JPWO2009099083A1 - Acrylamide polymer, acrylamide compound, chemically amplified photosensitive resin composition and pattern forming method - Google Patents

Abstract

The present invention is a polymer having at least a repeating structural unit represented by the general formula (2), and a raw material monomer for use in a chemically amplified photosensitive resin composition useful for forming an interlayer insulating film or a surface protective film. The present invention relates to an acrylamide compound represented by the general formula (1) and a chemically amplified photosensitive resin composition containing the polymer. The photosensitive resin composition has excellent resolution and can be developed with an aqueous alkaline solution. (In these formulas, R1 represents a hydrogen atom or a methyl group, R2 represents a group that decomposes with an acid, and R3 to R6 each independently represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms. .)

Description

  The present invention relates to an acrylamide polymer, a novel acrylamide compound, a photosensitive resin composition containing the polymer, and a pattern forming method using the composition. In particular, the present invention relates to an acrylamide polymer, a chemically amplified photosensitive resin composition, and a pattern forming method that can be applied to an interlayer insulating film and a surface protective film of a semiconductor device.

  Conventionally, polyimide resins having excellent film characteristics such as heat resistance, mechanical characteristics and electrical characteristics, and adhesion to substrates and wirings have been used for interlayer insulating films and surface protective films of semiconductor devices. When a non-photosensitive polyimide resin is used as an interlayer insulating film or the like, a positive resist is used in the pattern forming process, and etching, resist removal, and the like are required, and the manufacturing process becomes complicated. Therefore, photosensitive polyimide resins having excellent photosensitivity have been studied. As such a photosensitive polyimide resin composition, a positive photosensitive resin composition comprising a polyimide acid, an aromatic bisazide compound and an amine compound has been proposed (Patent Document 1). However, in the pattern formation process using a photosensitive polyimide resin, an organic solvent such as N-methyl-2-pyrrolidone or ethanol is required as a developing solvent, which is problematic in terms of safety and environmental impact. It was.

  Therefore, in recent years, a positive photosensitive resin composition has been developed as a pattern forming material that can be developed with an alkaline aqueous solution such as a tetramethylammonium hydroxide (TMAH) aqueous solution used in a semiconductor fine pattern forming process. ing. For example, a non-chemically amplified positive photosensitive resin composition comprising a polybenzoxazole precursor and a diazoquinone compound as a photosensitizer (Patent Document 2), a polybenzoxazole precursor and 1,2-naphthoquinonediazide-5- Non-chemically amplified positive photosensitive resin composition (non-patent document 1) comprising a sulfonic acid ester, chemically amplified positive composition comprising a polybenzoxazole precursor protected with an acid-decomposable group and a photoacid generator Type photosensitive resin composition (Non-patent Document 2) and the like have been reported.

  In recent years, in the field of semiconductor device manufacturing, higher density and higher integration of devices and miniaturization of wiring patterns are required. Along with this, demands for photosensitive resin compositions used for interlayer insulating films and surface protective films are becoming increasingly severe. However, these positive photosensitive resin compositions have not been sufficiently satisfactory in terms of resolution.

Therefore, development of a photosensitive resin composition capable of alkali development and maintaining high resolution while maintaining conventional film characteristics is awaited.
Japanese Patent Publication No. 3-36861 Japanese Examined Patent Publication No. 1-46862 M.M. Ueda et al., Journal of Photopolymer Science and Technology, Vol. 16, No. 2, 237-242 (2003) K. Ebara et al., Journal of Photopolymer Science and Technology, Vol. 16, No. 2, pp. 287-292 (2003)

  Accordingly, a first object of the present invention is to provide a polymer that can be preferably used as a raw material for a photosensitive resin composition, and an acrylamide compound useful as a raw material monomer for the polymer. The second object of the present invention is to provide a chemically amplified photosensitive resin composition that is excellent in film properties such as heat resistance, mechanical properties, electrical properties, and adhesion, is capable of alkali development, and provides high resolution. It is. Furthermore, the 3rd subject of this invention is providing the pattern formation method using this chemically amplified photosensitive resin composition.

  As a result of studies conducted by the present inventors to achieve the above object, a polymer obtained by polymerizing a monomer composition containing an acrylamide compound having a specific structure is a chemically amplified photosensitive resin composition using the polymer. It was found that the coating film can be developed with an alkaline aqueous solution, high resolution can be obtained, and the film characteristics are excellent, and the present invention has been completed.

  That is, the present invention is an acrylamide polymer containing a repeating structural unit represented by the following general formula (2).

（式中、Ｒ^１は水素原子又はメチル基を表し、Ｒ^２は水素原子又は酸により分解する基を表し、Ｒ^３〜Ｒ^６は、それぞれ独立に、水素原子、ハロゲン原子又は炭素数１〜４のアルキル基を表す。）

(In the formula, R ¹ represents a hydrogen atom or a methyl group, R ² represents a hydrogen atom or a group that decomposes with an acid, and R ^{3 to} R ⁶ each independently represents a hydrogen atom, a halogen atom, or a C 1 -C 1 group. 4 represents an alkyl group.)

  Furthermore, the present invention is an acrylamide polymer containing a repeating structural unit derived from a vinyl monomer different from the repeating structural unit represented by the general formula (2).

  Furthermore, the present invention is an acrylamide polymer in which the repeating structural unit derived from the vinyl monomer is a structural unit represented by the following general formula (3) and / or general formula (4).

（式中、Ｒ^７は水素原子又はメチル基を表し、Ｒ^８は水素原子又は酸により分解する基を表し、Ｒ^９〜Ｒ^１２は、それぞれ独立に、水素原子、ハロゲン原子又は炭素数１〜４のアルキル基を表す。）

(Wherein R ⁷ represents a hydrogen atom or a methyl group, R ⁸ represents a hydrogen atom or a group that decomposes with an acid, and R ^{9 to} R ¹² each independently represents a hydrogen atom, a halogen atom, or a carbon number of 1 to 4 represents an alkyl group.)

（式中、Ｒ^１３は水素原子又はメチル基を表し、Ｒ^１４はラクトン構造を有する有機基を表す。）

(Wherein R ¹³ represents a hydrogen atom or a methyl group, and R ¹⁴ represents an organic group having a lactone structure.)

  The polymer preferably has a weight average molecular weight of 2,000 to 200,000.

  Moreover, this invention is an acrylamide compound represented by General formula (1).

（式中、Ｒ^１は水素原子又はメチル基を表し、Ｒ^２は酸により分解する基を表し、Ｒ^３〜Ｒ^６はそれぞれ独立に水素原子、ハロゲン原子又は炭素数１〜４のアルキル基を表す。）

(In the formula, R ¹ represents a hydrogen atom or a methyl group, R ² represents a group that is decomposed by an acid, and R ^{3 to} R ⁶ each independently represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms. To express.)

  The present invention is also a chemically amplified photosensitive resin composition containing at least a photoresist polymer and a photoacid generator, wherein the photoresist polymer contains at least the above polymer. It is a chemically amplified photosensitive resin composition.

  The present invention is the above chemically amplified photosensitive resin composition further comprising a dissolution inhibitor and / or an adhesion improver.

  The dissolution inhibitor is preferably a compound represented by the following general formula (5) or the following general formula (6).

（式中、Ｒ^１５及びＲ^１６は酸により分解する基を表し、Ｒ^１７及びＲ^１８は炭素数１〜１０の直鎖状、分枝状あるいは環状のアルキル基又は芳香族炭化水素基であり、Ｚは直結合、−Ｃ（ＣＦ_３）_２−、−Ｃ（ＣＨ_３）_２−、−ＳＯ_２−、−ＣＯ−、−Ｏ−又は−ＣＨ_２−を表す。）

(In the formula, R ¹⁵ and R ¹⁶ represent a group capable of decomposing by an acid, and R ¹⁷ and R ¹⁸ are linear, branched or cyclic alkyl groups or aromatic hydrocarbon groups having 1 to 10 carbon atoms. Z represents a direct bond, —C (CF ₃ ) ₂ —, —C (CH ₃ ) ₂ —, —SO ₂ —, —CO—, —O— or —CH ₂ —.

（式中、Ｒ^１９は２価の芳香族炭化水素基又は環状脂肪族炭化水素基を表し、Ｒ^２０及びＲ^２１は酸により分解する基を表し、Ｒ^２２及びＲ^２３はそれぞれ独立に水素原子、ハロゲン原子又は炭素数１〜４のアルキル基を表す。）

(In the formula, R ¹⁹ represents a divalent aromatic hydrocarbon group or a cycloaliphatic hydrocarbon group, R ²⁰ and R ²¹ each represent a group decomposed by an acid, and R ²² and R ²³ each independently represents a hydrogen atom. Represents a halogen atom or an alkyl group having 1 to 4 carbon atoms.)

  The adhesion improver is preferably an organosilicon compound. Further, the organosilicon compound is more preferably a compound represented by the following general formula (7).

（式中、Ｒ^２４〜Ｒ^２９は１価の有機基を表し、Ｘ^１及びＸ^２は２価の有機基を表す。また、ｋは正の整数である。）

(Wherein R ^{24 to} R ²⁹ represent a monovalent organic group, X ¹ and X ² represent a divalent organic group, and k is a positive integer.)

Furthermore, the present invention is a pattern forming method characterized by comprising at least the following steps:
Applying the chemical amplification type photosensitive resin composition on a substrate to be processed;
Performing pre-baking;
Exposure step;
Performing post-exposure baking;
A step of developing; and a step of post-baking.

  Further, the present invention is the pattern forming method described above, further comprising a post-exposure step between the developing step and the post-baking step.

  The acrylamide polymer of the present invention is preferred as a raw material for the chemically amplified photosensitive resin composition. In addition, the chemically amplified photosensitive resin composition of the present invention is excellent in pattern resolution and can be developed with an alkaline developer, and the film formed from the chemically amplified photosensitive resin composition of the present invention is heat resistant. Excellent film properties such as properties, mechanical properties, electrical properties and adhesion. Furthermore, the pattern forming method of the present invention is excellent in film properties such as heat resistance, mechanical properties, and electrical properties, and can achieve a high-resolution pattern. The acrylamide compound of the present invention can be used as a raw material for producing an acrylamide polymer.

The acrylamide polymer of the present invention has a hydroxy group when R ² is a hydrogen atom, and when R ² is a group that is decomposed by an acid, the acid is generated by the action of an acid generated from a photoacid generator. Since the group that decomposes due to the above can be a hydroxy group, it has excellent adhesion to a substrate and wiring.

  Hereinafter, the present invention will be described in detail.

<Acrylamide compound>
The acrylamide compound of the present invention is a novel compound represented by the following general formula (1), and is useful as a raw material monomer for an acrylamide polymer described later.

式（１）中、Ｒ^１は水素原子又はメチル基を表し、Ｒ^２は酸により分解する基を表し、Ｒ^３〜Ｒ^６は、それぞれ独立に、水素原子、ハロゲン原子又は炭素数１〜４のアルキル基を表す。

In Formula (1), R ¹ represents a hydrogen atom or a methyl group, R ² represents a group that decomposes with an acid, and R ^{3 to} R ⁶ each independently represents a hydrogen atom, a halogen atom, or a carbon number of 1 to 4. Represents an alkyl group.

  Examples of the group that can be decomposed by an acid include tert-butyl group, tetrahydropyran-2-yl group, tetrahydrofuran-2-yl group, 4-methoxytetrahydropyran-4-yl group, 1-ethoxyethyl group, 1 -Butoxyethyl group, 1-propoxyethyl group, methoxymethyl group, ethoxymethyl group and tert-butoxycarbonyl group can be mentioned.

  As the halogen atom, a fluorine atom or a chlorine atom is preferable.

  Examples of the alkyl group having 1 to 4 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, and tert-butyl group.

  Specific examples of the acrylamide compound represented by the general formula (1) of the present invention include the following compounds. However, the present invention is not limited to these.

Among the acrylamide compounds represented by the general formula (1), a compound in which R ¹ is a hydrogen atom, R ² is an ethoxymethyl group, and R ^{3 to} R ⁶ are hydrogen atoms (A-1 in Table 1) is, for example, , N- (4-hydroxyphenyl) acrylamide (obtained by reacting p-aminophenol and acryloyl chloride) and chloromethyl ethyl ether in N-methyl-2-pyrrolidone (NMP).

<Acrylamide polymer>
The acrylamide polymer of the present invention contains at least one repeating structural unit represented by the following general formula (2).

式（２）中、Ｒ^１は水素原子又はメチル基を表し、Ｒ^２は水素原子又は酸により分解する基を表し、Ｒ^３〜Ｒ^６はそれぞれ独立に水素原子、ハロゲン原子又は炭素数１〜４のアルキル基を表す。

In Formula (2), R ¹ represents a hydrogen atom or a methyl group, R ² represents a hydrogen atom or a group that decomposes with an acid, and R ^{3 to} R ⁶ each independently represent a hydrogen atom, a halogen atom, or a carbon number of 1 to 4 represents an alkyl group.

  Examples of the group capable of decomposing by an acid include tert-butyl group, tetrahydropyran-2-yl group, tetrahydrofuran-2-yl group, 4-methoxytetrahydropyran-4-yl group, 1-ethoxyethyl group, 1-butoxy group. Examples include an ethyl group, 1-propoxyethyl group, methoxymethyl group, ethoxymethyl group, and tert-butoxycarbonyl group.

  As the halogen atom, a fluorine atom or a chlorine atom is preferable.

  Examples of the alkyl group having 1 to 4 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, and a tert-butyl group.

  More specific examples of the repeating structural unit represented by the general formula (2) include the following structural units. However, the present invention is not limited to these.

  Since the acrylamide polymer of the present invention has a hydroxy group or can easily form a hydroxy group, it has excellent adhesion to a substrate or wiring.

The raw material of the acrylamide polymer of the present invention is not particularly limited as long as it can synthesize a polymer containing at least one repeating structural unit represented by the general formula (2), but is represented by the general formula (1). An acrylamide compound can be preferably used. When the polymer contains a repeating structural unit represented by the general formula (2) and R ² is a hydrogen atom, N- (4-hydroxyphenyl) (meth) acrylamide is used as a raw material. be able to.

  The polymer of the present invention may be a polymer obtained by polymerizing one of the acrylamide compounds represented by the general formula (1), or a copolymer of two or more of the acrylamide compounds represented by the general formula (1). However, it may be a copolymer obtained by further using a comonomer copolymerizable with this acrylamide compound. Here, N- (4-hydroxyphenyl) (meth) acrylamide may be used as the monomer. The polymer obtained by copolymerization of this acrylamide compound and comonomer has comonomer properties added. Therefore, by using various comonomer, useful properties for chemically amplified photosensitive resin compositions containing this polymer. (Resolution, sensitivity), characteristics useful for interlayer insulating films and surface protective films formed of a photosensitive resin (for example, heat resistance, mechanical characteristics, electrical characteristics, adhesion, etc.) can be improved.

  As the comonomer, a vinyl monomer is preferable because it has sufficient polymerizability with the acrylamide derivative. Examples of vinyl monomers include (meth) acrylamide derivatives other than the acrylamide compound represented by the general formula (1), butadiene, acrylonitrile, styrene, (meth) acrylic acid, ethylene derivatives, styrene derivatives, and (meth) acrylic acid. An ester derivative or the like can be used.

  Examples of ethylene derivatives include ethylene, propylene, vinyl chloride, and examples of styrene derivatives include α-methylstyrene, p-hydroxystyrene, chlorostyrene, and styrene derivatives described in JP-A No. 2001-172315.

  In addition to vinyl monomers, maleic anhydride, N-phenylmaleimide derivatives and the like can also be used. Examples of N-phenylmaleimide derivatives include N-phenylmaleimide and N- (4-methylphenyl) maleimide. . These comonomers can be used alone or in combination of two or more.

  The repeating structural unit from the comonomer of the above-mentioned polymer has a structural unit derived from (meth) acrylamide represented by the following general formula (3) and a (meth) acryl having a lactone structure represented by the general formula (4) More preferably, it is a structural unit derived from an ester.

（式中、Ｒ^７は水素原子又はメチル基を表し、Ｒ^８は水素原子又は酸により分解する基、Ｒ^９〜Ｒ^１２はそれぞれ独立に水素原子、ハロゲン原子、又は炭素数１〜４のアルキル基を表す。）

(Wherein R ⁷ represents a hydrogen atom or a methyl group, R ⁸ represents a hydrogen atom or a group decomposed by an acid, R ^{9 to} R ¹² each independently represents a hydrogen atom, a halogen atom, or an alkyl having 1 to 4 carbon atoms. Represents a group.)

  Examples of the repeating structural unit represented by the general formula (3) include, but are not limited to, the following examples.

  In the case of the polymer having the structural unit represented by the general formula (3), the heat treatment is performed as it is, the heat treatment is performed after the pattern is formed, or the entire surface is exposed again after the pattern is formed. When the group is decomposed with an acid and then subjected to heat treatment, a ring closure reaction occurs, and an oxazole ring is formed.

For example, in the general formula (3), a polymer having a structural unit in which R ^{7 to} R ¹² are hydrogen atoms (structural unit C-1 in Table 3 above) is heat-treated as shown in the following reaction formula A. This causes a ring closure reaction to form a benzoxazole ring. Even when R ⁸ is an acid-decomposable group, the acid-decomposable group is decomposed with an acid to form a structure in which R ⁸ becomes a hydrogen atom.

  Since the benzoxazole ring has a stable structure, the polymer having the benzoxazole structure is useful for an interlayer insulating film or a surface protective film having excellent film characteristics such as mechanical characteristics and electrical characteristics.

（式中、Ｒ^１３は水素原子又はメチル基を表し、Ｒ^１４はラクトン構造を有する有機基を表す。）

(Wherein R ¹³ represents a hydrogen atom or a methyl group, and R ¹⁴ represents an organic group having a lactone structure.)

  Examples of the repeating structural unit represented by the general formula (4) include, but are not limited to, the following examples.

  The structural unit represented by the general formula (4) has a highly polar lactone skeleton in the structure. Therefore, the polymer having this structural unit is excellent in adhesion to the substrate and wiring.

In order to exhibit excellent film properties when the polymer of the present invention is used for an interlayer insulating film or a surface protective film, the proportion of the repeating structural unit represented by the general formula (2) in the polymer is 5 to 5%. 100 mol% is preferable and 10-100 mol% is more preferable. In the case where R ² contains a structural unit that is a hydrogen atom, the proportion of the copolymer in the polymer varies depending on the monomer to be copolymerized, but it does not dissolve in the alkali developer used for developing the chemically amplified photosensitive resin composition. Is desirable.

  In addition, as a weight average molecular weight (Mw) of a polymer, 2,000-200,000 is preferable normally and 4,000-100,000 are more preferable. When the polymer Mw is less than 2,000, it may be difficult to form a film uniformly when the polymer is used for an interlayer insulating film or a surface protective film. When the polymer Mw exceeds 200,000, the resolution may be deteriorated when the polymer is used for forming an interlayer insulating film or a surface protective film.

  Such a polymer is usually a monomer composition containing the acrylamide compound represented by the general formula (1) and / or N- (4-hydroxyphenyl) (meth) acrylamide, such as radical polymerization and anionic polymerization. It can be obtained by polymerizing by the polymerization method used.

  For example, when a polymer is obtained by radical polymerization, an appropriate radical polymerization initiator such as 2,2′-azobis (isobutyronitrile) is added to a methanol solution of the monomer composition, and then argon or nitrogen is added. The polymer can be obtained by stirring at 50 to 70 ° C. for 0.5 to 24 hours under an inert gas atmosphere such as.

<Chemically amplified photosensitive resin composition>
The chemically amplified photosensitive resin composition of the present invention contains at least a polymer having a repeating structural unit represented by the general formula (2) and a photoacid generator, and usually contains the polymer and the photoacid generator. And can be prepared by mixing.

  When this chemically amplified photosensitive resin composition is subjected to pattern exposure with actinic radiation, which will be described later, an acid is generated from the photoacid generator constituting the chemically amplified photosensitive resin composition of the exposed portion, and an acid-decomposable group in the resin is generated. The acid-decomposable group undergoes a decomposition reaction. As a result, in the exposed area, the polymer of the present invention becomes soluble in an alkaline developer, and a difference in solubility (dissolution contrast) occurs between the exposed area and the unexposed area. Pattern formation using this chemically amplified photosensitive resin composition is performed utilizing the difference in solubility in such an alkali developer.

In the present invention, in order to constitute such a chemically amplified photosensitive resin composition, it is necessary that the polymer has at least an acid-decomposable group. The acid-decomposable group may be contained as R ² of the repeating structural unit represented by the general formula (2), or may be introduced into a repeating structural unit other than the general formula (2). . The repeating structural unit having an acid-decomposable group is preferably at least 10 mol%, more preferably at least 20 mol%, based on all repeating structural units. Further, the repeating structural unit having an acid-decomposable group is preferably 100 mol% or less, more preferably 80 mol% or less in all repeating structural units. The polymer of the present invention includes a polymer having no acid-decomposable group. However, even in that case, in order to constitute the chemically amplified photosensitive resin composition of the present invention, a dissolution inhibitor (described later) is added so that a sufficient dissolution inhibitory effect can be obtained. Polymers can be used.

  The photoacid generator is a compound that generates an acid upon irradiation with light used for exposure. The photoacid generator is sufficiently dissolved in an organic solvent together with the polymer of the present invention, and the solution is used to form a film such as a spin coat. There is no particular limitation as long as a uniform coating film can be formed by the method. The photoacid generator may be used alone or in combination of two or more.

  Examples of photoacid generators include triarylsulfonium salt derivatives, diaryliodonium salt derivatives, dialkylphenacylsulfonium salt derivatives, nitrobenzyl sulfonate derivatives, sulfonate esters of N-hydroxynaphthalimide, and N-hydroxysuccinimides. Examples thereof include sulfonic acid ester derivatives.

  The content of the photoacid generator is 0.2 with respect to the total of the polymer and the photoacid generator from the viewpoint of realizing sufficient sensitivity of the chemically amplified photosensitive resin composition and enabling good pattern formation. % By mass or more is preferable, and 1% by mass or more is more preferable. On the other hand, it is preferably 30% by mass or less, more preferably 15% by mass or less, from the viewpoint of realizing formation of a uniform coating film and suppressing residue (scum) after development.

  When preparing the chemically amplified photosensitive resin composition of the present invention, an appropriate solvent is used as necessary. The solvent is not particularly limited as long as the chemical amplification type photosensitive resin composition can be sufficiently dissolved and the solution can be uniformly applied by a method such as spin coating. Specifically, γ-butyrolactone, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, ethyl lactate, 2-heptanone, 2-methoxybutyl acetate, 2-ethoxyethyl acetate, methyl pyruvate, ethyl pyruvate, 3 -Methyl methoxypropionate, ethyl 3-methoxypropionate, N-methylpyrrolidone (NMP), cyclohexanone, cyclopentanone, methyl isobutyl ketone (MIBK), ethylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether , Ethylene glycol monoisopropyl ether, diethylene glycol monomethyl ether, diethylene glycol dimethyl ether, etc. It is possible. These may be used alone or in combination.

  Furthermore, chemical amplification type photosensitivity is added by adding other components such as a dissolution accelerator, a dissolution inhibitor, an adhesion improver, a surfactant, a pigment, a stabilizer, a coating improver, and a dye as necessary. A resin composition can also be prepared.

  For example, by adding a dissolution inhibitor to the chemically amplified photosensitive resin composition, dissolution of an unexposed portion of the photosensitive resin in an alkaline developer is suppressed. On the other hand, in the exposed area, the acid-decomposable group in the structure of the dissolution inhibitor is also decomposed by the action of the acid generated from the photoacid generator constituting the chemically amplified photosensitive resin composition, so that the solubility in an alkali developer is increased. Will increase. As a result, the dissolution contrast between the exposed portion and the unexposed portion is increased, and a fine pattern can be formed.

  When a dissolution inhibitor is added to the chemically amplified photosensitive resin composition, the content is the sum of the polymer and the photoacid generator from the viewpoint of enabling good pattern formation of the chemically amplified photosensitive resin composition. Is preferably 1% by mass or more, and more preferably 5% by mass or more. On the other hand, in order to realize the formation of a uniform coating film, the content is preferably 70% by mass or less, and more preferably 50% by mass or less.

  Specific examples of the dissolution inhibitor include compounds represented by the following general formula (5) or the following general formula (6), but are not limited thereto.

（式（５）中、Ｒ^１５及びＲ^１６は酸により分解する基を表し、Ｒ^１７及びＲ^１８は炭素数１〜１０の直鎖状、分枝状あるいは環状のアルキル基又は芳香族炭化水素基であり、Ｚは直結合、−Ｃ（ＣＦ_３）_２−、−Ｃ（ＣＨ_３）_２−、−ＳＯ_２−、−ＣＯ−、−Ｏ−又は−ＣＨ_２−を表す。）

(In the formula (5), R ¹⁵ and R ¹⁶ represent groups that are decomposed by an acid, and R ¹⁷ and R ¹⁸ are linear, branched or cyclic alkyl groups or aromatic hydrocarbons having 1 to 10 carbon atoms. Z represents a direct bond, —C (CF ₃ ) ₂ —, —C (CH ₃ ) ₂ —, —SO ₂ —, —CO—, —O— or —CH ₂ —.

  In addition, t-butyl group, tetrahydropyran-2-yl group, tetrahydrofuran-2-yl group, 4-methoxytetrahydropyran-4-yl group, 1-ethoxyethyl group, 1-butoxyethyl are groups that can be decomposed by acid. Group, 1-propoxyethyl group, methoxymethyl group, ethoxymethyl group, t-butoxycarbonyl group and the like.

  Examples of the linear, branched or cyclic alkyl group having 1 to 10 carbon atoms include a methyl group, an ethyl group, a butyl group, a cyclohexyl group, a norbornyl group, and a 5-norbornen-2-yl group. Examples of the group hydrocarbon group include a phenyl group, a tolyl group, and a naphthyl group.

（式（６）中、Ｒ^１９は２価の芳香族炭化水素基又は環状脂肪族炭化水素基、Ｒ^２０及びＲ^２１は酸により分解する基を表し、Ｒ^２２及びＲ^２３は、それぞれ独立に、水素原子、ハロゲン原子又は炭素数１〜４のアルキル基を表す。）

(In the formula (6), R ¹⁹ represents a divalent aromatic hydrocarbon group or a cyclic aliphatic hydrocarbon group, R ²⁰ and R ²¹ each represent a group decomposed by an acid, and R ²² and R ²³ are each independently Represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 4 carbon atoms.)

  Examples of the divalent aromatic hydrocarbon group include a phenylene group and a naphthylene group. Examples of the divalent cycloaliphatic hydrocarbon group include a cyclohexanediyl group, a norbornenediyl group, an adamantanediyl group, and a norbornanediyl group.

  Examples of groups that can be decomposed by an acid include t-butyl group, tetrahydropyran-2-yl group, tetrahydrofuran-2-yl group, 4-methoxytetrahydropyran-4-yl group, 1-ethoxyethyl group, 1-butoxyethyl group, Examples include 1-propoxyethyl group, methoxymethyl group, ethoxymethyl group, t-butoxycarbonyl group and the like.

  Examples of the halogen atom include a fluorine atom and a chlorine atom.

  Examples of the alkyl group having 1 to 4 carbon atoms include a methyl group, an ethyl group, a propyl group, and a butyl group.

  Moreover, adhesiveness can be improved on the substrate of the photosensitive resin by adding an adhesion improver to the chemically amplified photosensitive resin composition. The adhesion improver is preferably an organosilicon compound.

  Examples of the organosilicon compound include γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, vinyltriethoxysilane, the organosilicon compound described in Japanese Patent No. 3422703, and the following general formula (7). And organosilicon compounds.

（式（７）中、Ｒ^２４〜Ｒ^２９は１価の有機基を表し、Ｘ^１及びＸ^２は２価の有機基を表す。また、ｋは正の整数である。）

(In formula (7), R ^{24 to} R ²⁹ represent a monovalent organic group, X ¹ and X ² represent a divalent organic group, and k is a positive integer.)

Examples of the monovalent organic group represented by R ^{26 to} R ²⁹ include alkyl groups such as methyl, ethyl, propyl, and butyl groups, and aryl groups such as phenyl, tolyl, and naphthyl groups. Can do.

Examples of the divalent organic group represented by X ¹ and X ² include alkylene groups such as methylene group, ethylene group, propylene group and butylene group, arylene groups such as phenylene group, and groups obtained by combining these. .

Further, as the monovalent organic group represented by R ²⁴ and R ²⁵ , specifically, a monovalent organic group having an imide bond or an amide bond represented by the following structure is preferable.

（これら式中、＊は結合位置を示す。）

(In these formulas, * indicates a bonding position.)

  k is preferably 1.

  When using an adhesion improver, 0.1 mass with respect to the total of the polymer and the photoacid generator from the viewpoint of enabling formation of a pattern having excellent adhesion in the chemically amplified photosensitive resin composition. % Or more is preferable, and 0.5 mass% or more is more preferable. In order to enable good resolution, the content is preferably 25% by mass or less, and more preferably 15% by mass or less.

  The chemically amplified photosensitive resin composition of the present invention is excellent in pattern resolution and can be developed with an alkaline developer, and the film made of the chemically amplified photosensitive resin composition of the present invention is heat resistant, mechanical Excellent film properties such as properties, electrical properties and adhesion. Therefore, such a chemically amplified photosensitive resin composition can be suitably used for forming an interlayer insulating film and a surface protective film.

<Pattern formation method>
The pattern forming method of the present invention comprises at least a coating step, a pre-bake step, an exposure step, a post-exposure bake step, a development step, and a post-bake step.

  Specifically, in the pattern forming method of the present invention, at least a coating step of applying the above chemically amplified photosensitive resin composition on the substrate to be processed, and fixing the chemically amplified photosensitive resin composition coating film on the substrate to be processed. Pre-baking step, exposure step of selectively exposing the chemically amplified photosensitive resin composition coating film, post-exposure baking step of baking the chemically amplified photosensitive resin composition coating film after exposure, chemical amplification type after exposure It consists of the development process which forms the pattern by dissolving and removing the exposed part of the photosensitive resin composition coating film, and the post-baking process which cures the chemically amplified photosensitive resin composition coating film on which the pattern is formed.

  The pattern forming method of the present invention may further include a post-exposure step between the development step and the post-bake step.

  The applying process is a process of applying the chemically amplified photosensitive resin composition to a substrate to be processed, for example, a silicon wafer, a ceramic substrate or the like. As the coating method, spin coating using a spin coater, spray coating using a spray coater, dipping, printing, roll coating, or the like can be used.

  The pre-baking process is a process for drying the chemically amplified photosensitive resin composition coating applied on the substrate to be processed, removing the solvent, and fixing it on the substrate to be processed. A prebaking process is normally performed at 60-150 degreeC.

  In the exposure step, the chemically amplified photosensitive resin composition coating film is selectively exposed through a photomask to generate an exposed portion and an unexposed portion, and a pattern on the photomask is chemically amplified photosensitive resin composition. It is the process of transferring to an object coating film. Actinic rays used for pattern exposure include ultraviolet rays, visible rays, excimer lasers, electron beams, X-rays, and the like, and any of them can be used. Among them, actinic radiation having a wavelength of 180 to 500 nm is preferable in the coating film made of the chemically amplified photosensitive resin composition of the present invention.

  The post-exposure baking step is a step of promoting the reaction between the acid generated by exposure and the acid-decomposable group of the polymer. The post-exposure bake step is usually performed at 60 to 150 ° C.

  The development step is a step of forming a pattern by dissolving and removing the exposed portion of the chemically amplified photosensitive resin composition coating film with an alkaline developer. By the exposure step described above, a difference in solubility (dissolution contrast) of the polymer in the alkali developer between the exposed portion and the unexposed portion of the chemically amplified photosensitive resin composition coating film is generated. By using this dissolution contrast, the exposed portion of the chemically amplified photosensitive resin composition coating film is dissolved and removed, and a chemically amplified photosensitive resin composition coating film (hereinafter simply referred to as “pattern”) is formed. ") Is obtained.

  Add appropriate amount of aqueous solution of quaternary ammonium base such as tetramethylammonium hydroxide (TMAH) and tetraethylammonium hydroxide, water-soluble alcohols such as methanol and ethanol, and surfactants as the alkaline developer used here. The aqueous solution etc. which were made can be used.

  As the developing method, paddle, dipping, spraying and the like are possible. After the development process, the formed pattern is rinsed with water.

  The post-bake process is a process in which the obtained pattern is subjected to heat treatment in the air or in an inert gas atmosphere, for example, a nitrogen atmosphere, to improve the adhesion between the pattern and the substrate to be processed, and to cure the pattern. . A post-baking process is normally performed at 100-380 degreeC. Further, the post-baking process may be performed in one stage or in multiple stages.

  The post-exposure process is a process of exposing the entire surface of the chemically amplified photosensitive resin composition coating film on which the pattern is formed, and promoting the curing of the pattern in the subsequent post-baking process. The actinic radiation used for the post-exposure may be the same as the actinic radiation used in the exposure step, and is preferably actinic radiation having a wavelength of 180 to 500 nm.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited only to these examples.

(Synthesis Example 1)
Synthesis of N- (4-hydroxyphenyl) acrylamide 25.6 g of lithium chloride and 60 g of p-aminophenol were dissolved in 400 ml of NMP, and 52.2 g of acryloyl chloride was added dropwise to the ice-cooled solution and stirred overnight at room temperature. The reaction solution was poured into water, and the deposited precipitate was filtered off and washed with water. Thereafter, the obtained precipitate was dissolved in 1 L of methanol and dried over magnesium sulfate. After distilling off methanol under reduced pressure, 200 ml of diethyl ether was added to the residue, washed with stirring, and filtered to obtain 30 g of N- (4-hydroxyphenyl) acrylamide.

(Synthesis Example 2)
Synthesis of acrylamide compound A-1 (in general formula (1), R ¹ , R ^{3 to} R ⁶ = H, R ² = —CH ₂ OC ₂ H ₅ , below)

To a solution of 30 g of N- (4-hydroxyphenyl) acrylamide obtained in Synthesis Example 1 and 35 g of N, N-diisopropylethylamine in 160 ml of NMP, 19.2 g of chloromethyl ethyl ether was added and stirred for 3 days. The reaction solution was then added to water and extracted with 500 ml of diethyl ether. The diethyl ether layer was washed with diluted sulfuric acid, 3% aqueous sodium hydrogen carbonate solution and saturated brine in that order, and dried over magnesium sulfate. The solvent was distilled off under reduced pressure, and the residue was recrystallized from ethyl acetate / hexane (1/1) to obtain 14.3 g of the desired product (yield 35%).
¹ H-NMR (THF-d ₈ , δ value): 1.18 (3H, t), 3.68 (2H, q), 5.16 (2H, s), 5.61 (1H, dd), 6.2-6.4 (2H, m), 6.96 (2H, d), 7.59 (1H, d), 9.04 (1H, br).

(Synthesis Example 3)
Synthesis of acrylamide compound A-4 (in general formula (1), R ¹ , R ^{3 to} R ⁶ = H, R ² = —CO—OC (CH ₃ ) ₃ , below)

  To a solution of 10 g of N- (4-hydroxyphenyl) acrylamide and 11.23 g of 4-dimethylaminopyridine dissolved in 70 ml of NMP, 13.37 g of di-t-butyl carbonate was added and stirred at room temperature. After 3 hours, the mixture was poured into 500 ml of water, and the organic layer was extracted with 200 ml of diethyl ether, and then washed with 0.2N hydrochloric acid, brine, 3% aqueous sodium hydroxide, and brine in this order. After drying over magnesium sulfate, ethyl acetate was distilled off under reduced pressure to obtain 11.3 g of the desired product (yield 70%).

(Synthesis Example 4)
Synthesis of N- (2-hydroxyphenyl) acrylamide 20 g of o-aminophenol was dissolved in 200 ml of NMP, ice-cooled, and then 8.546 g (1.1 moles) of lithium chloride was added. After all the lithium chloride was dissolved, 17.42 g (1.05 times mol) of acryloyl chloride was added dropwise and stirred for 5 hours under ice cooling. The reaction mixture was poured into 1.8 L of water, and the organic layer was extracted with 700 ml of diethyl ether. The diethyl ether layer was washed with 0.2N hydrochloric acid, brine and water in that order, and dried over magnesium sulfate. Thereafter, diethyl ether was distilled off under reduced pressure, and 80 ml of diisopropyl ether was added to the resulting residue, followed by washing with heating and filtration, followed by filtration. Further, the same washing treatment was performed again to obtain 10.2 g of N- (2-hydroxyphenyl) acrylamide (white powder, yield 34%).

(Synthesis Example 5)
Synthesis of N- (2-ethoxymethoxyphenyl) acrylamide 20 g of N- (2-hydroxyphenyl) acrylamide obtained in Synthesis Example 4 was dissolved in 150 ml of NMP together with 23.76 g of N, N-diisopropylethylamine, and chloromethyl ethyl ether was added thereto. 12.75 g was added and stirred at room temperature. Three days later, the mixture was poured into 1.0 L of water, and the organic layer was extracted with 400 ml of diethyl ether and washed with 0.2 N hydrochloric acid, brine, 3% aqueous sodium hydroxide and brine in this order. After drying over magnesium sulfate, diethyl ether was distilled off under reduced pressure, and the resulting residue was recrystallized from hexane / ethyl acetate (100/4) to give 13.23 g of N- (2-ethoxymethoxyphenyl) acrylamide. Obtained (white solid, 49% yield).

Example 1
Synthesis of polymer (represented below) whose repeating structural unit is only B-1 (in general formula (2), R ¹ , R ^{3 to} R ⁶ = H, R ² = —CH ₂ OC ₂ H ₅ )

  6 g of acrylamide compound A-1 obtained in Synthesis Example 2 was dissolved in 30 ml of methanol, 0.045 g of 2,2′-azobis (isobutyronitrile) was added thereto, and then the mixture was heated to reflux for 2 hours in an argon atmosphere. . After allowing to cool, it was reprecipitated in 300 ml of diethyl ether, and the precipitated polymer was filtered off. This was reprecipitated and purified again to obtain 5.12 g of the desired polymer (yield 85%). Mw and dispersity (Mw / Mn) measured by GPC analysis were 32000 (polystyrene conversion) and 2.54, respectively.

(Example 2)
A polymer in which the repeating structural unit is 50 mol% B-1 and B-17 (in the general formula (2), R ^{1 to} R ⁶ = H) is 50 mol% (the number given to the repeating structural unit below is mol%). Synthesis)

  5.424 g of the acrylamide compound A-1 obtained in Synthesis Example 2 and 4 g of N- (4-hydroxyphenyl) acrylamide obtained in Synthesis Example 1 were dissolved in 85 ml of methanol, and 2,2′-azobis (isobutyro) was added thereto. (Nitrile) 0.805 g was added, and the mixture was heated to reflux for 1 hour under an argon atmosphere. After allowing to cool, it was reprecipitated in 800 ml of diethyl ether, and the precipitated polymer was filtered off. This was purified again by reprecipitation to obtain 6.59 g of the target polymer (yield 70%). Mw and dispersity (Mw / Mn) measured by GPC analysis were 15600 (polystyrene equivalent) and 3.15, respectively.

(Example 3)
Repeating structural unit B-1 20 mol%, C-1 (in formula (3), R ^{7 to} R ¹² = H) 50 mol% and C-2 (in formula (3), R ⁷ , R ⁹ to Synthesis of polymer (R ¹² = H, R ⁸ = —CH ₂ OC ₂ H ₅ ) 30 mol% (the number given to the repeating structural unit below indicates mol%)

  6 g of acrylamide compound A-1 obtained in Synthesis Example 2, 9 g of N- (2-hydroxyphenyl) acrylamide obtained in Synthesis Example 4, and 20.339 g of N- (2-ethoxymethoxyphenyl) acrylamide obtained in Synthesis Example 5 After dissolving in 106 ml of methanol and adding 0.302 g of 2,2′-azobis (isobutyronitrile) thereto, the mixture was heated to reflux for 4 hours in an argon atmosphere. After standing to cool, it was reprecipitated in 1 L of diethyl ether, and the precipitated polymer was filtered off. This was purified again by reprecipitation to obtain 29.33 g of the target polymer (yield 83%). Mw and dispersity (Mw / Mn) measured by GPC analysis were 31800 (polystyrene equivalent) and 2.65, respectively.

Example 4
Synthesis of polymer in which the repeating structural unit is 20% by mole of B-17, 30% by mole of C-1 and 50% by mole of C-2 (the number given to the repeating structural unit below indicates mole%)

  4 g of N- (4-hydroxyphenyl) acrylamide obtained in Synthesis Example 1, 6 g of N- (2-hydroxyphenyl) acrylamide obtained in Synthesis Example 4, and N- (2-ethoxymethoxyphenyl) acrylamide obtained in Synthesis Example 5 13.56 g was dissolved in 130 ml of methanol, and 0.603 g of 2,2′-azobis (isobutyronitrile) was added thereto, followed by heating under reflux for 4 hours under an argon atmosphere. After standing to cool, it was reprecipitated in 1 L of diethyl ether, and the precipitated polymer was filtered off. This was reprecipitated and purified again to obtain 19.79 g of the desired polymer (yield 84%). The weight average molecular weight Mw and dispersity (Mw / Mn) measured by GPC analysis were 30500 (polystyrene conversion) and 2.77, respectively.

(Example 5)
The repeating structural unit is B-4 (in the general formula (2), R ¹ , R ^{3 to} R ⁶ = H, R ² = —CO—OC (CH ₃ ) ₃ ) 50 mol%, C-1 30 mol% and D-1 (in the general formula (4), R ¹³ = H, R ¹⁴ = 2,6-norbornanecarbolactone-5-yl) 20 mol% polymer (the number given to the repeating structural unit below is mol%) Synthesis)

  10 ml of acrylamide compound A-4 obtained in Synthesis Example 3, 3.71 g of N- (2-hydroxyphenyl) acrylamide obtained in Synthesis Example 4 and 3.16 g of 5-acryloyl-2,6-norbornanecarbolactone were added to 67 ml of tetrahydrofuran. After dissolution, 0.374 g of 2,2′-azobis (isobutyronitrile) was added thereto, followed by heating under reflux for 4 hours under an argon atmosphere. After allowing to cool, it was reprecipitated in 600 ml of diethyl ether, and the precipitated polymer was filtered off. This was reprecipitated and purified again to obtain 14.67 g of the desired polymer (yield 87%). Mw and dispersity (Mw / Mn) measured by GPC analysis were 33500 (polystyrene equivalent) and 2.89, respectively.

(Synthesis Example 6)
Dissolution inhibitor having the following structure (in general formula (5), R ¹⁵ , R ¹⁶ = —CH ₂ OC ₂ H ₅ , R ¹⁷ , R ¹⁸ = phenyl group, Z = —C (CF ₃ ) ₂ — ) Synthesis

  10 g of 2,2-bis (3-amino-4-hydroxyphenyl) hexafluoropropane was dissolved in 60 ml of NMP, 2.546 g of lithium chloride was added, and the mixture was ice-cooled. To the resulting solution, 8.06 g of benzoyl chloride was added, stirred for 1 hour under ice cooling, and further stirred overnight at room temperature. The reaction mixture was poured into 600 ml of water, and the deposited precipitate was filtered off and washed with water to obtain 12 g of 2,2-bis (3-benzamido-4-hydroxyphenyl) hexafluoropropane.

10 g of 2,2-bis (3-benzamido-4-hydroxyphenyl) hexafluoropropane obtained above was dissolved in 60 ml of NMP together with 6.75 g of N, N-diisopropylethylamine, and 3.62 g of chloromethyl ethyl ether was added. And stirred. One day later, the mixture was poured into 600 ml of water, and the organic layer was extracted with 300 ml of diethyl ether, and then washed with 0.06N hydrochloric acid, brine, 3% aqueous sodium hydroxide, and brine in this order. After drying over magnesium sulfate, diethyl ether was distilled off under reduced pressure, and the resulting residue was recrystallized from hexane / ethyl acetate (5/4) to obtain 7.8 g of the desired product (white solid, yield). Rate 65%).
¹ H-NMR (THF-d ₈ , δ value): 1.22 (6H, t), 3.79 (4H, q), 5.39 (4H, s), 7.12 (2H, d), 7.27 (2H, d), 7.45-7.55 (6H, m), 7.9-7.93 (4H, m), 8.73 (2H, s), 8.84 (2H, s).

(Synthesis Example 7)
Synthesis of dissolution inhibitor having the following structure (compound in general formula (6), R ¹⁹ = m-phenylene group, R ²⁰ , R ²¹ = -CH ₂ OC ₂ H ₅ , R ²² , R ²³ = H)

  To a solution of 27.548 g of o-aminophenol and 11.484 g of lithium chloride dissolved in 260 ml of NMP, 25 g of isophthaloyl chloride was added under ice cooling, and the mixture was stirred overnight at room temperature. The reaction mixture was poured into water, and the deposited precipitate was filtered off and washed with water. The obtained precipitate was dissolved in 500 ml of tetrahydrofuran and dried over magnesium sulfate, and then the solvent was distilled off under reduced pressure to obtain 40 g of N, N′-di (2-hydroxyphenyl) isophthalamide.

40 g of N, N′-di (2-hydroxyphenyl) isophthalamide obtained above and 44.52 g of N, N-dipropylethylamine were dissolved in 200 ml of NMP, and 23.88 g of chloromethyl ethyl ether was added thereto at room temperature. Stir for 3 days. The reaction mixture was added to 600 ml of water, and the organic layer was extracted with 300 ml of diethyl ether. The organic layer was washed with 0.06N hydrochloric acid, brine, 3% aqueous sodium hydroxide solution and brine in that order, and dried over magnesium sulfate. The solvent was distilled off under reduced pressure, and the resulting residue was recrystallized twice with hexane / ethyl acetate (1/1) to obtain 26 g of the desired compound (white solid, yield 49%).
¹ H-NMR (THF-d ₈ , δ value): 1.21 (6H, t), 3.78 (4H, q), 5.35 (4H, s), 6.99-7.08 (4H M), 7.24 (2H, dd), 7.64 (1H, s), 8.12 (2H, dd), 8.45 (2H, dd), 8.52 (2H, s), 9 .00 (H, brs).

(Synthesis Example 8)
Adhesion improver having the following structure (in the general formula (7), R ^{26 to} R ²⁹ = —CH ₃ , X ¹ , X ² = — (CH ₂ ) ₃ —, R ²⁴ , R ²⁵ = phenylmaleimide group, k Of organosilicon compounds in which = 1

8.389 g of 1,3-bis (3-aminopropyl) tetramethyldisiloxane was dissolved in 50 ml of NMP, and 10 g of phthalic anhydride was added dropwise thereto under ice cooling, followed by stirring at room temperature for 1 day. To the reaction mixture, 300 ml of ethyl acetate was added and washed with brine. After drying with magnesium sulfate, the solvent was distilled off under reduced pressure. 18.389 g of the obtained residue was dissolved in 80 ml of acetic anhydride, and 8.309 g of sodium acetate was added thereto, and reacted at 90 ° C. for 5 hours. After allowing to cool, the reaction mixture was poured into ice water and stirred for 1 hour. The precipitated crystals were filtered off and washed with water. The obtained crystals were dissolved in 200 ml of ethyl acetate, washed with 5% sodium carbonate, brine and water in this order, and dried over magnesium sulfate. Thereafter, the solvent was distilled off under reduced pressure, and 150 ml of hexane was added to the resulting residue, followed by stirring and washing. Further, recrystallization from hexane / ethyl acetate (5/3) gave 8.68 g of the desired product (white solid, total yield 71%).
¹ H-NMR (THF-d ₈ , δ value): 0.81 (12H, s), 0.56-0.61 (4H, m), 1.67-1.75 (4H, m), 3 .6-3.65 (4H, m), 7.72-7.76 (4H, m), 7.78-7.82 (4H, m).

(Synthesis Example 9)
Adhesion improver having the following structure (in the general formula (7), R ^{26 to} R ²⁹ = —CH ₃ , X ¹ , X ² = — (CH ₂ ) ₃ —, R ²⁴ , R ²⁵ = benzamide group, k = Of organosilicon compound 1)

  7.467 g of 1,3-bis (3-aminopropyl) tetramethyldisiloxane and 9.71 g of N, N-diisopropylethylamine were dissolved in 80 ml of tetrahydrofuran, and 8.87 g of benzoyl chloride was added dropwise under ice cooling to room temperature. For 1 day. The reaction mixture was poured into 500 ml of water, and the organic layer was extracted with 200 ml of diethyl ether. The organic layer was washed with 0.2N hydrochloric acid, brine, 3% aqueous sodium hydroxide, and brine in this order. After drying with magnesium sulfate, the solvent was distilled off under reduced pressure. The obtained object was a viscous liquid but solidified by leaving it in a refrigerator. The yield of the target product was 8 g (58% yield).

(Usage example 1)
A chemically amplified photosensitive resin composition having the following composition was prepared, a pattern was formed, and performance was evaluated.

(A) Polymer (obtained in Example 3): 4 g
(B) Photoacid generator (N- (p-toluenesulfonyloxy) naphthalimide, manufactured by Midori Chemical Co., Ltd., trade name: NAI-101): 0.096 g
(C) Dissolution inhibitor (obtained in Synthesis Example 6): 0.8 g
(D) Adhesion improver (obtained in Synthesis Example 8): 0.12 g
(F) γ-butyrolactone: 6 g
The above materials were mixed and dissolved, and filtered through a 0.45 μm Teflon (registered trademark) filter to prepare a chemically amplified photosensitive resin composition. This photosensitive resin composition was spin-coated on a 5-inch silicon substrate and then baked in an oven at 100 ° C./20 minutes to form a thin film having a thickness of 10 μm.

Next, this thin film was subjected to pattern exposure with actinic radiation (wavelength λ = 350 to 450 nm) through a photomask. After exposure, baking was performed in an oven at 90 ° C./10 minutes. Thereafter, it was developed by being immersed in an aqueous 2.38% tetramethylammonium hydroxide (TMAH) solution at room temperature for 2 minutes and 30 seconds. Next, the developed thin film was rinsed with pure water for 2 minutes. As a result, a positive pattern in which only the exposed portion of the photosensitive resin film was dissolved and removed was obtained. When the obtained pattern was observed with an SEM, it was found that a 10 μm through-hole pattern could be resolved when exposed at an exposure amount of 800 mJ / cm ² .

Next, the entire surface of the wafer on which the pattern is formed is exposed with actinic radiation (wavelength λ = 350 to 450 nm) at an exposure amount of 1000 mJ / cm ² , and further, at 95 ° C. for 30 minutes and at 250 ° C. for 1 hour in a nitrogen atmosphere, Each was baked in an oven to obtain a final pattern excellent in heat resistance and the like having a cured film thickness of 8 μm. As a result of SEM observation of the formed pattern, no crack or peeling was observed in the pattern.

(Usage examples 2 to 4)
In the same manner as in Use Example 1, the photosensitive resin compositions using the polymers obtained in Example 2, Example 4, and Example 5 were also evaluated. As a result, a 10 μm through hole pattern could be resolved at an exposure amount of 800 mJ / cm ² . Further, the entire surface of the wafer on which the pattern was formed was exposed to ultraviolet rays (wavelength λ = 350 to 450 nm) at an exposure amount of 1000 mJ / cm ² , and the obtained pattern was further heated at 95 ° C. for 30 minutes at 250 ° C. in a nitrogen atmosphere. By baking in an oven for 1 hour, a final pattern excellent in heat resistance and the like could be obtained. As a result of SEM observation, the formed pattern was free from cracks and peeling.

(Usage example 5)
(C) Chemical amplification type photosensitivity as in Example 1 except that the dissolution inhibitor obtained in Synthesis Example 7 and the adhesion improver obtained in Synthesis Example 9 were used as the dissolution inhibitor and (d) adhesion improver, respectively. The resin composition was prepared, formed into a pattern, and evaluated. As a result, an 8 μm through-hole pattern was resolved at an exposure amount of 800 mJ / cm ² , and no cracks or peeling were observed in the final pattern.

(Usage example 6)
A chemically amplified photosensitive resin composition having the following composition was prepared, a pattern was formed, and performance was evaluated.

(A) Polymer (obtained in Example 1): 4 g
(B) Photoacid generator (N- (p-toluenesulfonyloxy) naphthalimide, manufactured by Midori Chemical Co., Ltd., trade name: NAI-101): 0.112 g
(C) Dissolution inhibitor (obtained in Synthesis Example 6): 1.6 g
(D) Adhesion improver (obtained in Synthesis Example 8): 0.20 g
(F) γ-butyrolactone: 8 g
The above materials were mixed and dissolved, and filtered through a 0.45 μm Teflon (registered trademark) filter to prepare a chemically amplified photosensitive resin composition. This photosensitive resin composition was spin-coated on a 5-inch silicon substrate and then baked in an oven at 100 ° C./20 minutes to form a thin film having a thickness of 10 μm.

Next, this thin film was subjected to pattern exposure with actinic radiation (wavelength λ = 350 to 450 nm) through a photomask. After exposure, baking was performed in an oven at 90 ° C./10 minutes. Thereafter, it was developed by being immersed in a 2.38% tetramethylammonium hydroxide (TMAH) aqueous solution at room temperature for 3 minutes. Next, the developed thin film was rinsed with pure water for 2 minutes. As a result, a positive pattern in which only the exposed portion of the photosensitive resin film was dissolved and removed was obtained. When the obtained pattern was observed with an SEM, it was found that a 15 μm through-hole pattern could be resolved when exposed at an exposure amount of 600 mJ / cm ² .

Next, the entire surface of the wafer on which the pattern is formed is exposed with actinic radiation (wavelength λ = 350 to 450 nm) at an exposure amount of 800 mJ / cm ² , and further, at 95 ° C. for 30 minutes and at 250 ° C. for 1 hour in a nitrogen atmosphere, Each was baked in an oven to obtain a final pattern excellent in heat resistance and the like having a cured film thickness of 8 μm. As a result of SEM observation of the formed pattern, no crack or peeling was observed in the pattern.

  As is clear from the above description, in the photosensitive resin composition, by using a polymer obtained by polymerizing the polymer precursor containing the acrylamide derivative of the present invention, it can be developed with an alkaline aqueous solution and has a resolution. Can be used for an interlayer insulating film and a surface protective film of a semiconductor element.

  Moreover, even if the polymer has a repeating structural unit represented by the general formula (2) but does not have an acid-decomposable group, the polymer can be adhered to the substrate as long as the dissolution inhibitor is appropriately added. Therefore, it is useful as a base resin for a chemically amplified photosensitive resin composition.

Claims (12)

An acrylamide polymer containing a repeating structural unit represented by the following general formula (2).

(In the formula, R ¹ represents a hydrogen atom or a methyl group, R ² represents a hydrogen atom or a group that decomposes with an acid, and R ^{3 to} R ⁶ each independently represents a hydrogen atom, a halogen atom, or a C 1 -C 1 group. 4 represents an alkyl group.)   The acrylamide polymer according to claim 1, further comprising a repeating structural unit derived from a vinyl monomer different from the repeating structural unit represented by the general formula (2). The acrylamide polymer according to claim 2, wherein the repeating structural unit derived from the vinyl monomer is a structural unit represented by the following general formula (3) and / or general formula (4).

(Wherein R ⁷ represents a hydrogen atom or a methyl group, R ⁸ represents a hydrogen atom or a group that decomposes with an acid, and R ^{9 to} R ¹² each independently represents a hydrogen atom, a halogen atom, or a carbon number of 1 to 4 represents an alkyl group.)

(Wherein R ¹³ represents a hydrogen atom or a methyl group, and R ¹⁴ represents an organic group having a lactone structure.)   The acrylamide polymer according to any one of claims 1 to 3, wherein a weight average molecular weight (Mw) is 2,000 to 200,000. An acrylamide compound represented by the following general formula (1).

(In the formula, R ¹ represents a hydrogen atom or a methyl group, R ² represents a group that decomposes with an acid, and R ^{3 to} R ⁶ each independently represents a hydrogen atom, a halogen atom, or an alkyl having 1 to 4 carbon atoms. Represents a group.)   5. A chemically amplified photosensitive resin composition comprising at least a photoresist polymer and a photoacid generator, wherein the photoresist polymer is at least the acrylamide polymer according to claim 1. A chemically amplified photosensitive resin composition comprising:   The chemical amplification type photosensitive resin composition according to claim 6, further comprising a dissolution inhibitor and / or an adhesion improver. 8. The chemically amplified photosensitive resin composition according to claim 7, wherein the dissolution inhibitor is a compound represented by the following general formula (5) or the following general formula (6).

(In the formula, R ¹⁵ and R ¹⁶ represent a group capable of decomposing by an acid, and R ¹⁷ and R ¹⁸ are linear, branched or cyclic alkyl groups or aromatic hydrocarbon groups having 1 to 10 carbon atoms. Z represents a direct bond, —C (CF ₃ ) ₂ —, —C (CH ₃ ) ₂ —, —SO ₂ —, —CO—, —O— or —CH ₂ —.

(In the formula, R ¹⁹ represents a divalent aromatic hydrocarbon group or a cycloaliphatic hydrocarbon group, R ²⁰ and R ²¹ each represent a group decomposed by an acid, and R ²² and R ²³ each independently represents a hydrogen atom. Represents a halogen atom or an alkyl group having 1 to 4 carbon atoms.)   8. The chemically amplified photosensitive resin composition according to claim 7, wherein the adhesion improver is an organosilicon compound. The chemically amplified photosensitive resin composition according to claim 9, wherein the organosilicon compound is a compound represented by the following general formula (7).

(Wherein R ^{24 to} R ²⁹ represent a monovalent organic group, X ¹ and X ² represent a divalent organic group, and k is a positive integer.) A pattern forming method comprising at least the following steps:
The process of apply | coating the chemically amplified photosensitive resin composition of any one of Claims 6-10 on a to-be-processed substrate;
Performing pre-baking;
Exposure step;
Performing post-exposure baking;
A step of developing; and a step of post-baking.   The pattern forming method according to claim 11, further comprising a post-exposure step between the developing step and the post-baking step.