R ³ , X ¹ , Z ¹ , k ¹ and k ² are the same as above.)

The polymer compound of the present invention is a (meth) acrylate polymer having a plurality of tertiary alcoholic hydroxy groups which are acid labile groups. The following scheme shows, as an example, the case of the polymer compound (3a) in which R ² and R ³ are methyl groups and k ² is 2. When the polymer compound of the present invention is used as a base resin component of a resist material, exposure is performed. Water molecules are desorbed (hereinafter referred to as dehydration) by the action of the strong acid generated in the part, and the structure of the repeating unit changes. Depending on the structure of Z ^1, the formation of multiple olefins by dehydration (Route A) and the reaction (Route B) that forms a ring such as an oxetane ring or a tetrahydrofuran ring occurs in the molecule as a result of dehydration. It is thought to do. Before exposure, due to the presence of multiple high polar and hydrophilic groups, the affinity and solubility in alkali developer are high.However, the exposed area after exposure loses several hydroxy groups, so it is soluble in alkali developer. It drops significantly and becomes insoluble in the developer. In addition, only water molecules are lost after the polarity change, and the change in carbon density is extremely small. In particular, when a cyclic hydrocarbon group is included in the skeleton, only a change in polarity occurs while maintaining a rigid alicyclic skeleton. That is, the polymer compound of the present invention has a very high dissolution contrast with respect to an alkaline developer, and thus can be a base resin component that does not necessarily require insolubilization with a crosslinking agent. In addition, since high carbon density and resin film thickness can be maintained even after polarity change, there is a problem between the patterns due to swelling, which is a problem with conventional negative-change resist materials with polarity change or negative resist materials that require a cross-linking reaction. Therefore, it is possible to resolve a finer pattern.

（式中、Ｒ¹、Ｘ¹、Ｚ¹及びｋ¹は前記と同じ。）

(In the formula, R ¹ , X ¹ , Z ¹ and k ¹ are the same as above.)

As described above, the polymer compound of the present invention has a high polarity before the dehydration reaction and a low polarity after the dehydration, and thus has a high dissolution contrast in an alkaline aqueous solution. In the formula (3), the smaller the number of carbon atoms of the substituents R ² and R ^{3 in} the tertiary alcohol portion, the higher the polarity and the hydrophilicity, and the easier the introduction during the production of the monomer (1). , R ² and R ³ are preferably each independently a methyl group or an ethyl group. In view of maintaining the carbon density and rigidity before and after the dehydration reaction, Z ¹ is preferably a cyclic hydrocarbon group having 3 to 20 carbon atoms. Among these, Z ¹ is an alicyclic group having 3 to 10 carbon atoms, and k ² is preferable from the viewpoint of easy availability of raw materials when producing the monomer (1). When k ² exceeds 4, the difference in polarity change before and after dehydration can be larger, but the solubility of the monomer (1) in the polymerization solvent is remarkably lowered, and it is difficult to obtain raw materials. And the solvent solubility of the polymer compound itself of the present invention as a resist material is also unfavorable.

In addition to the repeating unit derived from the monomer represented by the formula (1), the polymer compound of the present invention is further represented by the following formulas (A) to (D) for the purpose of controlling solubility. It may contain at least one selected from units.

In the formula, R ¹ is the same as described above. Z ^A represents a fluoroalcohol-containing substituent having 1 to 20 carbon atoms. Z ^B represents a phenolic hydroxy group-containing substituent having 1 to 20 carbon atoms. Z ^C represents a carboxyl group-containing substituent having 1 to 20 carbon atoms. Z ^D represents a substituent containing a lactone skeleton, a sultone skeleton, a carbonate skeleton, a cyclic ether skeleton, an acid anhydride skeleton, an alcoholic hydroxy group, an alkoxycarbonyl group, a sulfonamide group, or a carbamoyl group. X ² represents a single bond, a methylene group, an ethylene group, a phenylene group, a fluorinated phenylene group, a naphthylene group, —O—R ⁰¹ —, or —C (═O) —Z ² —R ⁰¹ —, Z ² represents an oxygen atom or NH, and R ⁰¹ represents a linear, branched or cyclic alkylene group having 1 to 6 carbon atoms, a linear, branched or cyclic alkenylene group having 2 to 6 carbon atoms. Represents a phenylene group or a naphthylene group, and may contain a carbonyl group, an ester group, an ether group or a hydroxy group.

  The repeating unit represented by the formula (A) has a fluoroalcohol-containing substituent having high affinity with an alkaline aqueous solution. As preferable examples of these fluoroalcohol-containing units, those described in JP2007-297590A, JP2008-111103A, JP2008-122932A and JP2012-128067A, Examples thereof include a repeating unit having a 1,1,3,3,3-hexafluoro-2-propanol residue, a 2-hydroxy-2-trifluoromethyloxolane structure, and the like. These have a tertiary alcoholic hydroxy group or a hemiacetal structure, but have no reactivity to acids because they are substituted with fluorine.

  Since the repeating units represented by the formulas (A) to (C) are all structural units having a hydroxy group proton with high acidity, the alkali solubility of the polymer compound of the present invention increases as the introduction rate increases. be able to. On the other hand, excessive introduction of these units impairs the polarity change caused by the dehydration reaction caused by the repeating unit represented by the formula (1) and the acid, and the effect of insolubilization in alkali. Therefore, it is preferable to introduce the repeating units represented by the formulas (A) to (C) within a range that compensates for the alkali solubility in the unexposed area and does not impair the alkali insolubilizing effect in the exposed area.

Examples of the repeating unit represented by the formula (A) include, but are not limited to, those shown below.

Examples of the repeating unit represented by the formula (B) include, but are not limited to, those shown below.

Examples of the repeating unit represented by the formula (C) include, but are not limited to, those shown below.

  In addition, the fluoroalcohol is protected with an acyl group or an acid labile group, and the fluoroalcohol-containing unit corresponding to the formula (A) is generated by hydrolysis with an alkali developer or deprotection with an acid after exposure. You can also. In this case, suitable repeating units include those described in paragraphs [0036] to [0040] of JP2012-128067A, and formulas (2a), (2b) and (2f) in paragraph [0041]. ) And the like.

Examples of the repeating unit represented by the formula (D) include, but are not limited to, the following. In the following formulae, Me represents a methyl group.

Furthermore, the polymer compound of the present invention may contain at least one selected from repeating units represented by the following formulas (f1) to (f3).

In the formula, each R ¹¹ independently represents a hydrogen atom or a methyl group. R ¹² represents a single bond, a phenylene group, —O—R ²¹ — or —C (═O) —Z ²² —R ²¹ —, Z ²² represents an oxygen atom or NH, and R ²¹ represents the number of carbon atoms. 1 to 6 linear, branched or cyclic alkylene group, C2 to C6 linear, branched or cyclic alkenylene group, or phenylene group, carbonyl group (—CO—), ester group It may contain (—COO—), an ether group (—O—) or a hydroxy group. L represents a single bond or —Z ³³ —C (═O) —O—, wherein Z ³³ is a linear, branched or cyclic group which may be substituted with a heteroatom having 1 to 20 carbon atoms. Represents a divalent hydrocarbon group. Z ¹¹ represents a single bond, a methylene group, an ethylene group, a phenylene group, a fluorinated phenylene group, -O-R ²² -, or ^{-C (= O) -Z 44 -R} 22 - represents, Z ⁴⁴ is Represents an oxygen atom or NH, and R ²² represents a linear, branched or cyclic alkylene group having 1 to 6 carbon atoms, a linear, branched or cyclic alkenylene group having 2 to 6 carbon atoms, or phenylene. Represents a group and may contain a carbonyl group, an ester group, an ether group or a hydroxy group. M ⁻ represents a non-nucleophilic counter ion.

R ¹³ to R ²⁰ each independently may be substituted with a hetero atom, a linear having 1 to 20 carbon atoms that may heteroatoms intervene, monovalent hydrocarbon group branched or cyclic Represents. Examples of the monovalent hydrocarbon group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, t-butyl group, cyclopropyl group, cyclopentyl group, cyclohexyl group, cyclopropylmethyl group, 4- Alkyl groups such as methylcyclohexyl group, cyclohexylmethyl group, norbornyl group, adamantyl group; alkenyl groups such as vinyl group, allyl group, propenyl group, butenyl group, hexenyl group, cyclohexenyl group; phenyl group, naphthyl group, thienyl group, etc. Aryl groups, benzyl groups, 1-phenylethyl groups, 2-phenylethyl groups and the like, and aryl groups are preferred. In addition, some of the hydrogen atoms in these groups may be replaced with heteroatoms such as oxygen, sulfur, nitrogen and halogen atoms, and heteroatoms such as oxygen, sulfur and nitrogen atoms intervene. 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, a sultone ring, a carboxylic acid anhydride, a haloalkyl group, or the like may be formed or interposed. . R ¹³ and R ¹⁴ may be bonded to each other to form a ring together with the sulfur atom to which they are bonded, and any two or more of R ¹⁵ , R ¹⁶ and R ¹⁷ , or R ¹⁸ , R Any two or more of ¹⁹ and R ²⁰ may be bonded to each other to form a ring together with the sulfur atom to which they are bonded.

（式中、破線は結合手を示す。） When L is —Z ³³ —C (═O) —O—, linear, branched or cyclic 2 optionally substituted with a hetero atom having 1 to 20 carbon atoms represented by Z ³³ Examples of the valent hydrocarbon group include, but are not limited to, those shown below.

(In the formula, a broken line indicates a bond.)

When R ¹³ and R ¹⁴ are bonded to each other to form a ring together with the sulfur atom to which they are bonded, or any two or more of R ¹⁵ , R ¹⁶ and R ¹⁷ , or R ¹⁸ , R ¹⁹ and Specific examples of the case where any two or more of R ²⁰ are bonded to each other to form a ring together with the sulfur atom to which they are bonded include the following, but are not limited thereto.

In the formula, R ²³ represents a linear, branched or cyclic monovalent hydrocarbon group having 1 to 20 carbon atoms which may be substituted with a heteroatom and may be interposed by a heteroatom. Examples of the monovalent hydrocarbon group are the same as those described in the description of R ^{13 to} R ²⁰ .

Specific examples of the sulfonium cation in formulas (f2) and (f3) include, but are not limited to, those shown below.

Non-nucleophilic counter ions represented by M ⁻ include halide ions such as chloride ions and bromide ions; fluoroalkyl sulfonates such as triflate, 1,1,1-trifluoroethanesulfonate, and nonafluorobutanesulfonate; Aryl sulfonates such as tosylate, benzene sulfonate, 4-fluorobenzene sulfonate, 1,2,3,4,5-pentafluorobenzene sulfonate; alkyl sulfonates such as mesylate, butane sulfonate; bis (trifluoromethylsulfonyl) imide, bis ( Examples thereof include imido acids such as perfluoroethylsulfonyl) imide and bis (perfluorobutylsulfonyl) imide; and methide acids such as tris (trifluoromethylsulfonyl) methide and tris (perfluoroethylsulfonyl) methide.

Furthermore, as the non-nucleophilic counter ion, the sulfonate represented by the following formula (F-1) is fluoro-substituted, and the α and β-position represented by the following formula (F-2) are fluoro-substituted. Sulfonates.

In formula (F-1), R ³¹ represents a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, a linear, branched or cyclic alkenyl group having 2 to 20 carbon atoms. Or an aryl group having 6 to 20 carbon atoms, which may have an ether group, an ester group, a carbonyl group, a lactone ring or a fluorine atom. In the formula (F-2), R ³² is a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 30 carbon atoms, a linear, branched or cyclic acyl group having 2 to 30 carbon atoms. Represents a linear, branched or cyclic alkenyl group having 2 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an aryloxy group having 6 to 20 carbon atoms, an ether group, an ester group, a carbonyl group, or It may have a lactone ring.

The polymer compound of the present invention may further contain a repeating unit g having an oxirane ring or an oxetane ring. When the repeating unit g is included, the exposed part is cross-linked. Therefore, when the polymer compound of the present invention is used as a resist material, it can be expected to improve the insolubility with respect to an alkali developer and the etching resistance of a negative pattern. Examples of the monomer that gives the repeating unit g having an oxirane ring or oxetane ring include, but are not limited to, those shown below. In the following formulae, R ¹ is the same as described above.

The polymer compound of the present invention may further contain a repeating unit h derived from a monomer containing a carbon-carbon double bond. As the repeating unit h, for example, substituted acrylic acid esters such as methyl methacrylate, methyl crotonic acid, dimethyl maleate and dimethyl itaconate, unsaturated carboxylic acids such as maleic acid, fumaric acid and itaconic acid, norbornene and norbornene derivatives , tetracyclo [4.4.0.1 ^2,5 .1 ^7,10] cyclic olefins such as dodecene derivatives, unsaturated acid anhydrides such as itaconic anhydride, repeating units derived from monomers such as shown below Is mentioned. In the following formulae, R ¹ is the same as described above.

In the polymer compound of the present invention, a preferable content ratio of each repeating unit can be set, for example, in the following range (mol%), but is not limited thereto.
(I) One type or two or more types selected from the repeating unit represented by the formula (3) derived from the monomer of the formula (1) is more than 0 mol% and not more than 100 mol%, preferably 5 to 80 Mol%, more preferably 10 to 60 mol%.
(II) One or more selected from repeating units represented by formulas (A) to (D) are 0 mol% or more and less than 100 mol%, preferably 20 to 95 mol%, more preferably 40 to 40 mol%. 90 mol%.
(III) 1 type or 2 types or more selected from repeating units represented by formulas (f1) to (f3) are 0 to 30 mol%, preferably 0 to 20 mol%, more preferably 0 to 10 mol%. .
(IV) One or two or more selected from repeating units g and h are 0 to 80 mol%, preferably 0 to 70 mol%, more preferably 0 to 50 mol%.

  Examples of the method for synthesizing the polymer compound of the present invention include a method in which, among monomers giving each repeating unit, a desired monomer is subjected to heat polymerization by adding a radical polymerization initiator in an organic solvent.

  Examples of the organic solvent used in the polymerization include toluene, benzene, tetrahydrofuran, diethyl ether, dioxane, cyclohexane, cyclopentane, methyl ethyl ether (MEK), propylene glycol monomethyl ether acetate (PGMEA), γ-butyrolactone (GBL), and the like. It is done. As polymerization initiators, 2,2′-azobisisobutyronitrile (AIBN), 2,2′-azobis (2,4-dimethylvaleronitrile), dimethyl 2,2-azobis (2-methylpropionate) ), Benzoyl peroxide, lauroyl peroxide, and the like. The polymerization temperature is preferably 50 to 80 ° C. The reaction time is preferably 2 to 100 hours, more preferably 5 to 20 hours.

  When copolymerizing hydroxystyrene or hydroxyvinylnaphthalene, hydroxystyrene or hydroxyvinylnaphthalene and other monomers may be heated and polymerized in an organic solvent with the addition of a radical polymerization initiator. Acetoxystyrene or acetoxyvinylnaphthalene may be used, and after polymerization, the acetoxy group may be deprotected by alkali hydrolysis to form polyhydroxystyrene or hydroxypolyvinylnaphthalene.

  Ammonia water, triethylamine, etc. can be used as the base during the alkali hydrolysis. Moreover, reaction temperature becomes like this. Preferably it is -20-100 degreeC, More preferably, it is 0-60 degreeC. The reaction time is preferably 0.2 to 100 hours, more preferably 0.5 to 20 hours.

  The weight average molecular weight (Mw) of the polymer compound of the present invention is preferably 1,000 to 500,000, more preferably 3,000 to 50,000. If it is out of this range, the etching resistance may be extremely lowered, or the difference in dissolution rate before and after the exposure cannot be ensured and the resolution may be lowered. Moreover, the dispersity (Mw / Mn) of the polymer compound of the present invention is preferably 1.20 to 2.20, more preferably 1.30 to 1.80. In the present invention, Mw is a measured value in terms of polystyrene by gel permeation chromatography (GPC) using tetrahydrofuran as a solvent.

[Resist material]
The polymer compound of the present invention is suitable as a base resin for resist materials. The polymer compound of the present invention is used as a base resin, and an organic solvent, an acid generator, a dissolution controller, a basic compound, a surfactant, acetylene alcohols, and the like are appropriately combined in accordance with the purpose and used as a resist material. That's fine.

  When the polymer compound of the present invention is used, the dissolution rate of the polymer compound in the alkaline developing solution is reduced by a catalytic reaction in the exposed area, so that an extremely sensitive resist material can be obtained. The resist material of the present invention has a high dissolution contrast and resolution when used as a resist film, an exposure margin, excellent process adaptability, a good pattern shape after exposure, and a better etching resistance. In particular, since the acid diffusion can be suppressed, the dimensional difference in density is small. For these reasons, it is highly practical and can be very effective as a resist material for VLSI. In particular, when a chemically amplified resist material containing an acid generator and utilizing an acid catalyzed reaction is used, it can be made more highly sensitive and have excellent properties and is extremely useful.

  In addition, by adding a dissolution control agent to the resist material of the present invention, the difference in dissolution rate between the exposed area and the unexposed area can be further increased, and the resolution can be further improved. Furthermore, by adding a basic compound, for example, the acid diffusion rate in the resist film can be suppressed and the resolution can be further improved, and by adding a surfactant, the coating properties of the resist material can be improved. It can be further improved or controlled.

  The resist material of the present invention may contain an acid generator, particularly for functioning as a chemically amplified negative resist material. For example, the resist material contains a compound that generates an acid in response to actinic rays or radiation (photoacid generator). May be. In this case, 0.5-30 mass parts is preferable with respect to 100 mass parts of base resin, and, as for the compounding quantity of a photo-acid generator, 1-20 mass parts is more preferable.

  The photoacid generator is not particularly limited as long as it is a compound that generates an acid upon irradiation with high energy rays, and suitable photoacid generators include sulfonium salts described in JP-A-2009-269953 and the same publication. And (F) component photoacid generators, and photoacid generators described in Japanese Patent No. 3995755, sulfonium salts, iodonium salts, sulfonyldiazomethane, N-sulfonyloxyimide, oxime-O-sulfonate type acids Any of the generating agents may be used. These can be used individually by 1 type or in combination of 2 or more types.

  Examples of the acid generated from the acid generator include sulfonic acid, imide acid, and methide acid. Of these, a sulfonic acid having a fluorinated α-position is most commonly used. However, in the case of an acetal in which an acid labile group is easily deprotected, the α-position is not necessarily fluorinated.

  When the base resin contains at least one selected from repeating units represented by formulas (f1) to (f3), an additive type acid generator is not necessarily essential.

As the acid generator, those represented by the following formula (Z1) or (Z2) are preferable.

In the formula, R ¹⁰⁰ represents a straight, branched or cyclic monovalent hydrocarbon group having 1 to 35 carbon atoms which may contain a hydrogen atom, a fluorine atom, or a hetero atom. X ^a and X ^b each independently represent a hydrogen atom, a fluorine atom or a trifluoromethyl group. k represents an integer of 1 to 4. R ¹⁰¹ , R ¹⁰² and R ¹⁰³ are each independently a substituted or unsubstituted linear or branched alkyl group or oxoalkyl group having 1 to 10 carbon atoms, or linear group having 2 to 10 carbon atoms. Alternatively, it represents a branched alkenyl group, a substituted or unsubstituted aryl group having 6 to 18 carbon atoms, an aralkyl group or aryloxoalkyl group having 7 to 19 carbon atoms. Further, any two or more of R ¹⁰¹ , R ¹⁰² and R ¹⁰³ may be bonded to each other to form a ring together with the sulfur atom to which they are bonded. R ¹⁰⁴ and R ¹⁰⁵ are each independently a linear, branched or cyclic monovalent hydrocarbon group having 1 to 20 carbon atoms which may be substituted with a heteroatom and may be interspersed with a heteroatom. Represents. R ¹⁰⁶ represents a linear, branched or cyclic divalent hydrocarbon group having 1 to 20 carbon atoms which may be substituted with a heteroatom and may be interposed by a heteroatom. R ¹⁰⁴ and R ¹⁰⁵ may be bonded to each other to form a ring together with the sulfur atom to which they are bonded. L ′ is a straight, branched or cyclic divalent hydrocarbon group having 1 to 20 carbon atoms which may be substituted with a single bond, an ether bond, or a heteroatom, and may be intervened by a heteroatom. Represents.

Moreover, as said acid generator, what is represented by a following formula (Z3) or (Z4) is also preferable.

In the formula, R ¹⁰¹ , R ¹⁰² and R ¹⁰³ are the same as described above. A represents a hydrogen atom or a trifluoromethyl group. R ¹⁰⁷ represents a linear, monovalent hydrocarbon group branched or cyclic which may carbons 1 to 35 contain a hetero atom. R ¹⁰⁸ , R ¹⁰⁹ and R ¹¹⁰ each independently represents a hydrogen atom or a linear, branched or cyclic monovalent hydrocarbon group having 1 to 20 carbon atoms which may be intervened by a hetero atom. m and n each independently represents an integer of 0 to 5, and p represents an integer of 0 to 4. L ′ is a straight, branched or cyclic divalent hydrocarbon group having 1 to 20 carbon atoms which may be substituted with a single bond, an ether bond, or a heteroatom, and may be intervened by a heteroatom. Represents.

  The acid generator is an acid generator represented by the formula (Z3) or (Z4), preferably an acid generator in which A is a trifluoromethyl group in the formula (Z3) or (Z4). Thus, for example, a line and space pattern can form a pattern with low roughness (LWR) and improved acid diffusion length control, and a hole pattern can form a pattern with improved roundness and dimensional control. It becomes possible.

  Specific examples of the acid generator represented by the formulas (Z1) to (Z4) are shown below, but are not limited thereto. In the following formulae, Ac represents an acetyl group, Ph represents a phenyl group, and Me represents a methyl group. A is the same as described above.

  Specific examples of the organic solvent include ketones such as cyclohexanone, cyclopentanone, methyl-2-n-amyl ketone, diacetone alcohol; 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2- Alcohols such as propanol and 1-ethoxy-2-propanol; ethers such as propylene glycol monomethyl ether, ethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, propylene glycol dimethyl ether and diethylene glycol dimethyl ether; propylene glycol monomethyl Ether acetate, propylene glycol monoethyl ether acetate, methyl lactate, ethyl lactate, n-butyl lactate, ethyl pyruvate , Butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, t-butyl acetate, t-butyl propionate, propylene glycol mono t-butyl ether acetate, methyl 2-hydroxyisobutyrate, isopropyl 2-hydroxyisobutyrate , Esters such as isobutyl 2-hydroxyisobutyrate and n-butyl 2-hydroxyisobutyrate; lactones such as γ-butyrolactone; and mixed solvents thereof.

  Examples of the basic compound include primary, secondary, and tertiary amine compounds described in paragraphs [0146] to [0164] of JP-A-2008-111103, particularly hydroxy groups, ether groups, ester groups, and lactone rings. , A cyano group, an amine compound having a sulfonic acid ester group, a compound having a carbamate group described in Japanese Patent No. 3790649, and the like.

  Further, sulfonium salts, iodonium salts, and ammonium salts of sulfonic acids that are not fluorinated at the α-position described in JP 2008-158339 A and carboxylic acids described in JP 2013-37092 A An onium salt such as can also be used as a quencher. When the α-position sulfonate and carboxylate which are not fluorinated, and the sulfonic acid, imide acid and methide acid generated from the photoacid generator are fluorinated, the α-position is fluorine. Unmodified sulfonic acid and carboxylic acid are produced by salt exchange. Since the resist resin does not cause a deprotection reaction at the acid strength of the sulfonic acid and carboxylic acid in which the α-position is not fluorinated, these sulfonium salts, iodonium salts, and ammonium salts function as quenchers. In particular, sulfonic acids that are not fluorinated at the α-position, and sulfonium salts and iodonium salts of carboxylic acids are photodegradable, so the quenching ability of the portion with high light intensity is reduced and the α-position is fluorinated. The concentration of sulfonic acid, imidic acid, and methide acid thus increased. As a result, it is possible to form a pattern with good dimensional control in which the contrast of the exposed portion is improved and the focus margin (DOF) is further improved.

  When the polarity changing unit represented by the formula (3) in the base resin has a sensitive reactivity to the acid, the acid for elimination is not necessarily a sulfonic acid, imide acid, or methide having a fluorinated α-position. The deprotection reaction may proceed even if the α-position is not fluorinated and it may not be an acid. Since the onium salt of sulfonic acid cannot be used as the quencher at this time, it is preferable to use the onium salt of carboxylic acid alone in such a case.

  Specific examples of the sulfonate and carboxylate whose α-position is not fluorinated are shown below, but are not limited thereto.

  As the surfactant, those described in paragraphs [0165] to [0166] of JP-A-2008-111103 can be used. As the dissolution control agent, those described in paragraphs [0155] to [0178] of JP-A-2008-122932 can be used. As acetylene alcohols, those described in paragraphs [0179] to [0182] can be used.

  The blending amount of the organic solvent is preferably 50 to 10,000 parts by mass, more preferably 100 to 5,000 parts by mass with respect to 100 parts by mass of the base resin. 0-50 mass parts is preferable with respect to 100 mass parts of base resins, and, as for the compounding quantity of a dissolution control agent, 0-40 mass parts is more preferable. 0-100 mass parts is preferable with respect to 100 mass parts of base resins, and, as for the compounding quantity of a basic compound, 0.001-50 mass parts is more preferable. The blending amounts of the surfactant and acetylene alcohol can be appropriately selected according to the blending purpose.

  The resist material of the present invention may contain a water repellency improver in order to improve the water repellency of the resist surface after spin coating. This water repellency improver can be used in immersion lithography without using a top coat. Such a water repellency improver has a 1,1,1,3,3,3-hexafluoro-2-propanol residue having a specific structure and is disclosed in JP-A-2007-297590 and JP-A-2008-111103. JP-A-2008-122932, JP-A-2012-128067, and JP-A-2013-57836.

Furthermore, the polymer compound for improving water repellency will be specifically described. A polymer composed of one kind of fluorine-containing unit, a copolymer composed of two or more kinds of fluorine-containing units, or a fluorine-containing unit and other A copolymer consisting of units is preferred. Examples of the fluorine-containing unit and other units include, but are not limited to, the following. In the following formulae, R ⁵⁵ is a hydrogen atom or a methyl group.

  The water repellency improver needs to be dissolved in an alkaline aqueous solution of a developer. The above-mentioned water repellency improver having 1,1,1,3,3,3-hexafluoro-2-propanol residue has good solubility in a developer. As a water repellency improver, a polymer compound containing a repeating unit having an amino group or an amine salt prevents acid evaporation during post-exposure baking (PEB), resulting in poor opening of a hole pattern after development or a line and space pattern. Effective in preventing bridging. The addition amount of the water repellency improver is preferably 0.1 to 20 parts by mass, more preferably 0.5 to 10 parts by mass with respect to 100 parts by mass of the base resin.

  The cross-linking reaction with the cross-linking agent can compensate for the negative pattern formation due to the change in polarity of the polymer compound of the present invention. Specific examples of the crosslinking agent include those described in JP-A No. 2006-145755. When a crosslinking agent is used, it is preferable to use the crosslinking agent as long as the high resolution performance caused by the change in polarity and solubility due to the dehydration reaction of the repeating unit derived from the monomer of the present invention is not impaired. 1-30 mass parts is preferable with respect to 100 mass parts of base resins, and, as for the compounding quantity of a crosslinking agent, 3-20 mass parts is more preferable.

[Pattern formation method]
When the resist material of the present invention, for example, a chemically amplified resist material containing the polymer compound of the present invention, an organic solvent, an acid generator, a basic compound, etc. is used for manufacturing various integrated circuits, a known lithography technique is applied. It can be achieved through the steps of coating, heat treatment (pre-baking), exposure, heat treatment (post-exposure baking, PEB), and development. If necessary, some additional steps may be added.

For example, the negative 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, silicon-containing antireflection film or organic hydrocarbon film multilayer film). Alternatively, the coating film thickness can be increased by a suitable coating method such as spin coating, roll coating, flow coating, dip coating, spray coating, doctor coating, etc. on a mask circuit manufacturing substrate (Cr, CrO, CrON, MoSi, SiO _2, etc.). It is applied so as to be 0.01 to 2.0 μm. This is preferably pre-baked on a hot plate at 60 to 150 ° C. for 10 seconds to 30 minutes, more preferably at 80 to 120 ° C. for 30 seconds to 20 minutes. Next, a target pattern is passed through a predetermined mask with a light source selected from high energy rays such as ultraviolet rays, far ultraviolet rays, electron beams (EB), X-rays, excimer lasers, γ rays, synchrotron radiation, EUV, soft X-rays, etc. Alternatively, direct exposure is performed. The exposure dose, 1 to 200 mJ / cm ² or so, in particular 10 to 100 mJ / cm ^2, or 0.1~100μC / cm ² or so, it is preferable that exposure to particular a 0.5~50μC / cm ^2. Next, PEB is preferably performed on a hot plate at 60 to 150 ° C. for 10 seconds to 30 minutes, more preferably at 80 to 120 ° C. for 30 seconds to 20 minutes.

  Further, 0.1 to 10% by mass, preferably 2 to 5% by mass of tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide (TEAH), tetrapropylammonium hydroxide (TPAH), tetrabutylammonium hydroxide ( Development using an alkali developer such as TBAH), preferably 3 seconds to 3 minutes, more preferably 5 seconds to 2 minutes, by a conventional method such as a dip method, a paddle method, or a spray method By doing so, the portion irradiated with light is not dissolved in the developer, and the portion not exposed is dissolved, and a desired negative pattern is formed on the substrate. Further, rinsing can be performed using water after the development step, preferably for 3 seconds to 3 minutes, more preferably for 5 seconds to 2 minutes, by a conventional method such as a dipping method, a paddle method, or a spray method. The resist material of the present invention is particularly suitable for fine patterning using KrF excimer laser, ArF excimer laser, EB, EUV, soft X-ray, X-ray, γ-ray, synchrotron radiation, etc. among high energy rays.

  The hole pattern and trench pattern after development can be shrunk by thermal flow, RELACS technology, DSA technology or the like. A shrink agent is applied onto the hole pattern, and the crosslinking of the shrink agent occurs on the surface of the resist due to the diffusion of the acid catalyst from the resist layer during baking, and the shrink 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 baking time is 10 to 300 seconds. Finally, excess shrink agent is removed and the hole pattern is reduced.

  EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated concretely, this invention is not limited to the following Example etc. In the following examples, Mw is a polystyrene equivalent value by GPC using tetrahydrofuran (THF) as a solvent.

[1] Synthesis of monomer [Example 1] Synthesis of monomer 1

[Example 1-1] Synthesis of triol 1 Under a nitrogen atmosphere, a 1.0 mol / L methylmagnesium chloride-THF solution (1,080 mL) was mixed with a THF (150 mL) solution of hydroxy ester 1 (56 g) at 25 to 45 ° C. It was dripped at. After stirring at 50 ° C. for 10 hours, the reaction solution was ice-cooled, and a mixed aqueous solution of ammonium chloride (108 g) and 2.4 mass% hydrochloric acid aqueous solution (908 g) was added dropwise to stop the reaction. After normal aqueous work-up and solvent distillation, recrystallization (acetone-diisopropyl ether), filtration and drying were performed to obtain 48 g of triol 1 (yield 85%).
IR (D-ATR): ν = 3331, 2972, 2930, 2909, 2855, 1453, 1417, 1380, 1367, 1337, 1327, 1275, 1237, 1208, 1175, 1161, 1138, 1119, 1107, 1055, 1032 , 1025, 987, 970, 950, 910, 869, 841, 832, 786, 749, 633, 617, 601, 592 cm ^-1 .
¹ H-NMR (600 MHz, DMSO-d ₆ ): δ = 1.00 (12H, s), 1.26-1.38 (12H), 2.12 (1H, m), 3.84 (2H, s), 4.19 (1H, s) ppm .

[Example 1-2] Synthesis of monomer 1 Under a nitrogen atmosphere, methacryloyl chloride was added to a mixed solution of triol 1 (37 g), triethylamine (30 g), N, N-dimethylaminopyridine (1.7 g) and acetonitrile (200 mL). (23.3 g) was added dropwise at 25 to 45 ° C. After stirring at 45 ° C. for 8 hours, the reaction solution was ice-cooled, and saturated aqueous sodium hydrogen carbonate solution (100 mL) was added dropwise to stop the reaction. After normal aqueous work-up and solvent distillation, recrystallization (acetone-hexane), filtration and drying were performed to obtain 37 g of monomer 1 (yield 80%).
IR (D-ATR): ν = 3385, 2974, 2941, 2885, 2869, 1709, 1636, 1558, 1450, 1409, 1377, 1342, 1323, 1304, 1169, 1139, 1116, 1095, 1010, 995, 986 , 947, 914, 872, 813, 783, 748, 659, 618, 559 cm ^-1 .
¹ H-NMR (600 MHz, DMSO-d ₆ ): δ = 1.00 (12H, s), 1.30-1.38 (3H), 1.42-1.48 (3H), 1.78 (2H, d), 1.81 (3H, s), 1.89 (2H, d), 1.92 (2H, s), 2.23 (1H, m), 3.99 (2H, s), 5.56 (1H, s), 5.91 (1H, s) ppm.

[Example 2] Synthesis of monomer 2

[Example 2-1] Synthesis of triol 2 Under a nitrogen atmosphere, a 1.0 mol / L methylmagnesium chloride-THF solution (1,150 mL) was mixed with a solution of lactone 1 (50 g) in THF (200 mL) at 25 to 45 ° C. It was dripped. After stirring at 50 ° C. for 10 hours, the reaction solution was ice-cooled, and a mixed aqueous solution of ammonium chloride (115 g) and 2.4 mass% hydrochloric acid aqueous solution (960 g) was added dropwise to stop the reaction. After normal aqueous work-up and solvent distillation, recrystallization (ethyl acetate-hexane), filtration and drying were performed to obtain 52 g of triol 2 (yield 90%).
¹ H-NMR (600 MHz, DMSO-d ₆ ): δ = 1.11 (1H, dd), 1.19 (3H, s), 1.28 (1H, m), 1.29 (3H, s), 1.40 (3H, s), 1.50 (3H, s), 1.68-1.76 (2H), 2.09 (1H, d), 2.27-2.35 (2H), 2.44 (1H, m), 3.98 (1H, m), 6.21 (1H, s), 6.37 (1H, d), 7.30 (1H, s) ppm.

[Example 2-2] Synthesis of monomer 2 Under a nitrogen atmosphere, methacrylic acid was added to a mixed solution of triol 2 (45 g), triethylamine (40 g), N, N-dimethylaminopyridine (2.4 g) and THF (200 mL). Anhydride (43 g) was added dropwise at 25-45 ° C. After stirring at 45 ° C. for 10 hours, the reaction solution was ice-cooled, and saturated aqueous sodium hydrogen carbonate solution (100 mL) was added dropwise to stop the reaction. After normal aqueous work-up and solvent distillation, recrystallization (ethyl acetate-hexane), filtration and drying were performed to obtain 53 g of monomer 2 (yield 90%).
IR (D-ATR): ν = 3254, 3164, 3022, 2960, 2933, 2883, 1704, 1636, 1498, 1576, 1449, 1412, 1381, 1363, 1328, 1301, 1259, 1202, 1180, 1162, 1135 , 1107, 1047, 1018, 953, 934, 862, 850, 835, 814, 776, 733, 627, 570 cm ^-1 .
¹ H-NMR (600 MHz, DMSO-d ₆ ): δ = 1.12 (3H, s), 1.25 (1H, m), 1.24 (3H, s), 1.30 (1H, m), 1.41 (3H, s), 1.42 (3H, s), 1.68 (1H, m), 1.86 (3H, s), 2.16 (1H, ddd), 2.23 (1H, dd), 2.42 (1H, m), 2.58 (1H, m), 2.63 (1H, m), 4.94 (1H, m), 5.56 (2H), 5.81 (1H, s), 6.31 (1H, s) ppm.

[Example 3] Synthesis of monomer 3

[Example 3-1] Synthesis of triol 3 Triol 3 was synthesized by the same method as in Example 2-1, except that hydroxylactone 1 was used as a raw material. Triol 3 was used for the next reaction immediately after the reaction without any purification.

[Example 3-2] Synthesis of monomer 3 Monomer 3 was synthesized by the same method as in Example 2-2 except that triol 3 was used as a raw material (a yield of two steps from white crystals, hydroxylactone 1). 72%).
IR (D-ATR): ν = 3160, 3003, 2977, 2920, 2877, 1709, 1639, 1628, 1498, 1466, 1437, 1393, 1381, 1367, 1322, 1248, 1202, 1153, 1051, 1005, 985 , 956, 933, 902, 857, 847, 814, 779, 729, 701, 645, 610, 599 cm ^-1 .
¹ H-NMR (600 MHz, DMSO-d ₆ ): δ = 1.20 (3H, s), 1.21 (6H), 1.22 (3H, s), 1.31 (1H, d), 1.43 (1H, m), 1.47 ( 1H, d), 1.75 (1H, m), 1.83 (1H, m), 1.84 (3H, s), 1.87 (1H, m), 2.01 (1H, m), 2.05 (1H, d), 4.62 (1H , d), 5.62 (1H, m), 5.97 (1H, m), 6.03 (1H, s), 6.10 (1H, s) ppm.

[Example 4] Synthesis of monomer 4

[Example 4-1] Synthesis of triol 4 Triol 4 was synthesized by the same method as in Example 2-1, except that hydroxyester 2 was used as a raw material. Triol 4 was used for the next reaction immediately after the reaction without any purification.

[Example 4-2] Synthesis of monomer 4 Monomer 4 was synthesized in the same manner as in Example 2-2 except that triol 4 was used as a raw material (a yield of two steps from white crystals, hydroxyester 2). 70%).
IR (D-ATR): ν = 3314, 2973, 2922, 2898, 1709, 1636, 1468, 1446, 1421, 1384, 1371, 1338, 1322, 1300, 1206, 1173, 1159, 1141, 1120, 1055, 1038 , 1008, 979, 968, 939, 905, 896, 850, 815, 658, 620, 608 cm ^-1 .
¹ H-NMR (600 MHz, DMSO-d ₆ ): δ = 1.07 (3H, s), 1.17 (3H, s), 1.19 (3H, s), 1.28 (3H, s), 1.34 (1H, d), 1.38 (1H, d), 1.45 (1H, d), 1.48 (1H, m), 1.73 (1H, m), 1.84 (3H, s), 1.88 (1H, dd), 2.09 (1H, d), 2.29 (1H, d), 5.11 (1H, d), 5.19 (1H, s), 5.29 (1H, s), 5.62 (1H, m), 5.97 (1H, m) ppm.

[Example 5] Synthesis of monomer 5

  Monomer 5 was synthesized in the same manner as in Example 1-2 except that acryloyl chloride was used as a raw material (white crystals, yield 86%).

[Example 6] Synthesis of monomer 6

  Monomer 6 was synthesized in the same manner as in Example 1-2 except that methacryloyloxyacetyl chloride was used as a raw material (white crystals, yield 76%).

[Example 7] Synthesis of monomer 7

  Under a nitrogen atmosphere, a THF (500 mL) solution of hydroxy ester 3 (61 g) was added dropwise at 25 to 45 ° C. to a 1.0 mol / L methylmagnesium chloride-THF solution (1,500 mL). After stirring at 50 ° C. for 10 hours, the reaction solution was ice-cooled, and methacrylic anhydride (58 g) was subsequently added dropwise at 30 ° C. or lower to the alkoxide suspension corresponding to tetraol 1 in the above formula. After stirring at 25 ° C. for 4 hours, the reaction solution was ice-cooled, and a mixed aqueous solution of ammonium chloride (150 g) and 2.4 mass% hydrochloric acid aqueous solution (1,250 g) was added dropwise to stop the reaction. After normal aqueous work-up and solvent distillation, recrystallization (ethyl acetate-THF-hexane), filtration and drying were performed to obtain 37 g of monomer 7 (2 step yield: 51%). .

[Example 8] Synthesis of monomer 8

[Example 8-1] Synthesis of triol 5 Triol 5 was synthesized in the same manner as in Example 2-1, except that hydroxy ester 4 was used as a raw material. Triol 5 was used for the next reaction immediately after the reaction without any purification.

[Example 8-2] Synthesis of monomer 8 Monomer 8 was synthesized by the same method as in Example 2-2 except that triol 5 was used as a raw material (a yield of two steps from white crystals, hydroxy ester 4). 80%).
IR (D-ATR): ν = 3471, 3278, 2969, 2864, 1708, 1639, 1452, 1383, 1317, 1300, 1258, 1219, 1177, 1146, 1120, 1091, 1020, 982, 948, 898, 866 , 846, 815, 797, 755, 720, 652, 621, 611, 593, 567, 556cm ^-1 .
¹ H-NMR (600 MHz, DMSO-d ₆ ): δ = 0.68 (1H, m), 0.96-1.07 (14H), 1.30 (2H, m), 1.81-1.86 (4H), 2.01 (2H, m), 4.12 (2H, s), 4.66 (1H, m), 5.63 (1H, m), 5.99 (1H, m) ppm.

[2] Synthesis of polymer compound [Examples 9 to 27, Comparative Examples 1 to 9]
As the polymer compound used in the resist material, each monomer is combined and subjected to a copolymerization reaction in a cyclopentanone solvent, crystallized in hexane, further washed with hexane, then isolated and dried. Molecular compounds (Polymers 1-19, Comparative Polymers 1-9) were obtained. The composition of the obtained polymer compound was confirmed by ¹ H-NMR and ¹³ C-NMR.

[Example 9] Polymer 1
Mw = 8,500
Mw / Mn = 1.67

[Example 10] Polymer 2
Mw = 8,400
Mw / Mn = 1.65

[Example 11] Polymer 3
Mw = 8,300
Mw / Mn = 1.67

[Example 12] Polymer 4
Mw = 8,300
Mw / Mn = 1.66

[Example 13] Polymer 5
Mw = 8,500
Mw / Mn = 1.66

Example 14 Polymer 6
Mw = 8,600
Mw / Mn = 1.61

Example 15 Polymer 7
Mw = 8,400
Mw / Mn = 1.67

Example 16 Polymer 8
Mw = 8,500
Mw / Mn = 1.62

[Example 17] Polymer 9
Mw = 8,500
Mw / Mn = 1.64

[Example 18] Polymer 10
Mw = 8,600
Mw / Mn = 1.62

Example 19 Polymer 11
Mw = 8,300
Mw / Mn = 1.61

Example 20 Polymer 12
Mw = 8,500
Mw / Mn = 1.63

[Example 21] Polymer 13
Mw = 8,300
Mw / Mn = 1.62

[Example 22] Polymer 14
Mw = 8,300
Mw / Mn = 1.62

[Example 23] Polymer 15
Mw = 8,500
Mw / Mn = 1.60

[Example 24] Polymer 16
Mw = 8,100
Mw / Mn = 1.65

[Example 25] Polymer 17
Mw = 8,000
Mw / Mn = 1.63

Example 26 Polymer 18
Mw = 8,200
Mw / Mn = 1.64

Example 27 Polymer 19
Mw = 8,100
Mw / Mn = 1.63

[Comparative Example 1] Comparative polymer 1
Mw = 8,400
Mw / Mn = 1.65

[Comparative Example 2] Comparative polymer 2
Mw = 8,500
Mw / Mn = 1.63

[Comparative Example 3] Comparative polymer 3
Mw = 8,700
Mw / Mn = 1.65

[Comparative Example 4] Comparative polymer 4
Mw = 8,600
Mw / Mn = 1.62

[Comparative Example 5] Comparative polymer 5
Mw = 8,400
Mw / Mn = 1.66

[Comparative Example 6] Comparative polymer 6
Mw = 8,600
Mw / Mn = 1.63

[Comparative Example 7] Comparative polymer 7
Mw = 8,600
Mw / Mn = 1.63

[Comparative Example 8] Comparative polymer 8
Mw = 8,500
Mw / Mn = 1.61

[Comparative Example 9] Comparative polymer 9
Mw = 8,400
Mw / Mn = 1.65

[3] Preparation of resist material [Examples 28 to 46, Comparative Examples 10 to 18]
Using the polymer compounds obtained in the above-mentioned Examples and Comparative Examples, a resist material was prepared with the composition shown in Tables 1 and 2 below, and filtered through a 0.2 μm Teflon (registered trademark) filter to obtain a resist material R -01 to R-28 were prepared respectively.

  In Tables 1 and 2, the photoacid generator (PAG-1 to PAG-4), the water repellent polymer (SF-1), the sensitivity modifier (Q-1 to Q-4), and the crosslinking agent (XL-1) ) And solvents are as follows.

Photoacid generator: PAG-1 to PAG-4

Sensitivity adjuster: Q-1 to Q-4

Water repellent polymer: SF-1
Mw = 8,700
Mw / Mn = 1.85

Cross-linking agent: XL-1

PGEE: Propylene glycol monoethyl ether GBL: γ-butyrolactone

[4] Evaluation of swelling of resist material during development using QCM (quartz crystal microbalance) method [Examples 47 to 50, Comparative Example 19]
The resist materials of the present invention and comparative resist materials prepared with the compositions shown in Tables 1 and 2 were spin-coated on a QCM substrate to a thickness of 100 nm, and baked on a hot plate at 100 ° C. for 60 seconds. Thereafter, exposed with ArF open frame exposure apparatus exposure 1 mJ / cm ² at 13 mJ / cm ² to S 1 mJ / cm ^2, and PEB 60 seconds at a temperature shown in Table 3 by using the post-exposure hotplate. Thereafter, the resist film on the QCM substrate was observed using a development analysis apparatus RDA-Qz3 (manufactured by RISOTEC Japan Co., Ltd.) to observe the film thickness variation of the resist film with respect to the development time in a 2.38 mass% TMAH aqueous solution. . Table 3 shows the exposure amount indicating the maximum swell amount and the maximum swell amount ratio (value obtained by normalizing the maximum swell amount with the initial film thickness) from the graph showing the development time and film thickness variation at each exposure amount. As the maximum swelling ratio is smaller, the swelling of the resist film is suppressed.

  From the results in Table 3, it was confirmed that the resist material of the present invention had a smaller maximum swelling ratio than the resist material of the comparative example.

[5] Etching resistance evaluation [Examples 51 to 53, Comparative Examples 20 to 21]
The resist material of the present invention and the resist material for comparative example shown in Tables 1 and 2 were spin-coated on a silicon wafer surface-treated (90 ° C., 60 seconds) in a gas phase of hexamethyldisilazane (HMDS). Then, the resist film was baked (PAB) at 100 ° C. for 60 seconds using a hot plate so that the thickness of the resist film was 100 nm. Thereafter, the entire wafer surface was subjected to open frame exposure using an ArF excimer laser scanner (NSR-307E manufactured by Nikon Corporation, NA = 0.85). The exposure amount at that time was 50 mJ / cm ² so that a sufficient amount of acid for the deprotection reaction was generated from the photoacid generator. Thereafter, PEB was applied for 60 seconds at the temperature shown in Table 4 to promote the dehydration reaction or the crosslinking reaction with the base resin for forming the resist film. In the base resin of the present invention, the portion where the dehydration reaction has occurred corresponds to the insoluble portion during development. The ratio of the resist film thickness reduction amount by the exposure / PEB processing to the film thickness before processing was obtained and used as the PEB shrink amount (%). Further, development was performed with a 2.38 mass% TMAH aqueous solution for 30 seconds, and then the resist film thickness was measured, and the minimum dissolution rate (nm / sec) was determined from the difference between the film thickness after PEB treatment and the film thickness after development. . A smaller PEB shrinkage or minimum dissolution rate is preferable because a sufficient film thickness required for dry etching can be ensured or the initial film thickness can be reduced, which is advantageous in resolution. The results are shown in Table 4.

  From the results in Table 4, it was confirmed that the resist material of the present invention has a small PEB shrinkage amount and a low minimum dissolution rate. Therefore, it was suggested that the pattern film thickness after development remains thick and the etching resistance after patterning is excellent.

[6] ArF exposure patterning evaluation (1)
[Examples 54 to 69, Comparative Examples 22 to 29]
The resist material of the present invention prepared in the composition shown in Tables 1 and 2 and the resist material of the comparative example were spin-coated on a substrate on which ARC29A (Nissan Chemical Industry Co., Ltd.) was formed to a film thickness of 78 nm on a silicon wafer. Coating was performed, and baking was performed at 100 ° C. for 60 seconds using a hot plate, so that the thickness of the resist film was 100 nm. This is an ArF excimer laser scanner (NSR-S307E manufactured by Nikon Corporation, NA = 0.85, σ0.93 / 0.74, Annular illumination, 6% halftone phase shift mask). The dimensions on the wafer are space width 90nm and pitch 180nm. , Exposure of the space width 80 nm and 160 nm pitch, and the line and space pattern (LS pattern) having the space width 70 nm and pitch 140 nm and the trench pattern having the space width 90 nm and pitch 1,650 nm, and changing the exposure amount and focus (exposure) (Pitch: 1 mJ / cm ² , Focus pitch: 0.025 μm) After exposure, PEB was performed for 60 seconds at the temperature shown in Table 5, and paddle development was performed for 30 seconds with 2.38 mass% TMAH aqueous solution. Rinse and spin dry with pure water to obtain a negative pattern. The developed LS pattern and trench pattern were observed with a TD-SEM (S-9380, manufactured by Hitachi High-Technologies Corporation).

[Sensitivity evaluation]
As the sensitivity, the optimum exposure dose E _op (mJ / cm ² ) for obtaining the LS pattern having the space width of 90 nm and the pitch of 180 nm was determined. The results are shown in Table 5. The smaller this value, the higher the sensitivity.

[Exposure margin (EL) evaluation]
As exposure margin evaluation, exposure margin (unit:%) was calculated | required by following Formula from the exposure amount formed in the range of +/- 10% (81-99 nm) of the 90 nm space width in the said LS pattern. The results are shown in Table 5.
Exposure margin (%) = (| E ₁ −E ₂ | / E _op ) × 100
E ₁ : Optimum exposure dose that gives an LS pattern with a space width of 81 nm and a pitch of 180 nm E ₂ : Optimal exposure dose that gives an LS pattern with a space width of 99 nm and a pitch of 180 nm E _op : Optimal exposure that gives an LS pattern with a space width of 90 nm and a pitch of 180 nm amount

[Rine Widow Roughness (LWR) Evaluation]
The LS pattern obtained by irradiating with the optimum exposure amount in the sensitivity evaluation was measured at 10 positions in the longitudinal direction of the space width, and from the result, the triple value (3σ) of the standard deviation (σ) was obtained as LWR. It was. The results are shown in Table 5. The smaller this value, the smaller the roughness and the more uniform the space width pattern.

[Depth of focus (DOF) evaluation]
As the depth of focus evaluation, a focus range formed in a range of ± 10% (81 to 99 nm) of the 90 nm space width in the trench pattern was obtained. The results are shown in Table 5. The larger this value, the wider the depth of focus.

[Resolution evaluation]
The resolution of the pattern dimension that resolved the LS pattern of 70 to 90 nm (pitch 140 to 180 nm) was defined as the resolving power. The results are shown in Table 5. The smaller this value, the better the resolution.

  From the results in Table 5, it was confirmed that the resist material of the present invention has practical sensitivity. Further, it was confirmed that the exposure margin and the depth of focus have a wide margin and that the LWR is small compared to the resist of the comparative example. Furthermore, it was confirmed that the resolution was also excellent.

[7] ArF exposure patterning evaluation (2)
[Examples 70 to 73, Comparative Example 30]
The resist material of the present invention prepared in the composition shown in Tables 1 and 2 and the resist material of the comparative example were obtained by applying a spin-on carbon film ODL-180 (carbon content of 80% by mass) manufactured by Shin-Etsu Chemical Co., Ltd. to 180 nm. A silicon-containing spin-on hard mask SHB-A940 (silicon content: 43% by mass) was spin-coated on a substrate for a trilayer process having a film thickness of 35 nm, and was heated at 100 ° C. using a hot plate at 60 ° C. The resist film was baked for 2 seconds to a thickness of 60 nm. This is an ArF excimer laser immersion scanner (Nikon NSR-S610C, NA1.30, σ0.90 / 0.72, crosspole aperture 35 degrees, Azimuthally polarized illumination, 6% halftone phase shift mask, crosspole illumination) Then, exposure of a contact hole pattern (CH pattern) having a wafer size of 55 nm and a pitch of 110 nm is performed while changing the exposure amount and focus (exposure amount pitch: 1 mJ / cm ² , focus pitch: 0.025 μm). Thereafter, PEB was performed for 60 seconds at the temperature shown in Table 6, paddle development was performed for 30 seconds with a 2.38 mass% TMAH aqueous solution, rinse and spin drying were performed with pure water, and a negative pattern was obtained. The CH pattern after development was observed with a TD-SEM (CG4000 manufactured by Hitachi High-Technologies Corporation).

[Sensitivity evaluation]
As sensitivity, an optimum exposure dose E _op (mJ / cm ² ) for obtaining a CH pattern having a hole size of 55 nm and a pitch of 110 nm was determined. The results are shown in Table 6. The smaller this value, the higher the sensitivity.

[Exposure margin (EL) evaluation]
As an exposure margin evaluation, an exposure margin (unit:%) is calculated from the exposure amount formed within a range of ± 10% (49.5 to 60.5 nm) of the 55 nm hole size in the CH pattern by the following formula. Asked. The results are shown in Table 6.
Exposure margin (%) = (| E ₁ −E ₂ | / E _op ) × 100
E ₁ : Optimum exposure amount giving a CH pattern with a hole size of 49.5 nm and a pitch of 110 nm E ₂ : Optimum exposure amount giving a CH pattern with a hole size of 60.5 nm and a pitch of 110 nm E _op : CH pattern with a hole size of 55 nm and a pitch of 110 nm Optimal exposure to give

[Dimensional Uniformity (CDU) Evaluation]
The CH pattern obtained by irradiating with the optimum exposure dose in the sensitivity evaluation was measured at 10 locations (9 CH patterns per location) in the same exposure shot, and the standard deviation (σ) of 3 was determined from the result. The double value (3σ) was determined as dimensional uniformity (CDU). The results are shown in Table 6. The smaller this value, the better the dimensional uniformity of the CH pattern.

  From the results in Table 6, it was confirmed that the resist material of the present invention has practical sensitivity. In addition, it was confirmed that the exposure margin has a wide margin and the dimensional uniformity is excellent.

[8] EB drawing evaluation [Examples 74 to 77, Comparative Examples 31 to 32]
The resist material of the present invention prepared in the composition shown in Tables 1 and 2 and the resist material of the comparative example were spin-coated on a silicon wafer surface-treated (90 ° C., 60 seconds) in a HMDS gas phase, and a hot plate was used. The resist film was baked at 100 ° C. for 60 seconds to make the resist film thickness 60 nm. This is an electron beam lithography system (JEOL Co., Ltd. JBX-9000, acceleration voltage 50 kV). On the wafer, the LS pattern is drawn with a space width of 100 nm and a pitch of 200 nm. The irradiation dose is changed (irradiation pitch: 2 μC). / Cm ² ), after drawing, PEB at the temperature shown in Table 7 for 60 seconds, paddle development with 2.38 wt% TMAH aqueous solution for 30 seconds, rinse with pure water, spin dry, A mold pattern was obtained. The developed LS pattern was observed with a TD-SEM (S-9380, manufactured by Hitachi High-Technologies Corporation).

[Sensitivity evaluation]
As the sensitivity, an optimum exposure amount E _op (μC / cm ² ) for obtaining an LS pattern having a space width of 100 nm and a pitch of 200 nm was determined. The results are shown in Table 7. The smaller this value, the higher the sensitivity.

[Exposure margin (EL) evaluation]
As exposure margin evaluation, exposure margin (unit:%) was calculated | required by following Formula from the exposure amount formed within the range of +/- 10% (90-110 nm) of the space width of 100 nm in the said LS pattern. The results are shown in Table 7.
Exposure margin (%) = (| E ₁ −E ₂ | / E _op ) × 100
E ₁ : Optimum exposure amount that gives an LS pattern with a space width of 90 nm and a pitch of 200 nm E ₂ : Optimal exposure amount that gives an LS pattern with a space width of 110 nm and a pitch of 200 nm E _op : Optimal exposure that gives an LS pattern with a space width of 100 nm and a pitch of 200 nm amount

[Rine Widow Roughness (LWR) Evaluation]
The LS pattern obtained by irradiating with the optimum exposure amount in the sensitivity evaluation was measured at 10 positions in the longitudinal direction of the space width, and from the result, the triple value (3σ) of the standard deviation (σ) was obtained as LWR. It was. The results are shown in Table 7. The smaller this value, the smaller the roughness and the more uniform the space width pattern.

  From the results in Table 7, it was confirmed that the resist material of the present invention has practical sensitivity. Further, it was confirmed that the exposure margin has a wide margin and the LWR is small.

Claims (8)

The monomer represented by following formula (1).

[ Wherein, R ¹ represents a hydrogen atom or a methyl group. R ² and R ³ each independently represent a linear, branched or cyclic monovalent hydrocarbon group having 1 to 10 carbon atoms, and R ² and R ³ are bonded to each other. You may form an alicyclic group with a carbon atom. X ¹ represents a linear, branched or cyclic divalent hydrocarbon group having 1 to 20 carbon atoms, and —CH ₂ — constituting the divalent hydrocarbon group is —O— or —C (= Optionally substituted with O)- . k ¹ represents 0 or 1. k ² represents an integer of 2 to 4. Z ¹ represents a group represented by the following formula.

(In the formula, a broken line indicates a bond.)] The monomer according to claim 1, wherein Z ¹ is a cyclic aliphatic hydrocarbon group having 3 to 20 carbon atoms. The high molecular compound characterized by including the repeating unit represented by following formula (3).

[ Wherein, R ¹ represents a hydrogen atom or a methyl group. R ² and R ³ each independently represent a linear, branched or cyclic monovalent hydrocarbon group having 1 to 10 carbon atoms, and R ² and R ³ are bonded to each other. You may form an alicyclic group with a carbon atom. X ¹ represents a linear, branched or cyclic divalent hydrocarbon group having 1 to 20 carbon atoms, and —CH ₂ — constituting the divalent hydrocarbon group is —O— or —C (= Optionally substituted with O)- . k ¹ represents 0 or 1. k ² represents an integer of 2 to 4. Z ¹ represents a group represented by the following formula.

(In the formula, a broken line indicates a bond.)] Furthermore, the high molecular compound of Claim 3 containing at least 1 sort (s) chosen from the repeating unit represented by following formula (A)-(D).

(In the formula, R ¹ is the same as described above. Z ^A represents a fluoroalcohol-containing substituent having 1 to 20 carbon atoms. Z ^B represents a phenolic hydroxy group-containing substituent having 1 to 20 carbon atoms. Z ^C represents a carboxyl group-containing substituent having 1 to 20 carbon atoms Z ^D is a lactone skeleton, a sultone skeleton, a carbonate skeleton, a cyclic ether skeleton, an acid anhydride skeleton, an alcoholic hydroxy group, an alkoxycarbonyl group, a sulfonamide X ² represents a single bond, a methylene group, an ethylene group, a phenylene group, a fluorinated phenylene group, a naphthylene group, —O—R ⁰¹ —, or —C (= O) —Z ² —R ⁰¹ —, Z ² represents an oxygen atom or NH, R ⁰¹ represents a linear, branched or cyclic alkylene group having 1 to 6 carbon atoms, or 2 to 6 carbon atoms. Linear, branched Or cyclic alkenylene group, a phenylene group, or a naphthylene group, a carbonyl group, an ester group, which may contain an ether or hydroxyl group.)   A resist material comprising a base resin comprising the polymer compound according to claim 3, an acid generator, and an organic solvent. The resist material according to claim 5, which does not contain a crosslinking agent. A resist material according to claim 5 or 6 is applied on a substrate to form a resist film, the resist film is exposed with a high energy beam after heat treatment, and a pattern is obtained using a developer after the heat treatment. A pattern forming method. The pattern forming method according to claim 7 , wherein an unexposed portion is dissolved using an alkali developer to obtain a negative pattern in which the exposed portion is not dissolved.