JPH09120162A - Resist for alkali development - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a resist excellent in transparency to light of short wavelength, having high dry etching resistance and capable of forming a resist pattern having satisfactory resolution by alkali development. SOLUTION: This resist contains an alicyclic compd. into which an acidic substituent having pKa of 7-11 in an aq. soln. at 25 deg.C has been introduced. The alicyclic compd. is preferably blended as a copolymer with a vinyl compd. and the absorbance of the copolymer to light of 193nm wavelength is preferably <=3 per 1μm.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art Microfabrication technology using photolithography has been employed in the manufacturing process of electronic components such as LSIs. That is, first, a resist solution is applied on a substrate or the like to form a resist film, and then the obtained resist film is exposed to pattern light. After that, a resist pattern is formed by performing processing such as alkali development. Then, the exposed surface of the substrate or the like is dry-etched by using this resist pattern as an etching-resistant mask to form fine lines and openings, and finally the resist is removed by ashing.

Accordingly, the resist used here is generally required to have high dry etching resistance. From such a viewpoint, resists containing an aromatic compound have been widely used so far, and specifically, a large number of resists using an alkali-soluble novolak resin or the like as a base resin have been developed.

[0004] On the other hand, with the high-density integration of LSIs and the like, the above-mentioned fine processing technology has recently reached the sub-half micron order, and it is expected that such miniaturization will become more remarkable in the future. For this reason, the wavelength of the light source in photolithography has been shortened, and an attempt is currently being made to form a fine resist pattern using ArF excimer laser light having a wavelength of 193 nm or a fifth harmonic light of a YAG laser having a wavelength of 218 nm.

[0005] However, in a resist using a novolak resin as a base resin, which has been generally used until now, there is a tendency that light absorption by the benzene nucleus of the novolak resin is large for short-wavelength light as described above. Therefore, when trying to form a resist pattern, it is difficult to sufficiently reach light to 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 sensitivity and high precision. there were.

As described above, a resist using a novolac resin as a base resin has high dry etching resistance and can be developed with an alkali, but its transparency to short-wavelength light is insufficient, so that it cannot be exposed to ArF excimer laser light or Y light.
It is strongly desired to develop a resist suitable for photolithography using the 5th harmonic light of an AG laser. In consideration of such a point, recently, a resist containing an alicyclic compound in place of an aromatic compound has been attracting attention. For example, JP-A-4-39665 discloses a dry etching resistance,
As a resist having good transparency to short-wavelength light, a resist using a polymer having an adamantane skeleton as a base resin has been proposed. Also, here, an example is shown in which a compound having an adamantane skeleton is copolymerized with an acrylic compound having a carboxylic acid group to impart alkali solubility to the polymer, and a resist pattern is formed by alkali development.

[0007] However, when a resist pattern containing an alicyclic compound is formed by alkali development in this manner, alkali solubility differs greatly between an alicyclic structure such as an adamantane skeleton and a carboxylic acid group. , Various problems occur. For example, during development, dissolution / removal of a predetermined region of the resist film becomes non-uniform, resulting in a decrease in resolution. On the other hand, partial dissolution occurs even in a region where the resist film should remain, resulting in cracks and surface roughness. Cause. Further, the alkaline solution may permeate the interface between the resist film and the substrate, and the resist pattern may be peeled off. Furthermore, phase separation between a portion having an alicyclic structure and a carboxylic acid group portion in the polymer is apt to proceed, and it is difficult to prepare a uniform resist solution, and its coatability is not sufficient.

[0008]

SUMMARY OF THE INVENTION The present invention solves such a problem by providing a resist pattern having excellent transparency to short-wavelength light, high dry etching resistance, and good resolution in alkali development. It is an object of the present invention to provide an alkali developing resist capable of forming a film.

[0009]

According to the present invention, 25 ° C.
There is provided an alkali developing resist containing an alicyclic compound having an acidic substituent having a pKa in the aqueous solution of 7 to 11 inclusive.

Further, according to the present invention, there is provided an alkali developing resist containing a compound containing at least one structural unit represented by the following general formulas 1 to 3.

[0011]

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(Here, at least one of R ¹ to R ³ is a monovalent organic group containing an alicyclic group, and the other is an alkyl group. R ¹ and R ² are partially bonded to each other. It may form a cyclic compound, and R ³ may be a hydroxyl group.)

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(Here, at least one of R ¹ , R ² , R ⁴ and R ⁵ is a monovalent organic group containing an alicyclic group,
Others represent a hydrogen atom or an alkyl group. Also, R
¹ and R ² may be partially combined to form a cyclic compound. R ⁴ and R ⁵ may be partially bonded to form a cyclic compound. )

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[0014] (wherein at least one of R ^1, R ² and R ⁶ is a monovalent organic group containing an alicyclic, others represents a hydrogen atom or an alkyl group. Further, R ¹ and R
^Two may be partially bonded to form a cyclic compound. ) Furthermore, according to the invention, pKa in an aqueous solution at 25 ° C.
There is provided a resist for alkali development containing a polymer containing an alicyclic monomer compound having an acid substituent of 7 or more and 11 or less.

Furthermore, according to the present invention, a polymer containing an alicyclic monomer compound into which an acidic substituent having a pKa of 7 to 11 in an aqueous solution at 25 ° C. is introduced, and There is provided a resist for alkali development, wherein the alicyclic monomer compound is a compound represented by any one of the following general formulas 1 to 3.

[0016]

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(Here, at least one of R ¹ to R ³ is a monovalent organic group containing an alicyclic group, and the other is an alkyl group. R ¹ and R ² are partially bonded to each other. It may form a cyclic compound, and R ³ may be a hydroxyl group.)

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(Here, at least one of R ¹ , R ² , R ⁴ and R ⁵ is a monovalent organic group containing an alicyclic group,
Others represent a hydrogen atom or an alkyl group. Also, R
¹ and R ² may be partially bonded to each other to form a cyclic compound. Further, R ⁴ and R ⁵ may be partially bonded to each other to form a cyclic compound. )

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[0019] (wherein at least one of R ^1, R ² and R ⁶ is a monovalent organic group containing an alicyclic, others represents a hydrogen atom or an alkyl group. Further, R ¹ and R
^Two may be partially bonded to form a cyclic compound. Hereinafter, the present invention will be described in detail.

In the alkali developing resist of the present invention, the alicyclic structure as described above has the general formula C _n H
_Examples thereof include cyclic cyclo compounds and cyclic bicyclo compounds represented by _2n (n is an integer of 3 or more), and condensed rings thereof. Specifically, a cyclobutane ring, a cyclopentane ring, a cyclohexane ring, a cycloheptane ring or those in which a bridged hydrocarbon is introduced, spiroheptane, spiro rings such as spirooctane, norbonyl ring, adamantyl ring, bornene ring, Terpene rings such as Menthyl ring and Menthane ring, Tujan, Sabinene, Tujon, Curran, Karen, Pinan, Norpinan, Bornan, Fencan, Tricyclene, Cholesteric ring and other steroid skeleton, Tanjusan, Digitaloids, Shaunon ring, Isocamou ring, Sesqui Examples thereof include a terpene ring, a Sandton ring, a diterpene ring, a triterpene ring, and steroid saponins.

On the other hand, as the acidic substituent introduced into the alicyclic structure, an organic group containing a ketone oxime structure such as a propanone oxime group, a propanal oxime group, hydroxyiminopentanone and dimethylglyoxime; N-hydroxysuccin Organic group containing imide structure; cyclopentene 1,3-dione, acetylacetone, 3-methyl-2,
An organic group containing a dicarbonylmethylene structure such as 4-pentadione; an organic group containing a sulfamyl structure; an organic group containing a polysubstituted sulfonylmethane structure; an organic group containing a thiol such as hexanethiol; a tautomeric alcohol such as hydroxycyclopentenone, Examples include an organic group containing a carbamate group; an organic group containing a furfuryl alcohol; an organic group containing an amic acid structure; an organic group containing a phenolic hydroxyl group such as phenol, cresol, salicylaldehyde; and an organic group containing a triazine skeleton. However, since an organic group containing a phenolic hydroxyl group and an organic group containing a triazine skeleton have large light absorption for short wavelength light, it is preferable in the present invention to introduce an acidic substituent other than these into the alicyclic structure. Here, particularly preferable acidic substituents are shown below.

[0022]

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(Here, at least one of R ¹ to R ³ is a monovalent organic group containing an alicyclic group, and the other is an alkyl group. R ¹ and R ² are partially bonded to each other. It may form a cyclic compound, and R ³ may be a hydroxyl group.)

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(Here, at least one of R ¹ , R ² , R ⁴ and R ⁵ is a monovalent organic group containing an alicyclic group,
Others represent a hydrogen atom or an alkyl group. Also, R
¹ and R ² may be partially bonded to each other to form a cyclic compound. Further, R ⁴ and R ⁵ may be partially bonded to each other to form a cyclic compound. )

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[0025] (wherein at least one of R ^1, R ² and R ⁶ is a monovalent organic group containing an alicyclic, others represents a hydrogen atom or an alkyl group. Further, R ¹ and R
^Two may be partially bonded to form a cyclic compound. In the present invention, the reason why the pKa value of the acidic substituent introduced into the alicyclic structure is defined as 7 or more and 11 or less is that pKa
If it is less than 7, the difference in alkali solubility between the alicyclic structure and the acidic substituent is too large, so that it becomes difficult to form a resist pattern having good resolution by alkali development, and p
This is because when Ka exceeds 11, the alkali developability is not so improved. Further, the preferable pKa value of the acidic substituent is 9 or more and 10 or less. However, since the acidic substituent represented by the general formula (3) has a double bond, it has some reactivity that the double bond is cleaved by irradiation with light. In this case, the photoreaction product is pKa
It can be 7 or more and 11 or less. Therefore, in this case, the pKa value may be out of the range of 7 or more and 11 or less. In the compound represented by the above general formula (1), when R ³ is a hydrogen atom, a free amine is easily mixed as an impurity. In that sense, a compound in which R ³ is a hydroxyl group, an alkyl group, or a general formula (2) or (3) is most preferable.

In the present invention, the alicyclic compound introduced with the acidic substituent as described above may be contained in the polymer. In this case, a copolymer obtained by copolymerizing such an alicyclic compound monomer and a vinyl compound is particularly preferable. Such a polymer is a radically polymerized, cationically polymerized, anionically polymerized, or polymerized under a Ziegler-Natta catalyst of a polymerizable compound having an alicyclic structure having an acidic substituent and a polymerizable double bond in the molecule. By doing so, it can be easily obtained. Generally, a polymerizable compound having an alicyclic structure and a polymerizable double bond can be made into a high molecular weight polymer by using the latter catalyst. However, in the present invention, even if it is a low molecular weight polymer, there is no problem as long as it can be formed into a film. Therefore, polymerization is carried out by a simple method such as radical polymerization, and even in a situation where a low molecular weight compound and a high molecular weight compound are mixed. good.
It is preferable that the low molecular weight compound is contained because the alkali solubility is improved. However, when the ratio of the low molecular weight compound in the polymer is 50% or more, it becomes difficult to form a film, so the ratio is preferably less than 50%. At this time, from the viewpoint of adjusting the alkali solubility of the polymer compound and improving the adhesion to the substrate of the resist, acrylic acid and maleic anhydride and their ester substitution products, vinylphenol, vinylnaphthol, naphtholoxymethacrylate, hydroxyethyl. Acrylate, SO ₂
And the like are preferably copolymerized. Further, a compound obtained by protecting the alkali-soluble group of these alkali-soluble compounds with an acid-decomposable group having an ability to inhibit dissolution in an alkali solution may be copolymerized. However, considering the transparency of the resist for short wavelength light,
It is preferable to copolymerize with a compound that does not have a molecular skeleton such as benzene nucleus which has a large light absorption in a short wavelength region. Specifically, the absorbance of the polymer compound for light with a wavelength of 193 nm is 3 or less per 1 μm. desired. In this case, it is particularly effective for exposure using ArF excimer laser light.

However, the copolymerization ratio of the alkali-soluble compound such as acrylic acid is preferably 1 to 50%, more preferably 10 to 50% in the copolymer. If it is less than 1%, the alkali solubility of the polymer compound may be insufficient. On the contrary, if it exceeds 50%, uneven dissolution may occur and it may be difficult to form a resist pattern. is there.

The average molecular weight of the polymer compound 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 polymer compound is less than 500, it is disadvantageous in forming a resist film having sufficient mechanical strength. Conversely, if the average molecular weight of the polymer compound exceeds 500,000, the solution This is because it becomes difficult to form a resist pattern having good image quality. These compounds are usually a mixture containing components having various molecular weights, but in the present invention, they are effective even at a relatively low molecular weight. For example, 5
Even when it is highly localized in the average molecular weight of 00 to 1000, it is possible to suppress uneven dissolution. And in this case,
Even if many monomers remain in the resin, the solubility characteristics and the dry etching resistance do not deteriorate.

Further, in the alkali developing resist of the present invention, this polymer compound does not contain a hetero atom other than an oxygen atom and a nitrogen atom, in other words, other than a carbon atom and a hydrogen atom, it is selected from an oxygen atom and a nitrogen atom. It is preferable that at least one kind of atom is a constituent element. This is a polymer compound containing a hetero atom other than oxygen atom and nitrogen atom such as sulfur atom,
In addition to its environmental problems, alkali developing resists that use such heteroatom-containing polymer compounds as base resins complicate removal of ashing after forming a resist pattern and being used as an etching mask. This is because

As the resist composition of the alkali developing resist of the present invention, in the case of a positive type resist, an alkali-soluble resin whose main chain can be cleaved by irradiation of radiation, or a compound whose solubility in an alkali solution is increased by irradiation of radiation The resin composition containing is mentioned. On the other hand, in the case of a negative resist, an alkali-soluble resin that can be crosslinked by irradiation with radiation or a resin composition containing a compound whose solubility in an alkali solution decreases by irradiation with radiation is exemplified.

A chemically amplified resist which amplifies a photochemical reaction after exposure by a thermal reaction is effective in forming a resist pattern with high sensitivity. For example, as a positive type chemically amplified resist, an alkali-soluble resin,
Examples thereof include a photosensitive composition containing a dissolution inhibitor such as an acid-decomposable compound capable of inhibiting dissolution in an alkaline solution, and a photo-acid generator that generates an acid upon irradiation with radiation.
More specifically, it can be prepared by selecting an acid-decomposable compound as the above-mentioned alicyclic compound having an acidic substituent introduced therein and blending this compound with an alkali-soluble resin and a photo-acid generator. Further, in the case where the alicyclic compound introduced with the above-mentioned acidic substituent is contained in the polymer, the compound itself or an acid-decomposable one as a copolymerization component is selected, and You may mix | blend a photo-acid generator. Furthermore, the compounds listed here may be blended at the same time.

On the other hand, as a negative chemically amplified resist, a photosensitive resin containing an alkali-soluble resin, a compound which crosslinks this resin in the presence of an acid or whose solubility in an alkaline solution decreases, and a photoacid generator are used. A sexual composition is illustrated. More specifically, it may be prepared by selecting an acid-crosslinking compound as the alicyclic compound having the above-mentioned acidic substituent introduced therein, and mixing an alkali-soluble resin and a photoacid generator to the compound. it can. When the alicyclic compound having the acidic substituent introduced therein is contained in the polymer, an acid crosslinkable compound and a photoacid generator may be added to the polymer. Furthermore, the compounds listed here may be blended at the same time.

In the present invention, in any case, pKa
A polymer compound having an alicyclic structure having an acidic substituent of 7 or more and 11 or less is incorporated as a base resin in a resist for alkali development. Therefore, when this polymer compound is insoluble in an alkali solution before exposure and solubilized after exposure based on a combination with a dissolution inhibitor or a photoacid generator as described above, it becomes a positive resist,
On the contrary, when it is soluble in an alkaline solution before exposure and insoluble after exposure, it becomes a negative type resist.

In the present invention, it is preferable that the respective components are blended so that the amount of the alicyclic structure having the acidic substituent introduced therein is 30% by weight or more based on the solid content of the resist. If it is less than 30% by weight, it becomes difficult to form a resist pattern having good resolution by alkali development, and
This is because the dry etching resistance of the obtained resist pattern tends to decrease.

Further, the positive type chemically amplified resist protects the alkali-soluble group in the resin with an acid-decomposable group having a dissolution inhibiting ability instead of blending a dissolution inhibiting agent, and protects the resin and the photo-acid generator from each other. The photosensitive composition may contain it. Similarly, the negative chemically amplified resist may be a photosensitive composition containing an acid-crosslinkable group-introduced alkali-soluble resin and a photoacid generator.

In this case, specifically, pKa is 7 or more and 11
The following polymerizable compound having an alicyclic structure and a polymerizable double bond introduced with an acidic substituent in the molecule is copolymerized with a vinyl compound having an acid decomposable group or an acid crosslinkable group, It may be used as a polymer compound as a base resin. Here, a compound having an alkali-soluble group may be further copolymerized.

As the vinyl compound as described above,
For example, methyl acrylate, methyl methacrylate,
α-chloroacrylate, cyanoacrylate, trifluoromethyl acrylate, α-methylstyrene, trimethylsilyl methacrylate, trimethylsilyl α-chloroacrylate, trimethylsilylmethyl α-chloroacrylate, maleic anhydride, tetrahydropyranyl methacrylate, tetrahydropyranyl α-chloroacrylate , T-butyl methacrylate, t-butyl α-
Examples thereof include chloroacrylate, butadiene, glycidyl methacrylate, isobornyl methacrylate, menthyl methacrylate, norbornyl methacrylate, adamantyl methacrylate and allyl methacrylate. Among these, the derivative of acrylic acid represented by the following general formula is particularly preferable.

[0038]

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In the above general formula (4), R ⁷ is a hydrogen atom or a monovalent organic group, and R ⁸ , R ⁹ and R ¹⁰ may be the same or different, and each is a hydrogen atom or a halogen atom. Represents an alkyl group.

The acid-decomposable group for protecting the alkali-soluble group in the resin in the positive type chemically amplified resist is, for example, isopropyl ester, tetrahydropyranyl ester, tetrahydrofuranyl ester, methoxyethoxymethyl ester or 2-trimethylsilyl. Ethoxymethyl ester, 3-oxocyclohexyl ester, isobornyl ester, trimethylsilyl ester, triethylsilyl ester, isopropyldimethylsilyl ester, di-t-butylmethylsilyl ester, oxazole, 2-alkyl-1,3-oxazoline, 4- Esters such as alkyl-5-oxo-1,3-oxazoline, 5-alkyl-4-oxo-1,3-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, triethylsilyl ether, triisopropylsilyl ether,
Ethers such as dimethyl isopropyl silyl ether, diethyl isopropyl silyl ether, dimethyl sexyl silyl ether, t-butyl dimethyl silyl ether; methylene acetal, ethylidene acetal, 2,
2,2-trichloroethylidene acetal, 2,2,2
-Acetals such as tribromoethylidene acetal and 2,2,2-triiodoethylidene acetal; 1-
Ketals such as t-butyl ethylidene ketal, isopropylidene ketal (acetonide), cyclopentylidene ketal, cyclohexylidene ketal, cycloheptylidene ketal; methoxymethylene acetal, ethoxymethylene acetal, dimethoxymethylene orthoester, 1-methoxyethylidene Orthoester, 1
Cyclic orthoesters such as -ethoxyethylidene orthoester, 1,2-dimethoxyethylidene orthoester, 1-N, N-dimethylaminoethylidene orthoester, 2-oxacyclopentylidene orthoester; trimethylsilyl ketene acetal, triethylsilyl ketene Silyl ketene acetals such as 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 and 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 Acyclic acetals or ketals such as -2,2,2-triiodoethyl ketal, diacetyl acetal, 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-
Cyclic acetals or ketals such as 1,3-dioxolane; cyanohydrins such as O-trimethylsilyl cyanohydrin, O-1-ethoxyethyl cyanohydrin, O-tetrahydropyranyl cyanohydrin and the like can be mentioned.

In the present invention, among these acid-decomposable groups, t-butyl methacrylate, ethoxyethyl methacrylate, 3-oxocyclohexyl methacrylate, t-butyl-3-naphthyl-2-propenoate,
T-Butyl esters such as isobornyl methacrylate, trimethylsilyl methacrylate, tetrahydropyranyl methacrylate; trimethylsilyl ester; tetrahydropyranyl ester are preferred because they are easily decomposed by acid. Further, acrylate may be used instead of the methacrylate exemplified here.

Further, when the structural unit represented by the following general formula (5) is contained as the acid-decomposable compound, the effect of promoting the solubility of the exposed area and the structure of the present invention are obtained in addition to the appropriate hydrolyzability. It is desirable because it contains it.

[0043]

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Here, R ¹¹ , R ¹² and R ^{13 each} represent an alkyl group, and at least one of R ¹¹ , R ¹² and R ¹³ is an alicyclic group. Further, R ¹² and R ¹³ may partially bond to form a cyclic compound, and the bond to R ¹¹ may be a double bond. This is because this double bond is exposed to short wavelength ultraviolet light and is converted into a single bond as a result.

When the compound as described above is used by mixing with the alkali-soluble accelerator, it is preferably set within the range of 5 to 60%, more preferably 10 to 40% in the polymer. This is because if it is less than 5%, it is difficult to exhibit a sufficient dissolution accelerating property, and if it exceeds 40%, it becomes difficult to form a resist pattern having good resolution, and the coating property is also deteriorated.

When the above-mentioned copolymer is used as the base resin in the present invention, the copolymerization ratio of components such as a vinyl compound having an acid-decomposable group is set to 10 in the copolymer.
It is preferable to set in the range of -80%, and more preferably 15-70%. This is because if it is less than 10%, it is difficult to exert a sufficient dissolution inhibiting ability, and if it exceeds 80 mol%, it becomes difficult to form a resist pattern having good resolution.

In the present invention, when a polymer containing an alicyclic monomer compound into which an acidic substituent having a pKa of 7 or more and 11 or less in an aqueous solution at 25 ° C. is introduced is simply used as an alkali-soluble resin. Also, a polymerizable compound having such an alicyclic structure having an acidic substituent and a polymerizable double bond in the molecule is copolymerized with acrylic acid represented by the general formula (4), I don't care. Further, here, in acrylic acid, R ⁷ in the above general formula (4) is used.
Any organic group may be introduced to adjust the alkali solubility of the polymer compound. However, the copolymerization ratio of such an acrylic acid derivative is 1 to 70%, more preferably 1 to 5% in the copolymer in consideration of formation of a resist pattern having good resolution.
It is desired to be set within the range of 0%.

On the other hand, the above-mentioned dissolution inhibitor used in the present invention has sufficient dissolution inhibiting ability in an alkaline solution, and the product decomposed by an acid is-(C = O) in an alkaline solution. O-, -OS (= O)
Examples thereof include acid-decomposable compounds capable of forming _2- or -O-. Specifically, the phenolic compound is t-butoxycarbonyl ether, tetrahydropyranyl ether,
3-bromotetrahydropyranyl ether, 1-methoxycyclohexyl ether, 4-methoxytetrahydropyranyl 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, triethylsilyl ether, triisopropylsilyl ether, dimethylisopropyl Examples thereof include compounds modified with silyl ether, diethyl isopropyl silyl ether, dimethylthexyl silyl ether, t-butyl dimethyl silyl ether, and Meldrum's acid derivatives. Of these, compounds in which the hydroxyl group of a phenolic compound is protected with a t-butoxycarbonyl group, a t-butoxycarbonylmethyl group, a trimethylsilyl group, a t-butyldimethylsilyl group, or a tetrahydropyranyl group; naphthaldehyde with Meldrum's acid Compounds formed by addition; Compounds formed by adding Meldrum's acid to a carbonyl compound having an alicyclic structure 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-
It may be alkyl-4-oxo-1,3-dioxolane or the like. Further, the following compounds can also be used.

[0050]

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[0051]

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[0052]

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[0053]

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[0054]

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[0055]

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In the formula, t-Boc is-(C = O) O-C
(CH ₃ ) ₃ is shown.

[0057]

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[0058]

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[0059]

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[0060]

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[0061]

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In the present invention, among these dissolution inhibitors, conjugated polycyclic aromatic compounds are preferable 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 linked by forming a skeleton in which alternate unsaturated bonds are arranged. is there. That is, in such compounds, the light absorption band is shifted to the long wavelength region 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 possible to obtain a resist for alkali development which has excellent transparency to light and has sufficient heat resistance.

Specifically, naphthalene ring, anthracene ring, phenanthrene ring, pyrene ring, naphthacene ring, chrysene ring, 3,4-benzophenanthrene ring, perylene ring, pentacene ring, picene ring, pyrrole ring, benzofuran ring, benzo Thiophene ring, indole ring, benzoxazole ring, benzothiazole ring, indazole ring, chromene ring, quinoline ginnoline ring, phthalazine ring, quinazoline ring, dibenzofuran ring, carbazole ring, acridine ring, phenanthridine ring, phenanthroline ring, phenazine ring A compound having a ring, a thianthrene ring, an indolizine ring, a naphthyridine ring, a purine ring, a pteridine ring, a fluorene ring, and the like. Among them, a condensed polycyclic compound having a naphthalene ring, an anthracene ring, a phenanthrene ring, or the like has a wavelength of 193. It is superior in transparency to light of m. Therefore, hydroxyl groups of these polyhydroxy compounds having a condensed aromatic ring structure are protected with a t-butyl carbonate group, a t-butyl ester group, a tetrahydropyranyl ether group, an acetal group, a trimethylsilyl ether group, or a condensed aromatic ring thereof. A condensation compound of a structured aldehyde compound and Meldrum's acid is particularly preferable as the dissolution inhibitor.

In the present invention, a naphthol novolac compound having a molecular weight of about 200 to 2,000 can be preferably used as a dissolution inhibitor in addition to the above-mentioned acid-decomposable compound. Furthermore, when the alkali-soluble group in the base resin is protected by an acid-decomposable group having a dissolution inhibiting ability in an alkaline solution, this naphthol novolak compound may be added alone as a dissolution inhibiting agent. In addition, such a naphthol novolak compound can be easily obtained by condensing naphthol or a derivative thereof with a carbonyl compound.

In the alkali developing resist of the present invention, the amount of the dissolution inhibitor blended is set within the range of 3 to 50 mol%, more preferably 10 to 40 mol% based on the number of moles of the base resin corresponding to the monomers. It is preferable. This is because if the content of the dissolution inhibitor is less than 3 mol%, it becomes difficult to form a resist pattern with good resolution, and conversely 50 mol%.
If it exceeds, the mechanical strength of the resist film may be impaired when it is formed, and the dissolution rate when the resist film in the exposed area is dissolved or removed with an alkaline solution tends to be significantly reduced. is there.

Further, as the photo-acid generator blended when the alkali developing resist of the present invention is a chemically amplified resist, for example, aryl onium salts, naphthoquinone diazide compounds, diazonium salts, sulfonate compounds, sulfonium compounds, Sulfamide compounds, iodonium compounds, sulfonyldiazomethane compounds, etc. can be used. Specific examples of these compounds include triphenylsulfonium triflate, diphenyliodonium triflate, 2,3,4,4-tetrahydroxybenzophenone-4-naphthoquinonediazide sulfonate and 4-N-phenylamino-2-. Methoxyphenyldiazonium sulfate, 4-N-phenylamino-2-methoxyphenyldiazonium p-
Ethylphenyl sulfate, 4-N-phenylamino-2-methoxyphenyldiazonium 2-naphthylsulfate, 4-N-phenylamino-2-methoxyphenyldiazoniumphenylsulfate, 2,5-diethoxy-4-N-4 '-Methoxyphenylcarbonylphenyldiazonium 3-carboxy-4-hydroxyphenylsulfate, 2-methoxy-4-N-phenylphenyldiazonium 3-carboxy-4-hydroxyphenylsulfate, diphenylsulfonylmethane, diphenylsulfonyldiazomethane, diphenyldisulfone , Α-methylbenzointosylate, pyrogallol trimesylate, benzointosylate, MPI-103 manufactured by Midori Kagaku (CAS. NO. [87709-
41-9]), BDS-105 (CAS.
NO. [145612-66-4]), N manufactured by Midori Kagaku
DS-103 (CAS. NO. [11098-97-
0]), Midori Kagaku MDS-203 (CAS. NO.
[127855-15-5]), Midori Kagaku Pyrogall
ol tritosylate (CAS. NO. [20032-64-
8]), Midori Kagaku DTS-102 (CAS. NO.
[75482-18-7]), Midori Kagaku DTS-1
03 (CAS. NO. [71449-78-0]), MDS-103 manufactured by Midori Kagaku (CAS. NO. [1272]).
79-74-7]), MDS-105 (C
AS. NO. [116808-67-4]), MDS-205 manufactured by Midori Kagaku (CAS. NO. [81416-3]).
7-7]), Midori Kagaku BMS-105 (CAS.N
O. [149934-68-9]), TM manufactured by Midori Kagaku
S-105 (CAS. NO. [127820-38-
6]), Midori Kagaku NB-101 (CAS. NO.
[20444-09-1]), Midori Kagaku NB-20
1 (CAS. NO. [4450-68-4]), and Midori Kagaku's DNB-101 (CAS. NO. [114719]).
-51-6]), Midori Kagaku's DNB-102 (CA
S. NO. [131509-55-2]) and Midori Kagaku's DNB-103 (CAS. NO. [132828-8-3]).
5-2]), Midori Kagaku's DNB-104 (CAS.N
O. [132898-36-3]), Midori Chemical DN
B-105 (CAS. NO. [132828-37-
4]), Midori Kagaku DAM-101 (CAS. NO.
[1886-74-4]), DAM-10 manufactured by Midori Kagaku
2 (CAS. NO. [28343-24-0]) and DAM-103 manufactured by Midori Kagaku (CAS. NO. [14159]).
-45-6]), Midori Kagaku DAM-104 (CA
S. NO. [130290-80-1], CAS. N
O. [130290-82-3]), Midori Chemical DA
M-201 (CAS. NO. [28322-50-
1]), Midori Kagaku CMS-105, Midori Kagaku D
AM-301 (CAS No. [138529-81-
4]), Midori Kagaku SI-105 (CAS.
[34694-40-7]), Midori Kagaku NDI-1
05 (CAS. No. [133710-62-0]),
Midori Kagaku EPI-105 (CAS No. [135
133-12-9]) and the like. Further, the following compounds can also be used.

[0067]

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[0068]

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[0069]

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[0070]

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[0071]

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[0072]

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[0073]

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[0074]

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[0075]

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[0076]

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[0077]

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[0078]

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[0079]

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[0080]

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(Wherein C ¹ and C ² form a single bond or a double bond, R ¹⁴ is a hydrogen atom, a fluorine atom, an alkyl group or an aryl group which may be substituted with a fluorine atom, R ¹⁵ R ¹⁶ may be the same or different from each other and each represents a monovalent organic group, and R ¹⁵ and R ¹⁶ may be bonded to each other to form a ring structure.)

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In the formula, Z represents an alkyl group.

[0083]

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Regarding the photo-acid generator as described above, the conjugated polycyclic aromatic compound such as an arylonium salt having a naphthalene skeleton or a dibenzothiophene skeleton, a sulfonate compound, a sulfonyl compound or a sulfamide compound is transparent to short wavelength light. It is advantageous in terms of heat resistance and heat resistance. Specifically, a naphthalene ring, a pentalene ring, an indene ring, an azulene ring, a heptalene ring, a biphenylene ring, an as-indacene ring, an s-indacene ring, an acenaphthylene ring, a fluorene ring, a phenalene ring, a phenanthrene ring in which a hydroxyl group is introduced, Anthracene ring, fluoranthene ring, acephenanthrylene ring, aceanthrylene ring, triphenylene ring, pyrene ring, chrysene ring, naphthacene ring, preyaden ring, picene ring, perylene ring, pentaphene ring, pentacene ring, tetraphenylene ring, hexaphene Ring, hexacene ring, rubicene ring, coronene ring,
Trinaphthylene ring, heptaphene ring, heptacene ring, pyrantrene ring, ovalen ring, dibenzophenanthrene ring, benz [a] anthracene ring, dibenzo [a, j] anthracene ring, indeno [1,2-a] indene ring, anthra [2, 1
-a] naphthacene ring, 1H- benzo [a] cyclopento [j] sulfonyl or sulfonate compound having anthracene ring; naphthalene ring, pentalene ring, indene ring,
Azulene ring, heptalene ring, biphenylene ring, as-indacene ring, s-indacene ring, acenaphthylene ring, fluorene ring, phenalene ring, phenanthrene ring, anthracene ring, fluoranthene ring, acephenanthrylene ring, aceanthrylene ring, triphenylene ring , Pyrene ring, chrysene ring, naphthacene ring, pleiadene ring, picene ring, perylene ring, pentaphene ring, pentacene ring, tetraphenylene ring, hexaphene ring, hexacene ring, rubicene ring, coronene ring, trinaphthylene ring, heptafene ring,
Heptacene ring, pyranthrene ring, ovalen ring, dibenzophenanthrene ring, benz [a] anthracene ring, dibenzo [a, j] anthracene ring, indeno [1,2-a] indene ring, anthra [2,1-a] naphthacene ring , 1H-benzo [a] cyclopento [j] 4-quinonediazide compound having anthracene ring; naphthalene ring, pentalene ring, indene ring,
Azulene ring, heptalene ring, biphenylene ring, as-indacene ring, s-indacene ring, acenaphthylene ring, fluorene ring, phenalene ring, phenanthrene ring, anthracene ring, fluoranthene ring, acephenanthrylene ring, aceanthrylene ring, triphenylene ring , Pyrene ring, chrysene ring, naphthacene ring, pleiadene ring, picene ring, perylene ring, pentaphene ring, pentacene ring, tetraphenylene ring, hexaphene ring, hexacene ring, rubicene ring, coronene ring, trinaphthylene ring, heptaphene ring,
Heptacene ring, pyranthrene ring, ovalen ring, dibenzophenanthrene ring, benz [a] anthracene ring, dibenzo [a, j] anthracene ring, indeno [1,2-a] indene ring, anthra [2,1-a] naphthacene ring , 1H-benzo [a] cyclopento [j] anthracene and a salt of sulfonium or iodonium triflate having a side chain. In particular, a sulfonyl or sulfonate compound having a naphthalene ring or an anthracene ring;
A 4-quinonediazide compound having a naphthalene ring or anthracene ring in which a hydroxyl group is introduced; a salt with a triflate of sulfonium or iodonium having a naphthalene ring or anthracene ring as a side chain is preferable.

Among such photo-acid generators, triphenylsulfonium triflate, diphenyliodonium triflate, trinaphthyl sulfonium triflate, dinaphthyl iodonium triflate, dinaphthyl sulfonyl methane and green are used in the present invention. Chemical NA
T-105 (CAS No. [137867-61-
9]), Midori Kagaku NAT-103 (CAS No.
[131582-00-8]), NAI- manufactured by Midori Kagaku
105 (CAS. No. [85342-62-7]),
TAZ-106 manufactured by Midori Kagaku (CAS No. [694]
32-40-2]), Midori Kagaku NDS-105, Midori Kagaku PI-105 (CAS No. [41580]
-58-9]), s-alkylated dibenzothiophene triflate, s-fluoroalkylated dibenzothiophene triflate (manufactured by Daikin) and the like are preferably used. Among these, triphenylsulfonium triflate, trinaphthylsulfonium triflate,
Dinaphthyl iodonium triflate, dinaphthyl sulfonyl methane, Midori Kagaku NAT-105 (CA
S. No. [137867-61-9]), Midori Kagaku NDI-105 (CAS No. [133710-6]
2-0]), Midori Kagaku NAI-105 (CAS.N
o. [85342-62-7]) and the like are particularly preferable.

In the alkali developing resist of the present invention, the photoacid generator is preferably incorporated in an amount of 0.001 to 50 mol%, more preferably 0.
01-40 mol%, particularly preferably 0.1-20 mol%
Is within the range. That is, if it is less than 0.001 mol%, it is difficult to form a resist pattern with high sensitivity, and if it exceeds 50 mol%, when a resist film is formed, its mechanical strength may be impaired.

On the other hand, when a negative chemically amplified resist is prepared, as described above, for example, a cross-linking agent that cross-links a polymer compound as a base resin in the presence of an acid may be added instead of the dissolution inhibitor. Examples of the cross-linking agent here include vinyl compounds having an epoxy group in a side chain, acrylic acid represented by the above general formula and its derivatives, methylol-substituted triazines, melamine compounds such as naphthyridine and pteridine compounds. Etc. can be used.
Instead of blending such a cross-linking agent, a vinyl group, an allyl group or the like may be introduced into the polymer compound as an acid cross-linking group.

Further, in the compound represented by the general formula (5), when R ¹¹ is a double bond, it has some photoreactivity and can be used as it is as a sensitizer. For example, when the above compound is mixed with a copolymer with acrylic acid, it can be used as it is as a positive type deep UV resist. On the other hand, when it is mixed with a phenolic resin such as naphthol novolac, it can be used as it is as a negative type deep UV resist.

The alkali developing resist of the present invention is prepared by dissolving the above-mentioned compound, dissolution inhibitor, cross-linking agent, photo-acid generator and the like, and, if necessary, other alkali-soluble resin in an organic solvent. It is usually prepared as a varnish. However, in the resist for alkaline development of the present invention, in addition to these components, other polymers such as epoxy resin, polymethyl methacrylate, polymethyl acrylate, polymethyl methacrylate, propylene oxide-ethylene oxide copolymer, polystyrene, and environmental resistance An amine compound for improvement, a basic compound such as a pyridine derivative, a surfactant for modifying the 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 cellolube, methyl cellosolve acetate, ethyl cellosolve acetate and butyl cellosolve acetate, ethyl acetate and butyl acetate. , Isoamyl acetate, ester solvents such as γ-butyrolactone, glycol solvents such as propylene glycol monomethyl ether acetate, nitrogen-containing solvents such as dimethyl sulfoxide, hexamethylphosphoric triamide dimethylformamide and N-methylpyrrolidone, and solubility To improve these, dimethyl sulfoxide, dimethylformaldehyde, N
-A mixed solvent containing methylpyrrolidinone or the like can be used. In addition, propionic acid derivatives such as methyl methylpropionate, lactate esters such as ethyl lactate and PG
MEA (Propylene glycol monoethyl acetate)
Etc. have low toxicity and can be preferably used. In addition, in this invention, such a solvent can be used individually or in mixture of 2 or more types, and also isopropyl alcohol, ethyl alcohol, methyl alcohol, butyl alcohol, n-butyl alcohol, s-butyl alcohol, t-butyl. Aliphatic alcohols such as alcohol and isobutyl alcohol, and aromatic solvents such as toluene and xylene may be contained.

Next, the pattern forming method using the alkali developing resist of the present invention will be explained by taking the case of a positive chemically amplified resist as an example. First, after applying a resist varnish dissolved in an organic solvent as described above on a predetermined substrate by a spin coating method or a dipping method,
A resist film is formed by drying at 150 ° C. or lower, preferably 70 to 120 ° C. 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, GaA.
III-V compound semiconductor wafer such as s, AlGaAs, chromium or chromium oxide vapor deposition mask, aluminum vapor deposition substrate, IBPSG coated substrate, PSG coated substrate, SOG
A coated substrate, a carbon film sputtered substrate, or the like can be used.

Next, 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 alkali developing resist of the present invention has excellent transparency to light in a wide wavelength range including short-wavelength light, and therefore, actinic rays used herein include ultraviolet rays, X-rays, and low pressure. Mercury lamp light i line, h line, g line, xenon lamp light, KrF
It is possible to use deep UV light such as ArF excimer laser light, synchrotron orbital radiation (SOR), electron beam (EB), γ-ray, and ion beam.

Subsequently, the resist film is appropriately subjected to a baking treatment at about 170 ° C. or lower by heating on a hot plate or in an oven or by irradiating infrared rays. In particular, when the alkali developing resist of the present invention is a chemically amplified resist, it is preferable to perform a baking treatment. Thereafter, the resist film is developed by an immersion method, a spray method, or the like, and the exposed or unexposed portion of the resist film is selectively dissolved and removed in an alkaline solution to form a desired pattern. At this time, specific examples of the alkali solution include an aqueous solution of an organic alkali such as an aqueous solution of tetramethylammonium hydroxide and choline, an aqueous solution of an inorganic alkali such as potassium hydroxide and sodium hydroxide, and an alcohol and a surfactant added thereto. Solution. 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 resist for alkali development of the present invention has extremely good resolution. For example, by dry etching using this resist pattern as an etching mask, a quarter micron is exposed on an exposed substrate or the like. It is possible to faithfully transfer an extremely fine pattern. The resist pattern obtained here has high dry etching resistance because one carbon-carbon bond is broken in the alicyclic structure in the polymer compound as the base resin, but the other bond remains. 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.

[0095]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail with reference to specific examples of the present invention.

(Synthesis of polymer compound) pKa is 7 or more 1
N-trimethylsilyloxytetrahydrophthalimide (NTS) as a polymerizable compound having an alicyclic structure having 1 or less acidic substituents and a polymerizable double bond in the molecule.
THFI) 0.7 mol, and t-butyl methacrylate (t-BM) which is a polymerizable compound having an acid-decomposable group.
0.3 mol of 200 g of tetrahydrofuran (THF)
Was mixed. Subsequently, 2 g of azoisobutyl nitrile (AIBN) was added to this mixed solution, and the mixture was heated at 70 ° C. for 36 hours to be reacted, and the reaction solution was added dropwise to hexane to give a broad distribution and an average molecular weight of about 700 NSTTH.
An FI-t-BM copolymer was obtained. The ratio of NTSTFI and t-BM in the obtained copolymer was 50:50 as a result of NMR measurement.

0.7 mol of N-trimethylsilyloxytetrahydrophthalimide (NTSTFI) as a polymerizable compound having an alicyclic structure in which an acidic substituent having a pKa of 7 to 11 is introduced and a polymerizable double bond in the molecule,
And 0.3 mol of t-butyl methacrylate (t-BM), which is a polymerizable compound having an acid-decomposable group, were mixed with 150 g of tetrahydrofuran (THF). Subsequently, a Ziegler-Natta catalyst (titanium chloride-alkylaluminum catalyst) was added to this mixed solution and heated at 70 ° C. for 9 hours. After quenching the reaction solution, the reaction solution was added dropwise to a hexane solvent to give an average molecular weight of about 20. 1,000 NTSTFI-t-BM7
A 0:30 copolymer was synthesized.

Further, various polymer compounds were synthesized as follows.

NTSTFI was converted to 6-methyl-6,8,
9,10-Tetrahydro-1,4-methano-naphthalene-5,7dione (MTCDO), 2-cyclohexa-2
-Enyl-cyclohexane-1,3dione (CECD
O) was used, and the Ziegler-Natta catalyst was used in exactly the same manner as described above to obtain MTCDO-t-BM7.
0:30 copolymer, and CECDO-t-BM70:
30 copolymers were synthesized.

Further, NTSNDI-t was prepared in the same manner as described above, except that NTSTFI was changed to N-trimethylsilyloxy 5-norbornene-2,3-dicarboximide (NTSNDI).
-BM was synthesized. NTSTFI-t-BM and NTS
NDI-t-BM was further hydrolyzed by detrimethylsilylation with a 5 wt% methanol solution of acetic acid to obtain HTFI-t-BM 70:30 copolymer and HND, respectively.
An It-BM 70:30 copolymer was obtained.

Furthermore, 0.7 mol of NTSTFI and 0.3 mol of methacrylic acid (MA) as a polymerizable compound having an alkali-soluble group were mixed with 200 g of THF. After adding 2 g of AIBN to this mixed solution,
The mixture was heated for 9 hours for reaction, and the reaction solution was added dropwise to a hexane solvent to synthesize a THFI-MA copolymer having a broad distribution and an average molecular weight of about 1000. NMR
The ratio of NTSTFI-MA determined in (4) was 50:50.

4 Cyclopentene 1,3 dione (0.3 mol) and 2-adamantanone (0.3 mol) were subjected to cyclocondensation in tetrahydrofuran under an amine catalyst (DCU), and the reaction solution was concentrated and recrystallized with absolute ethanol. Then, a monomer (ADMCP) represented by the following chemical formula was obtained.

[0103]

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To 0.2 mol of this monomer, 0.1 mol of acrylic acid and tert-butyl methacrylate were added as T.
It was mixed with 70 g of HF. AIBN 0.0
Add 3 mol and polymerize at 60 ° C for 18 hours to obtain ADMCP
A copolymer of -MA-t-BM was obtained. The molecular weight of the obtained polymer was 5,600.

N-adamantyl maleimide (NAMI)
0.1 mol of acrylic acid and tert to 0.2 mol
-Butyl methacrylate was mixed with 80 g of THF.
To this mixed solution, add 0.03 mol of AIBN and
Polymerization was performed for 0 hours to obtain a copolymer of NAMI-MA-t-BM. The obtained copolymer had a molecular weight of 7,500.

After heating acrolein and Meldrum's acid in pyridine at 50 ° C. for 8 hours and dropping the product into water,
Recrystallization from ethanol gave a monomer (MALDM). NAMI 0.1 mol was mixed with THF 40g with respect to this monomer 0.1 mol. AIBN is added to this mixture.
Add 0.02 mol and polymerize at 60 ℃ for 24 hours.
A DM-NAMI copolymer was obtained. The obtained copolymer had a molecular weight of 3,200.

0.1 mol of deoxycholic acid and 0.1 mol of malonyl dichloride were dissolved in 0.3 mol of pyridine and reacted. The obtained reaction product was washed with water, dropped into ether and filtered to obtain a polymer (DECA-MAL). The molecular weight of this polymer was 1,800.

For 0.1 mol of menthyl acrylate,
0.1 mol of acrylic acid and tert-butyl methacrylate were mixed in 70 g of THF. Add AIB to this mixture
Add 0.03 mol of N, polymerize at 50 ° C. for 35 hours, and add ME
A copolymer of N-MA-t-BM was obtained. The obtained copolymer had a molecular weight of 11,000.

The chemical formula of the polymer compound synthesized here is shown below together with the weight average molecular weight thereof.

[0110]

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[0111]

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[0112]

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(Synthesis of alicyclic compound) 5- (2-adamantylidene) 2,2-dimethyl 1,3-dioxane 4,6
-The dione (ADDD) used the Aldrich reagent as it was.

0.1 mol of ADDD was dissolved in THF,
0.1 mol of separately prepared ethylmagnesium bromide was allowed to act under a copper chloride catalyst. Then, it was reprecipitated with a reflux-water solvent, and 5- (2-ethyladamantyl) 2,2-dimethyl 1,3-dioxane 4,6-dione (ADDM) was synthesized and used.

0.1 mol camphor and 0.1% Meldrum's acid.
1 mol was condensed in pyridine to obtain a reaction product. The reaction product was dropped into water to synthesize an alicyclic compound (CDDD) represented by the following chemical formula.

[0116]

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In the same manner, 0.1 mol of adamantanone was reacted with di-tert-butylmalonic acid to synthesize ADDT represented by the following chemical formula.

[0118]

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0.02 mol of di-tertbutyl malonate was slowly added dropwise to 0.02 mol of NaH dispersed in THF at 0 ° C. or lower. Then dissolved in THF 0.0
2 mol of 1-adamantyl bromomethyl ketone was slowly added dropwise at 0 ° C or lower, and the mixture was stirred for 3 hours. The reaction product was poured into water and extracted with hexane to synthesize ADMTB represented by the following chemical formula.

[0120]

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A solution obtained by dissolving 0.1 mol of 1,1 '' bi-2-naphthol in THF was added to a sufficient amount of di-t-butyl dicarbonate in the presence of 0.22 mol of sodium hydride. The ester was stirred at room temperature for 4 hours. Then, the reaction solution was poured into water and the generated precipitate was filtered off to obtain t-butoxycarbonylated 1,1 ″ bi-2-naphthol (tBo).
cBN) was synthesized.

Similarly, 0.1 mol of quinalyzanine was added to THF.
The solution obtained by dissolving in
In the presence of a mole, it was stirred with sufficient amount of di-t-butyl dicarbonate at room temperature for 6 hours. Then, the reaction solution was poured into water and the generated precipitate was filtered off to synthesize t-butoxycarbonylated quinalizanin (tBocQ).

Further, 0.1 mol naphthol equivalent of β-
The solution obtained by dissolving naphthol novolac in THF was stirred with a sufficient amount of di-t-butyl dicarbonate in the presence of 0.1 mol of sodium hydride at room temperature for 6 hours.
Then, the reaction solution was mixed with water and extracted with ethyl acetate to synthesize t-butoxycarbonylated naphthol novolak (tBocNN) having a molecular weight of 3,000.

Note that tBocBN and tBocQ here
The introduction rate of t-butoxycarbonyl in and tBocNN was 100 mol% of all hydroxyl groups.

On the other hand, 0.1 mol of pamoic acid was dissolved in a dimethylacetamide solvent, and the mixture was boiled and stirred for 16 hours while blowing 2-butene in the presence of a catalytic amount of trifluoromethanesulfonic acid. Water was added to the obtained reaction product and extracted with toluene, and then toluene was distilled off to synthesize t-butyl pamoic acid (PAtB). At this time, the introduction rate of t-butyl into the carboxyl group was 100 mol%.

Further, 0.1 mol of 1,5-dihydroxynaphthalene is reacted with t-butyl bromoacetate in a sufficient amount in the presence of potassium carbonate and potassium iodide as catalysts, and then extracted with ethyl acetate. Was synthesized t-butylated naphthol acetate (AtBN).

Further, 0.2 mol per 0.5 mol of α-naphthol
A 5 molar equivalent formaldehyde aqueous solution was mixed and heated until α-naphthol was dissolved, followed by stirring for 3 hours to cause reaction. Next, the obtained reaction product was depressurized to 2 mmHg and then gradually heated to 200 ° C. to remove components which were not sufficiently reacted, and α-naphthol novolak resin (αNN-1) having an average molecular weight of 700 was synthesized.

Further, α-naphthol novolak resins (αNN-2) and (αNN-3) having average molecular weights of 1,000 and 500, respectively, were prepared in the same manner as above except that formaldehyde was changed to butyral and glyoxylic acid.
Was synthesized.

(Preparation of Resist and Formation of Resist Pattern) The polymer compound, the dissolution inhibitor, and the photoacid generator synthesized as described above were dissolved in cyclohexanone according to the formulations shown in Tables 1 to 3 to prepare Example 1. Varnishes of ~ 29 resists were prepared. Here, as the photo-acid generator,
Midori Kagaku TPS-105, NAT-105, NDS
-105, NDI-105 and NAI-105 were used.

On the other hand, as polymer compounds, adamantyl methacrylate (AMM), t-BM and MA 35: 4.
Using a 0:25 copolymer, NAT- as a photoacid generator
A resist varnish of Comparative Example containing 105 was also prepared.

[0131]

[Table 1]

[0132]

[Table 2]

[0133]

[Table 3]

Next, each of these resist varnishes was spin-coated on a silicon wafer to form a resist film having a thickness of 0.6 μm, and a stepper with NA 0.54 using ArF excimer laser light having a wavelength of 193 nm as a light source was used. The surface of the resist film was exposed using a predetermined pattern light. Subsequently, after baking at 110 ° C. for 2 minutes, an aqueous solution of tetramethylammonium hydroxide (TMA)
H) or an exposed portion of the resist film was selectively dissolved and removed with a mixed solution of TMAH and isopropyl alcohol to form a positive resist pattern. The developer concentration, sensitivity and resolution at this time are shown in Tables 4 and 5.

[0135]

[Table 4]

[0136]

[Table 5]

As shown in Tables 4 and 5, Examples 1 to
In each of the 29 resists, a resist pattern having a high sensitivity and a good resolution was formed.
It can be seen that both transparency to 3 nm light and alkali developability are excellent. On the other hand, in the resist of the comparative example, TMAH
When a developing solution containing 30 wt% of isopropyl alcohol was used, a resist pattern with good resolution was formed, but with TMAH alone, the alkali developability was insufficient, resulting in a resolution of about 0.5 μm. Low. Moreover, the uniformity of the obtained resist pattern is inferior,
Moreover, peeling of the resist pattern and film cracks were also found.

Further, regarding these resists, CF
₄ Plasma etching rate was measured to evaluate its dry etching resistance. As a result, the etching rate of the resist using the novolac resin as the base resin is 1.0
And the etching rate of the resist of the comparative example was 1.
2, the etching rates of the resists of Examples 1 to 29 were 1.0 to 1.2, and it was confirmed that all of them have high dry etching resistance.

[0139]

As described above in detail, according to the present invention, it is possible to form a resist pattern having excellent transparency to short wavelength light, high dry etching resistance, and good resolution by alkali development. It is possible to realize a resist for alkali development that can be performed.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical location H01L 21/027 H01L 21/30 502R (72) Inventor Naomi Shinoda Komukai Toshiba, Kawasaki City, Kanagawa Prefecture Town No. 1 Incorporated company Toshiba Research & Development Center (72) Inventor Shin Nakase Komukai Toshiba Town No. 1 Komachi, Kawasaki City, Kanagawa Prefecture Incorporated company Toshiba Research & Development Center (72) Inventor Takeshi Okino Kawasaki City Kanagawa Prefecture Komukai-Toshiba-cho 1-ku, Toshiba Research & Development Center

Claims (12)

[Claims] 1. A pKa in an aqueous solution at 25 ° C. of 7 or more 1
An alkali developing resist containing an alicyclic compound having 1 or less acidic substituents introduced therein. 2. The alkali developing resist according to claim 1, wherein the alicyclic compound is an acid-decomposable compound, and an alkali-soluble resin and a photo-acid generator are blended with the compound. 3. An alkali developing resist containing a compound containing at least one structural unit represented by the following general formulas 1 to 3. Embedded image (Here, at least one of R ¹ to R ³ is a monovalent organic group containing an alicyclic group, and the other is an alkyl group. R ¹ and R ² are partially bonded to form a cyclic compound. R ³ may be a hydroxyl group.) (Wherein at least one of R ¹ , R ² , R ⁴ and R ⁵
One is a monovalent organic group containing an alicyclic group, and the other is a hydrogen atom or an alkyl group. Also, R ¹ and R ² are
It may be partially bonded to form a cyclic compound. Also,
R ⁴ and R ⁵ may partially combine to form a cyclic compound. ) (Wherein at least one of R ¹ , R ² and R ⁶ is
It is a monovalent organic group containing an alicyclic group, and the others represent a hydrogen atom or an alkyl group. Further, R ¹ and R ² may be partially bonded to each other to form a cyclic compound. ) 4. The pKa of the compound represented by any one of formulas 1 to 3 in an aqueous solution at 25 ° C. is 7 or more and 1 or more.
The alkali developing resist according to claim 3, which is 1 or less. 5. The alkali developing resist according to claim 3, which contains a dissolution inhibitor. 6. The resist for alkali development according to claim 3, which contains an alkali-soluble resin having an alicyclic structure and a photoacid generator. 7. The resist for alkali development according to claim 6, which contains a dissolution inhibitor. 8. The pKa in an aqueous solution at 25 ° C. is 7 or more 1
An alkali developing resist containing a polymer containing an alicyclic monomer compound having 1 or less acidic substituents introduced. 9. A pKa in an aqueous solution at 25 ° C. of 7 or more 1
A polymer containing an alicyclic monomer compound in which one or less acidic substituents are introduced, and the alicyclic monomer compound is a compound represented by any one of the following general formulas 1 to 3. A resist for alkali development. Embedded image (Here, at least one of R ¹ to R ³ is a monovalent organic group containing an alicyclic group, and the other is an alkyl group. R ¹ and R ² are partially bonded to form a cyclic compound. May be formed and R ³ may be a hydroxyl group.) (Wherein at least one of R ¹ , R ² , R ⁴ and R ⁵
One is a monovalent organic group containing an alicyclic group, and the other is a hydrogen atom or an alkyl group. Further, R ¹ and R ² may be partially bonded to each other to form a cyclic compound. Further, R ⁴ and R ⁵ may be partially bonded to each other to form a cyclic compound. ) (Wherein at least one of R ¹ , R ² and R ⁶ is
It is a monovalent organic group containing an alicyclic group, and the others represent a hydrogen atom or an alkyl group. Further, R ¹ and R ² may be partially bonded to each other to form a cyclic compound. ) 10. The alkali developing resist according to claim 8, wherein the copolymerization component of the polymer is an acid-decomposable monomer compound, and a photo-acid generator is added to the copolymer. 11. The resist for alkali development according to claim 8, wherein the polymer is blended with an acid crosslinkable compound and a photoacid generator. 12. The alkali developing resist according to claim 8, wherein the polymer is a copolymer containing a vinyl compound as a copolymerization component.