JP2010176012A - Positive resist composition and resist pattern forming method using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a positive resist composition for suppressing the generation of residues after the development of a resist film thereof, while maintaining good adhesion of the resist film to a substrate so as to form a fine resist pattern, and a resist pattern forming method using the same. <P>SOLUTION: The positive resist composition includes (A) an alkali-soluble novolac resin, (B) a photosensitizing agent, and (C) a predetermined benzotriazole-based compound, wherein since the predetermined benzotriazole-based compound is included, good adhesion of a resist film of the composition to a substrate is maintained, a fine resist pattern is formed, and the generation of residues is suppressed even after the development of the resist film. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a positive resist composition capable of forming a fine resist pattern and generating less residue after development of a resist film, and a resist pattern forming method using the same.

  A technology that forms a fine pattern on a substrate and performs etching using this as a mask to process the lower layer of the pattern (pattern formation technology) and a technology that forms wiring, bumps, etc. by plating are used in the semiconductor industry. It has been widely adopted in the production of integrated circuits and attracts great attention.

  Here, in this pattern formation technique, the fine pattern is usually made of an organic material, and is formed by a technique such as a lithography method or a nanoimprint method. In the lithography method, a resist film made of a resist composition containing a resin or the like is formed on a support such as a substrate, and a mask (mask pattern) in which a predetermined pattern is formed on the resist film, A step of forming a resist pattern of a predetermined shape on the resist film is performed by irradiating active rays such as light and electron beam to perform selective exposure and developing.

  In the resist film, a positive resist composition is a resist composition that changes so that the exposed portion has a property of dissolving in the developer, and a resist composition that changes so that the exposed portion does not dissolve in the developer. It is called a negative resist composition.

  In recent years, electronic devices such as mobile phones and digital cameras have been reduced in size and weight. Along with this, development of SiP (System in Package) and CSP (Chip Size Package), which are an extension of the conventional package technology, has been actively conducted. Since the CSP finishes the package to the size of the chip, it is necessary to perform rewiring mounting on the top of the chip, and the wiring pitch is required to be miniaturized. This wiring formation is mainly performed by patterning a resist and then performing copper plating or copper etching along the resist pattern. Therefore, high resolution of the resist is indispensable for miniaturization of the wiring pitch. Under such circumstances, there is an increasing demand from the market for high resolution resist patterns.

  Further, since the contact area between the resist pattern and the substrate becomes smaller as the resist composition becomes higher in resolution, improvement in substrate adhesion is also required. If the adhesion is weak, there is a problem that the resist pattern is peeled off during development, etching, or plating. As means for improving the substrate adhesion, use of an adhesion improver such as benzotriazole can be exemplified (for example, see Patent Document 1).

JP 2008-158157 A

  However, with the conventional additive (adhesion improver), residues derived from the resist film after development remain as residues (scum) between the resist patterns as a compensation for improving the adhesion between the resist pattern and the substrate. There was a problem that it was easy.

  The present invention has been made in view of the above problems, and the generation of residues after development of the resist film while maintaining good adhesion between the resist film and the substrate in order to form a fine resist pattern. It is an object of the present invention to provide a positive resist composition capable of reducing the amount of the resist and a method of forming a resist pattern using the same.

  In view of the above problems, the present inventors conducted extensive research. As a result, the present inventors have found that a positive resist composition containing an alkali-soluble novolak resin, a photosensitizer, and a predetermined benzotriazole-based compound can solve the above problems, and has completed the present invention.

  Specifically, the present invention provides the following.

［一般式（１）において、Ｒ^１は炭素数１以上１０以下のアルキル基、水酸基、カルボキシル基、水素原子、又は−ＣＯＯＲ’（Ｒ’は炭素数１以上５以下のアルキル基）を示し、Ｒ^２及びＲ^３は、それぞれ独立に水素原子、炭素数１以上６以下のアルキル基、又は炭素数１以上６以下のヒドロキシアルキル基である。ただし、Ｒ^２及びＲ^３から選ばれる少なくとも一種は、炭素数１以上６以下のヒドロキシアルキル基である。］ A first aspect of the present invention comprises (A) an alkali-soluble novolak resin, (B) a photosensitizer, and (C) a benzotriazole compound, and the benzotriazole compound is represented by the following general formula (1). Is a positive resist composition.

[In General Formula (1), R ¹ represents an alkyl group having 1 to 10 carbon atoms, a hydroxyl group, a carboxyl group, a hydrogen atom, or —COOR ′ (R ′ represents an alkyl group having 1 to 5 carbon atoms); R ² and R ³ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a hydroxyalkyl group having 1 to 6 carbon atoms. However, at least one selected from R ² and R ³ is a hydroxyalkyl group having 1 to 6 carbon atoms. ]

［一般式（１）において、Ｒ^１は炭素数１以上１０以下のアルキル基、水酸基、カルボキシル基、水素原子、又は−ＣＯＯＲ’（Ｒ’は炭素数１以上５以下のアルキル基）を示し、Ｒ^２及びＲ^３は、それぞれ独立に水素原子、炭素数１以上６以下のアルキル基、又は炭素数１以上６以下のヒドロキシアルキル基である。ただし、Ｒ^２及びＲ^３から選ばれる少なくとも一種は、炭素数１以上６以下のヒドロキシアルキル基である。］ In a second embodiment of the present invention, (A ′) an alkali-soluble novolak resin in which at least a part of hydrogen atoms of a phenolic hydroxyl group is substituted with a 1,2-naphthoquinonediazidosulfonyl group, and (C) a benzotriazole type A positive resist composition containing a compound, wherein the benzotriazole-based compound is a compound represented by the following general formula (1).

[In General Formula (1), R ¹ represents an alkyl group having 1 to 10 carbon atoms, a hydroxyl group, a carboxyl group, a hydrogen atom, or —COOR ′ (R ′ represents an alkyl group having 1 to 5 carbon atoms); R ² and R ³ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a hydroxyalkyl group having 1 to 6 carbon atoms. However, at least one selected from R ² and R ³ is a hydroxyalkyl group having 1 to 6 carbon atoms. ]

  The third aspect of the present invention is a coating process for applying a positive resist composition of the present invention on a substrate to obtain a resist film, and an exposure process for selectively irradiating the resist film with active rays for exposure. And a development step of performing development after the exposure step to obtain a resist pattern.

  According to the positive resist composition of the present invention, since the positive resist composition contains a predetermined benzotriazole-based compound, the adhesion between the resist film and the substrate is well maintained, and a fine resist pattern can be formed. In addition, even after development of the resist film, the generation of residues can be suppressed to a low level.

  Hereinafter, embodiments of the present invention will be described in detail.

<Positive resist composition>
The positive resist composition according to the first aspect of the present invention comprises (A) an alkali-soluble novolak resin (hereinafter also referred to as “component (A)”), (B) a photosensitizer, and a predetermined (C) benzotriazole type. Contains compounds.

  Further, the positive resist composition according to the second aspect of the present invention is an alkali-soluble novolak resin in which (A ′) at least a part of hydrogen atoms of the phenolic hydroxyl group is substituted with a 1,2-naphthoquinonediazidesulfonyl group. (Hereinafter also referred to as “component (A ′)”) and a predetermined (C) benzotriazole-based compound.

[(A) Alkali-soluble novolak resin]
The component (A) contained in the positive resist composition in the first aspect of the present invention is not particularly limited, but is an aromatic compound having a phenolic hydroxyl group (hereinafter simply referred to as “phenols”) and an aldehyde. And those obtained by addition-condensation in the presence of an acid catalyst are preferred.

(Phenols)
Examples of the phenols include cresols such as phenol, o-cresol, m-cresol, and p-cresol; 2,3-xylenol, 2,4-xylenol, 2,5-xylenol, and 2,6-xylenol. Xylenols such as 3,4-xylenol and 3,5-xylenol; ethylphenols such as o-ethylphenol, m-ethylphenol and p-ethylphenol, 2-isopropylphenol, 3-isopropylphenol, 4 -Alkylphenols such as isopropylphenol, o-butylphenol, m-butylphenol, p-butylphenol and p-tert-butylphenol; trialkylphenols such as 2,3,5-trimethylphenol and 3,4,5-trimethylphenol Polyhydric phenols such as resorcinol, catechol, hydroquinone, hydroquinone monomethyl ether, pyrogallol, and phlorogricinol; alkyl polyhydric phenols such as alkyl resorcin, alkyl catechol, and alkyl hydroquinone (all alkyl groups have 1 carbon atom) 4 or less); α-naphthol; β-naphthol; hydroxydiphenyl; and bisphenol A. These phenols may be used alone or in combination of two or more.

  Among these phenols, m-cresol and p-cresol are preferable, and it is more preferable to use m-cresol and p-cresol in combination. In this case, various characteristics such as sensitivity and heat resistance as the positive resist composition can be adjusted by adjusting the blending ratio of the two. The blending ratio of m-cresol and p-cresol is not particularly limited, but the ratio of m-cresol / p-cresol is preferably 3/7 or more and 8/2 or less (mass ratio). Sensitivity can be improved by setting the ratio of m-cresol to 3/7 or more, and heat resistance can be improved by setting it to 8/2 or less.

(Aldehydes)
Examples of aldehydes include formaldehyde, paraformaldehyde, furfural, benzaldehyde, nitrobenzaldehyde, and acetaldehyde. These aldehydes may be used alone or in combination of two or more.

(Acid catalyst)
Examples of the acid catalyst include inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, and phosphorous acid; organic acids such as formic acid, oxalic acid, acetic acid, diethylsulfuric acid, and paratoluenesulfonic acid; and zinc acetate Examples thereof include metal salts. These acid catalysts may be used alone or in combination of two or more.

(Molecular weight)
The weight average molecular weight of the component (A) is preferably 1000 or more and 50000 or less from the viewpoints of developability, resolution, and plating solution resistance of the positive resist composition.

(Separation process)
The component (A) is preferably a fractionation resin in which the content of the low nuclei is reduced to 80% by mass or less, more preferably 50% by mass or less before the fractionation process, by the fractionation process. Here, the low nuclear body means the above-described phenols, that is, a phenol monomer, a dimer obtained from two molecules of the phenol monomer, a trimer obtained from three molecules of the phenol monomer, and the like. By using such a fractionation resin, the perpendicularity of the resist pattern cross-sectional shape is further improved, resist residues (scum) are less likely to occur during development, resolution is improved, and heat resistance is also excellent. Become.

  The fractionation treatment can be performed by, for example, the following well-known fractional precipitation treatment. First, as described above, after an addition condensation reaction between phenols and aldehydes, the resulting addition condensation product (novolak resin) is dissolved in a polar solvent, and water, heptane, hexane is added to this solution. Add a poor solvent such as, pentane, and cyclohexane. At this time, since the low nuclei have a relatively high solubility, they remain dissolved in the poor solvent, and thus a fractionated resin with a reduced content of the low nuclei can be obtained by filtering the precipitate. .

  Examples of the polar solvent include alcohols such as methanol and ethanol; ketones such as acetone and methyl ethyl ketone; glycol ether esters such as ethylene glycol monoethyl ether acetate; and cyclic ethers such as tetrahydrofuran. it can.

  (A) Content of the low nucleus in a component can be confirmed from the result of GPC measurement. That is, from the GPC chart, the molecular weight distribution of the synthesized phenol novolak resin can be confirmed, and the content can be calculated by measuring the intensity ratio of the peak corresponding to the elution time of the low-nuclear body. . Since the elution time of the low nuclei varies depending on the measurement means, it is important to specify the column, eluent, flow rate, temperature, detector, sample concentration, injection amount, measuring instrument, and the like.

  The dispersity [mass average molecular weight (Mw) / number average molecular weight (Mn)] of the fractionated resin is preferably 30 or less, and more preferably 15 or more and 25 or less.

[(A ′) Alkali-soluble novolak resin in which at least part of hydrogen atoms of phenolic hydroxyl group is substituted with 1,2-naphthoquinonediazidesulfonyl group]
The component (A ′) contained in the positive resist composition in the second aspect of the present invention is not particularly limited, but a part of the hydrogen atoms of all phenolic hydroxyl groups contained in the component (A) is 1 , 2-naphthoquinonediazidesulfonyl group is preferable. When the component (A ′) is used, the sensitivity of the positive resist composition can be further improved because the naphthoquinonediazidesulfonyl group having a small amount of the component (A ′) itself has photosensitivity.

  Substitution with a 1,2-naphthoquinonediazidesulfonyl group can be performed by an esterification reaction of the component (A) with a 1,2-naphthoquinonediazidesulfonic acid compound. Examples of 1,2-naphthoquinone diazide sulfonic acid compounds include halides of quinone diazide compounds such as 1,2-naphthoquinone diazide-4-sulfonic acid chloride and 1,2-naphthoquinone diazide-5-sulfonic acid chloride. Can do.

  In the component (A ′), the ratio in which the hydrogen atom of the phenolic hydroxyl group is substituted with a 1,2-naphthoquinonediazidosulfonyl group, that is, the esterification reaction rate is 2 mol% or more and 10 mol% or less. Is preferably 3 mol% or more and 7 mol% or less, more preferably 3 mol% or more and 5 mol% or less. By setting the reaction rate to 2 mol% or more, film loss in the unexposed portion can be suppressed, and by setting the reaction rate to 10 mol% or less, the sensitivity is improved and the perpendicularity of the resist pattern cross-sectional shape is improved. be able to.

[(B) Photosensitive agent]
The photosensitizer contained in the positive resist composition of the present invention is not particularly limited, but a quinonediazide group-containing compound is preferable. Examples of the quinonediazide group-containing compound include 2,3,4-trihydroxybenzophenone, 2,4,4′-trihydroxybenzophenone, 2,4,6-trihydroxybenzophenone, and 2,3,6-trihydroxybenzophenone. 2,3,4-trihydroxy-2'-methylbenzophenone, 2,3,4,4'-tetrahydroxybenzophenone, 2,2 ', 4,4'-tetrahydroxybenzophenone, 2,3', 4 4 ′, 6-pentahydroxybenzophenone, 2,2 ′, 3,4,4′-pentahydroxybenzophenone, 2,2 ′, 3,4,5-pentahydroxybenzophenone, 2,3 ′, 4,4 ′, Polyhydroxybenzenes such as 5 ′, 6-hexahydroxybenzophenone, 2,3,3 ′, and 4,4 ′, 5′-hexahydroxybenzophenone Nzophenones; bis (2,4-dihydroxyphenyl) methane, bis (2,3,4-trihydroxyphenyl) methane, 2- (4-hydroxyphenyl) -2- (4′-hydroxyphenyl) propane, 2- (2,4-dihydroxyphenyl) -2- (2 ′, 4′-dihydroxyphenyl) propane, 2- (2,3,4-trihydroxyphenyl) -2- (2 ′, 3 ′, 4′-tri Hydroxyphenyl) propane, 4,4 ′-{1- [4- [2- (4-hydroxyphenyl) -2-propyl] phenyl] ethylidene} bisphenol, and 3,3′-dimethyl- {1- [4- Bis [(poly) hydroxyphenyl] alkanes such as [2- (3-methyl-4-hydroxyphenyl) -2-propyl] phenyl] ethylidene} bisphenol; Tris (4- Droxyphenyl) methane, bis (4-hydroxy-3,5-dimethylphenyl) -4-hydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -4-hydroxyphenylmethane, bis (4- Hydroxy-3,5-dimethylphenyl) -2-hydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -2-hydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl)- Tris (hydroxyphenyl) methanes such as 3,4-dihydroxyphenylmethane and bis (4-hydroxy-3,5-dimethylphenyl) -3,4-dihydroxyphenylmethane or methyl-substituted products thereof; bis (3-cyclohexyl) -4-hydroxyphenyl) -3-hydroxyphenylmethane, bi (3-cyclohexyl-4-hydroxyphenyl) -2-hydroxyphenylmethane, bis (3-cyclohexyl-4-hydroxyphenyl) -4-hydroxyphenylmethane, bis (5-cyclohexyl-4-hydroxy-2-methylphenyl) ) -2-hydroxyphenylmethane, bis (5-cyclohexyl-4-hydroxy-2-methylphenyl) -3-hydroxyphenylmethane, bis (5-cyclohexyl-4-hydroxy-2-methylphenyl) -4-hydroxyphenyl Methane, bis (3-cyclohexyl-2-hydroxyphenyl) -3-hydroxyphenylmethane, bis (5-cyclohexyl-4-hydroxy-3-methylphenyl) -4-hydroxyphenylmethane, bis (5-cyclohexyl-4- Hydroxy-3- Tilphenyl) -3-hydroxyphenylmethane, bis (5-cyclohexyl-4-hydroxy-3-methylphenyl) -2-hydroxyphenylmethane, bis (3-cyclohexyl-2-hydroxyphenyl) -4-hydroxyphenylmethane, bis (3-cyclohexyl-2-hydroxyphenyl) -2-hydroxyphenylmethane, bis (5-cyclohexyl-2-hydroxy-4-methylphenyl) -2-hydroxyphenylmethane, and bis (5-cyclohexyl-2-hydroxy-) Bis (cyclohexylhydroxyphenyl) (hydroxyphenyl) methanes such as 4-methylphenyl) -4-hydroxyphenylmethane or methyl-substituted products thereof; phenol, p-methoxyphenol, dimethylphenol, hydroquinone, naphtho A compound having a hydroxyl group or an amino group, such as alcohol, pyrocatechol, pyrogallol, pyrogallol monomethyl ether, pyrogallol-1,3-dimethyl ether, gallic acid, aniline, p-aminodiphenylamine, and 4,4′-diaminobenzophenone; and novolak , Pyrogallol-acetone resin, and a copolymer of p-hydroxystyrene homopolymer or a monomer copolymerizable therewith, and naphthoquinone-1,2-diazide-5-sulfonic acid, naphthoquinone-1,2-diazide Examples include a complete ester compound, a partial ester compound, an amidated product, or a partially amidated product with quinonediazide group-containing sulfonic acid such as -4-sulfonic acid and orthoanthraquinonediazidesulfonic acid. These photosensitizers may be used alone or in combination of two or more.

［一般式（Ｂ−１）及び（Ｂ−２）中、Ｒ^１ｂからＲ^７ｂはそれぞれ独立して水素原子、置換基を有していてもよい炭素数１以上５以下のアルキル基、及び置換基を有していてもよい炭素数４以上８以下のシクロアルキル基を示す。］ Among these photosensitizers, quinonediazide sulfonic acid esters of compounds represented by the following general formulas (B-1) and (B-2) are preferable.

[In General Formulas (B-1) and (B-2), R ^1b to R ^7b are each independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms which may have a substituent, and a substituent. A cycloalkyl group having 4 to 8 carbon atoms, which may have a group, is shown. ]

Among the quinonediazide sulfonic acid esters of the compounds represented by the general formulas (B-1) and (B-2), the quinonediazide sulfonic acid ester of the compound represented by the following chemical formula (B-3) is particularly preferable.

  Here, in the quinonediazide sulfonic acid ester of the compound represented by the general formulas (B-1) and (B-2) and the chemical formula (B-3), the naphthoquinone-1,2-diazide-sulfonyl group is 4 Those having a sulfonyl group bonded to the 5th or 5th position are preferred. These compounds dissolve well in a solvent that is usually used when the positive resist composition is used as a solution, and have good compatibility with the components (A) and (A ′). When used as a photosensitizer, a positive resist composition having high sensitivity, excellent image contrast and cross-sectional shape, excellent heat resistance, and no foreign matter even when used as a solution is provided.

  Examples of the compound represented by the general formula (B-1) include 1-hydroxy-4- [1,1-bis (4-hydroxyphenyl) ethyl] benzene and naphthoquinone-1,2-diazide-sulfonyl chloride. It can be produced by condensing in a solvent such as dioxane in the presence of an alkali such as triethanolamine, an alkali carbonate, and an alkali hydrogencarbonate, and completely or partially esterified. The compound represented by the general formula (B-2) is, for example, 1- [1- (4-hydroxyphenyl) isopropyl] -4- [1,1-bis (4-hydroxyphenyl) ethyl] benzene and Condensing naphthoquinone-1,2-diazide-sulfonyl chloride in a solvent such as dioxane in the presence of an alkali such as triethanolamine, alkali carbonate, and alkali hydrogen carbonate to complete esterification or partial esterification. Can be manufactured.

  As naphthoquinone-1,2-diazide-sulfonyl chloride, it is preferable to use naphthoquinone-1,2-diazide-4-sulfonyl chloride or naphthoquinone-1,2-diazide-5-sulfonyl chloride.

  When the component (A) is used as the base resin, the content of the photosensitive agent is preferably 5 parts by mass or more and 100 parts by mass or less, and preferably 10 parts by mass or more and 50 parts by mass or less with respect to 100 parts by mass of the component (A). Is more preferable. When the content is 5 parts by mass or more, a desired resist pattern can be obtained, and when the content is 50 parts by mass or less, sufficient sensitivity can be maintained.

  On the other hand, when the component (A ′) is used as the base resin, the photosensitizer is not essential, but when the photosensitizer is contained, 1 part by mass or more and 30 parts by mass or less is used with respect to 100 parts by mass of the component (A ′). It is preferable to use 5 parts by mass or more and 20 parts by mass or less.

［一般式（１）において、Ｒ^１は炭素数１以上１０以下のアルキル基、水酸基、カルボキシル基、水素原子、又は−ＣＯＯＲ’（Ｒ’は炭素数１以上５以下のアルキル基）を示し、Ｒ^２及びＲ^３は、それぞれ独立に水素原子、炭素数１以上６以下のアルキル基、又は炭素数１以上６以下のヒドロキシアルキル基である。ただし、Ｒ^２及びＲ^３から選ばれる少なくとも一種は、炭素数１以上６以下のヒドロキシアルキル基である。］ [(C) Benzotriazole compound]
The benzotriazole compound contained in the positive resist composition of the present invention is represented by the following general formula (1).

[In General Formula (1), R ¹ represents an alkyl group having 1 to 10 carbon atoms, a hydroxyl group, a carboxyl group, a hydrogen atom, or —COOR ′ (R ′ represents an alkyl group having 1 to 5 carbon atoms); R ² and R ³ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a hydroxyalkyl group having 1 to 6 carbon atoms. However, at least one selected from R ² and R ³ is a hydroxyalkyl group having 1 to 6 carbon atoms. ]

  When the positive resist composition contains the benzotriazole-based compound represented by the general formula (1), the adhesion between the resist film and the substrate is maintained well, and a fine resist pattern can be formed. At the same time, even after development of the resist film, the generation of residues can be suppressed to a minimum.

Here, the alkyl group having 1 to 10 carbon atoms in R ¹ is not particularly limited, and includes a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, a nonyl group, a decyl group, and the like. Can be mentioned. In the positive resist composition of the present invention, R ¹ is preferably an alkyl group having 1 to 3 carbon atoms, and more preferably a methyl group.

Examples of the alkyl group having 1 to 6 carbon atoms as R ² and R ³ include methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, sec-butyl group, tert-butyl group, Examples thereof include an n-heptyl group and an n-hexyl group. Examples of the hydroxyalkyl group having 1 to 6 carbon atoms include groups in which at least one hydrogen atom of the alkyl group having 1 to 6 carbon atoms is substituted with a hydroxyl group.

As described above, at least one selected from R ² and R ³ is a hydroxyalkyl group having 1 to 6 carbon atoms. By having the hydroxyalkyl group as R ² or R ³ , the solubility of the benzotriazole-based compound in the positive resist composition can be sufficiently maintained, and adhesion between the positive resist composition and the substrate can be maintained. Sex can be sufficiently maintained. R ² and R ³ are preferably both a hydroxyalkyl group having 1 to 6 carbon atoms, and more preferably a 2-hydroxyethyl group.

Specifically, benzotriazole compounds represented by the following chemical formulas (C-1) to (C-4) can be preferably used.

  The benzotriazole-based compound represented by the general formula (1) can be produced, for example, by the method shown below (see, for example, Japanese Patent Application Laid-Open No. 2000-044549).

［一般式（２）において、Ｒ^１は上記と同様である。］ A compound represented by the following chemical formula (2) such as methyl-1H-benzotriazole, a secondary alcohol amine such as diethanolamine, and formaldehyde are charged at a molar ratio of 1: 1: 1, and reacted for 5 hours under methanol reflux. After the reaction, the target compound is obtained by removing methanol and water by distillation.

[In General Formula (2), R ¹ is the same as described above. ]

  The benzotriazole compound represented by the general formula (1) is preferably added in an amount of 0.1 parts by mass or more and 5 parts by mass or less per 100 parts by mass of the component (A) or the component (A ′). More preferably, 2 parts by mass or more and 2 parts by mass or less are added. When the addition amount of the benzotriazole-based compound is 0.1 parts by mass or more, the adhesion between the resist film obtained from the positive resist composition of the present invention and the substrate can be made sufficiently high. . Moreover, when the addition amount of the benzotriazole-based compound is 5 parts by mass or less, a good resist pattern with few residues can be obtained even after the development of the resist film.

［一般式（Ｄ−１）において、Ｒ^４１からＲ^４８はそれぞれ独立に、水素原子、ハロゲン原子、炭素数１以上６以下のアルキル基、炭素数１以上６以下のアルコキシ基、又はシクロアルキル基を表し；Ｒ^４９からＲ^５１はそれぞれ独立に水素原子又は炭素数１以上６以下のアルキル基を示し；Ｑは水素原子、炭素数１以上６以下のアルキル基、Ｒ^４９と結合して形成される、炭素鎖数３以上６以下のシクロ環、又は下記の化学式（Ｄ−２）で表される残基を示し；ｗ、ｓは１以上３以下の整数を示し；ｕは０以上３以下の整数を示し；ｖは０以上３以下の整数を示す。］ [(D) Sensitizer]
The positive resist composition of the present invention contains a sensitizer as necessary. The sensitizer that can be used in the present invention is not particularly limited, and can be arbitrarily selected from sensitizers that are usually used in positive resist compositions. Specifically, a phenol compound represented by the following general formula (D-1) can be used.

[In General Formula (D-1), R ⁴¹ to R ⁴⁸ are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a cycloalkyl group. Each of R ⁴⁹ to R ⁵¹ independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; Q is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or R ⁴⁹ formed by bonding. Or a cyclic ring having 3 to 6 carbon chains, or a residue represented by the following chemical formula (D-2); w, s represents an integer of 1 to 3; u is 0 to 3 V represents an integer of 0 or more and 3 or less. ]

［一般式（Ｄ−２）において、Ｒ^５２及びＲ^５３はそれぞれ独立に、水素原子、ハロゲン原子、炭素数１以上６以下のアルキル基、炭素数１以上６以下のアルコキシ基、又はシクロアルキル基を示し；ｔは１以上３以下の整数を示す。］

[In General Formula (D-2), R ⁵² and R ⁵³ are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a cycloalkyl group. T represents an integer of 1 or more and 3 or less. ]

  Examples of the phenol compound represented by the general formula (D-1) include bis (4-hydroxy-2,3,5-trimethylphenyl) -2-hydroxyphenylmethane, 1,4-bis [1- (3 , 5-dimethyl-4-hydroxyphenyl) isopropyl] benzene, 2,4-bis (3,5-dimethyl-4-hydroxyphenylmethyl) -6-methylphenol, bis (4-hydroxy-3,5-dimethylphenyl) ) -2-hydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -2-hydroxyphenylmethane, bis (4-hydroxy-3,5-dimethylphenyl) -3,4-dihydroxyphenylmethane, 1- [1- (4-hydroxyphenyl) isopropyl] -4- [1,1-bis (4-hydroxyphenyl) ethyl Benzene, 1- [1- (3-methyl-4-hydroxyphenyl) isopropyl] -4- [1,1-bis (3-methyl-4-hydroxyphenyl) ethyl] benzene, 2,6-bis [1 -(2,4-dihydroxyphenyl) isopropyl] -4-methylphenol, 4,6-bis [1- (4-hydroxyphenyl) isopropyl] resorcin, 4,6-bis (3,5-dimethoxy-4-hydroxy) Phenylmethyl) pyrogallol, 4,6-bis (3,5-dimethyl-4-hydroxyphenylmethyl) pyrogallol, 2,6-bis (3-methyl-4,6-dihydroxyphenylmethyl) -4-methylphenol, 2 , 6-bis (2,3,4-trihydroxyphenylmethyl) -4-methylphenol, and 1,1-bis (4-hydroxyphenol) Le) cyclohexane, and the like. In addition, 6-hydroxy-4a- (2,4-dihydroxyphenyl) -9-1'-spirocyclohexyl-1,2,3,4,4a, 9a-hexahydroxanthene, and 6-hydroxy-5- Methyl-4a- (2,4-dihydroxy-3-methylphenyl) -9-1'-spirocyclohexyl-1,2,3,4,4a, 9a-hexahydroxanthene and the like can also be used. These sensitizers may be used alone or in combination of two or more. Among them, 1- [1- (4-hydroxyphenyl) isopropyl] -4- [1,1-bis ( 4-Hydroxyphenyl) ethyl] benzene and bis (4-hydroxy-2,3,5-trimethylphenyl) -2-hydroxyphenylmethane are preferred in terms of high sensitivity and excellent space pattern perpendicularity.

［一般式（Ｄ−３）において、Ｒ^６１からＲ^６３は、それぞれ独立に、低級アルキル基、シクロアルキル基、又は低級アルコキシ基を示し；ｑ及びｒは、それぞれ独立に、１以上３以下、好ましくは１以上２以下の整数を示し；ｌ、ｏ、及びｐは、それぞれ独立に、０以上３以下の整数を示す。］ Moreover, as a sensitizer, the phenol compound represented by the following general formula (D-3) can be used.

[In General Formula (D-3), R ⁶¹ to R ⁶³ each independently represent a lower alkyl group, a cycloalkyl group, or a lower alkoxy group; q and r each independently represent 1 or more and 3 or less; Preferably, it represents an integer of 1 or more and 2 or less; l, o and p each independently represent an integer of 0 or more and 3 or less. ]

Here, the lower alkyl group and lower alkoxy group represented by R ⁶¹ to R ⁶³ may be linear or branched, and preferably have 1 to 5 carbon atoms, more preferably 1 to 3 carbon atoms. is there. The cycloalkyl group represented by R ⁶¹ to R ⁶³ preferably has 5 to 7 carbon atoms.

More specifically, examples of the compound represented by the general formula (D-3) include compounds represented by the following chemical formulas (D-4) to (D-8).

［一般式（Ｄ−９）において、Ｒ^７１からＲ^７９は、それぞれ独立に、水素原子、アルキル基、ハロゲン原子、又はヒドロキシル基を示し、Ｒ^７１からＲ^７９のうち、少なくとも一つはヒドロキシル基である。Ｒ^８０からＲ^８５は、それぞれ独立に、水素原子、アルキル基、アルケニル基、シクロアルキル基、又はアリール基を示す。］ Moreover, as a sensitizer, the phenol compound represented by the following general formula (D-9) can be used.

[In General Formula (D-9), R ⁷¹ to R ⁷⁹ each independently represents a hydrogen atom, an alkyl group, a halogen atom, or a hydroxyl group, and at least one of R ⁷¹ to R ⁷⁹ is a hydroxyl group. It is. R ⁸⁰ to R ⁸⁵ each independently represent a hydrogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, or an aryl group. ]

Here, it is preferable that at least one of R ⁷¹ to R ⁷⁴ and at least one of R ⁷⁵ to R ⁷⁹ are hydroxyl groups. The alkyl group represented by R ⁷¹ to R ⁷⁹ may be linear or branched, and preferably has 1 to 5 carbon atoms, more preferably 1 to 3 carbon atoms. Furthermore, the alkyl group represented by R ⁸⁰ to R ⁸⁵ may be linear or branched, and preferably has 1 to 10 carbon atoms, and the alkenyl group represented by R ⁸⁰ to R ⁸⁵ may have 1 carbon atom. It is preferably 4 or less.

［一般式（Ｄ−１０）において、Ｒ^８６及びＲ^８７は、それぞれ独立にアルキル基を示し、ｆ及びｇは、１以上３以下、好ましくは１以上２以下の整数を示し、ｊ及びｚは０以上３以下の整数を示す。］ More specifically, examples of the phenol compound represented by the general formula (D-9) include a compound represented by the following general formula (D-10).

[In General Formula (D-10), R ⁸⁶ and R ⁸⁷ each independently represent an alkyl group, f and g each represent an integer of 1 to 3, preferably 1 to 2, j and z being An integer of 0 or more and 3 or less is shown. ]

Here, the alkyl group represented by R ⁸⁶ and R ⁸⁷ may be linear or branched, and preferably has 1 to 5 carbon atoms, more preferably 1 to 3 carbon atoms.

More specifically, examples of the phenol compound represented by the general formula (D-9) include compounds represented by the following chemical formulas (D-11) and (D-12).

  The blending amount of the sensitizer is preferably 1% by mass or more and 30% by mass or less, and more preferably 3% by mass or more and 25% by mass or less with respect to the component (A) or the component (A ′). preferable.

[Other ingredients]
(solvent)
The positive resist composition of the present invention is preferably used in the form of a solution by dissolving the above components in a suitable solvent. Examples of such solvents include ethylene glycol alkyl ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, and ethylene glycol monobutyl ether; diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether Diethylene glycol dialkyl ethers such as diethylene glycol dibutyl ether; ethylene glycol alkyl ether acetates such as methyl cellosolve acetate and ethyl cellosolve acetate; propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, and propylene glycol mono Propylene glycol alkyl ether acetates such as propyl ether acetate; ketones such as acetone, methyl ethyl ketone, cyclohexanone, and methyl amyl ketone; aromatic hydrocarbons such as toluene and xylene; cyclic ethers such as dioxane; and 2-hydroxy Methyl propionate, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxyacetate, ethyl oxyacetate, methyl 2-hydroxy-3-methylbutanoate, 3-methoxybutyl acetate, 3-methyl- Examples thereof include esters such as 3-methoxybutyl acetate, ethyl formate, ethyl acetate, butyl acetate, methyl acetoacetate, and ethyl acetoacetate. These solvents may be used alone or in combination of two or more.

  In order to obtain a film thickness of, for example, 3 μm or more by using the spin coating method, it is preferable to use an amount of solvent in which the solid content concentration in the positive resist composition is 20% by mass or more and 65% by mass or less.

(Surfactant)
In addition, the positive resist composition of the present invention may contain a surfactant in order to improve coating properties, antifoaming properties, leveling properties, and the like. As the surfactant, for example, BM-1000, BM-1100 (manufactured by BM Chemie), MegaFuck F142D, MegaFuck F172, MegaFac F173, MegaFack F183 (Dainippon Ink Chemical Co., Ltd.), Florard FC-135, Fluoraro FC-170C, Fluorado FC-430, Fluorado FC-431 (Sumitomo 3M), Surflon S-112, Surflon S-113, Surflon S-131, Surflon S-141, Surflon S-145 (Asahi Glass Co., Ltd.) Fluorine-based surfactants commercially available under the names of SH-28PA, SH-190, SH-193, SZ-6032, SF-8428 (manufactured by Toray Silicone Co., Ltd.) and the like can be used.

  The content of the surfactant is preferably 5 parts by mass or less per 100 parts by mass of the component (A) or the component (A ′).

(Plasticizer)
In the positive resist composition of the present invention, an alkali-soluble acrylic resin may be blended as a plasticizer in order to further improve plating resistance such as generation of cracks. Generally as an alkali-soluble acrylic resin, what is mix | blended with the positive photoresist composition as a plasticizer can be used.

  More specifically, as the alkali-soluble acrylic resin, a constitutional unit derived from a polymerizable compound having a carboxyl group and a constitutional unit derived from a polymerizable compound having an ether bond is 30% by mass or more and 90% by mass or less. 2 parts by mass or more and 50 parts by mass or less.

  Examples of the polymerizable compound having an ether bond include 2-methoxyethyl (meth) acrylate, methoxytriethylene glycol (meth) acrylate, 3-methoxybutyl (meth) acrylate, ethyl carbitol (meth) acrylate, phenoxy polyethylene glycol (meta ), Radically polymerizable compounds such as (meth) acrylic acid derivatives having an ether bond and an ester bond such as methoxypolypropylene glycol (meth) acrylate and tetrahydrofurfuryl (meth) acrylate. Among these, it is preferable to use 2-methoxyethyl acrylate and methoxytriethylene glycol acrylate. These compounds may be used independently and may be used in mixture of 2 or more types.

  Examples of the polymerizable compound having a carboxyl group include monocarboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid; dicarboxylic acids such as maleic acid, fumaric acid, and itaconic acid; and 2-methacryloyloxyethyl succinic acid, 2- Examples thereof include radically polymerizable compounds such as methacrylic acid derivatives having a carboxyl group and an ester bond such as methacryloyloxyethylmaleic acid, 2-methacryloyloxyethylphthalic acid, and 2-methacryloyloxyethylhexahydrophthalic acid. Among these, it is preferable to use acrylic acid and methacrylic acid. These compounds may be used alone or in combination of two or more.

  The content of the polymerizable compound having an ether bond in the alkali-soluble acrylic resin component is preferably 30% by mass or more and 90% by mass or less, and more preferably 40% by mass or more and 80% by mass or less. When the content is 90% by mass or less, the compatibility of the component (A) or the component (A ′) with the solution is not deteriorated, and the pre-baked benard cell (gravity or surface tension gradient is applied to the coating film surface). The resulting non-uniform pentagonal to heptagonal network pattern) does not occur, so that a uniform resist film is obtained, and when it is 30% by mass or more, cracks do not occur during plating.

  The content of the polymerizable compound having a carboxyl group in the alkali-soluble acrylic resin component is preferably 2% by mass or more and 50% by mass or less, and more preferably 5% by mass or more and 40% by mass or less. When the content is 2% by mass or more, the alkali solubility of the alkali-soluble acrylic resin component is maintained high, and sufficient developability can be obtained, and the releasability is not lowered, and the resist film is formed on the substrate. There is no residual film. By being 50% by mass or less, the remaining film ratio after development is maintained high, and the plating resistance is kept good.

  The mass average molecular weight of the alkali-soluble acrylic resin component is preferably 10,000 or more and 800,000 or less, and more preferably 30,000 or more and 500,000 or less. By being 10,000 or more, the strength of the resist film becomes sufficient, and the occurrence of swelling of the profile and generation of cracks during plating are not caused. By being 800000 or less, the peelability does not decrease.

  Further, the alkali-soluble acrylic resin component may contain structural units derived from other radical polymerizable compounds for the purpose of appropriately controlling physical and chemical properties. Here, the “other radical polymerizable compound” means a radical polymerizable compound other than the above-described polymerizable compound.

  Examples of such radical polymerizable compounds include (meth) acrylic acid alkyl esters such as methyl (meth) acrylate, ethyl (meth) acrylate, and butyl (meth) acrylate; 2-hydroxyethyl (meth) acrylate, and 2 -(Meth) acrylic acid hydroxyalkyl esters such as hydroxypropyl (meth) acrylate; phenyl (meth) acrylate and (meth) acrylic aryl esters such as benzyl (meth) acrylate; diethyl maleate and dibutyl fumarate Dicarboxylic acid diesters such as styrene; vinyl group-containing aromatic compounds such as styrene and α-methylstyrene; vinyl group-containing aliphatic compounds such as vinyl acetate; conjugated diolefins such as butadiene and isoprene; acrylonitrile and methacrylonite Nitrile group-containing polymerizable compounds such as Le; can be used as well as amide-bond-containing polymerizable compounds such as acrylamide and methacrylamide; chlorine-containing polymerizable compounds such as vinyl chloride and vinylidene chloride. These compounds may be used alone or in combination of two or more. Among these compounds, it is particularly preferable to use n-butyl acrylate, benzyl methacrylate, methyl methacrylate, and the like. The content of the other radical polymerizable compound in the alkali-soluble acrylic resin component is preferably less than 50% by mass, and more preferably less than 40% by mass.

  Examples of the polymerization solvent used in the synthesis of the alkali-soluble acrylic resin component include alcohols such as ethanol and diethylene glycol; alkyl ethers of polyhydric alcohols such as ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, and diethylene glycol ethyl methyl ether; Alkyl ether acetates of polyhydric alcohols such as ethylene glycol ethyl ether acetate and propylene glycol methyl ether acetate; aromatic hydrocarbons such as toluene and xylene; ketones such as acetone and methyl isobutyl ketone; and ethyl acetate and butyl acetate Ester etc. can be used. Among these polymerizable solvents, it is particularly preferable to use polyhydric alcohol alkyl ethers and polyhydric alcohol alkyl ether acetates.

  As a polymerization catalyst used when synthesizing the alkali-soluble acrylic resin component, a normal radical polymerization initiator can be used, for example, an azo compound such as 2,2′-azobisisobutyronitrile; and benzoyl peroxide, and An organic peroxide such as di-tert-butyl peroxide can be used.

  In the positive resist composition of the present invention, the blending amount of the alkali-soluble acrylic resin component is preferably 30 parts by mass or less, and 20 parts by mass or less with respect to 100 parts by mass of the aforementioned component (A) or component (A ′). More preferred.

[Preparation of positive resist composition]
The positive resist composition of the present invention can be prepared by mixing and stirring by a usual method. Moreover, you may further filter using a mesh, a membrane filter, etc. as needed.

<Method for forming resist pattern>
The resist pattern forming method of the present invention comprises a coating step of applying a positive resist composition of the present invention on a substrate to obtain a resist film, and exposure by selectively irradiating the resist film with active rays for exposure. And a development step of performing development after the exposure step to obtain a resist pattern.

[Coating process]
The positive resist composition of the present invention can be used, for example, when forming a protective film or a resist film for semiconductor production during etching or plating of a substrate made of copper. In the coating step in the resist pattern forming method, the positive resist composition of the present invention is applied to these substrates with a film thickness of 3 μm to 30 μm using a spinner or the like. A pre-bake (post-apply bake (PAB)) is performed for 40 seconds to 600 seconds, preferably 60 seconds to 360 seconds under a temperature condition of 80 ° C. to 150 ° C. to form a resist film.

[Exposure process]
For example, a low-pressure mercury lamp, a high-pressure mercury lamp, or an ultrahigh-pressure mercury lamp, which is a light source that emits light having a wavelength of 365 nm (I line), 405 nm (H line), or 435 nm (G line), is used as the resist film. After selectively irradiating through the pattern, post-exposure heating (PEB) is performed for 40 seconds to 600 seconds, preferably 60 seconds to 360 seconds, if necessary, under a temperature condition of 80 ° C. to 150 ° C. The active rays used for the exposure include ArF excimer laser, KrF excimer laser, F ₂ excimer laser, extreme ultraviolet rays as well as G-line, H-line, and I-line from the low-pressure mercury lamp, high-pressure mercury lamp, and ultra-high pressure mercury lamp. (EUV), vacuum ultraviolet (VUV), electron beam (EB), X-ray, and soft X-ray can also be used.

[Development process]
Next, the exposed resist film is developed at a temperature of 20 ° C. or higher and 30 ° C. or lower using an alkali developer, for example, an aqueous solution of 0.1% by mass to 10% by mass of tetramethylammonium hydroxide, and pure water is used. Rinse with water and dry. In some cases, a baking process (post-bake) may be performed after the development process. In this way, a resist pattern faithful to the mask pattern can be obtained.

  According to the positive resist composition of the present invention and the method of forming a resist pattern using the same, since the positive resist composition contains a predetermined benzotriazole compound, the adhesion between the resist film and the substrate is excellent. Thus, a fine resist pattern can be formed, and generation of a residue can be suppressed even after development of the resist film.

<Preparation Example 1; Synthesis of alkali-soluble novolak resin A>
m-cresol and p-cresol are mixed at m-cresol / p-cresol = 60/40 (mass ratio), formalin is added, and cresol novolak resin is obtained by addition condensation using an oxalic acid catalyst by a conventional method. It was. This resin was subjected to a fractionation treatment, and a low molecular region was cut to obtain an alkali-soluble novolak resin A having a mass average molecular weight of 20000.

<Example 1>
69 parts by mass of alkali-soluble novolac resin A, 2 mol of all hydroxyl groups of 1- [1- (4-hydroxyphenyl) isopropyl] -4- [1,1-bis (4-hydroxyphenyl) ethyl] benzene as a photosensitizer % Of hydrogen atoms are substituted with 1,2-naphthoquinonediazide-5-sulfonyl group 20 parts by mass, 1,1-bis (4-hydroxyphenyl) cyclohexane 20 parts by mass as a sensitizer, adhesion improver As a certain benzotriazole-based compound, 1 part by mass of a compound represented by the following chemical formula (C-1) is dissolved in propylene glycol monoethyl ether acetate and adjusted so that the solid content concentration is 43% by mass. A resist composition was prepared.

<Example 2>
As a benzotriazole-based compound, the compound represented by the following chemical formula (C-2) was used in place of the compound represented by the above chemical formula (C-1). A mold resist composition was prepared.

<Comparative Example 1>
A positive resist composition was prepared in the same manner as in Example 1 except that carboxybenzotriazole was used in place of the compound represented by the above chemical formula (C-1) as the benzotriazole-based compound.

<Comparative example 2>
A positive resist composition was prepared in the same manner as in Example 1 except that pyridineethanol was used in place of the compound represented by the above chemical formula (C-1), which is a benzotriazole-based compound, as an adhesion improver. Prepared.

<Comparative Example 3>
A positive resist composition was prepared in the same manner as in Example 1 except that the compound represented by the above chemical formula (C-1) which was a benzotriazole compound was not added.

<Performance evaluation>
[Residue occurrence]
The positive resist compositions of Examples 1 and 2 and Comparative Examples 1 to 3 were applied to a substrate obtained by sputtering copper on a silicon wafer with a thickness of 5000 mm, and dried on a hot plate at 110 ° C. for 240 seconds. A resist film having a thickness of 10 μm was obtained.

  Next, the film can be developed with a reduction projection exposure apparatus “NSR-2005i10D” (trade name, manufactured by Nikon Corporation, NA = 0.50) through a mask on which a predetermined light-shielding pattern is drawn. The exposure was performed up to 1.2 times the exposure amount (ETH).

  As a developing operation, a 2.38 mass% tetramethylammonium hydroxide (TMAH) aqueous solution at 23 ° C. was applied as a developing solution to this resist film, held for 60 seconds, and then the developing solution was shaken off by rotating a spinner. . This development operation was repeated three times, and then washed with water for 30 seconds and dried.

  Thereafter, the resist-substrate interface of the obtained 20 μm space pattern was observed with a scanning electron microscope (SEM), and a resist dissolution residue (scum) that could be confirmed around the pattern was evaluated as x, and that that could not be confirmed as ○. did.

[Adhesion evaluation 1 (adhesion during development)]
The positive resist compositions of Examples 1 and 2 and Comparative Examples 1 to 3 were applied onto a substrate obtained by sputtering copper on a silicon wafer to a thickness of 500 mm, and dried at 110 ° C. for 240 seconds on a hot plate. Thus, a resist film having a thickness of 10 μm was obtained.

  Next, the film can be developed with a reduction projection exposure apparatus “NSR-2005i10D” (trade name, manufactured by Nikon Corporation, NA = 0.50) through a mask on which a predetermined light-shielding pattern is drawn. The exposure was performed from 1.0 to 1.4 times the exposure amount (ETH).

  As a developing operation, a 2.38 mass% tetramethylammonium hydroxide (TMAH) aqueous solution was applied as a developing solution to the resist film, held for 60 seconds, and then the developing solution was shaken off by rotating a spinner. This development operation was repeated three times, and then washed with water for 30 seconds and dried.

  Then, the resist pattern was observed with an optical microscope, and the 10 μm line and space and dot repetitive patterns were in close contact with only 1.0 times ETH. The thing which adhered closely to 1.4 times was set as (circle).

[Adhesion evaluation 2 (measurement of side etch amount)]
In the same manner as in [Adhesion Evaluation 1], a positive resist composition was applied, a resist film was exposed and developed on a substrate on which copper was sputtered to a thickness of 500 mm on a silicon wafer. After immersing in a ferric chloride solution 45 ° Baume "(trade name, manufactured by Junsei Chemical Co., Ltd.) for 5 seconds, the copper erosion length at the bottom of the resist was measured using a scanning electron microscope (SEM). The erosion length was 5 μm or more, x was 3 μm or more and less than 5 μm, and Δ was less than 3 μm.

[Solubility test]
In a 300 ml beaker, 65 parts by mass of alkali-soluble novolac resin A and 5 parts by mass of an adhesion improver in the compositions of Examples 1 and 2 and Comparative Examples 1 and 2 were added, and the solid content concentration was 43. Propylene glycol monoethyl ether acetate was added so that it might become the mass%, and it stirred with the stirrer for 1 hour. As a result of visual observation, the sample completely dissolved was marked with ◯, and the sample with undissolved residue was marked with ×.

The results are shown in Table 1.

  As apparent from Table 1, in Examples 1 and 2 using the benzotriazole-based compound according to the present invention, carboxybenzotriazole not included in the benzotriazole-based compound represented by the general formula (1) was used. Compared with Comparative Example 1, it can be seen that the generation of residues is suppressed to a small extent. In Examples 1 and 2, compared with Comparative Examples 2 and 3 in which no benzotriazole-based compound is used, the adhesion between the resist film and the substrate is good, and the generation of residues is reduced. Yes.

  From the above, it can be seen that the positive resist composition of the present invention can suppress the generation of residue while maintaining good adhesion between the resist film and the substrate.

Claims (7)

(A) an alkali-soluble novolak resin, (B) a photosensitizer, and (C) a benzotriazole-based compound,
A positive resist composition in which the benzotriazole-based compound is a compound represented by the following general formula (1).

[In General Formula (1), R ¹ represents an alkyl group having 1 to 10 carbon atoms, a hydroxyl group, a carboxyl group, a hydrogen atom, or —COOR ′ (R ′ represents an alkyl group having 1 to 5 carbon atoms); R ² and R ³ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a hydroxyalkyl group having 1 to 6 carbon atoms. However, at least one selected from R ² and R ³ is a hydroxyalkyl group having 1 to 6 carbon atoms. ] (A ′) an alkali-soluble novolak resin in which at least a part of hydrogen atoms of the phenolic hydroxyl group is substituted with a 1,2-naphthoquinonediazidesulfonyl group, and (C) a benzotriazole compound,
A positive resist composition in which the benzotriazole-based compound is a compound represented by the following general formula (1).

[In General Formula (1), R ¹ represents an alkyl group having 1 to 3 carbon atoms, a hydroxyl group, a carboxyl group, a hydrogen atom, or —COOR ′ (R ′ is an alkyl group having 1 to 5 carbon atoms); R ² and R ³ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a hydroxyalkyl group having 1 to 6 carbon atoms. However, at least one selected from R ² and R ³ is a hydroxyalkyl group having 1 to 6 carbon atoms. ]   The positive resist composition according to claim 2, further comprising (B) a photosensitizer. The positive resist composition according to claim 1, wherein R ² and R ³ are hydroxyalkyl groups having 1 to 6 carbon atoms. The positive resist composition according to claim 4, wherein R ² and R ³ are 2-hydroxyethyl groups. The positive resist composition according to any one of claims 1 to 5, wherein R ¹ is an alkyl group having 1 to 3 carbon atoms. An application step of applying a positive resist composition according to any one of claims 1 to 6 to obtain a resist film on a substrate;
An exposure step of selectively irradiating the resist film with active rays for exposure;
A development step of performing development after the exposure step to obtain a resist pattern.