JP2000330287A - Resin for resist, resist composition and pattern forming method using same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a resin for a resist excellent in transparency of short- wavelength light, having high dry etching resistance and capable of forming a resist pattern having good adhesion and resolution by alkali development, to obtain a resist composition and to provide a pattern forming method using the resist composition. SOLUTION: The resin for a resist has a structure having a bridged alicycle and at least two oxygen-containing polar groups bonding to the tertiary carbon position of the bridged alicycle. The resist composition contains at least the resin and a photo-acid generating agent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a resist resin, a resist composition, and a pattern forming method.

[0002]

2. Description of the Related Art In the process of manufacturing electronic components such as LSIs, a fine processing technique utilizing photolithography is employed. 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,
A resist pattern is formed by performing processing such as alkali development. Subsequently, the surface of the exposed substrate or the like is dry-etched using the resist pattern as an etching-resistant mask to form fine-width 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 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.

[0005] However, in the case of a resist which has been generally used so far and is made of a resin containing an aromatic compound as a base resin,
As described above, light absorption by the benzene nucleus tends to be large for short-wavelength light. 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.

Against this background, development of a highly transparent resist resin suitable for photolithography using ArF excimer laser light or fifth harmonic light of YAG laser is strongly desired.

In view of the above, a resist containing an alicyclic compound instead of an aromatic compound has recently attracted attention. For example, Japanese Patent Application Laid-Open No. 4-39665 discloses a dry etching resistance and a transparency to short wavelength light. As a good resist, a compound having adamantane, which is a bridged alicyclic compound, was copolymerized with another acrylic compound to impart alkali solubility to the polymer, and a resist pattern was formed by alkali development. Have been.

Further, a resist material having a tricyclodecanyl structure as disclosed in JP-A-7-199467 is known as an alicyclic compound having a 5-membered ring among the bridged alicyclic compounds.

However, when a resist pattern containing these alicyclic compounds is formed by alkali development using an alicyclic structure such as an adamantane skeleton, the alicyclic structure has a very high hydrophobicity. Greatly differ in alkali solubility, and various problems occur.

For example, during the development, the dissolution / removal of a predetermined region of the resist film becomes non-uniform, resulting in a decrease in resolution. On the other hand, a decrease in resolution due to swelling after development of the resist pattern, Even in the region that should remain, partial dissolution occurs, causing cracks and surface roughness. In addition, the alkaline solution often permeates the interface between the resist film and the substrate, and the resist pattern is often stripped. further,
In the polymer, the phase separation between a portion having an alicyclic structure and a group imparting alkali solubility, for example, a carboxylic acid group portion, easily proceeds, and it is difficult to prepare a uniform resist solution, and its coatability is not sufficient.

In order to reduce the hydrophobicity of these alicyclic compounds, it has been known to introduce a polar group such as a COOH group or an OH group into the alicyclic compound (JP-A-10-830).
76, JP-A-7-252324, JP-A-9
It has been known that the solubility of any of these compounds is considerably improved.

However, these alicyclic compounds are
The OOH group or OH group has a structure bonded to a secondary or lower carbon position of the alicyclic ring, and has many side reactions with other substituents in the resist, or has a low glass transition temperature and a high resolution. There has been a problem that the pattern tends to be reduced and the pattern swells after development.

[0013]

Accordingly, the present invention solves such a problem and has excellent transparency to short-wavelength light, high dry etching resistance, and adhesion and resolution by alkali development. An object of the present invention is to provide a resist resin, a resist composition, and a method for forming a pattern, which constitute a resist composition capable of forming a good resist pattern.

[0014]

SUMMARY OF THE INVENTION The present invention relates to a resist resin having a structure having a bridged alicyclic ring and having at least two oxygen-containing polar groups bonded to the tertiary carbon position of the bridged alicyclic ring. is there.

The present invention also comprises a polymer or condensate of a monomer having a bridged alicyclic ring and having a structure in which at least two oxygen-containing polar groups are bonded to the tertiary carbon position of the bridged alicyclic ring. It is a resin for resist.

Further, the present invention provides the resist resin,
A resist composition comprising at least a photoacid generator.

Further, the present invention comprises at least a step of applying the resist composition on a substrate, a step of patternwise exposing the applied resist composition, and a step of developing the exposed resist composition. This is a characteristic pattern forming method.

The operation and effect of the present invention will be described below.

That is, in the present invention, a resin having a structure having a bridged alicyclic ring and having an oxygen-containing polar group at the tertiary carbon position of the bridged alicyclic ring is used as the base resin of the resist composition. It is.

The movement of the oxygen-containing polar group around carbon is restricted as compared with the case where the oxygen-containing polar group is added to the secondary carbon position or the primary carbon position as in the conventional example. For example, when considering a resin having a bridged alicyclic ring in which a hydroxyl group is introduced at the tertiary carbon position, the hydroxyl group has only a rotational degree of freedom and a small molecular motion with respect to the carbon to which the hydroxyl group is bonded. . On the other hand, when a hydroxyl group is introduced into a secondary or lower carbon, there is a degree of freedom not only in rotation but also in a parallel direction, and the molecular motion is large.

Therefore, when a resin having a bridged alicyclic ring and having a structure in which an oxygen-containing polar group is introduced at the tertiary carbon position of the bridged alicyclic ring is used as the base resin of the resist composition, the free volume decreases. Therefore, the glass transition temperature (Tg) increases, and as a result, the resolution increases.

In fact, a comparison is made between a resin having a structure in which an OH group is introduced at the secondary carbon position of a bridged alicyclic ring and a resin having a structure having an OH group introduced at the tertiary carbon position of a bridged alicyclic ring. Then T
It can be seen that g increases by at least 10 to 20 ° C. or more. Further, when an OH group is introduced into the alicyclic skeleton via methylene, such as a hydroxymethyltricyclodecanyl acrylate system commonly found in known compounds, the Tg is further reduced by about 10 to 20 ° C. So the difference becomes clearer.

Further, as described above, since the developer does not easily penetrate into the unexposed portions due to the small molecular motion, the pattern does not easily swell.

Further, the resin according to the present invention comprises a bridged alicyclic 3
It must have at least two oxygen-containing polar groups introduced at the secondary carbon position. These groups play an important role for the resist in improving the adhesion to the substrate and improving the alkali solubility. Since these groups are bonded to the tertiary carbon position, the degree of freedom is limited to the direction of rotation, and they cannot be turned sideways. For this reason, there is a high probability of facing outward with respect to the main chain. Therefore, the affinity for the alkali solvent in contact with the resin is high, and the adhesion to the substrate is high.

The oxygen-containing polar group bonded to the secondary or lower carbon position, in particular, the OH group and the COOH group have high reactivity.
There is also a disadvantage that secondary cross-linking reaction or the like is easily caused by heating or the like. Particularly, in the case of a positive chemically amplified resist, there is a decisive problem that a pattern cannot be easily formed during a heating process. This tendency can be even more pronounced when the resin structure has an acid anhydride structure.

However, the oxygen-containing polar group bonded to the tertiary carbon position as in the present invention has low reactivity and is unlikely to cause a secondary crosslinking reaction due to heating or the like, so that the above-mentioned problems do not occur.

Therefore, 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 adhesion and resolution by alkali development.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION The resist composition according to the present invention comprises at least a resist resin and a photoacid generator as main components. Hereinafter, each component will be described in detail. <Resin for Resist> Hereinafter, the resin for resist according to the present invention will be described.

The resin according to the present invention has a structure having at least a bridged alicyclic ring and at least two oxygen-containing polar groups bonded to the tertiary carbon position of the bridged alicyclic ring in a main chain or a side chain. Including.

The resin according to the present invention has a bridged alicyclic ring.
Examples of the bridged alicyclic ring include a cyclic cyclo compound represented by the general formula C _n H _2n (n is an integer of 3 or more), a bridged compound of a cyclic bicyclo compound, and a condensed ring compound. Specifically, a cyclobutane ring, a cyclopentane ring,
Cyclohexane ring, cycloheptane ring with bridging hydrocarbon introduced, spiro heptane, spiro octane and other spiro ring, norbornane ring, adamantane ring, bornene ring, bornane, fencan, tricyclene, cholesteric ring and other steroid skeleton, bile Acids, digitaloids, camnon ring, isocamphor ring, sesquiterpene ring, sandton ring, diterpene ring, triterpene ring,
Steroid sapogenins are exemplified.

Particularly preferred bridged alicyclic rings include adamantane ring, tricyclodecane ring, tetracyclododecane ring,
Norbornane rings are desirable because they increase dry etching resistance.

In the resin according to the present invention, at least two oxygen-containing polar groups are bonded to the tertiary carbon position of the bridged alicyclic ring. When the number of oxygen-containing polar groups bonded to the tertiary carbon position of the bridged alicyclic ring is three or more, the contribution of these groups to the improvement of adhesion to a substrate and the improvement of alkali solubility This is more preferable because it has the advantage of being able to increase the

The oxygen-containing polar groups bonded to one bridged alicyclic ring may be the same or different.

In the present invention, the oxygen-containing polar group is a substituent having a carbon-oxygen bond having a large change in electronegativity, such as a substituted or unsubstituted carboxyl group,
Examples include a substituted or unsubstituted cyclic lactone group, a substituted or unsubstituted hydroxyl group, an aldehyde group, a group containing a peroxide, a substituted or unsubstituted urethane group, an acyl group, and a carbonate group.

From the tertiary carbon position of the alibridge alicyclic ring,-(C
H ₂ ) When bonded to the oxygen-containing polar group via n- (n is a natural number), the polar group has a high degree of freedom, and is bonded to the tertiary carbon position of the bridged alicyclic ring as described above. Since the same effects as those described above cannot be obtained, they are excluded from the “oxygen-containing polar group bonded to the tertiary carbon position” in the present invention.

Among them, from the viewpoint of polarity in terms of the performance of the resist composition, the oxygen-containing polar group is selected from a substituted or unsubstituted carboxyl group, a substituted or unsubstituted hydroxyl group, and a substituent containing a cyclic lactone. Desirably, it is at least one organic group. By using these, the effect of improving adhesion and solubility can be obtained.

Further, the oxygen-containing polar group is such that the substituent introduced into the carboxyl group is a cyclic lactone or the carboxyl group forms an acid anhydride with a bridged alicyclic compound having another carboxylic acid. It is preferable to use any of the formed compounds because the solubility becomes particularly high.

Further, in addition to two or more tertiary oxygen-containing polar groups, a non-reactive polar group such as a ketone or lactone structure is introduced in the secondary or lower position in the bridged alicyclic ring. Also allows this.

In the resin according to the present invention, the proportion of the bridged alicyclic moiety in the resin is preferably at least 20% to 90% by weight. Outside of this range, dry etching resistance or alkali solubility decreases.

The resin according to the present invention is preferably used when a dissolution inhibiting group (soluble group which can be decomposed by an acid) is introduced into the molecule, because the resolution is improved. The dissolution inhibiting group can be introduced into the resin by using a monomer compound having a dissolution inhibiting group when synthesizing the resin.

Examples of the dissolution inhibiting group include a cyclic tertiary ester group having a lactone and a dissolution which can be decomposed by an acid when a substituent having an acid anhydride structure with a bridged alicyclic compound having a carboxylic acid is introduced. It becomes a functional group and can be used particularly preferably.

Examples of the dissolution inhibiting group include esters such as t-butyl ester, isopropyl ester, ethyl ester, methyl ester and benzyl ester; ethers such as tetrahydropyranyl ether; t-butoxycarbonate, methoxycarbonate and ethoxy. Alkoxycarbonates such as carbonates; isopropyl esters, tetrahydropyranyl esters, such as silyl ethers such as trimethylsilyl ether, triethylsilyl ether and triphenylsilyl ether;
Tetrahydrofuranyl ester, methoxyethoxymethyl ester, 2-trimethylsilylethoxymethyl ester, 3-oxocyclohexyl ester, isobornyl ester, trimethylsilyl ester, triethylsilyl ester, isopropyldimethylsilyl ester,
Di-t-butylmethylsilyl ester, oxazole,
2-alkyl-1,3-oxazoline, 4-alkyl-
5-oxo-1,3-oxazoline, 5-alkyl-4
Esters such as -oxo-1,3-dioxolane, t
-Butoxycarbonyl ether, t-butoxymethyl ether, 4-pentenyloxymethyl ether, tetrahydropyranyl ether, tetrahydrothiopyranyl ether, 3-bromotetrahydropyranyl ether, 1-
Methoxycyclohexyl ether, 4-methoxytetrahydropyranyl ether, 4-methoxytetrahydrothiopyranyl ether, 1,4-dioxan-2-yl ether, tetrahydrofuranyl ether, tetrahydrothiofuranyl 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 dimethylisopropylsilyl ether, diethylisopropylsilylether, dimethylsexylsilylether, t-butyldimethylsilylether, methylene acetal, ethylidene acetal, 2,
Acetals such as 2,2-trichloroethylidene acetal, 1-t-butylethylidene ketal, isopropylidene ketal (acetonide), ketals such as cyclopentylidene ketal, cyclohexylidene ketal, cycloheptylidene ketal, and methoxy methylene acetal Ethoxymethylene acetal, dimethoxymethylene orthoester, 1-methoxyethylidene orthoester, 1-ethoxyethylidene orthoester,
1,2-dimethoxyethylidene orthoester, 1-
N, N-dimethylaminoethylidene orthoester, 2
Cyclic orthoesters such as -oxacyclopentylidene orthoester, etc., silylketene acetals such as trimethylsilylsilylketene acetal, triethylsilylketene acetal, t-butyldimethylsilylketene acetal, di-t-butylsilyl ether, 1, Silyl ethers such as 3-1 ′, 1 ′, 3 ′, 3′-tetraisopropyldisiloxanylidene ether, tetra-t-butoxydisiloxane-1,3-diylidene ether, dimethyl acetal, dimethyl ketal, bis -2,2,2-trichloroethyl acetal,
Acyclic acetal and ketal such as bis-2,2,2-trichloroethyl ketal, diacetyl acetal, diacetyl ketal, 1,3-dioxane, 5-
Methylene-1,3-dioxane, 5,5-dibromo-
1,3-dioxane, 1,3-dioxolan, 4-bromomethyl-1,3-dioxolan, 4-3′-butenyl-1,3-dioxolan, 4,5-dimethoxymethyl-1,3-dioxolan and the like Cyclic acetals and ketals, O-trimethylsilyl cyanohydrin, O-1-ethoxyethyl cyanohydrin, cyanohydrins such as O-tetrahydropyranyl cyanohydrin, and elimination properties such as tertiary alicyclic esters having an alkyl group. An alicyclic skeleton and the like can be mentioned.

The proportion of the dissolution inhibiting group in the resin is more preferably about 35 to 65 mol%. Note that this value is considerably larger than the dissolution inhibiting group introduction ratio of an acrylic polymer generally considered. For this reason, the contrast of solubility is higher than that of a general acrylic resist, and development can be performed with a high resolution using a standard developer such as a 2.38% aqueous solution of tetramethylammonium hydroxide (TMAH).

The resin according to the present invention may also contain a dissolution inhibiting group and an alkali-soluble group in the molecule at the same time, and one component can provide two functions of alkali solubility and dissolution inhibiting property. .

Examples of the alkali-soluble group include a carboxyl group and a phenolic hydroxyl group.

In this case, the proportion of the dissolution inhibiting group in the resin is preferably about 10 to 80 mol%.
If it is less than 10 mol%, the dissolution inhibiting function does not appear,
The unexposed portion also dissolves and the pattern cannot be resolved.
On the other hand, if it exceeds 80 mol%, the adhesion is extremely deteriorated,
Pattern formation becomes difficult, and the hydrophobicity of the resist composition becomes too strong, so that the developer repels and the pattern cannot be formed.

In this case, the ratio of the alkali-soluble group in the resin is determined by exposure / PEB (Post Exposure Bake).
Thereafter, it is preferably at least 20 mol% in a portion removed by development. This is because if the alkali-soluble group in the same site is less than 20 mol%, the alkali developability deteriorates.

However, when one alicyclic unit has both a dissolution inhibiting group and a polar group such as a hydroxyl group capable of improving the adhesion, the above-mentioned problem of adhesion does not appear. The dissolution inhibiting group can be introduced in an amount of 80 mol% or more.

In the resin according to the present invention, it is preferable that at least one of the oxygen-containing polar groups is a group in which a COOH group is protected by a dissolution inhibiting group (soluble group which can be decomposed by an acid). When such a group is present, the resist layer exhibits alkali solubility after a deprotection reaction is caused by an acid. Further, the dissolution rate of the unexposed portion can be reduced by the protection, and a high dissolution contrast can be realized. In addition, since it has hydrophilicity, alkali solubility can be appropriately maintained.

In particular, as such a protected resin, for example, a resin obtained by copolymerizing hydroxyadamantyl acrylate having a hydroxyl group at the tertiary carbon position with tetrahydropyranyl acrylate can be mentioned. The resin has no alkali-soluble group in the unexposed area, but the hydroxyl group jumps out of the polymer chain to increase the hydrophilicity, so that the unexposed area of the resist film does not cause uneven dissolution etc. . In addition, the effect of close contact with the substrate is enhanced.

The resin in the present invention preferably has an acid anhydride structure in its structure, that is, in the main chain or side chain, and preferably has at least one of the oxygen-containing polar groups as a hydroxyl group. That is, when the OH group which does not participate in the bond in the resin structure and the acid anhydride structure are simultaneously present, the secondary self-crosslinking reaction is suppressed, so that the effect of the tertiary position is more remarkably exhibited. This is desirable because the contrast is increased as a positive resist.

The resin according to the present invention can be obtained by polymerizing or condensing the raw material monomers by various methods such as radical polymerization and living polymerization using the following combinations of (a) to (d). I. Structure having a bridged alicyclic ring and at least two oxygen-containing polar groups bonded to the tertiary carbon position of the bridged alicyclic ring (structure A)
B. A combination of one or more monomers having A structure having at least one monomer having a structure A and a bridged alicyclic ring and having at least two oxygen-containing polar groups bonded to the secondary or primary carbon position of the bridged alicyclic ring (structure B) A combination of one or more monomers having Combination of one or more monomers having structure A and one or more monomers having a structure that is neither structure A nor structure B (structure C) d. Combination of one or more monomers having structure A, one or more monomers having structure B, and one or more monomers having structure C The bridged alicyclic ring and oxygen-containing polar group in structures A and B are respectively The above-mentioned bridged alicyclic ring and oxygen-containing polar group can be exemplified.

The resin according to the present invention comprises Or the above b. In this case, the oxygen-containing polar group bonded to the bridged alicyclic ring in the resin is preferably bonded to the tertiary carbon position as much as possible, and at least 70% of the oxygen-containing polar group bonded to the bridged alicyclic ring. More preferably 90% or more of the bridged alicyclic 3
It is sufficient if the bond is at the lower carbon position. As a result of a side reaction during the synthesis of the monomer having the structure A, an introduced compound at the secondary carbon position is mixed, and In some cases, the structure must be adopted, but this is allowed.

The resin according to the present invention comprises: Or d. In the case of, the effect of the introduced compound at the tertiary position is observed at least in the total molar amount of the monomer constituting the resin, although it varies depending on the copolymerization ratio of the monomer having the structure A and the other monomer. In contrast, the amount of the monomer having the structure A exceeds about 15%. It is more preferably at least 20%.

In the present invention, a monomer having a bridged alicyclic ring as a monomer raw material and having a structure in which at least two oxygen-containing polar groups are bonded to the tertiary carbon position of the bridged alicyclic ring (structure A) is as follows: It is obtained by subjecting an alicyclic compound to an oxidation reaction and extracting a target component. Alternatively, it can be suitably obtained by hydrolyzing a part thereof by bromination, or by an air oxidation method using a catalyst (JP-A-11-35522). Further, these compounds may be acrylated or methacrylated by an addition reaction using a catalyst or esterification by an acid chloride method.

When the resin of the present invention is obtained by polymerization, it is desirable to use an acrylic compound or a vinyl compound as a monomer having the structure A and a monomer having another structure. In particular, the resin of the present invention is preferably an acrylic resin or a methacrylic resin using an acrylic compound as a monomer because polymerization is easy.
The acrylic resin or the methacrylic resin is obtained by polymerizing a monomer having the structure A, in which at least one of the oxygen-containing polar groups bonded to the bridged alicyclic ring is an acryloyloxy group or a methacryloyloxy group. be able to.

In particular, when the resin of the present invention is polymerized using a compound represented by the following general formula (1) or (2) as a monomer having the structure A, dry etching resistance, solubility, and adhesion are obtained. And the glass transition temperature is high.

Embedded image (However, R1 represents an acryloyl group or a methacryloyl group, R2 represents a hydrogen atom or an oxygen-containing polar group,
3 represents a hydrogen atom, or an acid-decomposable group, a cyclic substituent having a lactone, or a substituent having an acid anhydride structure with a bridged alicyclic compound having a carboxylic acid. Examples of the acid-decomposable group for R3 include a tert-butyl group, a tetrahydropyranyl group, and an acetal group. Also,
In order to obtain a contrast between an exposed portion and an unexposed portion, it is preferable that R3 also functions as a dissolution inhibiting group.

Embedded image (However, R1 represents an acryloyl group or a methacryloyl group, R2 represents a hydrogen atom or an oxygen-containing polar group,
4 represents a hydroxyl group, a lactone-containing cyclic substituent or a carboxylic acid-containing bridged alicyclic compound having an acid anhydride structure. When the resin of the present invention is obtained by condensation, the resin has the structure A
A monomer having a bridged alicyclic ring having at least one organic group of a carboxyl group and a hydroxyl group at two or more tertiary carbon positions, or
A main chain alicyclic polymer or oligomer obtained by dehydration-condensation using a monomer having a lactone skeleton at the secondary carbon position is desirable.

In the polymer or oligomer, the monomer is bonded to the polymer main chain via a bond decomposable by an acid. Examples of the bond include an ester bond and an acid anhydride bond. In this case, the resin becomes a main chain alicyclic type and has a polyester or polyanhydride structure.

When the resin has a main chain alicyclic polyester or polyanhydride structure, the resist composition undergoes significant decomposition of the molecular skeleton including the resin main chain before and after exposure, and the resolution is increased. Further, since the resin has few free secondary oxygen-containing polar groups, dehydration-condensation side reaction hardly occurs and Tg is increased, which is desirable.
In addition, since it has a bridged alicyclic skeleton, it is possible to significantly improve the solubility of the exposed portion of the resist while improving the coating properties and adhesion of the resist, and thereby improve the dissolution contrast of the unexposed portion of the exposed portion. it can. Furthermore, since the main chain of the resist has an alicyclic structure, the dry etching resistance can be sufficient.

In particular, when the resin according to the present invention has a polyester or polyanhydride bond formed by dehydration condensation between a carboxyl group and a hydroxyl group and / or a carboxyl group, not only is it excellent in acid decomposability but also in stability. This is desirable because of high transparency, high transparency and easy synthesis.

The ester bond is obtained by a method of dehydrating and condensing an alicyclic polyhydric alcohol compound or the like with a polyhydric carboxylic acid using a catalyst or the like, or by a method of desalting the polyhydric alcohol compound to a polyhydric carboxylic acid chloride. Alternatively, it is obtained by dehydrating and condensing one or more compounds having a plurality of carboxyls and alcohol groups.

The above acid anhydride bond is obtained by dehydrating and condensing one or more polycarboxylic acid compounds.

In the case where a bond is formed by the same type of reaction, particularly a dehydration condensation reaction, a plurality of types (for example, an ester bond and an acid anhydride bond) are simultaneously mixed in a resin. It doesn't matter.

In general, polymers or oligomers having an acid anhydride bond have a great advantage of being excellent in alkali solubility. Usually, these acid anhydride compounds are considered to be easily hydrolyzed and have poor stability, but the acid anhydride bond sandwiched by the bulky alicyclic compounds as in the present invention is extremely stable. In addition, it provides a suitable alkali solubility for pattern formation. On the other hand, the polymer or oligomer having an ester bond is stable regardless of the solvent, and further,
Since a large dissolution rate change is caused by the acid-catalyzed decomposition, there is an advantage that the resolution is enhanced. By using these bonds in combination, it is possible to further achieve both favorable solubility and resolution as a resist. In this case, the ratio of the acid anhydride bond to the ester bond is 1: 2.
It may be in the range of 0 to 5: 1, and more preferably, the acid anhydride bond is preferably 10% or more and less than 50%.

In the resin of the present invention, the resin containing an acid anhydride structure in its structure, that is, in the main chain or the side chain, and at least one of the oxygen-containing polar groups is a hydroxyl group, Is desirable.

Such a resin has a structure A in which at least one of the oxygen-containing polar groups is a hydroxyl group as a monomer.
May be obtained by performing polymerization as described above using the above monomer, or may be obtained by performing condensation. For example, not only a poly (ester-acid anhydride) compound but also a copolymer containing at least an alicyclic structure having a tertiary OH group and maleic anhydride may be mentioned.

On the other hand, as the compound having the structure C, for example,
tert-butyl acrylate, tert-butyl methacrylate, methacrylic acid, acrylic acid, α-chloroacrylic acid and its ester, trifluoromethyl acrylate, α-methylstyrene, trimethylsilyl methacrylate, trimethylsilyl α-chloroacrylate, trimethylsilylmethyl α-chloro Acrylate, maleic anhydride, tetrahydropyranyl methacrylate, tetrahydropyranyl α-chloroacrylate, methyl methacrylate, t-butyl α-chloroacrylate, butadiene, glycidyl methacrylate, isobornyl methacrylate, menthyl methacrylate, norbornyl methacrylate, adamantyl methacrylate , Cycloolefin compounds, acrylates and epoxies having a lactone skeleton on the acrylic side chain Acrylate having a rank and the like. Among them, particularly, tetrahydropyranyl methacrylate and maleic anhydride are preferable for improving the resolution, since secondary reactions which are usually likely to occur are suppressed, and for improving the dry etching resistance of the resin, cycloolefin is preferred. An acrylic compound having a lactone skeleton in a side chain is preferably used as a copolymer partner in order to improve the developability of the compound.

When the resin according to the present invention is an acrylic resin or a methacrylic resin, the polystyrene equivalent weight average molecular weight (Mw) varies depending on the desired properties of the resist composition, but is preferably from 2,000 to 100,000. ,
More preferably, it is 5,000 to 60,000.
When Mw is less than 2,000, the film-forming property tends to deteriorate, and when Mw exceeds 100,000, developability, resolution and the like tend to deteriorate. In addition, the molecular weight dispersity Mw / M
n is preferably 1 to 5, more preferably 1 to 2.

When the resin according to the present invention is a main-chain alicyclic polyester or polyanhydride-based condensate, the average molecular weight in terms of polystyrene is preferably set in the range of 100 to 30,000. . If the average molecular weight is less than 100, it is disadvantageous in forming a resist film having sufficient mechanical strength, heat resistance and coatability, and if the average molecular weight of the high molecular compound exceeds 30,000, This is because the alkali solubility is deteriorated and it becomes difficult to form a resist pattern having good resolution. These compounds are usually mixtures of various molecular weight components.

The resin of the present invention is effective even at a relatively low molecular weight such as about a dimer.
There is also an effect when a large amount is localized at the average molecular weight of 00. Further, in this case, even if less than 10% of the monomer remains in the copolymer, the solubility characteristics and dry etching resistance are hardly deteriorated. <Photoacid Generator> Examples of the photoacid generator blended in the resist composition of the present invention include arylonium salts, naphthoquinonediazide compounds, diazonium salts, sulfonate compounds, sulfonium compounds, sulfamide compounds, iodonium compounds, and sulfonyldiazomethanes. Compounds and the like can be used. Specific examples of these compounds include triphenylsulfonium triflate, diphenyliodonium triflate, 2,3,
4,4-tetrahydroxybenzophenone-4-naphthoquinonediazidosulfonate, 4-N-phenylamino-2-methoxyphenyldiazonium sulfate,
4-N-phenylamino-2-methoxyphenyldiazonium p-ethylphenyl sulfate, 4-N-phenylamino-2-methoxyphenyldiazonium 2-naphthyl sulfate, 4-N-phenylamino-2-methoxyphenyldiazonium phenyl Sulfate,
2,5-diethoxy-4-N-4′-methoxyphenylcarbonylphenyldiazonium 3-carboxy-4-
Hydroxyphenyl sulfate, 2-methoxy-4-
N-phenylphenyldiazonium 3-carboxy-4
-Hydroxyphenyl sulfate, diphenylsulfonylmethane, diphenylsulfonyldiazomethane,
Diphenyldisulfone, α-methylbenzoin tosylate, pyrogallol trimesylate, benzoin tosylate, MPI-103 manufactured by Midori Kagaku (CAS. NO. [8
7709-41-9]), Midori Kagaku BDS-105
(CAS. NO. [145612-66-4]), Midori Kagaku NDS-103 (CAS. NO. [11009]
8-97-0]), Midori Kagaku MDS-203 (CA
S. NO. [127855-15-5]), Midori Chemical's Pyrogallol tritosylate (C
AS. NO. [23032-64-8]), DTS-102 manufactured by Midori Kagaku (CAS. NO. [75482-18]).
-7]), Midori Kagaku DTS-103 (CAS.N
O. [71449-78-0]), Midori Chemical MDS
-103 (CAS. NO. [127279-74-
7]), MDS-105 manufactured by Midori Kagaku (CAS. NO.
[116808-67-4]), Midori Chemical MDS-
205 (CAS. NO. [81416-37-7]);
BMS-105 manufactured by Midori Kagaku (CAS. NO. [149]
934-68-9]), TMS-105 manufactured by Midori Kagaku
(CAS. NO. [127820-38-6]), Midori Kagaku NB-101 (CAS. NO. [20444-]).
09-1]), Midori Kagaku NB-201 (CAS.N
O. [4450-68-4]), Midori Kagaku DNB-
101 (CAS. NO. [114719-51-
6]), Midori Kagaku's DNB-102 (CAS. NO.
[131509-55-2]), Midori Kagaku DNB-
103 (CAS. NO. [132898-35-
2]), Midori Kagaku's DNB-104 (CAS. NO.
[132898-36-3]), Midori Kagaku DNB-
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 No.
[34694-40-7]), Midori Kagaku NDI-1
05 (CAS No. [133710-62-0]),
EPI-105 manufactured by Midori Kagaku (CAS No. [135]
133-12-9]). Further, the following compounds can also be used.

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Embedded image (Wherein C1 and C2 form a single bond or a double bond, R10 is a hydrogen atom, a fluorine atom, an alkyl group or an aryl group optionally substituted with a fluorine atom, R1
1 and R12 may be the same or different and each represents a monovalent organic group, and R11 and R12 may be bonded to each other to form a ring structure. )

Embedded image (In the formula, Z represents an alkyl group.)

Embedded image Also, as for the photoacid generators described above, conjugated polycyclic aromatic compounds such as arylonium salts having a naphthalene skeleton or a dibenzothiophene skeleton, sulfonate compounds, sulfonyl compounds, and sulfamide compounds have transparency to short-wavelength light and heat resistance. It is advantageous in terms of sex. Specifically, 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, pleiaden ring, picene ring, perylene ring, pentaphene ring, pentacene ring, tetraphenylene ring, hexaphene ring, hexacene ring, Rubicene ring, coronene ring, trinaphthylene ring, heptaphen ring,
Heptacene ring, pyranthrene ring, ovalene ring, dibenzophenanthrene ring, benz [a] anthracene ring, dibenzo [a, j] anthracene ring, indeno [1,2-
a] a sulfonyl or sulfonate compound having an indene ring, an anthra [2,1-a] naphthacene ring, 1H-benzo [a] cyclopent [j] anthracene ring; a naphthalene ring, a pentalene ring, an indene ring, an azulene ring, a 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, preyaden ring, picene ring, perylene ring, pentaphene ring, pentacene ring, tetraphenylene ring, hexaphene ring, hexacene ring, rubicene ring,
Coronene ring, trinaphthylene ring, heptaphen ring, heptacene ring, pyranthrene ring, ovalene 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
A 4-quinonediazide compound having a benzo [a] cyclopent [j] anthracene ring; 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,
Acenaphthylene ring, fluorene ring, phenalene ring, phenanthrene ring, anthracene ring, fluoranthene ring, acephenanthrylene ring, aceanthrylene ring, triphenylene ring, pyrene ring, chrysene ring, naphthacene ring, preiaden ring, picene ring, perylene ring , A pentaphen ring,
Pentacene ring, tetraphenylene ring, hexaphen ring,
Hexacene ring, rubicene ring, coronene ring, trinaphthylene ring, heptaphen ring, heptacene ring, pyranthrene ring, ovalene 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] cyclopent [j] anthracene and the like with salts of sulfonium or iodonium having a side chain and triflate. In particular, a sulfonyl or sulfonate compound having a naphthalene ring or an anthracene ring; a 4-quinonediazide compound having a naphthalene ring or an anthracene ring having a hydroxyl group introduced; a sulfonium or iodonium triflate having a naphthalene ring or an anthracene ring with a side chain; Salts are preferred.

Among such photoacid generators, in the present invention, triphenylsulfonium triflate, diphenyliodonium triflate, trinaphthylsulfonium triflate, dinaphthyliodonium triflate, dinaphthylsulfonylmethane, green Chemical NA
T-105 (CAS No. [137867-61-
9]), Midori Kagaku NAT-103 (CAS No.
[131582-00-8]), Midori Kagaku NAI-
105 (CAS. No. [85342-62-7]),
TAZ-106 manufactured by Midori Kagaku (CAS No. [694]
32-40-2]), NDS-105 manufactured by Midori Kagaku,
Midori Kagaku PI-105 (CAS No. [4158]
0-58-9]), s-alkylated dibenzothiophene triflate, s-fluoroalkylated dibenzothiophene triflate (manufactured by Daikin) and the like are preferably used. Among these, triphenylsulfonium triflate, trinaphthylsulfonium triflate, dinaphthyliodonium triflate, dinaphthylsulfonylmethane, NAT-105 manufactured by Midori Kagaku (C
AS. No. [137867-61-9]), Midori Kagaku NDI-105 (CAS. No. [133710-
62-0]), Midori Kagaku NAI-105 (CAS.
No. [85342-62-7]) and the like are particularly preferable.

In the resist composition of the present invention, the preferable amount of the photoacid generator is 0.1% based on the whole other solids.
001 to 50% by weight, more preferably 0.01 to 40%
% By weight, particularly preferably in the range from 0.1 to 20% by weight. That is, if it is less than 0.001% by weight, it is difficult to form a resist pattern with high sensitivity, and if it exceeds 50% by weight, the mechanical strength and the like may be impaired when a resist film is formed. <Other components> In the resist composition of the present invention,
It may contain a dissolution inhibitor, an alkali-soluble resin, or a resinous compound whose solubility in an alkali solution increases upon irradiation with radiation.

Hereinafter, the dissolution inhibitor will be described.

The resin according to the present invention is decomposed into an alkali-soluble resin by decomposing an alkali-insoluble resin by an acid catalyst generated by irradiating the compounded photoacid generator with light. Therefore, it is not essential to introduce a dissolution inhibiting group into the resin or to add a dissolution inhibiting agent to the resist composition. However, it is preferable to introduce a dissolution inhibiting group into the resin or to add a dissolution inhibitor in order to increase the difference in dissolution rate between the exposed part and the unexposed part.

The dissolution inhibiting compounds used as dissolution inhibitors include, for example, US Pat.
Of the compounds described in JP-A-603101 and JP-A-63-27829, any of the compounds having an aromatic ring of the condensed polycyclic aromatic ring can be used. Alternatively, a compound having a carboxylic acid or a phenolic hydroxyl group in the condensed polycyclic aromatic ring skeleton can be used as long as a part or all of the hydroxy terminal is substituted with an acid-decomposable protecting group.

For example, the protecting group includes tert-butyl ester, tert-butyl carbonate, tetrahydropyranyl group, acetal group and the like.

Specific examples of such compounds include tertiary butyl carbonate of polyhydroxy compound, tertiary butyl carbonate of naphthol phthalein, quinazaline and quinizarin of naaphthalene and anthracene, tertiary butyl carbonate of naphthol novolak resin. , Etc. are exemplified.

The addition amount of these compounds to the resist composition is desirably at least 3% by weight and less than 40% by weight based on the polymer. The reason for this is that if the amount added to the resist composition is less than 3% by weight, no effect is obtained or the resolution is lowered, and if it is 40% by weight or more, the coating film performance or dissolution rate is remarkably high. It is because it falls. Usually between 10 and 30% by weight is more desirable.

When a dissolution inhibitor is provided, the resin does not necessarily need to have a dissolution inhibiting group, and a vinyl compound having an alkali-soluble group, such as methacrylic acid, which imparts alkali solubility as a copolymer composition is copolymerized. May be done.
As a dissolution inhibitor, it has a sufficient dissolution inhibiting ability with respect to an alkaline solution, and the product after decomposition with an acid is-(C = O) O-, -OS (= O)
Acid-decomposable compounds capable of producing _2- or -O- are exemplified. Specifically, the phenolic compound is converted to 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, diethylisopropylsilyl ether, dimethylsexylsilyl ether, t-butyldimethylsilyl ether, and Meldrum's acid derivatives. Among these, a compound 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, a tetrahydropyranyl group, or the like, And a compound obtained by adding Meldrum's acid to an aldehyde having an alicyclic structure.

Further, dissolution inhibitors include isopropyl esters of polycarboxylic acids, tetrahydropyranyl esters,
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-dioxolane and the like.
Further, the following compounds can be exemplified.

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Embedded image In the present invention, among these dissolution inhibitors, a conjugated polycyclic aromatic compound is preferred because of its excellent transparency to short-wavelength light. That is, in such a compound, the light absorption band is shifted to a low wavelength region due to the conjugate stabilization of π electrons,
In the present invention, in particular, by using a conjugated polycyclic aromatic compound as a dissolution inhibitor, a resist having excellent transparency to short-wavelength light and sufficient heat resistance can be obtained.

Of the other components in the present resist composition, as the alkali-soluble resin, it is basically possible to add any alkali-soluble resin, but preferably, the known resins used for ArF resists are used. Can be given,
They may have a function as a chemically amplified resist.

Further, the resist composition of the present invention can be processed at a high temperature by using a resin containing an acid anhydride structure as a resin component, or a specific 3 component having a hydroxyl group as a resin component which is liable to cause a dehydration reaction due to the action of an acid catalyst. In the case where it is attached to the class portion, a negative image may be formed in some cases, and this may be positively used to form a negative image in some cases.

The resist composition of the present invention is usually prepared as a varnish by dissolving a resin component, a photoacid generator, a dissolution inhibitor, a crosslinking agent, an alkali-soluble resin and the like in an organic solvent and filtering. However, in the alkali developing resist of the present invention, in addition to these components, epoxy resin, polymethyl methacrylate, polymethyl acrylate, polymethyl methacrylate, propylene oxide-ethylene oxide copolymer, other polymers such as polystyrene, and environmental resistance An amine compound for improvement, 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 compounded.

Examples of the organic solvent include ketone solvents such as cyclohexanone, acetone, methyl ethyl ketone and methyl isobutyl ketone; cellosolve solvents such as methyl cellorub, 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, N-methylpyrrolidone, and solubility For the purpose of improvement, dimethyl sulfoxide, dimethyl formaldehyde, N
A mixed solvent to which -methylpyrrolidinone or the like is added can be used. Also, propionic acid derivatives such as methyl methyl propionate, lactate esters such as ethyl lactate, and PG
MEA (propylene glycol monomethyl ether acetate) and the like have low toxicity and can be preferably used. Among them, PGMEA and ethyl lactate are particularly preferred because of their high solubility in the resin of the present invention.

In the present invention, such solvents can be used alone or in combination of two or more. Further, isopropyl alcohol, ethyl alcohol, methyl alcohol, butyl alcohol, n-butyl alcohol,
aliphatic alcohols such as s-butyl alcohol, t-butyl alcohol, isobutyl alcohol, toluene,
An aromatic solvent such as xylene may be contained. However, when the resist composition of the present invention has an acid anhydride structure, if the solvent has a hydroxyl group, it is likely to react and the stability is impaired, and in this case, the solvent must not have an OH group. Is desirable.

Next, a method of forming a pattern using the resist composition of the present invention will be described with reference to a positive chemically amplified resist as an example. First, a varnish of a resist 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.
Thereafter, the resist film is dried preferably at 70 to 120 ° C. to form a resist film. The substrate used here is, for example, a silicon wafer, a silicon wafer having various insulating films, electrodes, wirings, etc. formed on the surface thereof, a blank mask, GaAs, Al
III-V compound semiconductor wafer such as GaAs, chromium or chromium oxide deposition mask, aluminum deposition substrate, BP
An SG coated substrate, a PSG coated substrate, a BSG coated substrate, an SOG coated substrate, a carbon film sputtered substrate, or the like can be used.

Next, the resist film is exposed by irradiating actinic radiation through a predetermined mask pattern or by directly scanning the resist film surface with actinic radiation. 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. Water source lamp light i-line, h-line, g-line, xenon lamp light, KrF
And deepU of excimer laser light or the like, such as ArF and _{F 2}
V light and synchrotron orbital radiation (SO
R), electron beam (EB), γ-ray, ion beam and the like can be used.

Subsequently, particularly in the case of a chemically amplified resist, the resist film is appropriately subjected to a baking treatment of about 170 ° C. or less by heating on a hot plate or in an oven or irradiating infrared rays. 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. Here, the concentration of the alkaline solution is set at 1 from the viewpoint of ensuring a sufficient dissolution rate difference between the exposed part and the unexposed part.
It is preferably at most 5% by weight.

The resist pattern formed by using the resist composition of the present invention has an extremely good resolution. For example, by dry etching using this resist pattern as an etching mask, an exposed substrate or the like is exposed to the order of quarter microns. Can be faithfully transferred. In the resist pattern obtained here,
In the alicyclic structure in the polymer compound as the base resin, even if one carbon-carbon bond is broken, the other bond remains, so that it has high dry etching resistance.

It should be noted that other steps other than the above-described steps may be added without any problem. For example, a step of forming a flattening layer as a base of the resist film, a step of improving the adhesion between the resist film and the base, and the like. A processing step, a rinsing step of removing the developing solution with water or the like after development of the resist film, and a step of re-irradiating ultraviolet rays before dry etching can be appropriately performed.

[0091]

EXAMPLES (Example 1) 1-acryloyl-3-hydroxyadamantane and tetrahydropyranyl methacrylate were used as monomers, and the total of both was 0.05 mol.
Were mixed at a mixing ratio shown in Table 1, the mixture was dissolved in 20 g of tetrahydrofuran (THF), and 0.0125 mol of azobisbutyronitrile (AIBN) was added as a polymerization initiator. Under an argon atmosphere, freeze degassing was performed three times at the temperature of liquid nitrogen. This is placed in an argon atmosphere at 60 ° C.
For 30 hours. 2 ml of methanol was added to the reaction solution to stop the reaction. While stirring 250 g of hexane,
The reaction solution was dropped one by one and reprecipitated. The mixture was filtered with a glass filter, and the solid content was vacuum-dried at 60 ° C. for 3 days to obtain six kinds of resins.

The molecular weight was 3 in terms of polystyrene.
From 500 to 8000. Mw / Mn is 1.7 or more.
1.9. When the mixing ratio of the obtained resin was measured by NMR, it was within ± 2% of the charging ratio.

To 1.0 g of the obtained resin, 0.05 g of triphenylsulfonium triflate as a photoacid generator was added.
In addition, the resultant was dissolved in 4.2 g of ethyl lactate to obtain six types of resists 1 to 6.

The obtained six kinds of resist solutions were spin-coated on a silicon wafer at 3,000 rpm for 30 seconds by spin coating. Then on a hot plate,
A pre-exposure bake was performed at 120 ° C. for 90 seconds. The thickness of the resist was 0.5 μm. This was exposed to ArF excimer laser light (wavelength 193 nm), and the line &
Space was patterned. An ArF exposure apparatus (NA = 0.55, σ = 0.7) manufactured by Nikon Corporation was used for exposure wave setting.

This was exposed to light at 100 ° C. for 180 seconds, baked, and then developed in a 2.38% aqueous tetramethylammonium hydroxide solution at 25 ° C. for 60 seconds. As a result, the exposed portion of the resist film was selectively dissolved and removed to form a positive pattern. Table 1 also shows the sensitivity and resolution of each resist.

[Table 1] Example 2 As a monomer, 0.02 mol of 1-acryloyl-3-hydroxyadamantane was homopolymerized in the same manner as in Example 1. The molecular weight was 3,500 in terms of polystyrene, and Mw / Mn was 1.9.

A resist 7 was prepared by replacing the acid generator with naphthyl imido camphorsulfonate, and was patterned in the same manner as in Example 1. However, baking after exposure was performed at 160 ° C. As a result, the exposure amount 42 m
It was found that a pattern was formed although it was as large as 0.45 μmL / S in J / cm ² .

[Table 2] Example 3 Polymerization was carried out in the same manner as in Example 1 except that 1-acryloyl-3-hydroxyadamantane was replaced with 1-acryloyl-3-carboxyadamantane and mixed at a mixing ratio shown in Table 3. A resist was prepared using the polymer in the same manner as in Example 1, and a resist 11 was prepared.
~ 15 were prepared. Using the resists 11 to 15, patterning was performed in the same manner as in Example 1. Table 3 shows the results.

[Table 3] The difference in the optimum mixing ratio from that in Example 1 is considered to be due to the difference in acidity, but it can be seen that patterning can be performed similarly. Example 4 1-acryloyl-3-te as a monomer
A method similar to that of Example 1 except that rt-butyloxycarbonyl adamantane, 1-acryloyl-3-hydroxyadamantane, and maleic anhydride were used, and a mixture of the three was used at a mol ratio of 1: 1: 2. The resist was prepared in the same manner as in Example 1 using the polymer to prepare a resist 16. Using the resist 16, patterning was performed in the same manner as in Example 1. As a result, the exposure amount 12
It was found that a pattern of 0.17 μmL / S could be resolved at mJ / cm ² . Table 4 shows the results.

On the other hand, 2-acryloyl-
Using 7-tert-butyloxycarbonyltricyclodecane, 2-acryloyl-7-hydroxymethyltricyclodecane and maleic anhydride, the three were treated in a 1: 1: 2 mo ratio.
Polymerization was carried out in the same manner as described above, except that the resin mixed at a mixing ratio of 1 was used, and the resist was evaluated in the same manner using the polymer. However, no pattern could be formed due to the crosslinking reaction. Was. As described above, it has been found that the resin having the structure according to the present invention exhibits a remarkable effect when combined with an acid anhydride at the same time.

[Table 4] (Mixing ratio is mol ratio of 1-acryloyl-3-tert-butyloxycarbonyladamantane, 1-acryloyl-3-hydroxyadamantane and maleic anhydride) (Example 5) 1-acryloyl-3-hydroxy of Example 1 Polymerization was carried out in the same manner as in Example 1 except that adamantane was replaced with 1-acryloyl-3-tetrahydropyranylcarboxyadamantane and 1-acryloyl-3-hydroxyadamantane and mixed at a mixing ratio shown in Table 5. Using the polymer, a resist was prepared in the same manner as in Example 1 to prepare resists 21 to 25. Patterning was performed in the same manner as in Example 1 using the resists 21 to 25. Table 5 shows the results.

[Table 5] (Mixing ratio is the charging ratio of 1-acryloyl-3-tetrahydropyranylcarboxyadamantane to 1-acryloyl-3-hydroxyadamantane) (Example 6) Compound 28; 0.06 mol and Compound 29; 0.0
The mixture of 4 mol was subjected to radical polymerization using AIBN 0.01 mol as a polymerization initiator, and a molecular weight of about 1
1,000 resins were obtained. To 1.0 g of the obtained resin, 0.01 g of triphenylsulfonium triflate as a photoacid generator was added and dissolved in 10 g of PGMEA, and the obtained resist solution was silicon-coated at 3,000 rpm for 30 seconds by a spin coating method. Spin-coated on wafer. Thereafter, a pre-exposure bake was performed on a hot plate at 120 ° C. for 90 seconds. The thickness of the resist was 0.2 μm. This was exposed to ArF excimer laser light to pattern lines and spaces. This one
After exposure and baking at 30 ° C. for 90 seconds, 2.38%
Develop in an aqueous TMAH solution at 25 ° C for 60 seconds,
A positive pattern of μmL / S was obtained. Sensitivity is 7.0m
J / cm ² .

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Embedded image (Example 7) Chemical formula 28; 0.04 mol and Chemical formula 31; 0.0
Radical polymerization of a 6 mol mixture was performed using 0.01 mol of AIBN as a polymerization initiator to obtain a resin having a molecular weight of about 10,000 shown in Chemical formula 32. To 1.0 g of the obtained resin, 0.01 g of triphenylsulfonium triflate was added as a photoacid generator.
g of PGMEA and dissolved in 10 g of PGMEA, and the obtained resist solution is subjected to spin coating at 3,000 rpm / min.
Spin coating was performed on the silicon wafer in 0 seconds. afterwards,
A pre-exposure bake was performed on a hot plate at 120 ° C. for 90 seconds. The thickness of the resist was 0.2 μm. This is exposed to ArF excimer laser light, and the line &
Space was patterned. This is 90 at 110 ° C.
After baking after exposure for 2 seconds, development was carried out in a 2.38% TMAH aqueous solution at 25 ° C. for 60 seconds to obtain a 0.15 μmL / S positive pattern. The sensitivity was 30 mJ / cm ² .

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Embedded image Example 8 The monomers shown in Chemical Formulas 33 (1) to 38 (1) are radically polymerized with the monomer shown in Chemical Formula 29 or 1-acryloyloxy-3-carboxyl adamantane, whereby Chemical Formulas 33 (2) to 38 (38) are obtained, respectively. (2)
Was obtained. The above polymer compound;
(2) to (38) are used as the acid generator TPS-105.
(1 wt%), and dissolved in a PGMEA solution, and these varnishes were spin-coated on Si wafers. Wavelength 193n
The substrate was exposed to light using an ArF excimer laser stepper, and baked at 110 ° C. for 5 minutes. 0.36N T
When developed using an MAH alkaline developer, a negative pattern was formed in which exposed portions remained and unexposed portions dissolved.

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[Table 6] As described above, it was found that a negative pattern was favorably formed without swelling in any of the resists. Further, when etching was performed by using CF ₄ plasma, the etching rate was 1.2 to
It was 1.0 times. (Examples 9 to 11 and Comparative Examples 1 to 5) Homopolymers of Polymers 1 to 8 shown in Chemical Formulas 39 to 41 were obtained by radical polymerization of monomers 1 to 8. The molecular weight of each polymer was about 10,000.

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Embedded image The glass transition temperatures (Tg) of these polymers were measured by differential scanning calorimetry (DSC). Table 7 shows the results.

[Table 7] As shown in Table 7, the polymer 1 in which a hydroxyl group or a group in which a hydroxyl group is esterified is bonded to two tertiary carbon positions (Example 9) is a polymer 2 having only one place (Comparative Example 1),
Tg about 10 ° C. higher than polymer 3 (Comparative Example 2),
It can be seen that the temperature is higher by 20 ° C. than that of Polymer 4 having no one (Comparative Example 3).

Also, in Polymer 5 (Example 10) or Polymer 7 (Example 11) having different types of alicycles, a hydroxyl group at two tertiary carbon positions or a polymer thereof is esterified with Tg. Is high.

Table 7 also shows the results obtained by calculating the Tg of these polymers. Calculation is CAch
It was performed by the Bicerano method on the e-system. The results are almost the same as the experimental results. In the post-exposure bake step, which is essential for chemically amplified resist,
A bake of ~ 150 ° C is essential. At this time, if Tg is low, the pattern will be degraded. Therefore, the resist composition of the present invention using the polymer of the present invention having a high Tg can form a resist pattern with high resolution. (Test Example 1) Monomer 1 and tetrahydropyranyl were polymerized to obtain a copolymer. This copolymer is exactly the same as the resist 4 used in Example 1. Using this, a resist was prepared in the same manner as in Example 1. In the same manner as in Example 1, a copolymer of monomer 2 and tetrahydropyranyl was polymerized to prepare a comparative resist. Using these resists, exposure and processing were performed in the same manner as in Example 1 to obtain resist patterns.

As a result, while the resist using the copolymer with the monomer 1 had a resolution of 0.15 μmL / S, the pattern with the copolymer with the monomer 2 had a resolution of only about 0.3 μmL / S. I didn't. This is because the Tg of the copolymer with the monomer 2 was lower than that of the copolymer with the monomer 1, so that the copolymer was in a rubbery state during the first post-exposure and the pattern was fluidized. (Test Example 2) Monomer 5 and tetrahydropyranyl were combined with 5
Polymerization was carried out at 0:50 mol% to obtain a copolymer. The polymerization method is the same as in Example 1. Using this, a resist was prepared in the same manner as in Example 1. In the same manner as in Example 1, a copolymer of monomer 6 and tetrahydropyranyl was polymerized at 50:50 mol% to prepare a comparative resist. Using these resists, exposure and processing were performed in the same manner as in Example 1 to obtain resist patterns.

As a result, in the resist using the copolymer with the monomer 5, 0.16 μmL / S was changed to 5.2 mJ / c.
It was resolved in m ^2. In a resist using a copolymer with a monomer, a pattern was flowing and only about 0.4 μmL / S was resolved.

This is because the copolymer with the monomer 5 in the copolymer with the monomer 5 has a low Tg, so that the copolymer becomes a rubbery state during the post-exposure bake and the pattern becomes fluid. (Test Example 3) Monomer 7 and tetrahydropyranyl in 5
Polymerization was carried out at 0:50 mol% to obtain a copolymer. The polymerization method is the same as in Example 1. Using this, a resist was prepared in the same manner as in Example 1. In the same manner as in Example 1, a copolymer of monomer 8 and tetrahydropyranyl was polymerized at 50:50 mol% to prepare a comparative resist. Using these resists, exposure and processing were performed in the same manner as in Example 1 to obtain resist patterns.

As a result, in the resist using the copolymer with the monomer 7, 0.16 μmL / S was changed to 5.2 mJ / c.
It was resolved in m ^2. In a resist using a copolymer with monomer 8, a pattern flows and 0.4 μmL / S
It was only resolved to a degree.

This is because the Tg of the copolymer with the monomer 8 was lower than that of the copolymer with the monomer 7, so that the copolymer was in a rubbery state during the post-exposure bake and the pattern was fluidized. (Examples 12 to 13, Comparative Example 6) [Synthesis of Raw Materials] 1,3-dihydroxyadamantane 1 m
was heated and stirred in an acetic acid-acetic anhydride solution containing CrO ₃ as an oxidizing agent, and after reacting for 8 hours, the reaction solution was neutralized to obtain a mixture of polyhydroxylated compounds of hydroxyadamantane. This mixture was separated by high performance liquid chromatography to obtain 1,3,5-trihydroxyadamantane.

1,3,5-Trihydroxyadamantane was dissolved in methylene chloride, a small amount of trimethylamine was added, an equimolar amount of trimethylsilyl chloride was added, and the mixture was reacted at room temperature. The reaction product was separated by high performance liquid chromatography to obtain 1,3-dihydroxy-5-trimethylsiloxyadamantane.

1,3-Dicarboxyadamantane was oxidized and fractionated in the same manner to obtain 1,3-dicarboxy-5-hydroxyadamantane.

The compound 1,3-dicarboxy-5-hydroxyadamantane was dissolved in THF and refluxed with an excess amount of thionyl chloride for 4 hours. Excess thionyl chloride and the solvent were distilled off to remove 1,3-dicarboxy. −5-
Acid chloride compound of hydroxyadamantane, 1,3-
Dichloroformyl-5-hydroxyadamantane was obtained.

1,3-Dichloroformyl-5-hydroxyadamantane was dissolved in methylene chloride, a small amount of trimethylamine was added, and an equimolar amount of trimethylsilyl chloride was added, followed by reaction at room temperature. 1,3-Dichloroformyl-5-trimethylsiloxyadamantane was obtained. [Synthesis of polymer] 0.05 mol of 1,3-dihydroxy-5-trimethylsiloxyadamantane was dissolved in THF, and 0.040 mol of compound 1,3-dichloroformyl-5-trimethylsiloxyadamantane was added thereto. 0.010 mol of the compound 1,3-dicarboxy-5-hydroxyadamantane was added. Keep the temperature at room temperature, stir, and add 0.1 mol of TH
The F solution was gradually added dropwise. After stirring for 2 hours and then at room temperature for another 2 hours, the reaction solution was separated by filtration. The reaction solution was gradually dropped into water and reprecipitated. This was dissolved again in THF, and tetrabutylammonium fluoride (TBA
F) was added to remove trimethylsilyl, and the reaction solution was gradually dropped into water to reprecipitate. As a result, an ester oligomer (including the polyanhydride) 1 was obtained. The molecular weight was 4000. The chemical formula of the ester oligomer 1 is as follows.

Embedded image 0.05 mol of 1,3-dichloroformyl-5-trimethylsiloxyadamantane is dissolved in THF, 0.040 mol of menthandiol is added thereto, and 0.010 mol of the compound 1,3-dicarboxy-5-hydroxyadamantane is further added. added. The temperature was maintained at room temperature, and the mixture was stirred, and a 0.1 mol solution of triethylamine in THF was gradually added dropwise. Stir for 2 hours, then at room temperature for another 2 hours
After stirring for an hour, the reaction solution was separated by filtration. The reaction solution was gradually dropped into water and reprecipitated. This is dissolved again in THF and TB
AF was added to remove trimethylsilyl, and the reaction solution was slowly dropped into water to reprecipitate. Ester oligomer (including polyanhydride) 2 was obtained. The molecular weight was 3500. The chemical formula of the ester oligomer 2 is shown below.

Embedded image 0.05 mol of 1,3-dichloroformyl-5-trimethylsiloxyadamantane was dissolved in THF, and 0.050 mol of menthandiol was added thereto. The temperature was maintained at room temperature, and the mixture was stirred, and a 0.1 mol solution of triethylamine in THF was gradually added dropwise. Stir for 2 hours, then
After stirring at room temperature for another 4 hours, the reaction solution was separated by filtration. The reaction solution was gradually dropped into water and reprecipitated. TH again
F was dissolved in F and TBAF was added thereto to remove trimethylsilyl, and the reaction solution was gradually dropped into water to obtain an ester oligomer 3 which was reprecipitated. The molecular weight was 3000. The chemical formula of the ester oligomer 3 is shown below.

Embedded image [Synthesis of Comparative Polymer] [Synthesis of Comparative Ester Oligomer] 0.05 mol of 1,3-diacetylchloridadamantane was dissolved in THF, and 0.05 mol of menthanediol was added thereto.
The mixture was stirred while maintaining the temperature at room temperature, and a THF solution of 0.1 mol of triethylamine was gradually added dropwise. After stirring for 2 hours and then at room temperature for another 2 hours, the reaction solution was separated by filtration. The reaction solution was gradually dropped into water, and the precipitated precipitate was further reprecipitated with a water-acetone solvent to obtain a comparative ester oligomer A. The chemical formula of the comparative ester oligomer A is shown below.

Embedded image [Synthesis of dissolution inhibitor] 0.1 mol equivalent of β-naphthol novolak was dissolved in THF, and sodium hydride 0.1% was dissolved in THF.
After stirring for 6 hours at room temperature with a sufficient amount of di-t-butyl dicarbonate in the presence of mol, the reaction mixture was mixed with water and extracted with ethyl acetate to give t-butoxycarbonyl having a molecular weight of 3,000. Naphthol novolak (tBocN)
N) was synthesized. Here, the introduction rate of toftokidicarbonyl in tBocNN is 100 mol of the total hydroxyl groups.
1%.

An equimolar amount of sodium hydride was added to tert-butyl malonate in THF, bromomethyladamantyl ketone was added, and the mixture was stirred for 3 hours. The salt formed is filtered off, the solution is concentrated and di-tert-butyl 2-((1-adamantyl) carbonylmethyl) malonate (ADT
B) was obtained.

1-naphthol was condensed with glyoxylic acid under an oxalic acid catalyst to obtain a novolak compound. This was dissolved in dihydropyran, and a catalytic amount of hydrochloric acid was added to obtain a pyranylated novolak compound (NV4THP). [Preparation of resist and formation of resist pattern] As a polymer compound synthesized as described above, TPS-105 or NAI manufactured by Midori Kagaku as a dissolution inhibitor and a photoacid generator.
-105 was dissolved in cyclohexanone according to the formulation shown in Table 8 to prepare resist varnishes of Examples 12 to 16. On the other hand, as a comparative resist, a varnish of Comparative Example 6 was prepared as shown in Table 8 together with a resist varnish containing TPS-105 as a photoacid generator.

[Table 8] Next, a varnish of each of these resists is spin-coated on a silicon wafer to form a resist film having a thickness of 0.3 μm, and a stepper with NA = 0.55 using ArF excimer laser light having a wavelength of 193 nm as a light source is used. Then, a predetermined pattern light was exposed on the surface of the resist film. Then 110
After a baking treatment at 2 ° C. for 2 minutes, a 2.38% aqueous solution of tetramethylammonium hydroxide (TMA
The exposed portion was selectively dissolved and removed with a mixed solution of H) and isopropyl alcohol to form a positive resist pattern. The sensitivity and resolution at this time are shown in Table 9.

[Table 9] As shown in Table 9, in each of the resists of Examples 12 to 16, a resist pattern having high sensitivity and good resolution was formed, and transparency to light having a wavelength of 193 nm and alkali developability were excellent. You can see that there is.
On the other hand, in the resist of Comparative Example 6, it was also found that a resist pattern having good resolution was not formed, and it was found that there was a problem that the resist pattern was easily peeled off.

Further, regarding these resists, CF ₄
The dry etching resistance was evaluated by measuring the etching rate by plasma. As a result, when the etching rate of the resist using polyhydroxystyrene resin as the base resin was 1.0, the etching rate of Comparative Example 6 was 1.0, and the etching rate of the resists of Examples 12 to 16 was 0.1. 9 to 1.2, all of which were confirmed to have high dry etching resistance. (Examples 17 to 19) The monomers represented by the following formulas (Formula 46) and (Formula 47) were mixed at a ratio of 2: 8 in THF, and 10 mol
1% of AIBN was added and copolymerized at 60 ° C. for 40 hours.
This reaction solution was dropped into hexane, filtered and exposed to light to obtain a resin of Example 17. The molecular weight was 12,000.

Embedded image

Embedded image The monomers represented by the following formulas (48), (49) and (50) were mixed at a ratio of 7: 2: 1 in THF, 10 mol% of AIBN was added, and the mixture was copolymerized at 60 ° C. for 40 hours. The reaction solution was dropped into hexane, filtered and exposed to light to obtain a resin of Example 18. The molecular weight is 47,000 with a wide distribution, and it is estimated that the polymer is partially three-dimensionally crosslinked.

Embedded image

Embedded image

Embedded image The monomers represented by the following formulas (51) and (52) are used in a ratio of 6: 4
Mix in THF, add 10 mol% AIBN and add
It copolymerized at 40 degreeC for 40 hours. This reaction solution was dropped into hexane, filtered and exposed to light to obtain a resin of Example 19. The molecular weight was 17,000.

Embedded image

Embedded image To the polymer of Examples 17 to 19 synthesized as described above, 1 part by weight of Midori Kagaku TPS-105 as a photoacid generator was added, dissolved in cyclohexanone, and filtered to obtain Example 1.
Varnishes of 7 to 19 resists were prepared.

Next, a varnish of each of these resists was spin-coated on a silicon wafer to form a resist film having a thickness of 0.3 μm, and a stepper having an NA of 0.54 using an ArF excimer laser beam having a wavelength of 193 nm as a light source. A predetermined pattern light was exposed on the surface of the resist film. Subsequently, after baking at 110 ° C. for 2 minutes, an aqueous solution of tetramethylammonium hydroxide (TMA)
In H), the exposed portion was selectively dissolved and removed to form a positive resist pattern. Table 10 shows the sensitivity and resolution at this time.

[Table 10] As shown in Table 10, in each of the resists of Examples 17 to 19, a resist pattern having high sensitivity and good resolution was formed, and transparency to light having a wavelength of 193 nm and alkali developability were excellent. It turns out that there is.

Further, regarding these resists, CF ₄
The dry etching resistance was evaluated by measuring the etching rate by plasma. As a result, when the etching rate of the resist using the novolak resin as the base resin was 1.0, the etching rate of the resist of Comparative Example 6 was 1.
In contrast to 2, the etching rates of the resists of Examples 17 to 19 were 0.9 to 1.0, and it was confirmed that all of them had high dry etching resistance. (Examples 20 and 21) The monomers represented by the following formulas 53 and 47 were mixed in THF at a ratio of 4: 6, and 10 mol
1% of AIBN was added and copolymerized at 60 ° C. for 40 hours.
This reaction solution was dropped into hexane, filtered and exposed to light to obtain a resin of Example 20. The molecular weight was 10,000.

Embedded image Embedded image and a monomer represented by the following formula (54) were mixed at a ratio of 6: 4 in THF, 10 mol% of AIBN was added, and copolymerization was performed at 60 ° C. for 40 hours. The reaction solution was dropped into hexane, filtered and exposed to light to obtain a resin of Example 21. The molecular weight was 12,000.

Embedded image (Examples 22 and 23) The monomers represented by the following formulas (55) and (47) were mixed in THF at a ratio of 4: 6, and 10 mol
1% of AIBN was added and copolymerized at 60 ° C. for 40 hours.
This reaction solution was dropped into hexane, filtered and exposed to light to obtain a polymer of Example 22. The molecular weight was 6000.

Embedded image The monomers represented by the following formulas (56) and (48) are used in a ratio of 2: 8.
And mix in THF, add 10 mol% AIBN and add
Copolymerized at 0 ° C. for 40 hours. The reaction solution was dropped into hexane, filtered and exposed to light to obtain a resin of Example 23. The molecular weight was 7,500.

Embedded image To the polymer compounds of Examples 20 to 23 synthesized as described above, TPS-105 manufactured by Midori Kagaku as a photoacid generator was added.
The mixture was dissolved in cyclohexanone and filtered to prepare resist varnishes of Examples 20 to 23.

Next, a varnish of each of these resists was spin-coated on a silicon wafer to form a resist film having a thickness of 0.3 μm, and a stepper having an NA of 0.55 using ArF excimer laser light having a wavelength of 193 nm as a light source. A predetermined pattern light was exposed on the surface of the resist film. Subsequently, after baking at 110 ° C. for 2 minutes, an aqueous solution of tetramethylammonium hydroxide (TMA)
In H), the exposed portion was selectively dissolved and removed to form a positive resist pattern. Table 11 shows the sensitivity and resolution at this time.

[Table 11] As shown in Table 11, the etching resistance of the resists of Examples 20 to 23 was 0.8 to 1.0 times that of the novolak resin when the etching rate by CF ₄ plasma was measured to evaluate the dry etching resistance. It was confirmed that there was. (Examples 24 and 25, Comparative Example 7) The monomers represented by the following formulas (57) and (58) were mixed in THF at a ratio of 4: 6, 10 mol% of AIBN was added, and the mixture was added at 60 ° C for 40 hours.
It was copolymerized. This reaction solution is dropped into hexane, filtered,
It dried and the resin of Example 24 was obtained. The molecular weight was 6000.

Embedded image

Embedded image The monomers shown in Chemical formulas 59 and 60 and maleic anhydride are mixed in THF at 3.5: 3: 3.5, and
mol% of AIBN was added and copolymerized at 60 ° C. for 40 hours. This reaction solution was dropped into hexane, filtered and dried to obtain a resin of Example 21. The molecular weight was 5,500.

Embedded image

Embedded image Further, as Comparative Example 7, a monomer represented by Chemical Formula 59 and 2
-Acroyloxy-7-hydroxymethyltricyclodecane and maleic anhydride were mixed at 3.5: 3: 3.5 in THF, 10 mol% AIBN was added and the mixture was added at 60 ° C for 40 hours,
It was copolymerized. This reaction solution is dropped into hexane, filtered,
It was exposed to light and a resin 7 of a comparative example was obtained. The molecular weight was 9000.

Examples 24 to 25 synthesized as described above,
To the polymer compound of Comparative Example 7, 1 part by weight of Midori Kagaku TPS-105 as a photoacid generator was added, dissolved in cyclohexanone, and filtered to prepare resist varnishes of Examples 24 to 25.

Next, a varnish of each of these resists was spin-coated on a silicon wafer to form a resist film having a thickness of 0.3 μm, and a stepper having an NA of 0.55 using an ArF excimer laser beam having a wavelength of 193 nm as a light source. A predetermined pattern light was exposed on the surface of the resist film. Subsequently, after baking at 110 ° C. for 2 minutes, an aqueous solution of tetramethylammonium hydroxide (TMA)
In H), the exposed portion was selectively dissolved and removed to form a positive resist pattern. Table 12 shows the sensitivity and resolution at this time.

[Table 12] As shown in Table 12, it can be seen that the combination of maleic anhydride and the resin structure of the present invention also gives a particularly good effect. Its etch resistance even when assessed resistance to dry etching, it was confirmed that Der 0.8-1.0 times the novolak resin was measured CF ₄ plasma by the etching rate in the resists of Examples 24-25.

[0117]

As described in detail above, according to the resist resin, resist composition and pattern forming method of 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.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 21/027 H01L 21/30 502R (72) Inventor Takeshi Okino 1 Komukai Toshiba-cho, Saiwai-ku, Kawasaki-shi, Kanagawa-ken Address: In the Toshiba R & D Center (72) Inventor: Naomi Shinda 1 in Komukai Toshiba-cho, Yuki-ku, Kawasaki-shi, Kanagawa Prefecture In-house Toshiba R & D Center (72) Inventor: Satoshi Saito Sachi-ku, Kawasaki-shi, Kanagawa No. 1 Muko Toshiba Town F-term in Toshiba Research & Development Center Co., Ltd. (Reference) EQ016 EV016 EV046 EV206 EV216 EV246 EV256 EV306 EV316 EV346 FD206 GP03 4J029 AA03 AB07 AC01 AC02 AD01 AE04 BD05C BD10 CD07 HA 01 HB01 HB05 KA02 KB02 KE09

Claims (16)

[Claims] 1. A resist resin having a bridged alicyclic ring and a structure in which at least two oxygen-containing polar groups are bonded to the tertiary carbon position of the bridged alicyclic ring. 2. A polymer or condensate of a monomer having a bridged alicyclic ring and having a structure in which at least two oxygen-containing polar groups are bonded to a tertiary carbon position of the bridged alicyclic ring. Resist resin. 3. A resin having a structure having a bridged alicyclic ring and at least two oxygen-containing polar groups bonded to a tertiary carbon position of the bridged alicyclic ring, and a photoacid generator. A resist composition comprising: 4. The method according to claim 3, wherein the oxygen-containing polar group bonded to the tertiary carbon position of the bridged alicyclic ring is three or more.
The resist composition as described in the above. 5. The resist according to claim 3, wherein the bridged alicyclic ring is at least one selected from the group consisting of an adamantane ring, a tricyclodecane ring, a tetracyclododecane ring, and a norbornane ring. Composition. 6. At least one organic compound wherein at least one of the oxygen-containing polar groups is selected from the group consisting of a substituted or unsubstituted carboxyl group, a substituted or unsubstituted hydroxyl group, and a substituent containing a cyclic lactone. 4. The resist composition according to claim 3, wherein the group is a group. 7. The resist composition according to claim 3, wherein at least one of the oxygen-containing polar groups is a carboxyl group protected by a soluble group that can be decomposed by an acid. 8. The resist composition according to claim 3, wherein the resin contains an acid anhydride structure, and at least one of the oxygen-containing polar groups is a hydroxyl group. 9. A resin comprising a polymer or condensate of a monomer having a bridged alicyclic ring and having a structure in which at least two oxygen-containing polar groups are bonded to a tertiary carbon position of the bridged alicyclic ring; A resist composition comprising at least a photoacid generator. 10. The resist composition according to claim 9, wherein the number of oxygen-containing polar groups bonded to the tertiary carbon position of the bridged alicyclic ring is three or more. 11. The polymer of a monomer having a bridged alicyclic ring and having a structure in which at least two oxygen-containing polar groups are bonded to a tertiary carbon position of the bridged alicyclic ring, The resist composition according to claim 9, wherein at least one of the oxygen-containing polar groups bonded to the bridged alicyclic ring of the monomer is an acryloyloxy group or a methacryloyloxy group. 12. The resin is a polymer of a monomer having a bridged alicyclic ring and having a structure in which at least two oxygen-containing polar groups are bonded to the tertiary carbon position of the bridged alicyclic ring, The resist composition according to claim 9, wherein the monomer is a compound represented by the following general formula (1). Embedded image (However, R1 represents an acryloyl group or a methacryloyl group, R2 represents a hydrogen atom or an oxygen-containing polar group, and R3
Represents a hydrogen atom, an acid-decomposable group, a cyclic substituent having a lactone, or a substituent having an acid anhydride structure with a bridged alicyclic compound having a carboxylic acid. ) 13. A polymer of a monomer having a bridged alicyclic ring and having a structure in which at least two oxygen-containing polar groups are bonded to a tertiary carbon position of the bridged alicyclic ring, The resist composition according to claim 9, wherein the monomer is a compound represented by the following general formula (2). Embedded image (However, R1 represents an acryloyl group or a methacryloyl group, R2 represents a hydrogen atom or an oxygen-containing polar group,
4 represents a hydroxyl group, a lactone-containing cyclic substituent or a carboxylic acid-containing bridged alicyclic compound having an acid anhydride structure. ) 14. The resin according to claim 1, wherein at least one organic group of at least a carboxyl group and a hydroxyl group is two or more.
The resist composition according to claim 9, which is a main-chain alicyclic resin obtained by dehydrating and condensing a monomer having a bridged alicyclic ring having at least one tertiary carbon position. 15. The resist composition according to claim 14, wherein the resin has at least one of a polyester structure and a polyanhydride structure. 16. At least a step of applying the resist composition according to claim 3 on a substrate, a step of patternwise exposing the applied resist composition, and a step of developing the exposed resist composition A pattern forming method, comprising: