JPH09166868A - Photosensitive composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a photosensitive compsn. excellent in transmittance to light of short wavelength such as ArF excimer laser light and capable of forming a resist pattern having satisfactory resolution with high sensitivty by incorporating a compd. having an acid-decomposable group or an acid- crosslinkable group and a specified compd. SOLUTION: This photosensitive compsn. for forming a pattern by exposure with ArF or F2 excimer laser light contains a compd. having an acid- decomposable group or an acid-crosslinkable group and a compd. represented by the formula, wherein each of Ar<1> and Ar<2> is an arom. ring or a condensed arom. ring, each of R<1> and R<2> is halogen or a monovalent org. group, X is CF3 SO3 , SbF6 , AsF6 , etc., Z is Cl, Br, I, S-R (R is 1-10C alkyl or perfluoroalkyl), etc., and each of (m) and (n) is 0 or a positive integer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photosensitive composition used for fine processing in the manufacturing process of semiconductor devices and the like.

[0002]

2. Description of the Related Art In the manufacturing process of electronic parts such as LSI, a fine processing technique utilizing photolithography has been used for a long time, and a resist is widely used in the fine processing technique. Furthermore, in recent years, in order to cope with high-density integration of electronic components, it has been required to form an ultrafine resist film pattern in the production of electronic components.

Therefore, recently, a light source for forming a pattern of a resist film has been shortened in wavelength. That is, a process of forming an ultrafine pattern by using KrF excimer laser light having a wavelength of 248 nm as a light source or irradiating ionizing radiation such as an electron beam or an X-ray has been developed. Many resists having high sensitivity to are reported.

For example, JP-A-63-27829 discloses a chemically amplified resist comprising a composition containing an alkali-soluble resin, a dissolution inhibitor and a photo-acid generator. In other words, in this type of chemically amplified resist, the dissolution inhibitor suppresses the solubility of the resist in the alkali developing solution in the unexposed area, while the photoacid generator generates acid in the exposed area and baking after exposure is performed. Upon processing this decomposes the dissolution inhibitor. As a result, the resist in the exposed area is solubilized in the alkali developing solution. Here, in the chemically amplified resist, many dissolution inhibitors can be decomposed even if the amount of acid generated from the photoacid generator is small,
Generally, it becomes possible to form an ultrafine pattern with high sensitivity.

On the other hand, with the high-density integration of LSIs and the like, the above-mentioned fine processing technology has reached the sub-half micron order in recent years, and it is predicted that such fine processing will become more remarkable in the future. For this reason, the wavelength of light sources in photolithography has been shortened,
ArF excimer laser light with a wavelength of 193 nm or wavelength 2
Attempts have been made to form a fine resist pattern using fifth harmonic light of an 18 nm YAG laser. Furthermore, F ₂
Research on exposure using excimer laser light has also begun to be attempted.

However, conventional chemically amplified resists usually use an arylonium salt having a benzene ring as a photoacid generator, and the chemically amplified resist containing such a photoacid generator has the above-mentioned composition. The light absorption of the benzene ring tends to be large for ordinary short wavelength light. Therefore, when forming a resist pattern, it is difficult to allow light to sufficiently reach the substrate side of the resist film during exposure, and as a result, it is difficult to form a pattern having a good pattern shape with high accuracy.

[0007]

As described above, the conventional chemically amplified resist is expensive when the g-line and i-line, which are the bright lines of a mercury lamp, or the KrF excimer laser beam having a wavelength of 248 nm is used as a light source. Even if it is possible to form an ultrafine pattern with high sensitivity, its transparency to ArF excimer laser light is not sufficient and it is difficult to form a resist pattern with good resolution.

An object of the present invention is to provide a photosensitive composition which is excellent in transparency to short-wavelength light such as ArF excimer laser light and can form a resist pattern with high sensitivity and good resolution. To do.

[0009]

According to the present invention, ArF
A photosensitive composition for forming a pattern by exposure with either excimer laser light or F ₂ excimer laser light, which comprises a compound having one of an acid decomposable group and an acid crosslinkable group, and A photosensitive composition containing the compound represented by formula (1) is provided.

[0010]

Embedded image (In the formula, Ar ¹ and Ar ² are aromatic rings or condensed aromatic rings, R
¹ , R ² is a halogen atom or a monovalent organic group, X is CF
₃ SO ₃ , CH ₃ SO ₃ , CF ₃ COOH, ClO ₄ ,
SbF ₆ and is selected from the group consisting of AsF _6, Z is Cl, Br, I, S- R and Se-R (R is 1 carbon atoms
Selected from the group consisting of 10 or more alkyl groups or perfluoroalkyl groups), and m and n each represent 0 or a positive integer. According to the present invention, ArF excimer laser light and F
₂ A photosensitive composition for forming a pattern by exposure with any one of excimer laser light, comprising a resin having one of an acid decomposable group and an acid crosslinkable group, and a resin represented by the following general formula (1): Photosensitive compositions containing the compounds represented are provided.

[0011]

Embedded image (In the formula, Ar ¹ and Ar ² are aromatic rings or condensed aromatic rings, R
¹ , R ² is a halogen atom or a monovalent organic group, X is CF
₃ SO ₃ , CH ₃ SO ₃ , CF ₃ COOH, ClO ₄ ,
SbF ₆ and is selected from the group consisting of AsF _6, Z is Cl, Br, I, S- R and Se-R (R is 1 carbon atoms
Selected from the group consisting of 10 or more alkyl groups or perfluoroalkyl groups), and m and n each represent 0 or a positive integer. Hereinafter, the present invention will be described in detail.

The photosensitive composition of the present invention includes, for example, an alkali-soluble resin, a compound introduced with an acid-decomposable group capable of inhibiting dissolution in an alkaline solution (hereinafter referred to as a dissolution inhibitor), and a photoacid generator. And a positive chemically amplified resist containing a. At this time, instead of adding a dissolution inhibitor, the alkali-soluble group in the alkali-soluble resin is protected by an acid-decomposable group having a dissolution inhibitory ability, and a photosensitive composition containing such a resin and a photo-acid generator is prepared. You can also

On the other hand, in the present invention, a negative chemically amplified resist having a composition containing a photoacid generator and a compound having an acid-crosslinkable group that crosslinks the alkali-soluble resin and the acid in the presence of an acid is used. Can be mentioned. Further, here, it may be a photosensitive composition containing an alkali-soluble resin having an acid crosslinkable group introduced therein and a photoacid generator.

In the photosensitive composition of the present invention, as the above-mentioned alkali-soluble resin, a resin having a hydroxy group-introduced aromatic ring or condensed aromatic ring, or a resin having a carboxyl group can be used. . Specifically, acrylic acid derivative, methacrylic acid derivative, acrylonitrile derivative, styrene derivative; acrylic acid or its derivative, methacrylic acid or its derivative, acrylonitrile derivative, styrene derivative polymer; isopropenylphenol and acrylic acid or its derivative, Copolymer of methacrylic acid or its derivative, acrylonitrile derivative, styrene derivative; Copolymer of styrene or its derivative with acrylic resin, acrylic acid derivative, methacrylic acid derivative, acrylonitrile derivative; 4-hydroxymaleimide resin; polyamic acid or , Those into which a silicon atom is appropriately introduced, and the like. In the present invention, from the viewpoint of adjusting the alkali solubility of the photosensitive composition and the like, these alkali-soluble resins can be used alone or in combination of two or more.

Further, in the present invention, from the viewpoint of improving the dry etching resistance of the photosensitive composition without impairing the transparency to short-wavelength light such as ArF excimer laser light, preferably a hydroxyl group is introduced as the alkali-soluble resin. It is desirable to use a condensed aromatic ring or one having an alicyclic skeleton in which an acidic substituent is introduced, if necessary. Examples of the condensed aromatic ring here include a naphthalene ring, an anthracene ring, and a phenanthrene ring. Specifically, a naphthol novolac resin obtained by condensing naphthol or a derivative thereof with a carbonyl compound such as formaldehyde, vinyl naphthalene, or vinyl. Polymers of naphthol, vinylanthracene, vinylanthol, and the like can be used.

On the other hand, as the alicyclic skeleton as described above,
Examples thereof include cyclic cyclo compounds and cyclic bicyclo compounds represented by the general formula C _p H _2p (p is an integer of 3 or more), and condensed rings thereof, such as cyclobutane ring, cyclopentane ring, cyclohexane ring, cycloheptane ring and the like. Introduced with bridged hydrocarbons, spiro rings such as sproheptane and spirooctane; terpene rings such as norbonyl ring, adamantyl ring, bornene ring, menthyl ring and menthane ring; tsujan, sabinene, tujon, karan, karen, pinan Steroid skeletons such as norpinane, bornane, fencan, tricyclene, and cholesteric ring, tanjusan, digitaloids, camphor ring, isocamphor ring, sesquiterpene ring, sandton ring, diterpene ring, triterpene ring, and steroid saponins are exemplified. . At this time, specifically, a copolymer of a polymerizable compound having an alicyclic skeleton and a vinyl compound having an alkali-soluble group is used as the alkali-soluble resin.

Here, the acidic substituent that is optionally introduced into the alicyclic skeleton preferably has a pKa of 7 or more and 11 or less in an aqueous solution at 25 ° C. Specifically, a propanone oxime group, a propanal oxime group,
Organic groups containing a ketone oxime structure such as hydroxyiminopentanone and dimethylglyoxime; succinimide,
Organic groups containing dicarboxylic acid imide or N-hydroxysuccinimide structure such as pyrrolidinedione; Organic groups containing dicarbonylmethylene structure such as cyclopentene 1,3-dione, acetylacetone, 3-methyl-2,4-pentadione; Hexanethiol and other thiols Containing organic group; tautomeric alcohol such as hydroxycyclopentenone; organic group containing furfuryl alcohol; organic group containing amic acid structure; organic group containing phenolic hydroxyl group such as phenol, cresol, salicylaldehyde; triazine skeleton And organic groups including.

The average molecular weight of the alkali-soluble resin as described above in the present invention is preferably set within the range of 500 to 500,000. If the average molecular weight of the alkali-soluble resin is less than 500, it is disadvantageous in forming a resist film having sufficient mechanical strength. Conversely, if the average molecular weight of the alkali-soluble resin exceeds 500,000, the solution This is because it becomes difficult to form a resist pattern having good image quality.

In the present invention, the amount of the alkali-soluble resin blended is preferably set to about 5 to 85 wt% in the solid content of the photosensitive composition. That is, the blending amount is 5 wt
If it is less than%, the coating property of the photosensitive composition tends to be deteriorated, and if it exceeds 85 wt%, it may be difficult to obtain sufficient sensitivity.

As described above, when the photosensitive composition of the present invention is used as a positive type chemically amplified resist, a compound into which an acid-decomposable group having a dissolution inhibiting ability in an alkaline solution is introduced is usually a dissolution inhibitor. Is formulated as. Such a dissolution inhibitor used in the present invention has a sufficient dissolution inhibiting ability in an alkaline solution, and a product after decomposition by an acid is-(C = O) in an alkaline solution.
Examples thereof include compounds having an acid-decomposable group capable of forming O-, -OS (= O) _2- , or -O-. Such compounds include low-molecular weight compounds such as bisphenol A, bisphenol F, tri (hydroxyphenyl) methane, phenolphthalein, cresolphthalein, thymolphthalein, catechol, pyrogallol, naphthol, bisnaphthol A, bisnaphthol F, and benzoic acid derivatives. It can be obtained by introducing an acid-decomposable group into a low molecular weight aliphatic alcohol such as a molecular aromatic compound, cholate, steroids, terpenoid derivative or saccharide.

Specifically, a phenolic compound is t-butoxycarbonyl ether, tetrahydropyranyl ether, 3-bromotetrahydropyranyl ether, 1-methoxycyclohexyl ether, 4-methoxytetrahydropyranyl ether, 1,4-dioxane-2- Yl ether, tetrahydrofuranyl ether, 2,3,3a, 4,5,6,7,7a-octahydro-7,8,8-trimethyl-4.7-methanobenzofuran-2-yl ether, t-butyl ether, trimethylsilyl ether, Triethylsilyl ether, triphenylsilyl ether, triisopropylsilyl ether,
Examples thereof include compounds modified with dimethylisopropylsilyl ether, diethylisopropylsilyl ether, dimethylthexylsilyl ether, t-butyldimethylsilyl ether and the like. Of these, compounds in which the hydroxyl group of the phenolic compound is protected with a t-butoxycarbonyl group, a t-butoxycarbonylmethyl group, a trimethylsilyl group, a t-butyldimethylsilyl group, a tetrahydropyranyl group, or the like are preferable.

Further, the dissolution inhibitor in the present invention is isopropyl ester of polycarboxylic acid, tetrahydropyranyl ester, tetrahydrofuranyl ester, methoxyethoxymethyl ester, 2-trimethylsilylethoxymethyl ester, t-butyl ester, trimethylsilyl ester, triethylsilyl. Ester, t-butyldimethylsilyl ester, isopropyldimethylsilyl ester, di-t-butylmethylsilyl ester, oxazole, 2-alkyl-1,3-oxazoline, 4-alkyl-5-oxo-1,3-oxazoline, 5 -Alkyl-4-oxo-1,3-
It may be dioxolane or the like. Further, the following compounds can also be used. In the present invention, these dissolution inhibitors can be used alone or in combination of two or more.

[0023]

[Chemical 6]

[0024]

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[0025]

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[0026]

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[0027]

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[0028]

Embedded image Wherein, tBoc is - shows the (C = O) O-C (CH 3) 3.

[0029]

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[0030]

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[0031]

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[0032]

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[0033]

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In the present invention, among these dissolution inhibitors, conjugated polycyclic aromatic compounds are preferred because of their excellent transparency to short wavelength light. The conjugated polycyclic aromatic compound is a non-condensed polycyclic compound or a condensed polycyclic compound in which a plurality of aromatic rings are planarly connected by forming a skeleton in which alternate unsaturated bonds are arranged. . That is, these compounds
The light absorption band is shifted to the long wavelength side due to the conjugated stabilization of π electrons, and in the present invention, by using a conjugated polycyclic aromatic compound as a dissolution inhibitor, it is excellent for short wavelength light. It is advantageous in obtaining a photosensitive composition which has transparency and also has sufficient heat resistance and dry etching resistance. On the contrary, when a compound having a benzene ring is blended as a dissolution inhibitor in the present invention, it is used in combination with such a conjugated polycyclic aromatic compound or a low molecular weight aliphatic alcohol having an acid-decomposable group introduced therein. Is desired.

Specific examples of the conjugated polycyclic aromatic compound include naphthalene ring, anthracene ring, phenanthrene ring, pyrene ring, naphthacene ring, chrysene ring, 3,4-benzophenanthrene ring, perylene ring, pentacene ring and picene ring. , Pyrrole ring, benzofuran ring, benzothiophene ring, indole ring, benzoxazole ring, benzothiazole ring, indazole ring, chromene ring, quinolinzinnoline ring, phthalazine ring, quinazoline ring, dibenzofuran ring, carbazole ring, acridine ring, phenant ring Examples thereof include compounds having a lysine ring, a phenanthroline ring, a phenazine ring, a thianthrene ring, an indolizine ring, a naphthyridine ring, a purine ring, a pteridine ring, and a fluorene ring. The ring system compound has a wavelength of 193
It is excellent in terms of transparency with respect to nm light. Therefore, those obtained by protecting the hydroxyl groups of these polyhydroxy compounds having a condensed aromatic ring with t-butyl carbonate group, t-butyl ester group, tetrahydropyranyl ether group, acetal group, trimethylsilyl ether group, etc. preferable.

In the photosensitive composition of the present invention, the content of the dissolution inhibitor is 0.1-40 with respect to the alkali-soluble resin.
It is preferable to set it in the range of wt%, more preferably 0.5 to 10 wt%. This has a dissolution inhibitor content of 0.1.
If it is less than wt%, it becomes difficult to form a resist pattern having good resolution, and if it exceeds 40 wt%,
This is because the coating property of the photosensitive composition may be impaired, and the dissolution rate when the resist film in the exposed area is dissolved / removed with an alkaline solution tends to be significantly reduced.

Further, in the photosensitive composition of the present invention, a resin obtained by protecting the alkali-soluble group in the alkali-soluble resin with an acid-decomposable group can be used instead of incorporating such a dissolution inhibitor. Examples of the acid-decomposable group here include isopropyl ester, tetrahydropyranyl ester, tetrahydrofuranyl ester, methoxyethoxymethyl ester, 2-trimethylsilylethoxymethyl ester, 3-oxocyclohexyl ester, isobornyl ester, trimethylsilyl ester, and triethyl ester. Silyl ester, isopropyldimethylsilyl ester, di-t-butylmethylsilyl ester, oxazole, 2-alkyl-1,3-oxazoline, 4-alkyl-5-oxo-1,3-oxazoline, 5-alkyl-4-oxo -1,3-
Esters such as dioxolane; t-butoxycarbonyl ether, t-butoxymethyl ether, 4-pentenyloxymethyl ether, tetrahydropyranyl ether, 3-
Bromotetrahydropyranyl ether, 1-methoxycyclohexyl ether, 4-methoxytetrahydropyranyl ether, 4-methoxytetrahydrothiopyranyl ether, 1,4-dioxan-2-yl ether, tetrahydrofuranyl ether, 2,3,3a, 4,5 , 6,7,7a-octahydro-7,
8,8-trimethyl-4,7-methanobenzofuran-2-yl ether, t-butyl ether, trimethylsilyl ether,
Ethers such as triethylsilyl ether, triphenylsilyl ether, triisopropylsilyl ether, dimethylisopropyl silyl ether, diethylisopropylsilyl ether, dimethylthexylsilyl ether, t-butyldimethylsilyl ether; methylene acetal, ethylidene acetal, 2 Acetals such as 2,2,2-trichloroethylidene acetal, 2,2,2-tribromoethylidene acetal, and 2,2,2-triiodoethylidene acetal; 1-t-butylethylidene ketal, isopropylidene ketal (acetonide), Ketals such as cyclopentylidene ketal, cyclohexylidene ketal and cycloheptylidene ketal; methoxymethylene acetal, ethoxymethylene acetal, dimethoxymethylene orthoester, 1- Cyclic orthoesters such as toxyethylidene orthoester, 1-ethoxyethylidene orthoester, 1,2-dimethoxyethylidene orthoester, 1-N, N-dimethylaminoethylidene orthoester, 2-oxacyclopentylidene orthoester; trimethylsilyl Silyl ketene acetals such as ketene acetal, triethylsilyl ketene acetal, triisopropylsilyl ketene acetal, t-butyldimethylsilyl ketene acetal; di-t-butyl silyl ether, 1,3-1 ', 1', 3 ', 3 Silyl ethers such as'-tetraisopropyldisiloxanilidene ether, tetra-t-butoxydisiloxane-1,3-diylidene ether; dimethyl acetal, dimethyl ketal, bis-2,
2,2-trichloroethyl acetal, bis-2,2,2-tribromoethyl acetal, bis-2,2,2-triiodoethyl acetal, bis-2,2,2-trichloroethyl ketal, bis-2, 2,2-tribromoethyl ketal, bis-2,
Acyclic acetals or ketals such as 2,2-triiodoethyl ketal, diacetyl acetal and diacetyl ketal; 1,3-dioxane, 5-methylene-1,3-dioxane, 5,5-dibromo-1,3- Dioxane, 1,3-dioxolane, 4-bromomethyl-1,3-dioxolane, 4,3'-butenyl-1,3-dioxolane, 4,5-dimethoxymethyl-1,3-
Cyclic acetals or ketals such as dioxolane; and cyanohydrins such as 0-trimethylsilyl cyanohydrin, 0-1-ethoxyethyl cyanohydrin and 0-tetrahydropyranyl cyanohydrin can be mentioned.

In the present invention, among these acid-decomposable groups, t-butyl methacrylate, ethoxyethyl methacrylate, 3-oxocyclohexyl methacrylate, t-butyl methacrylate
Esters such as butyl-3-naphthyl-2-propenoate, isobornyl methacrylate, trimethylsilyl methacrylate, tetrahydropyranyl methacrylate are preferred because they are easily decomposed by an acid. Also, instead of the methacrylate exemplified here, an acrylate, α
Even if -cyanoacrylate and α-methoxyacrylate are used, they cannot be used at all.

When using a resin having an acid-decomposable group as described above in the present invention, the blending amount of such a resin is
It is preferably set to about 5 to 95 wt% in the solid content of the photosensitive composition. That is, if the blending amount is less than 5 wt%, the coating property of the photosensitive composition tends to deteriorate, and conversely, if it exceeds 95 wt%, it may be difficult to obtain sufficient sensitivity.

In the present invention, the resin having an acid-decomposable group may be used alone or in combination of two or more. It is also possible to use an alkali-soluble resin in combination with a resin having an acid-decomposable group, or to copolymerize these resins.

Further, in the photosensitive composition of the present invention,
In addition to the compound having an acid-decomposable group as described above, a low molecular weight naphthol novolak having a molecular weight of about 2,000 or a derivative thereof can be preferably used in combination as a dissolution inhibitor. However, when a resin having an acid-decomposable group is used in the present invention, the naphthol novolac or its derivative may be added alone as a dissolution inhibitor.

On the other hand, when the photosensitive composition of the present invention is used as a negative chemically amplified resist, a compound having an acid crosslinkable group which crosslinks an alkali-soluble resin in the presence of an acid as a crosslinking agent is dissolved. It may be blended in place of the deterrent. As the crosslinking agent here, for example, a vinyl compound having an epoxy group in a side chain, acrylic acid or a derivative thereof, methylol-substituted triazine, and a melamine compound such as a naphthyridine compound can be used. In the present invention, these crosslinking agents may be used alone or in combination of two or more.

In the photosensitive composition of the present invention, the blending amount of the crosslinking agent is 1 to 100 wt% with respect to the alkali-soluble resin.
Furthermore, it is preferable to set it in the range of 5 to 30 wt%. If the amount of the cross-linking agent is less than 1 wt%, it becomes difficult to form a resist pattern having good resolution, and if it exceeds 100 wt%, the coating property of the photosensitive composition is impaired. This is because there is a risk.

In the photosensitive composition of the present invention, an acid-crosslinkable group may be introduced into the alkali-soluble resin instead of incorporating such a crosslinking agent. The resin having such an acid-crosslinkable group can be obtained by introducing a vinyl group, an allyl group or the like into about 10 to 40 mol% of the alkali-soluble group of the alkali-soluble resin.

When a resin having an acid-crosslinkable group is used in the present invention, the compounding amount of such a resin is preferably set to about 1 to 95 wt% in the solid content of the photosensitive composition. That is, if the blending amount is less than 1 wt%, the coating property of the photosensitive composition tends to deteriorate, and conversely, if it exceeds 95 wt%,
It may be difficult to obtain sufficient sensitivity.

Further, in the present invention, the resin having the acid-crosslinkable group can be used alone or in combination of two or more kinds, and the resin having the acid-crosslinkable group is used in combination with the alkali-soluble resin, or these resins can be used together. It is also possible to copolymerize and use a resin. In the case of a resin having both an acid-decomposable group and an acid-crosslinkable group, the average molecular weight thereof may be about 500 to 500,000, like the alkali-soluble resin. Further, from the viewpoint of adjusting the alkali solubility of the photosensitive composition, etc., a resin in which the alkali-soluble group of the alkali-soluble resin is replaced with an organic group other than an acid-decomposable group such as a methyl group and an acid-crosslinkable group is appropriately used. Also, when such a resin is used, it may be simply mixed with the above-mentioned resin having an alkali-soluble resin or an acid-decomposable group or an acid-crosslinkable group, or may be copolymerized.

In the photosensitive composition of the present invention, the compound represented by the above general formula (1) is used as a photoacid generator. Here, this compound is characterized in that the ortho positions of two benzene rings are directly chemically bonded, which causes the light absorption band to shift to the long wavelength side, thereby causing a short wavelength such as ArF excimer laser light. Transparency to light is improved.

That is, an arylonium salt having a benzene ring is generally used as a photoacid generator in a conventional chemically amplified resist.
As mentioned above, the light absorption of the benzene ring is large in the short wavelength range,
When short-wavelength light is used as a light source, there is a problem that it is difficult to form a resist pattern having good resolution. On the other hand, if the benzene ring conjugation length of the arylonium salt can be lengthened, the inventors of the present invention shift the peak of π-π ^* light absorption to the long wavelength side and improve the transparency in the short wavelength region. I got the knowledge. Furthermore, based on such knowledge, the present inventors have found that in the compound represented by the general formula (1),
By chemically bonding the ortho positions of the two benzene rings, the relative rotation of these benzene rings is hindered and they are arranged in a plane, resulting in a π electron cloud of the two benzene rings. The energy state is reduced by conjugating with each other,
As a result, it was found that a window of transmittance opens near the wavelength of 193 nm of ArF excimer laser light, and the present invention was completed.

As described above, the compound represented by the above-mentioned general formula (1) used in the present invention has a high quantum yield when an acid is generated by irradiation of radiation as a photo-acid generator, and is an aryl onium salt. Compared with the case where a condensed aromatic ring such as a naphthalene ring is introduced instead of the benzene ring to broaden the conjugation of the π electron cloud, the transparency to short wavelength light such as ArF excimer laser light is excellent. It should be noted that the compound in which the benzene ring of the aryl onium salt is simply substituted with an alkyl group is difficult to obtain a sufficient quantum yield and is not satisfactory as a photo-acid generator.

On the other hand, the reaction efficiency of the acid-decomposable group or the acid-crosslinkable group by the acid generated from the photo-acid generator, in other words, the catalytic ability of the photo-acid generator depends on the structure of its cation moiety. Since it is mainly determined by the anion species X ⁻ ,
In the compound represented by the general formula (1), such catalytic ability is no different from that of an arylonium salt having a benzene ring, which is a conventional photoacid generator. Therefore, in the present invention, by using the compound represented by the general formula (1) as a photoacid generator, it becomes possible to obtain a chemically amplified resist having extremely high sensitivity even to short wavelength light.

In the photoacid generator used in the present invention, Ar ¹ and Ar ² in the general formula (1) are an aromatic ring or a condensed aromatic ring as described above, and specifically, a benzene ring. , Naphthalene ring, anthracene ring, tetracene ring, pentacene ring, phenanthrene ring, pyrene ring and the like. Further, considering the sensitivity to short wavelength light, Ar ¹ and Ar ² are preferably benzene rings. In addition, these aromatic rings and condensed aromatic rings have R ¹ , R
Examples of the monovalent organic group appropriately introduced as ² include a methyl group, a methoxy group, a hydroxyl group, an ethyl group, a propyl group, a butyl group, and a phenyl group.

Further, in the present invention, the hydrogen atom of these organic groups may be substituted with a halogen atom, a nitro group, a cyano group or the like. However, considering transparency to short-wavelength light such as ArF excimer laser light, it is preferable that R ¹ and R ² are organic groups having no benzene ring, and a resist pattern with good resolution is formed. In this regard, an alkyl group having 6 or less carbon atoms is preferable.

Further, in the present invention, Z in the above general formula (1) is
Is S—R or Se—R, R is an alkyl group having 1 to 10 carbon atoms or a perfluoroalkyl group. When R is an aryl group having a benzene ring, the benzene ring here rotates in the molecule and is appropriately arranged non-planarly with the aromatic ring or condensed aromatic ring introduced as Ar ¹ , Ar ^2. Therefore, the conjugation of the π-electron cloud of the benzene ring does not spread, and the transparency for short wavelength light such as ArF excimer laser light cannot be improved. Further, R is preferably a perfluoroalkyl group from the viewpoint of the solvent solubility of the photosensitive composition and the pattern shape when a resist pattern is formed. Therefore, in view of these points, at least one of the compounds represented by the following general formulas (2), (3) and (4) is particularly preferably used as the photo-acid generator in the photosensitive composition of the present invention. .

[0054]

Embedded image (In the formula, R ¹ and R ² are halogen atoms or monovalent organic groups, X is CF ₃ SO ₃ , CH ₃ SO ₃ , CF ₃ COO.
It is selected from the group consisting of H, ClO ₄ , SbF ₆ and AsF ₆ , and m and n represent 0 or a positive integer. ) In the present invention, the compounding amount of the photo-acid generator as described above is
In the case of a positive type chemically amplified resist, it is preferably 0.1 mol% or more based on the acid-decomposable groups in the resin and the dissolution inhibitor. Although this amount varies depending on the type of resin used and the like, it generally corresponds to about 0.01 wt% or more in the solid content of the photosensitive composition. Furthermore, the more preferable blending amount of the photo-acid generator is 0.5 to the acid-decomposable group.
It is 5 mol%. On the other hand, in the case of a negative chemically amplified resist, the amount of the photoacid generator compounded is preferably 1 mol% or more based on the acid-crosslinkable group in the resin and the crosslinking agent. Generally, it corresponds to about 2 to 5 wt% or more in the solid content of the photosensitive composition, though it varies depending on the above. Furthermore, the more preferable blending amount of the photo-acid generator at this time is 5 to 20 mol% with respect to the acid crosslinkable group.

In the present invention, the preferable content of the photo-acid generator is defined within the above-mentioned range. When the content of the photo-acid generator is too small, a sufficient sensitivity is obtained in the photosensitive composition. This is because it is difficult to obtain, and if the amount of the photo-acid generator blended is too large, the coating property of the photosensitive composition tends to deteriorate. Further, in the present invention, these photo-acid generators may be used alone or in combination of two or more.

The photosensitive composition of the present invention is usually prepared as a varnish by dissolving the above components in an organic solvent and filtering. However, in the photosensitive composition of the present invention,
Other than these components, epoxy resin, propylene oxide-ethylene oxide copolymer, other polymers such as polystyrene, amine compounds for improving environmental resistance,
A basic compound such as a pyridine derivative, a surfactant for modifying a coating film, a dye as an antireflection agent, and the like may be appropriately mixed.

Examples of the organic solvent here include ketone solvents such as cyclohexanone, acetone, methyl ethyl ketone, and methyl isobutyl ketone; cellosolve solvents such as methyl cellosolve, methyl cellosolve acetate, ethyl cellosolve acetate, and butyl cellosolve acetate; ethyl acetate, acetic acid. Butyl, isoamyl acetate, γ-butyrolactone, ester solvents such as methyl 3-methoxypropionate, glycol solvents such as propylene glycol monomethyl ether acetate, dimethyl sulfoxide, hexamethylphosphoric triamide dimethylformamide, N-methylpyrrolidone, etc. Nitrogen-containing solvents, dimethyl sulfoxide,
A mixed solvent to which dimethylformaldehyde, N-methylpyrrolidinone and the like are added can be used. In addition, propionic acid derivatives such as methyl methyl propionate, lactic acid esters such as ethyl lactate, PGMEA (propylene glycol monoethyl acetate), propylene glycol monomethyl ether acetate, etc. have low toxicity and can be preferably used. In the present invention, such a solvent may be used alone or in combination of two or more, and further, isopropyl alcohol, ethyl alcohol, methyl alcohol, butyl alcohol, n-butyl alcohol, s-butyl alcohol, t-butyl. alcohol,
Aliphatic alcohols such as isobutyl alcohol and aromatic solvents such as toluene and xylene may be contained.

Next, the pattern forming method using the photosensitive composition of the present invention will be described by taking the case of a positive chemically amplified resist as an example. First, a resist varnish dissolved in an organic solvent as described above is applied on a predetermined substrate by a spin coating method, a dipping method, or the like, and then dried at 150 ° C. or less, preferably at 70 to 120 ° C., to form a resist film. Film. The substrate here is, for example, a silicon wafer; a silicon wafer on the surface of which various insulating films, electrodes, wirings, etc. are formed; a blank mask; GaAs, AlG
III-V compound semiconductor wafers such as aAs; chromium or chromium oxide deposition mask; aluminum deposition substrate; IBPS
G-coated substrate; PSG-coated substrate; SOG-coated substrate;
A carbon film sputtered substrate or the like can be used.

Then, the resist film is exposed by irradiating it with an actinic ray through a predetermined mask pattern or by scanning the surface of the resist film directly with the actinic ray. As described above, the photosensitive composition of the present invention has excellent transparency with respect to light in a wide wavelength range including short-wavelength light. Mercury lamp light i
Line, h line, g line, xenon lamp light, KrF or ArF excimer laser light, F ₂ excimer laser light, etc.
pUV light, ultraviolet rays, synchrotron radiation (S
R), synchrotron orbital radiation (SO
R), electron beam (EB), γ ray, ion beam or the like can be used. In particular, the photosensitive composition of the present invention exhibits its effect when using ArF excimer laser light or F ₂ excimer laser light as a light source.

Subsequently, the resist film is heated to 5 by heating on a hot plate or in an oven or irradiation with infrared rays.
A baking treatment at 0 to 180 ° C., preferably about 60 to 120 ° C. is appropriately performed. If the temperature at this time is less than 50 ° C., the chemical reaction due to the acid generated from the photo-acid generator in the exposed area cannot be promoted so much, and conversely 1
If the temperature exceeds 80 ° C., the photo-acid generator is decomposed even in the unexposed area to generate an acid, which may make it impossible to form a resist pattern having good resolution. However, if the resist film is left for a sufficiently long time before being developed after the exposure of the resist film, it is possible to omit the baking treatment as described above.

Next, the resist film is developed by a dipping method, a spray method or the like, and the resist film in the exposed or unexposed area is selectively dissolved and removed in an alkaline solution to form a desired resist pattern. At this time, as a specific example of the alkaline solution, a tetramethylammonium hydroxide aqueous solution,
Organic alkali aqueous solution such as trimethylhydroxyethyl ammonium hydroxide aqueous solution, choline aqueous solution,
Potassium hydroxide, sodium hydroxide, sodium carbonate,
Examples thereof include an inorganic alkaline aqueous solution such as sodium silicate and sodium metasilicate, and a solution obtained by adding an alcohol or a surfactant to these. The concentration of the alkaline solution here is preferably 15% by weight or less from the viewpoint of making a sufficient difference in dissolution rate between the exposed portion and the unexposed portion.

Thus, the resist pattern formed by using the photosensitive composition of the present invention has extremely good resolution, and for example, by dry etching using this resist pattern as an etching mask, a quarter micron pattern is formed on an exposed substrate. It is possible to faithfully transfer an extremely fine pattern. Incidentally, there is no problem even if other steps other than the above-mentioned steps are added, for example, a flattening layer forming step as a base of the resist film, a pretreatment step for improving adhesion between the resist film and the base, A rinsing step of removing the developing solution with water or the like after the development of the resist film, and an ultraviolet ray re-irradiation step before dry etching can be appropriately performed.

[0063]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on embodiments. First, in FIG. 1, a photo-acid generator used in the present invention or a conventional photo-acid generator is shown as resin S- manufactured by Sumitomo Chemical
3 shows an ultraviolet absorption spectrum of a composition prepared by blending 2 μmol / g with respect to lec. In the figure, 1 to 4 are S- (trifluoromethyl) dibenzothiophenium trifluoromethanesulfonic acid (PAG-1) and Se, which are photoacid generators in the photosensitive composition of the present invention.
-(Trifluoromethyl) dibenzoselenophenium trifluoromethanesulfonic acid (PAG-2), I-dibenzoiodonofenium trifluoromethanesulfonic acid (PAG-3) and S- (perfluoroethyl) dibenzothiophenium trifluoromethane Sulfonic acid (PA
G-4) is an ultraviolet absorption spectrum diagram, 5 and 6 are triphenylsulfonium trifluoromethanesulfonic acid (TPS.OT) which is a conventional photoacid generator.
f) is a UV absorption spectrum when diphenyliodonium trifluoromethanesulfonic acid (DPI · OTf) is blended. However, FIG. 1 shows the values obtained by normalizing the absorbance of the coating film of each composition as described above to a thickness of 1 μm. The chemical formula of the photo-acid generator used here is shown below.

[0064]

Embedded image

As shown in FIG. 1, the composition containing the conventional photo-acid generator has a large light absorption peak near the wavelength of 193 nm. On the other hand, (PAG-1) to (P
In the composition containing the photoacid generator of AG-4),
It is clear that in both cases, the window of the transmittance opens in the vicinity of the wavelength of 193 nm and the transparency in the short wavelength region is excellent.

Next, regarding each of these photo-acid generators, polymethyl methacrylate (PMMA) manufactured by Poly Science Co., Ltd.
(Molecular weight of 20,000) The quantum yield per photon having a medium wavelength of 193 nm was calculated according to the following formula. As a result, the quantum yield of (TPS · OTf) is 0.036, (D
The quantum yield of (PI.OTf) was 0.032, while the quantum yields of (PAG-1) to (PAG-4) were 0.16, 0.09, 0.22, 0. 13,
With the photoacid generator in the photosensitive composition of the present invention, a sufficient quantum yield could be obtained.

Quantum Yield = (Number of Acids Generated from Photo-Acid Generator) / (Number of Photons Absorbed by Photo-Acid Generator) Here, the number of acids is per unit volume generated in the polymer matrix. It is defined as the number of acids. Specifically, it was determined by measuring the discoloration of an indicator prepared by dissolving tetrabromophenol blue sodium salt in ethyl cellosolve acetate in 7.9 × 10 ⁻⁵ mol with a UV spectroscope. . The number of photons absorbed by the photo-acid generator was calculated from the difference in transmittance before and after mixing the photo-acid generator with PMMA.

Further, as described above, (PAG-1) to
The photoacid generator of (PAG-4) is added to each resin having an acid decomposition group to prepare a photosensitive composition of the present invention,
The ultraviolet absorption spectrum was measured. Incidentally, here, a resin obtained by introducing t-butyl group as an acid-decomposable group into 30 mol% of the carboxyl group of polyacrylic acid which is an alkali-soluble resin (weight average molecular weight: 20,000)
0) was used and the compounding amount of the photo-acid generator was 2 μmol / g as in the case of FIG.

On the other hand, as a comparative example, a resin (weight average molecular weight: 7,000) obtained by introducing a t-butyl group into 20 mol% of hydroxyl groups of polyhydroxystyrene was added with (TPS.OTf) as a photoacid generator. A photosensitive composition for KrF excimer laser light containing 2 μmol / g, and a cresol novolac resin (weight average molecular weight: 5,50).
Similarly, the ultraviolet absorption spectrum of the photosensitive composition for i-ray obtained by blending 0) with 2,3,4,4'-tetrahydroxybenzophenone-4-naphthoquinonediazide sulfonic acid ester at 2 μmol / g It was measured. The results are shown in FIG.

In the figure, 1'to 4'are (PAG-
1) to (PAG-4) UV absorption spectrum of the photosensitive composition of the present invention containing the photoacid generator, 5'is an ultraviolet absorption spectrum of a photosensitive composition for KrF excimer laser light, 6 '. FIG. 3 is an ultraviolet absorption spectrum diagram of a photosensitive composition for i-line. Here, as in FIG. 1, the absorbance of the resist film made of each of the photosensitive compositions as described above is calculated to be 1
The value normalized to μm is shown.

As shown in FIG. 2, each of the photosensitive compositions of the present invention has an absorbance of 1 or less at a wavelength of 193 nm, and has excellent transparency to ArF excimer laser light. On the other hand, the photosensitive composition of Comparative Example has a wavelength of 193n.
The absorbance at m is as high as about 30, and it is clear that the transparency of ArF excimer laser light is completely insufficient.

Next, the sensitivity of the photosensitive composition of the present invention and the photosensitive composition for the KrF excimer laser light as a comparative example to the ArF excimer laser light was examined. That is, first, a resist film having a thickness of 0.6 μm made of the above-described photosensitive composition is formed, and the resist film is irradiated with ArF excimer laser light through a mask for sensitivity measurement. The residual film thickness of the resist film was measured after baking treatment for 90 seconds and subsequent development with a 0.28N tetramethylammonium hydroxide aqueous solution. The sensitivity curve of each photosensitive composition thus obtained is shown in FIG. The residual film thickness of the resist film in FIG. 3 is standardized by the ratio to the thickness of the resist film when it is formed.

In the figure, 1'-4 'are (PAG-
1) to (PAG-4) are the sensitivity curves of the photosensitive composition of the present invention containing the photoacid generator, and 5'is the sensitivity curve of the photosensitive composition for KrF excimer laser light. As is clear from FIG. 3, the photosensitive composition for KrF excimer laser light of the comparative example is hardly exposed to ArF excimer laser light, whereas the photosensitive composition of the present invention uses ArF excimer laser light as a light source. High sensitivity is obtained even when Example 1 To 1.2 g of a resin obtained by introducing a t-butyl group into polyacrylic acid as described above, 0.06 g of the photoacid generator (PAG-1) was added, and these components were mixed with ethyl acetate. Example 1 was dissolved in 8.8 g of cellosolve acetate.
To prepare a photosensitive composition. The solution of the obtained photosensitive composition was spin-coated on a silicon wafer at 3000 rpm for 30 seconds, and then 110 ° C. for 10 seconds on a hot plate.
It was dried for 0 seconds to form a resist film having a thickness of 0.5 μm.

Next, the resist film is exposed to pattern light of a predetermined line and space pattern using ArF excimer laser light having a wavelength of 193 nm as a light source, and then 100
A baking treatment was performed at 180 ° C. for 180 seconds. After this,
The resist film was developed with a 0.28N tetramethylammonium hydroxide aqueous solution at 25 ° C. for 60 seconds. With the photosensitive composition of this example, a positive resist pattern was formed in this way, and as a result, a 0.35 μm line-and-space pattern could be resolved at an exposure dose of 38 mJ / cm ² . (Example 2) A positive resist pattern was formed in exactly the same manner as in Example 1 except that the same amount of the photoacid generator of (PAG-2) was used instead of (PAG-1). As a result,
In the present embodiment, the exposure amount of 60 mJ / cm ² is 0.
A line and space pattern of 25 μm could be resolved. (Example 3) A positive resist pattern was formed in exactly the same manner as in Example 1 except that the same amount of the photoacid generator of (PAG-3) was used instead of (PAG-1). As a result,
In the present embodiment, the exposure amount of 31 mJ / cm ² is 0.
A line and space pattern of 30 μm could be resolved. (Example 4) A positive resist pattern was formed in exactly the same manner as in Example 1 except that the same amount of the photoacid generator of (PAG-4) was used instead of (PAG-1). As a result,
In this example, the exposure dose of 40 mJ / cm ² was 1.
A line and space pattern of 0 μm could be resolved. (Example 5) I in place of the photoacid generator of (PAG-1)
A positive resist pattern was formed in exactly the same manner as in Example 1 except that dibenzoiodonofenium trifluoroacetic acid was also used. As a result, in this example, a line-and-space pattern of 0.35 μm could be resolved with an exposure dose of 100 mJ / cm ² . (Example 6) I in place of the photoacid generator of (PAG-1)
A positive resist pattern was formed in exactly the same manner as in Example 1 except that dibenzoiodonofenium methanesulfonic acid was also used. As a result, in this example, a line-and-space pattern of 0.35 μm could be resolved with an exposure dose of 80 mJ / cm ² . (Example 7) I in place of the photoacid generator of (PAG-1)
-In exactly the same manner as in Example 1 except that dibenzoiodonofenium hexafluoroantimonate was also used,
A positive resist pattern was formed. As a result, in this embodiment, the exposure amount of 22 mJ / cm ² is 0.25 μm.
m line and space pattern could be resolved. (Example 8) I in place of the photoacid generator of (PAG-1)
A positive resist pattern was formed in exactly the same manner as in Example 1 except that dibenzoiodonofenium tetrafluoroborate was also used. As a result, in this example, a line-and-space pattern of 0.25 μm could be resolved with an exposure dose of 15 mJ / cm ² . (Example 9) I in place of the photoacid generator of (PAG-1)
A positive resist pattern was formed in exactly the same manner as in Example 1 except that dibenzoiodonofenium hexafluorophosphate was also used. As a result, in this example, the exposure amount of 25 mJ / cm ² was 0.25 μm.
Could be resolved. (Example 10) In exactly the same manner as in Example 1 except that I-dibenzoiodonofenium hexafluoroarsanate was used in place of the photoacid generator of (PAG-1),
A positive resist pattern was formed. As a result, in this example, the exposure amount of 15 mJ / cm ² was 0.25 μm.
m line and space pattern could be resolved. (Example 11) An acid-decomposable group was added to 26 mol% of the hydroxyl groups of polyhydroxystyrene which is an alkali-soluble resin.
2.5 g of a resin (weight average molecular weight: 5,100) obtained by introducing a t-butoxycarbonyl group was mixed with 0.05 g of the photoacid generator (PAG-1), and these components were mixed with ethyl cellosolve acetate. It was dissolved in 7.5 g to prepare a photosensitive composition of Example 11. A solution of the obtained photosensitive composition was applied onto a silicon wafer at 3000 rpm for 30 minutes.
Spin coating for 2 seconds, then 110 ° C on a hot plate,
It was dried for 100 seconds to form a resist film having a thickness of 0.94 μm.

Next, the resist film is exposed to pattern light of a predetermined line-and-space pattern using KrF excimer laser light having a wavelength of 248 nm as a light source, and further 120
A baking treatment was performed at 90 ° C. for 90 seconds. After this, 0.
The resist film was developed with a 28N tetramethylammonium hydroxide aqueous solution at 25 ° C. for 60 seconds. With the photosensitive composition of this example, a positive resist pattern was formed in this manner, and as a result, an exposure dose of 38 mJ / cm ² resulted in 0.3.
It was possible to resolve a line and space pattern of 5 μm. (Example 12) Instead of (PAG-1) (PAG-2)
A positive resist pattern was formed in exactly the same manner as in Example 11 except that the same amount of the photo-acid generator as in 1 was used. As a result, in this example, a line and space pattern of 0.25 μm could be resolved with an exposure dose of 35 mJ / cm ² . (Example 13) Instead of (PAG-1) (PAG-3)
A positive resist pattern was formed in exactly the same manner as in Example 11 except that the same amount of the photo-acid generator as in 1 was used. As a result, in this example, a line and space pattern of 0.30 μm could be resolved with an exposure dose of 24 mJ / cm ² . (Example 14) Instead of (PAG-1) (PAG-4)
A positive resist pattern was formed in exactly the same manner as in Example 11 except that the same amount of the photo-acid generator as in 1 was used. As a result, in this example, a line and space pattern of 1.0 μm could be resolved with an exposure dose of 44 mJ / cm ² . (Example 15) 30:30:30: Methyl methacrylate, methyl acrylate, t-butyl methacrylate and naphthyl methacrylate as a resin having an acid-decomposable group.
Ten quaternary copolymers (weight average molecular weight: 16,000)
A photoacid generator of (PAG-1) 0.06 g was added to 1.5 g, and these components were further dissolved in ethyl cellosolve acetate 8.5 g to prepare a photosensitive composition of Example 15. The resulting photosensitive composition solution was spin-coated on a silicon wafer at 3000 rpm for 30 seconds, and then dried on a hot plate at 110 ° C. for 100 seconds to form a resist film having a thickness of 0.55 μm. did.

Next, the ArF excimer laser light having a wavelength of 193 nm is used as a light source to expose the resist film with pattern light of a predetermined line-and-space pattern, and then 100
A baking treatment was performed at 180 ° C. for 180 seconds. After this,
The resist film was developed with a 0.014N tetramethylammonium hydroxide aqueous solution at 25 ° C. for 15 seconds. With the photosensitive composition of this example, a positive resist pattern was formed in this way, and as a result, a line and space pattern of 0.25 μm could be resolved at an exposure dose of 230 mJ / cm ² . (Example 16) (PAG-2) instead of (PAG-1)
A positive resist pattern was formed in exactly the same manner as in Example 15 except that the same amount of the photo-acid generator of was used. As a result, in this example, a 0.18 μm line-and-space pattern could be resolved with an exposure dose of 260 mJ / cm ² . (Example 17) (PAG-3) instead of (PAG-1)
A positive resist pattern was formed in exactly the same manner as in Example 15 except that the same amount of the photo-acid generator of was used. As a result, in this example, a line and space pattern of 0.20 μm could be resolved with an exposure dose of 180 mJ / cm ² . (Example 18) (PAG-4) instead of (PAG-1)
A positive resist pattern was formed in exactly the same manner as in Example 15 except that the same amount of the photo-acid generator of was used. As a result, in this example, a line-and-space pattern of 1.0 μm could be resolved with an exposure dose of 150 mJ / cm ² . (Example 19) To 1.2 g of a 35:35:30 terpolymer of methyl acrylate, t-butyl methacrylate and menthyl methacrylate as a resin having an acid-decomposable group (weight average molecular weight: 13,000) , (PAG-1)
0.06 g of the photo-acid generator of was mixed, and these components were further dissolved in 8.8 g of cyclohexanone to prepare a photosensitive composition of Example 19. The solution of the obtained photosensitive composition was spin-coated on a silicon wafer at 3000 rpm for 30 seconds, and then 110 ° C. at 100 ° C. on a hot plate.
It was dried for 2 seconds to form a resist film having a thickness of 0.50 μm.

Next, the resist film is exposed to pattern light of a predetermined line-and-space pattern using ArF excimer laser light having a wavelength of 193 nm as a light source.
A baking treatment was performed at 180 ° C. for 180 seconds. After this,
The resist film was developed with a 0.14N tetramethylammonium hydroxide aqueous solution at 25 ° C. for 15 seconds. In the photosensitive composition of this example, a positive resist pattern was formed in this way, and as a result, a line and space pattern of 0.55 μm could be resolved with an exposure dose of 55 mJ / cm ² . (Example 20) Instead of (PAG-1) (PAG-2)
A positive resist pattern was formed in exactly the same manner as in Example 19 except that the same amount of the photo-acid generator as in 1 was used. As a result, in this example, a line-and-space pattern of 0.45 μm could be resolved with an exposure dose of 72 mJ / cm ² . (Example 21) (PAG-3) instead of (PAG-1)
A positive resist pattern was formed in exactly the same manner as in Example 19 except that the same amount of the photo-acid generator as in 1 was used. As a result, in this example, a line and space pattern of 0.25 μm could be resolved with an exposure dose of 34 mJ / cm ² . (Example 22) Instead of (PAG-1) (PAG-4)
A positive resist pattern was formed in exactly the same manner as in Example 19 except that the same amount of the photo-acid generator as in 1 was used. As a result, in this example, a line and space pattern of 1.5 μm could be resolved with an exposure dose of 30 mJ / cm ² . (Example 23) To 35 g of 35:35:30 terpolymer (weight average molecular weight: 13,000) of methyl acrylate, t-butyl methacrylate and menthyl methacrylate as a resin having an acid-decomposable group , Naphthol novolak as a dissolution inhibitor (weight average molecular weight: 1,000
0) 0.9 g and (PAG-1) photoacid generator 0.06
g, and then these components were dissolved in 8.8 g of cyclohexanone to prepare a photosensitive composition of Example 23. The solution of the obtained photosensitive composition was spin-coated on a silicon wafer at 3000 rpm for 30 seconds, and then dried on a hot plate at 110 ° C. for 100 seconds to form a resist film having a thickness of 0.48 μm. did.

Next, the resist film is exposed to pattern light of a predetermined line-and-space pattern using ArF excimer laser light having a wavelength of 193 nm as a light source.
A baking treatment was performed at 180 ° C. for 180 seconds. After this,
The resist film was developed with a 0.28N tetramethylammonium hydroxide aqueous solution at 25 ° C. for 30 seconds. With the photosensitive composition of this example, a positive resist pattern was formed in this way, and as a result, a 0.35 μm line-and-space pattern could be resolved at an exposure dose of 35 mJ / cm ² . (Example 24) Instead of (PAG-1) (PAG-2)
A positive resist pattern was formed in exactly the same manner as in Example 23 except that the same amount of the photo-acid generator as in (4) was used. As a result, in this example, a line and space pattern of 0.30 μm could be resolved with an exposure dose of 42 mJ / cm ² . (Example 25) Instead of (PAG-1) (PAG-3)
A positive resist pattern was formed in exactly the same manner as in Example 23 except that the same amount of the photo-acid generator as in (4) was used. As a result, in this example, a line and space pattern of 0.25 μm could be resolved with an exposure dose of 30 mJ / cm ² . (Example 26) Instead of (PAG-1) (PAG-4)
A positive resist pattern was formed in exactly the same manner as in Example 23 except that the same amount of the photo-acid generator as in (4) was used. As a result, in this example, a line and space pattern of 1.2 μm could be resolved with an exposure dose of 36 mJ / cm ² . (Example 27) In 1.5 g of a 60:40 copolymer of acrylic acid and menthyl methacrylate (weight average molecular weight: 15,000) as an alkali-soluble resin, a di-t- represented by the following chemical formula as a dissolution inhibitor was used. 0.3 g of butoxycarbonylated 1,5-naphthodiol and 0.06 g of a photoacid generator of (PAG-1) were mixed, and these components were further dissolved in 8.2 g of cyclohexanone. A composition was prepared. The solution of the obtained photosensitive composition was spin-coated on a silicon wafer at 3000 rpm for 30 seconds, and then 110 ° C. at 100 ° C. on a hot plate.
It was dried for 2 seconds to form a resist film having a thickness of 0.45 μm.

[0079]

Embedded image

Next, the resist film is exposed to pattern light of a predetermined line-and-space pattern using ArF excimer laser light having a wavelength of 193 nm as a light source, and further 120
A baking treatment was performed at 180 ° C. for 180 seconds. After this,
The resist film was developed with a 0.28N tetramethylammonium hydroxide aqueous solution at 25 ° C. for 30 seconds. With the photosensitive composition of this example, a positive resist pattern was formed in this way, and as a result, a line-and-space pattern of 0.35 μm could be resolved at an exposure dose of 50 mJ / cm ² . (Example 28) Instead of (PAG-1) (PAG-2)
A positive resist pattern was formed in exactly the same manner as in Example 27 except that the same amount of the photo-acid generator as in Example 1 was used. As a result, in this example, a line and space pattern of 0.30 μm could be resolved with an exposure dose of 65 mJ / cm ² . (Example 29) Instead of (PAG-1) (PAG-3)
A positive resist pattern was formed in exactly the same manner as in Example 27 except that the same amount of the photo-acid generator as in Example 1 was used. As a result, in this example, a line and space pattern of 0.25 μm could be resolved with an exposure dose of 35 mJ / cm ² . (Example 30) Instead of (PAG-1) (PAG-4)
A positive resist pattern was formed in exactly the same manner as in Example 27 except that the same amount of the photo-acid generator as in Example 1 was used. As a result, in this example, a line and space pattern of 1.0 μm could be resolved with an exposure dose of 42 mJ / cm ² . (Example 31) Instead of di-t-butoxycarbonylated 1,5-naphthodiol as a dissolution inhibitor, di-t-butoxycarbonylated 1,1'-bis (4-hydroxynaphthyl) cyclohexane represented by the following chemical formula A positive resist pattern was formed in exactly the same manner as in Example 27 except that the same amount was used. As a result, in this embodiment, 55 mJ / cm
A line and space pattern of 0.35 μm could be resolved with an exposure amount of ² .

[0081]

Embedded image (Example 32) Instead of di-t-butoxycarbonylated 1,5-naphthodiol as a dissolution inhibitor, di-t-butoxycarbonylated 1,1'-bis (4-hydroxynaphthyl) cyclo represented by the following chemical formula A positive resist pattern was formed in exactly the same manner as in Example 27 except that the same amount of pentane was used. As a result, in this example, 52 mJ / cm.
A line and space pattern of 0.35 μm could be resolved with an exposure amount of ² .

[0082]

Embedded image (Example 33) The photosensitive composition of the present invention was mixed in a random copolymer of methyl methacrylate and t-butyl methacrylate in an amount of 1 wt% and dissolved in ethyl cellosolve acetate. After spin-coating this solution on a silicon wafer, baking was performed at 120 ° C. for 90 seconds to form a resist film having a film thickness of 0.3 μm.

F ₂ excimer laser light (wavelength 159n
The light from m) was made into a light beam having a diameter of 5 mm and was irradiated on the resist film. Subsequently, baking was performed at 100 ° C. for 90 seconds, followed by development with a 0.14N tetramethylammonium hydroxide aqueous solution. As a result, the exposure dose at which the resist film was dissolved was as follows.

[0084]

[Table 1]

From the above results, it can be seen that these photosensitive compositions are also sensitive to F ₂ excimer laser light. Thus, in the photosensitive composition of the present invention, Kr
Even when not only the F excimer laser light but also the ArF excimer laser light or the F ₂ excimer laser light was used as a light source, a resist pattern with high sensitivity and good resolution could be formed. That is, it was confirmed that the photosensitive composition of the present invention can be applied as a chemically amplified resist having extremely high sensitivity to light in a wide wavelength range including short wavelength light such as ArF excimer laser light having a wavelength of 193 nm. It was

[0086]

As described above in detail, according to the present invention, a photosensitive composition capable of forming a resist pattern having excellent transparency to ArF excimer laser light having an extremely short wavelength, high sensitivity and good resolution. It becomes possible to realize things.

[Brief description of the drawings]

FIG. 1 is an ultraviolet absorption spectrum diagram of a composition containing each photoacid generator.

FIG. 2 is an ultraviolet absorption spectrum diagram of the photosensitive compositions of the present invention and Comparative Example.

FIG. 3 is a characteristic diagram showing sensitivity curves of photosensitive compositions of the present invention and comparative examples.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Shin Nakase 1 Komukai Toshiba-cho, Kouki-ku, Kawasaki-shi, Kanagawa Incorporated Toshiba Research and Development Center

Claims (4)

[Claims] 1. A photosensitive composition for forming a pattern by exposure with either ArF excimer laser light or F ₂ excimer laser light, comprising either an acid decomposable group or an acid crosslinkable group. A photosensitive composition comprising a compound having: and a compound represented by the following general formula (1). Embedded image (In the formula, Ar ¹ and Ar ² are aromatic rings or condensed aromatic rings, R
¹ , R ² is a halogen atom or a monovalent organic group, X is CF
₃ SO ₃ , CH ₃ SO ₃ , CF ₃ COOH, ClO ₄ ,
SbF ₆ and is selected from the group consisting of AsF _6, Z is Cl, Br, I, S- R and Se-R (R is 1 carbon atoms
Selected from the group consisting of 10 or more alkyl groups or perfluoroalkyl groups), and m and n each represent 0 or a positive integer. ) 2. The photosensitive composition according to claim 1, which further contains an alkali-soluble resin. 3. A photosensitive composition for forming a pattern by exposure with either ArF excimer laser light or F ₂ excimer laser light, comprising either an acid decomposable group or an acid crosslinkable group. A photosensitive composition comprising a resin having the same and a compound represented by the following general formula (1). Embedded image (In the formula, Ar ¹ and Ar ² are aromatic rings or condensed aromatic rings, R
¹ , R ² is a halogen atom or a monovalent organic group, X is CF
₃ SO ₃ , CH ₃ SO ₃ , CF ₃ COOH, ClO ₄ ,
SbF ₆ and is selected from the group consisting of AsF _6, Z is Cl, Br, I, S- R and Se-R (R is 1 carbon atoms
Selected from the group consisting of 10 or more alkyl groups or perfluoroalkyl groups), and m and n each represent 0 or a positive integer. ) 4. The compound represented by the general formula (1) is
The compound according to any one of claims 1 to 3, which is at least one kind of compounds represented by the following general formulas (2), (3) and (4).
The photosensitive composition according to the item. Embedded image (In the formula, R ¹ and R ² are halogen atoms or monovalent organic groups, X is CF ₃ SO ₃ , CH ₃ SO ₃ , CF ₃ COO.
It is selected from the group consisting of H, ClO ₄ , SbF ₆ and AsF ₆ , and m and n represent 0 or a positive integer. )