JP4212515B2 - Resist monomer - Google Patents

Description

  The present invention relates to a photosensitive composition and a pattern forming method used for fine processing in a manufacturing process of a semiconductor element or the like.

  In the manufacturing process of electronic components such as LSI, a microfabrication technique using photolithography is employed. That is, first, a photosensitive composition is applied onto a substrate or the like to form a resist film, and then the resulting resist film is exposed to pattern light, and then subjected to treatment such as alkali development to form a resist. Form a pattern. Subsequently, the surface of the substrate or the like exposed using the resist pattern as an etching resistant mask is dry-etched to form fine width lines and openings, and finally the ashing is removed from the resist film. .

  Therefore, the resist film used here is generally required to have high dry etching resistance. From this point of view, photosensitive compositions containing aromatic compounds have been widely used as resists. Specifically, many resists based on alkali resins such as phenol resins have been developed. ing.

  On the other hand, with the high-density integration of LSIs and the like, the fine processing technology as described above has recently reached the sub-quarter micron order, and such miniaturization is expected to become more remarkable in the future. For this reason, the shortening of the wavelength of the light source in photolithography is progressing and attempts are being made to form a fine resist pattern using ArF excimer laser light having a wavelength of 193 nm or YAG laser having a wavelength of 218 nm and a fifth harmonic light.

  However, a photosensitive composition using a phenol resin as a base resin, which has been common so far, tends to have a large light absorption in the benzene nucleus with respect to the short wavelength light as described above. Therefore, when trying to form a resist pattern, it is difficult to make light sufficiently reach the substrate side of the resist film during exposure, and as a result, it is difficult to form a pattern with a good pattern shape with high sensitivity and high accuracy. there were.

  In view of such a background, development of a highly transparent photosensitive composition suitable for photolithography using ArF excimer laser light or fifth harmonic light of YAG laser is strongly desired.

  Recently, a photosensitive composition using an alicyclic compound instead of an aromatic compound such as a phenol resin has attracted attention from such a point. For example, JP-A-4-39665 discloses dry etching resistance and short wavelength. A polymer obtained by copolymerizing a compound having an adamantane skeleton, which is a bridged alicyclic compound, and another acrylate ester-based compound imparting solubility as a base resin of a photosensitive composition having good transparency to light An example is shown in which a resist pattern is formed by alkali development. JP-A-7-199467 discloses a photosensitive composition using a compound having a tricyclodecanyl structure which is a bridged alicyclic compound.

  However, when forming a resist pattern by alkali development using a photosensitive composition based on these alicyclic compounds as a resist, alicyclic structures such as an adamantane skeleton and tricyclodecanyl structure are very hydrophobic. The alkali solubility is greatly different from that of a soluble group such as a carboxylic acid group, and various problems occur.

  For example, the dissolution / removal of a predetermined region of the resist film at the time of development becomes uneven, resulting in a decrease in resolution. On the other hand, a decrease in resolution resulting from swelling after development of the resist pattern, or the resist film should remain. Even in this region, 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 peeled off. Furthermore, in the polymer, phase separation between the part having an alicyclic structure and a soluble group such as a carboxylic acid group part easily proceeds, and it is difficult to prepare a uniform resist solution, and the coating property is not sufficient.

  In order to reduce the hydrophobicity of these alicyclic compounds, mild acidic substituents are introduced into the alicyclic compounds (Japanese Patent Application Laid-Open No. 9-120162), or substituents having an OH group (Japanese Patent Application Laid-Open No. Hei 7). No. -252324), and examples in which a nitro group or a sulfonyl group is introduced (Japanese Patent Laid-Open No. 10-3169) are known, and in any of these compounds, the solubility and adhesion are considerably improved. It has been known.

  However, the OH group has a drawback that it easily causes swelling in the resist pattern and is easily condensed and negatively condensed with other substituents in the resist, while the other substituents have two or more oxygen atoms. In addition, it has been found that due to the high reactivity with the etching gas, the dry etching resistance often decreases.

  Also, the main chain decomposition type alicyclic resist material disclosed in JP-A-10-171120 has some problems in adhesion. When a large number of OH groups were introduced into the alicyclic ring to improve this, there was a problem that the resin was cross-linked to become three-dimensional, resulting in a decrease in solubility.

  Therefore, the present invention solves the above-mentioned problems in the conventional photosensitive composition, has excellent transparency to short wavelength light, has high dry etching resistance, can be developed with alkali, has adhesion and resolution. It aims at providing the photosensitive composition and pattern formation method which can form a favorable resist pattern.

  The present invention relates to a resin containing in its structure a bridged alicyclic skeleton composed of a combination of at least two or more rings selected from the group consisting of 5-membered rings, 6-membered rings, and 7-membered rings, and a photoacid generator And at least one carbon constituting the bridged alicyclic skeleton in the resin is bonded to oxygen through a double bond. It is.

  The present invention also provides a pattern forming method in which a resist film is formed on a substrate, exposed to actinic radiation, heated after exposure, and further developed with an aqueous alkaline solution to form the pattern. It is a pattern formation method characterized by using.

  That is, in the present invention, as the base resin of the photosensitive composition, a bridged alicyclic skeleton comprising a combination of at least two or more rings selected from the group consisting of a 5-membered ring, a 6-membered ring, and a 7-membered ring. (Hereinafter referred to as “Aribashi alicyclic skeleton”) in the structure is used. Thereby, the dry etching resistance of the photosensitive composition and the transparency with respect to short wavelength light are made compatible.

  Further, at least one carbon constituting the bridged alicyclic skeleton is bonded to oxygen through a double bond, that is,> C═O is introduced into the bridged alicyclic skeleton. . Thereby, the alkali solubility, dry etching resistance, adhesion, and resolution of the photosensitive composition are improved.

  When a resin having> C = O introduced into the bridged alicyclic skeleton in the resin is used, hydrophilicity similar to that when a substituent having an OH group described in the prior art is introduced can be imparted, and Since it is not highly reactive as in the case of introducing a substituent having an OH group, a negative reaction due to a side reaction hardly occurs. Furthermore, it is desirable because it is difficult to swell against water. Moreover, when a nitro group or a sulfonyl group is introduced, the dry etching resistance tends to be lowered, but when> C = O is introduced, a relatively high dry etching resistance is exhibited.

  As described above in detail, according to the present invention, it is possible to form a resist pattern that has excellent transparency to short-wavelength light, has high dry etching resistance, and has good resolution and high adhesion by alkali development. It becomes possible to realize a photosensitive composition.

<Resin>
The resin according to the photosensitive composition of the present invention will be described below.

  The basic resin in the photosensitive composition of the present invention is a bridged alicyclic skeleton comprising a combination of at least two or more rings selected from the group consisting of 5-membered rings, 6-membered rings, and 7-membered rings ( Hereinafter, it is referred to as “Aribashi alicyclic skeleton”).

  The bridged alicyclic skeleton may be a combination of alicyclic rings having the same number of members, or may be a combination of alicyclic members having different numbers of members. Moreover, the element which comprises the said bridged alicyclic skeleton may contain elements, such as oxygen, sulfur, nitrogen other than carbon.

  Specific examples of the bridged alicyclic skeleton include a norbornyl ring, an adamantyl ring, a dicyclopentane ring, a tricyclodecane ring, a tetracyclododecane ring, a bornene ring, a decahydronaphthalene ring, a polyhydroanthracene ring, and a tricyclene. And steroid skeleton such as cholesteric ring, tanjusan, digitaloids, camphor ring, iso camphor ring, sesquiterpene ring, sandton ring, diterpene ring, triterpene ring, steroid saponins and the like.

  The resin according to the present invention contains the bridged alicyclic skeleton in the structure, and at least one carbon constituting the bridged alicyclic skeleton is bonded to oxygen via a double bond, that is,> C = O.

  In the resin according to the present invention, each component is desirably blended so that the amount of> C = O is 40% by weight or more in the solid content of the photosensitive composition. This is because if it is less than 40% by weight, it becomes difficult to obtain a resist pattern with good resolution and adhesion by alkali development, and the dry etching resistance of the resulting resist pattern may be lowered.

  Furthermore, the resin according to the present invention may include the bridged alicyclic skeleton in the structure, and at least one of the rings constituting the bridged alicyclic skeleton may be a lactone ring. That is, it contains -C (= O) -O- in the ring.

  By having such a bridged alicyclic skeleton having a lactone ring, the alkali solubility, dry etching resistance, and adhesion can be further improved.

  When the bridged alicyclic skeleton of the resin is a lactone ring, higher hydrophilicity can be imparted than when a substituent having a OH group, a sulfonyl group, or a nitro group described in the prior art is introduced. In addition, since it is not highly reactive as in the case of introducing a substituent having an OH group, a negative reaction due to a side reaction hardly occurs.

  In this case, it is preferable that each component is blended so that the amount of lactonyl groups of the resin is 30 mol% or more in the resin. This is because if it is less than 30 mol%, it becomes difficult to form a resist pattern having good resolution and adhesion by alkali development, and the adhesion of the resulting resist pattern tends to be lowered.

  The resin according to the present invention can be obtained, for example, by the following methods (a) and (b). (A) First, a part of carbon of the alicyclic compound having the bridged alicyclic skeleton is oxidized by applying a strong oxidizing agent. As a result, the methylene carbon in the bridged alicyclic skeleton is oxidized, and an alicyclic compound (alicyclic compound (A)) having the bridged alicyclic skeleton introduced with> C═O is obtained. .

  Further, when the oxidant is allowed to act, an alicyclic compound having the above-mentioned bridged alicyclic skeleton in which —O— is introduced into the ring and the bridged alicyclic skeleton becomes a lactone ring when oxidized (alicyclic) Compound (B)) is obtained.

  Next, using the alicyclic compound (A) or (B) as a monomer, or an alicyclic compound (A) or (B) into which a group that acts as a binding moiety in the subsequent polymerization is introduced. The resin according to the present invention can be obtained by using a derivative of the formula compound (A) or (B) as a monomer and homopolymerizing it or copolymerizing with another monomer.

  (B) The resin according to the present invention can be obtained by oxidizing a part of carbon of the resin having a bridged alicyclic skeleton by the action of a strong oxidizing agent.

Specific examples of the polymerization method described in (a) above include the following [1] and [2].
[1] Aliphatic compound (A) or (B), which is a monomer for synthesizing the resin according to the present invention, or a compound having a polymerizable double bond as a derivative thereof, radical polymerization or anionic polymerization, Polymerization is carried out under cationic polymerization or Ziegler-Natta catalyst. In general, a monomer having a polymerizable double bond having an alicyclic group in the main chain can be polymerized using a Ziegler-Natta catalyst to obtain a polymer having a high molecular weight. However, since the resin according to the present invention has no problem as long as the resin has a low molecular weight, it can be polymerized using a simple technique such as radical polymerization and mixed with a low molecular weight compound and a high molecular weight compound. May be used.

  As the compound having a polymerizable double bond, norbornyl di (mono) ene, tricyclodeca (mono) diene, or tetracyclodeca (mono) diene is oxidized, and at least one of the alicyclic rings is> C = O, or- Examples thereof include a compound into which C (═O) —O— has been introduced.

  The compound having a polymerizable double bond is preferably an ester compound of alcohol or carboxylic acid because polymerization is easy.

  Further, when the compound having a polymerizable double bond is an acrylic acid ester compound or a methacrylic acid ester compound, it is desirable because it is highly polymerizable and can be polymerized at an arbitrary composition ratio. At this time, it is more preferable that the acrylic ester compound or the methacrylic ester compound has an adamantane, tricyclodecane, tetracyclodecane, or hydronaphthalene skeleton in the side chain.

（ただしＲはアクリロイル基又はメタクリロイル基を示す。） なお、一般式（１）で示される化合物においてはカルボニル基が２位に導入されたものであっても良い。 In particular, the resin of the present invention is preferably polymerized by using a compound represented by any one of the following general formulas (1a) and (1b) as a monomer because it is excellent in dry etching resistance and adhesion. Become.

(However, R represents an acryloyl group or a methacryloyl group.) In the compound represented by the general formula (1), a carbonyl group introduced at the 2-position may be used.

（ただしＲはアクリロイル基又はメタクリロイル基を示し、Ｒ１、Ｒ２はアルキル基又は酸分解基を示す。）
Ｒ１、Ｒ２は一部で架橋して環状化合物を形成していてもかまわない。また、アダマンチリデン基が２位に導入されていてもかまわない。 In addition, the resin of the present invention is polymerized with a compound represented by any one of the following general formulas (2a) and (2b) as a monomer, and has high polymerizability and can be polymerized at an arbitrary composition ratio. Therefore, it is desirable.

(However, R represents an acryloyl group or a methacryloyl group, and R1 and R2 represent an alkyl group or an acid-decomposable group.)
R1 and R2 may be partially crosslinked to form a cyclic compound. An adamantylidene group may be introduced at the 2-position.

（ただしＲはアクリロイル基又はメタクリロイル基を示す。）
なお、一般式（３ａ）、（３ｂ）、（３ｃ）で示される化合物においてはラクトニル基が２位に導入されたものであっても良い。 Further, the resin of the present invention is excellent in dry etching resistance and adhesion when polymerized by using a compound represented by any one of the following general formulas (3a), (3b), and (3c) as a monomer. Therefore, it becomes desirable.

(However, R represents an acryloyl group or a methacryloyl group.)
In the compounds represented by the general formulas (3a), (3b), and (3c), a lactonyl group may be introduced at the 2-position.

（ただしＲ1はアクリロイル基又はメタクリロイル基を示す。）
［２］本発明に係る樹脂を合成するためのモノマーである、脂環式化合物（Ａ）又は（Ｂ）あるいはその誘導体としてヒドロキシル基とカルボキシル基の少なくとも一方を２個以上含む化合物を用い、この化合物単独または他の、ヒドロキシル基とカルボキシル基の少なくとも一方を２個以上の有する化合物との縮合によって重合させ、ポリエステル樹脂あるいはポリ酸無水物樹脂の少なくとも一方を得る。 Further, the resin of the present invention is desirable when it is polymerized using a compound represented by the following general formula (4) as a monomer because it is highly polymerizable and can be polymerized at an arbitrary composition ratio.

(However, R1 represents an acryloyl group or a methacryloyl group.)
[2] A compound for synthesizing the resin according to the present invention is a alicyclic compound (A) or (B) or a derivative thereof using a compound containing at least one of hydroxyl groups and carboxyl groups. Polymerization is carried out by condensation of the compound alone or another compound having at least one of hydroxyl group and carboxyl group, and at least one of polyester resin or polyanhydride resin is obtained.

[2] -1: In the case of a polyester resin, a compound having a monohydroxy-monocarboxylic acid skeleton as the alicyclic compound (A) or (B) or a derivative thereof, which is a monomer for synthesizing the resin according to the present invention Can be obtained by dehydration condensation. Alternatively, as the alicyclic compound (A) or (B) or a derivative thereof, which is a monomer for synthesizing the resin according to the present invention, a polyvalent carboxylic acid having at least one of hydroxyl group and carboxyl group and It may be obtained by using a polyhydric alcohol compound and subjecting it to dehydration condensation. Alternatively, the cycloaliphatic compound (A) or (B) or a derivative thereof, which is a monomer for synthesizing the resin according to the present invention, has at least one of at least one of a hydroxyl group and a carboxyl group, and is a conjugated compound. You may obtain by making both react using the polyhydric alcohol and polyhydric carboxylic acid compound which have a ring condensed aromatic skeleton. These polyvalent carboxylic acids or polyhydric alcohols may contain a plurality of compounds.

In addition to the above, many commonly used polyester synthesis methods such as lactone ring-opening reaction, polymerization with polyhydric alcohol by ring-opening reaction of polyhydric carboxylic acid anhydride, It can also be obtained by utilizing polymerization in which an acid chloride and a polyhydric alcohol are desalted by using triethylamine or the like as a catalyst, polymerization by reaction of a polyvalent carboxylic acid and a polyvalent epoxy compound, or the like.
[2] -2: In the case of a polyanhydride resin, as the alicyclic compound (A) or (B) or a derivative thereof, which is a monomer for synthesizing the resin according to the present invention, hydroxyl group and carboxyl group It can be obtained by using a polycarboxylic acid having two or more at least one and dehydrating and condensing it alone. Alternatively, the alicyclic compound (A) or (B), or a derivative thereof, which is a monomer for synthesizing the resin according to the present invention, a polyvalent carboxylic acid having at least one of hydroxyl groups or carboxyl groups and It can also be obtained by desalting using polyvalent carboxylic acid chloride and using triethylamine or the like as a catalyst.

  The resin according to the present invention may be one in which a polyester bond or a polyanhydride bond is mixed at the same time.

  The resin according to the present invention can be obtained by polymerizing the alicyclic compound (A) or (B) or a derivative thereof as described above, but obtained by copolymerizing with various other vinyl compounds. But you can. 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-chloroacrylate, butadiene, glycidyl methacrylate, isobornyl methacrylate, menthyl methacrylate, norbornyl methacrylate, adamantyl methacrylate, allyl methacrylate and the like.

  In addition, from the viewpoint of adjusting the alkali solubility of the resin and improving the adhesion of the resist to the substrate, alkali-soluble compounds such as acrylic acid, maleic anhydride and their ester-substituted products, vinylphenol, vinylnaphthol, naphtholoxymethacrylate, and SO2 It is preferable to copolymerize with. Furthermore, you may copolymerize the compound formed by protecting the alkali-soluble group of these alkali-soluble compounds with an acid-decomposable group having dissolution inhibiting ability.

  Examples of the acid-decomposable group include isopropyl ester, tetrahydropyranyl ester, 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 xo-1,3-dioxolane; t-butoxycarbonyl ether, t-butoxymethyl ether, 4-pentenyloxymethyl ether, tetrahydropyranyl ether, -Bromotetrahydropyranyl ether, 1-methoxycyclohexyl ether, 4-methoxytetrahydropyranyl ether, 4-methoxytetrahydrothiopyranyl ether, 1,4-dioxane-2-yl ether, tetrahydrofuranyl ether, 2,3,3a, 4 5,6,7,7a-octahydro-7,8,8-trimethyl-4,7-methanobenzofuran-2-yl ether, t-butyl ether, trimethylsilyl ether, triethylsilyl ether, triisopropylsilyl ether, dimethylisopropylsilyl ether , Ethers such as diethyl isopropyl silyl ether, dimethyl hexyl silyl ether, t-butyl dimethyl silyl ether; methylene acetal, ethylidene acetal 2, 2, 2-to Acetals such as chloroethylidene acetal, 2,2,2-tribromoethylidene acetal, 2,2,2-triiodoethylidene acetal; 1-t-butyl ethylidene ketal, isopropylidene ketal (acetonide), cyclopentylidene ketal, Ketals such as cyclohexylidene ketal and cycloheptylidene ketal; methoxymethylene acetal, ethoxymethylene acetal, dimethoxymethylene orthoester, 1-methoxyethylidene orthoester, 1-ethoxyethylidene orthoester, 1,2-dimethoxyethylidene orthoester Cyclic orthoesters such as 1-N, N-dimethylaminoethylidene orthoester and 2-oxacyclopentylidene orthoester; Silyl ketene acetals such as ten acetal, triethylsilyl ketene acetal, triisopropylsilyl ketene acetal, t-butyldimethylsilyl ketene acetal; di-tert-butylsilyl ether, 1,3-1 ′, 1 ′, 3 ′, 3 Silyl ethers such as' -tetraisopropyldisiloxanylidene 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-2,2,2-triiodoethyl ketal, diacetyl Acyclic acetals or ketals such as acetal and diacetyl ketal; 1,3-dioxane, 5-methylene-1,3-dioxane, 5,5-dibromo-1,3-dioxane, 1,3-dioxolane, 4- Cyclic acetals or ketals such as bromomethyl-1,3-dioxolane, 4-3′-butenyl-1,3-dioxolane, 4,5-dimethoxymethyl-1,3-dioxolane; O-trimethylsilylcyanohydrin, O— And cyanohydrins such as 1-ethoxyethyl cyanohydrin and O-tetrahydropyranyl cyanohydrin.

  Among these acid-decomposable groups, t-butyl group, ethoxyethyl group, 3-oxocyclohexyl group, isobornyl group, trimethylsilyl group, tetrahydropyranyl group, azalactone group, alicyclic compound having tertiary ester structure, for example A 2-alkyladamantyl ester, a dialkylmonoadamantyl methanol ester, a tertiary ester of menthanediol, and an ester compound of hydroxypinanone are preferred in that they are easily decomposed with an acid.

  It is more desirable that these acid-decomposable groups themselves have an alicyclic ring from the viewpoint of dry etching resistance. That is, in the resin according to the present invention, it is desirable to use a compound capable of generating a carboxylic acid by removing an alicyclic ring with an acid as a copolymer component of the resin. As such a compound, pyranyl acrylate or methacrylate, alicyclic acrylate / methacrylate having pyranyl-protected carboxyl group in the side chain, or tertiary acrylic / methacrylic acid ester of menthanediol is desirable, and further disclosed in JP-A-9-73173. As described above, acrylic / methacrylic acid ester of 2-alkyl-2-adamantanol, acrylic acid / methacrylic acid ester of 2-adamantyl propanol, dialkyl monoadamantyl methanol and the like are more preferable.

  When polymerizing the resin according to the present invention, the polymerization ratio of the compound having an acid-decomposable group is preferably set in the range of 10 to 80 mol%, more preferably 15 to 70 mol% in the polymer. . This is because if it is less than 10 mol%, it is difficult to exhibit sufficient dissolution inhibiting ability, and if it exceeds 80 mol%, it becomes difficult to form a resist pattern with good resolution.

  The photosensitive composition of the present invention preferably has these acid-decomposable groups in which an alkali-soluble group is protected not only in the resin but also in a part of the structure of an additive (dissolution inhibitor) described later.

  When the resin according to the present invention is polymerized, if the compound to be polymerized is water-soluble, the alkali solubility is improved, but there is a problem because it is necessary to use a dilute developer. In the resin according to the present invention, the polymerization ratio of a vinyl compound having a high water solubility of more than 0.1 g / 1 g of water is preferably as low as possible, and most preferably not included. The polymerization rate of the compound having a water solubility exceeding 0.1 g / 1 g of water is 0 to 20 wt% in the polymer at most.

  When polymerizing the resin according to the present invention, a compound that does not have a molecular skeleton having a large light absorption in a short wavelength region such as a benzene nucleus is used in consideration of the transparency of the compound to be polymerized with respect to the short wavelength light of the resist. Specifically, it is desirable that the absorbance of the resin with respect to light having a wavelength of 193 nm is 4 or less per 1 μm.

  The resin according to the present invention is desirable because a part or all of> C = O of the resin can be further dehydrated and condensed with a compound having active methylene, thereby further imparting adhesion and acid decomposability. It becomes.

  The compound having active methylene corresponds to, for example, a compound having an electron-withdrawing substituent on both sides of methylene. For example, the electron-withdrawing group includes a carbonyl group, a carboxyl group, and an ester thereof, a sulfonyl group and a sulfonate group, a cyano group, a halogen atom, and the like. Among these, a malonic acid derivative represented by the general formula (5) is desirable from the viewpoint of adhesion, resolution, and developability.

R ₃ O (CO) CH ₂ (CO) OR ₄ (5)
Here, R ₃ and R ₄ may be the same or different and each represents an alkyl group or a group decomposable with an acid. R ₃ and R ₄ may be partially bonded to form a cyclic compound. Among these, when R ₃ and R ₄ are tertbutyl groups, or when the compound having active methylene is a Meldrum's acid compound, the acid decomposability and solubility are improved, respectively.

  In the present invention, each component is preferably blended so that the amount of the alicyclic structure into which a double bond formed by condensation with active methylene is introduced is 10% by weight or more in the solid content of the resist. . This is because if it is less than 10% by weight, it becomes difficult to form a resist pattern having good resolution and adhesion by alkali development, and the dry etching resistance of the resulting resist pattern tends to decrease. . On the other hand, if the introduction amount exceeds 90%, there is a problem because the transparency is lowered.

The average molecular weight of the resin according to the present invention is preferably set in the range of 500 to 500,000 in terms of polystyrene. If the average molecular weight of the resin is less than 500, it is disadvantageous in forming a resist film having sufficient mechanical strength. Conversely, if the average molecular weight of the polymer compound exceeds 500,000, a resist having good resolution is obtained. This is because it becomes difficult to form a pattern. The resin component of the photosensitive composition is usually a mixture composed of various molecular weight components. The resin according to the present invention is effective even at a relatively low molecular weight, and for example, even when localized at an average molecular weight of 500-1000, it is desirable because it suppresses non-uniform dissolution. Furthermore, in this case, there is no problem even if many monomers remain in the resin as long as there is no problem of film formation.
<Photo acid generator>
The photoacid generator according to the photosensitive composition of the present invention will be described below.

（式中、Ｃ１及びＣ２は単結合または二重結合を形成し、Ｒ１０は水素原子、フッ素原子、フッ素原子で置換されていてもよいアルキル基またはアリール基、Ｒ１１、Ｒ１２は、互いに同一であっても異なっていてもよく、それぞれ１価の有機基を示し、Ｒ１１とＲ１２はこれらが結合して環構造を形成していてもよい。）

（式中、Ｚはアルキル基を示す。）

また上述したような光酸発生剤についても、ナフタレン骨格やジベンゾチオフェン骨格を有するアリールオニウム塩、スルフォネート化合物、スルフォニル化合物、スルファミド化合物など共役多環芳香族系化合物は、短波長光に対する透明性、耐熱性の点で有利である。具体的には、水酸基が導入されたナフタレン環、ペンタレン環、インデン環、アズレン環、ヘプタレン環、ビフェニレン環、ａｓ−インダセン環、ｓ−インダセン環、アセナフチレン環、フルオレン環、フェナレン環、フェナントレン環、アントラセン環、フルオランテン環、アセフェナントリレン環、アセアントリレン環、トリフェニレン環、ピレン環、クリセン環、ナフタセン環、プレイアデン環、ピセン環、ペリレン環、ペンタフェン環、ペンタセン環、テトラフェニレン環、ヘキサフェン環、ヘキサセン環、ルビセン環、コロネン環、トリナフチレン環、ヘプタフェン環、ヘプタセン環、ピラントレン環、オバレン環、ジベンゾフェナントレン環、ベンズ［ａ］アントラセン環、ジベンゾ［ａ、ｊ］アントラセン環、インデノ［１、２−ａ］インデン環、アントラ［２、１−ａ］ナフタセン環、１Ｈ−ベンゾ［ａ］シクロペント［ｊ］アントラセン環を有するスルフォニルまたはスルフォネート化合物；ナフタレン環、ペンタレン環、インデン環、アズレン環、ヘプタレン環、ビフェニレン環、ａｓ−インダセン環、ｓ−インダセン環、アセナフチレン環、フルオレン環、フェナレン環、フェナントレン環、アントラセン環、フルオランテン環、アセフェナントリレン環、アセアントリレン環、トリフェニレン環、ピレン環、クリセン環、ナフタセン環、プレイアデン環、ピセン環、ペリレン環、ペンタフェン環、ペンタセン環、テトラフェニレン環、ヘキサフェン環、ヘキサセン環、ルビセン環、コロネン環、トリナフチレン環、ヘプタフェン環、ヘプタセン環、ピラントレン環、オバレン環、ジベンゾフェナントレン環、ベンズ［ａ］アントラセン環、ジベンゾ［ａ、ｊ］アントラセン環、インデノ［１、２−ａ］インデン環、アントラ［２、１−ａ］ナフタセン環、１Ｈ−ベンゾ［ａ］シクロペント［ｊ］アントラセン環を有する４−キノンジアジド化合物；ナフタレン環、ペンタレン環、インデン環、アズレン環、ヘプタレン環、ビフェニレン環、ａｓ−インダセン環、ｓ−インダセン環、アセナフチレン環、フルオレン環、フェナレン環、フェナントレン環、アントラセン環、フルオランテン環、アセフェナントリレン環、アセアントリレン環、トリフェニレン環、ピレン環、クリセン環、ナフタセン環、プレイアデン環、ピセン環、ペリレン環、ペンタフェン環、ペンタセン環、テトラフェニレン環、ヘキサフェン環、ヘキサセン環、ルビセン環、コロネン環、トリナフチレン環、ヘプタフェン環、ヘプタセン環、ピラントレン環、オバレン環、ジベンゾフェナントレン環、ベンズ［ａ］アントラセン環、ジベンゾ［ａ、ｊ］アントラセン環、インデノ［１、２−ａ］インデン環、アントラ［２、１−ａ］ナフタセン環、１Ｈ−ベンゾ［ａ］シクロペント［ｊ］アントラセンを側鎖を有するスルフォニウムまたはヨードニウムのトリフレートなどとの塩などが挙げられる。特に、ナフタレン環またはアントラセン環を有するスルフォニルまたはスルフォネート化合物；水酸基が導入されたナフタレン環またはアントラセン環を有する４−キノンジアジド化合物；ナフタレン環またはアントラセン環を側鎖を有するスルフォニウムまたはヨードニウムのトリフレートなどとの塩が好ましい。 The photosensitive composition of the present invention comprises a photoacid generator in addition to the resin. Examples of the photoacid generator according to the present invention include arylonium salts, naphthoquinonediazide compounds, diazonium salts, sulfonate compounds, sulfonium compounds, sulfamide compounds, iodonium compounds, sulfonyldiazomethane compounds, and the like. Specific examples of these compounds include triphenylsulfonium triflate, diphenyliodonium triflate, 2,3,4,4-tetrahydroxybenzophenone-4-naphthoquinone diazide sulfonate, 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 phenylsulfate, 2,5-diethoxy-4-N-4′-methoxyphenylcarbonylphenyldiazonium-3-carboxy-4-hydroxyphenylsulfate, 2-methoxy-4-N -Phenylphenyldiazonium-3-carboxy-4-hydroxyphenylsulfate, diphenylsulfonylmethane, diphenylsulfonyldiazomethane, diphenyldisulfone, α-methylbenzoin tosylate, pyrogallol trimesylate, benzoin tosylate, MPI-103 (CAS No. [87709-41-9]), BDS-105 manufactured by Midori Chemical (CAS. NO. [145612-66-4]), NDS-103 manufactured by Midori Chemical (CAS. NO. [110098-97-0]). ), Midori Chemical MDS-203 (CAS.NO. [127855-15-5]), Midori Chemical Pyrogallol tritosylate (CAS.NO. [20032-64-8]), Midori Chemical DTS-102 ( AS.NO. [75482-18-7]), Midori Chemical DTS-103 (CAS.NO. [71449-78-0]), Midori Chemical MDS-103 (CAS.NO. [127279-74-7]). ] MDS-105 (CAS.NO. [116808-67-4]), Midori Chemical MDS-205 (CAS.NO. [81416-37-7]), Midori Chemical BMS-105 ( CAS.NO. [149934-68-9]), Midori Chemical TMS-105 (CAS.NO. [127820-38-6]), Midori Chemical NB-101 (CAS.NO. [20444-09-1) ), Midori Chemical NB-201 (CAS.NO. [4450-68-4]), Midori Chemical DNB-101 (CAS.NO. [114719-51]) 6]), Midori Chemical Co., DNB-102 (CAS. NO. [131509-55-2]), Midori Chemical DNB-103 (CAS.NO. [132898-35-2]), Midori Chemical DNB-104 (CAS.NO. [132898-36-3]), Midori Chemical DNB-105 (CAS.NO. [132898-37-4]), Midori Chemical DAM-101 (CAS.NO. [1886-74-4]), Midori Chemical DAM-102 (CAS.NO. [28343-24-0]), Midori Chemical DAM-103 (CAS.NO. [14159-45-6]), Midori Chemical DAM-104 (CAS.NO. [130290-80-1], CAS. No. [130290-82-3]), DAM-201 manufactured by Midori Chemical (CAS. NO. [2832-50-1]), CMS-105 manufactured by Midori Chemical. DAM-301 (CAS. No. [138529-81-4]), Midori Chemical SI-105 (CAS. No. [34694-40-7]), Midori Chemical NDI-105 (CAS. No.) [13310-62-0]), EPI-105 (CAS. No. [135133-12-9]) manufactured by Midori Chemical. Furthermore, the compounds shown below can also be used.

(In the formula, C1 and C2 form a single bond or a double bond, R10 is a hydrogen atom, a fluorine atom, or an alkyl or aryl group optionally substituted with a fluorine atom, and R11 and R12 are the same as each other. And each may represent a monovalent organic group, and R11 and R12 may combine to form a ring structure.)

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

As for the photoacid generators as described above, conjugated polycyclic aromatic compounds such as arylonium salts having a naphthalene skeleton or a dibenzothiophene skeleton, sulfonate compounds, sulfonyl compounds, sulfamide compounds, and the like have transparency and heat resistance. It is advantageous in terms of sex. 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, into which a hydroxyl group is introduced Anthracene ring, fluoranthene ring, acephenanthrylene ring, aceanthrylene ring, triphenylene ring, pyrene ring, chrysene ring, naphthacene ring, preaden ring, picene ring, perylene ring, pentaphen ring, pentacene ring, tetraphenylene ring, hexaphen Ring, hexacene ring, rubicene ring, coronene ring, trinaphthylene ring, heptaphene ring, heptacene ring, pyranthrene ring, ovalene ring, dibenzophenanthrene ring, benz [a] anthracene ring, dibenzo [a, j] anthracene ring, indeno [1, -A] sulfonyl or sulfonate compounds having an indene ring, anthra [2,1-a] naphthacene ring, 1H-benzo [a] cyclopent [j] 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, acanthrylene ring, triphenylene ring, pyrene ring, chrysene Ring, naphthacene ring, preaden ring, picene ring, perylene ring, pentaphen ring, pentacene ring, tetraphenylene ring, hexaphen ring, hexacene ring, rubicene ring, coronene ring, trinaphthylene ring, heptaphen ring, heptacene ring, pyran Len 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- 4-quinonediazide compound having benzo [a] cyclopent [j] 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, aceantolylene ring, triphenylene ring, pyrene ring, chrysene ring, naphthacene ring, preaden ring, picene ring, perylene ring, pentaphen ring, pentacene Ring, tetraphenylene ring, Hexaphen ring, hexacene ring, rubicene ring, coronene ring, trinaphthylene ring, heptaphen ring, heptacene ring, pyrantolen 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, salt with 1H-benzo [a] cyclopent [j] anthracene having a side chain such as sulfonium or iodonium 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 into which a hydroxyl group has been introduced; a sulfonium or iodonium triflate having a naphthalene ring or an anthracene ring as a side chain Salts are preferred.

  Among such photoacid generators, in the present invention, triphenylsulfonium triflate, diphenyliodonium triflate, trinaphthylsulfonylium triflate, dinaphthyliodonium triflate, dinaphthylsulfonylmethane, NATURAL CHEMICAL NATS. -105 (CAS. No. [137867-61-9]), Midori Chemical NAT-103 (CAS. No. [131582-00-8]), Midori Chemical NAI-105 (CAS. No. [85342). 62-7], Midori Chemical TAZ-106 (CAS. No. [69432-40-2]), Midori Chemical NDS-105, Midori Chemical PI-105 (CAS. No. [41580-58- 9]), s-alkylated dibenzothiophene triflate, s-fluoroal Such as Le of dibenzothiophene triflate (manufactured by Daikin) is preferably used. Among these, triphenylsulfonium triflate, trinaphthyl sulphonium triflate, dinaphthyl iodonium triflate, dinaphthyl sulphonylmethane, NAT-105 (CAS. No. [137867-61-9]) manufactured by Midori Kagaku, NDI-105 (CAS. No. [133710-62-0]) manufactured by Midori Chemical, NAI-105 (CAS. No. [85342-62-7]) manufactured by Midori Chemical are particularly preferable.

In the photosensitive composition of the present invention, the preferable amount of the photoacid generator is 0.001 to 50 mol%, more preferably 0.01 to 40 mol%, and particularly preferably 0.1 to the entire base resin. Within the range of ~ 20 mol%. 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%, the mechanical strength may be impaired when a resist film is formed.
<Other ingredients>
Hereinafter, components that can be blended in the photosensitive composition of the present invention will be described.

  In addition to the resin and the photoacid generator, the photosensitive composition of the present invention may contain a so-called dissolution inhibitor that increases the solubility in an alkaline solution upon irradiation with radiation.

Such a dissolution inhibitor has a sufficient ability to inhibit dissolution in an alkaline solution, and the product after decomposition with an acid is-(C = O) O-, -OS (= O) _2- , Or the acid-decomposable compound which can produce -O- is illustrated.

  Specifically, the phenolic compound is t-butoxycarbonyl ether, tetrahydropyranyl ether, 3-bromotetrahydropyranyl ether, 1-methoxycyclohexyl ether, 4-methoxytetrahydropyranyl ether, 1,4-dioxane-2-yl ether, Tetrahydrofuranyl ether, 2,3,3a, 4,5,6,7,7a-octahydro-7,8,8-trimethyl-4,7-methanobenzofuran-2-yl ether, t-butyl ether, trimethylsilyl ether, triethyl Compounds modified to silyl ether, triisopropyl silyl ether, dimethyl isopropyl silyl ether, diethyl isopropyl silyl ether, dimethyl sexyl silyl ether, t-butyl dimethyl silyl ether, etc. Such as lamb acid derivatives and the like. Among these, compounds in which the hydroxyl group of the phenolic compound is protected with a t-butoxycarbonyl group, a t-butoxycarbonylmethyl group, a trimethylsilyl group, a t-butyldimethylsilyl group, or a tetrahydropyranyl group, or naphthalaldehyde with meldrum acid A compound in which meldrum acid is added to an aldehyde having an alicyclic structure is preferred.

これらの溶解抑止剤のうち、共役多環芳香族系化合物が短波長光に対する透明性が優れる点で好ましい。なおこの共役多環芳香族系化合物とは、不飽和結合がひとつおきに配列した骨格とすることで複数の芳香環が平面的に連結された非縮合多環系や縮合多環系の化合物である。すなわちこうした化合物は、π電子の共役安定化に起因して光吸収帯が低波長域にシフトしており、本発明では特に共役多環芳香族系化合物を溶解抑止剤として用いることで、短波長光に対し優れた透明性を有するとともに、耐熱性も充分なアルカリ現像用の感光性組成物を得ることができる。 Further, the dissolution inhibitor is an isopropyl ester, tetrahydropyranyl ester, tetrahydrofuranyl ester, methoxyethoxymethyl ester, 2-trimethylsilylethoxymethyl ester, t-butyl ester of a polyvalent carboxylic acid of a condensed polycyclic (alicyclic or aromatic) compound. , 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. Moreover, the compound shown below can also be used.

Of these dissolution inhibitors, conjugated polycyclic aromatic compounds are preferred because of their excellent transparency to short wavelength light. This conjugated polycyclic aromatic compound is a non-condensed polycyclic compound or condensed polycyclic compound in which a plurality of aromatic rings are planarly connected by forming a skeleton in which every other unsaturated bond is arranged. is there. That is, in these compounds, the light absorption band is shifted to a low wavelength region due to the conjugated stabilization of π electrons, and in the present invention, particularly by using a conjugated polycyclic aromatic compound as a dissolution inhibitor, A photosensitive composition for alkali development having excellent transparency to light and sufficient heat resistance can be obtained.

  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, benzothiophene ring, Indole ring, benzoxazole ring, benzothiazole ring, indazole ring, chromene ring, quinoline dinolin ring, phthalazine ring, quinazoline ring, dibenzofuran ring, carbazole ring, acridine ring, phenanthridine ring, phenanthroline ring, phenazine ring, thianthrene A compound having a ring, an indolizine ring, a naphthyridine ring, a purine ring, a pteridine ring, a fluorene ring, etc. Among them, a condensed polycyclic compound having a naphthalene ring, an anthracene ring, a phenanthrene ring or the like is suitable for light having a wavelength of 193 nm. That is excellent in terms of transparency. Therefore, the polyhydroxy compound having a condensed aromatic ring structure in which the hydroxyl group is protected with a t-butyl carbonate group, a t-butyl ester group, a tetrahydropyranyl ether group, an acetal group, a trimethylsilyl ether group, or the like, or these condensed aromatic rings A condensation compound of an aldehyde compound having a structure and Meldrum's acid is particularly preferred as a dissolution inhibitor.

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

  In the photosensitive composition of the present invention, the blending amount of the dissolution inhibitor is preferably set in the range of 3 to 40 mol%, more preferably 10 to 30 mol%, relative to the number of moles corresponding to the monomer of the base resin. . If the blending amount of the dissolution inhibitor is less than 3 mol%, it becomes difficult to form a resist pattern with good resolution, and conversely if it exceeds 40 mol%, the machine is formed when a resist film is formed. This is because the strength of the resist may be impaired, and the dissolution rate when the resist film in the exposed area is dissolved and removed with an alkaline solution tends to be greatly reduced.

  The photosensitive composition of the present invention is usually prepared as a varnish by dissolving and filtering an additive such as a resin, a photoacid generator, a dissolution inhibitor, or other alkali-soluble resin in some cases in an organic solvent. Is done.

  In the photosensitive composition of the present invention, in addition to these components, other resins such as epoxy resin, polymethyl methacrylate, polymethyl acrylate, polymethyl methacrylate, propylene oxide-ethylene oxide copolymer, polystyrene, and environmental resistance improvement A basic compound such as an amine compound, a pyridine derivative, a surfactant for coating film modification, a dye as an antireflection agent, and the like may be appropriately blended.

  Examples of the organic solvent include ketone solvents such as cyclohexanone, acetone, methyl ethyl ketone, and methyl isobutyl ketone, cellosolv solvents such as methyl cellorub, methyl cellosolve acetate, ethyl cellosolve acetate, and butyl cellosolve acetate, ethyl acetate, butyl acetate, and 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 for improved solubility A mixed solvent in which dimethyl sulfoxide, dimethylformaldehyde, N-methylpyrrolidinone, or the like is added to these can be used. Further, propionic acid derivatives such as methyl methyl propionate, lactic acid esters such as ethyl lactate, PGMEA (propylene glycol monoethyl acetate) and the like are low in toxicity and can be preferably used.

  In the present invention, these solvents can be used alone or in combination of two or more, and further, isopropyl alcohol, ethyl alcohol, methyl alcohol, butyl alcohol, n-butyl alcohol, s-butyl alcohol, t-butyl. Aliphatic alcohols such as alcohol and isobutyl alcohol, and aromatic solvents such as toluene and xylene may be contained.

  Next, a pattern forming method using the photosensitive composition of the present invention will be described by way of example. First, a varnish of a photosensitive composition dissolved in an organic solvent as described above is applied on a predetermined substrate by a spin coating method or a dipping method, and then dried at 150 ° C. or less, preferably 70 to 120 ° C. A film is formed. As the substrate here, for example, a silicon wafer, a silicon wafer on which various insulating films, electrodes, wirings and the like are formed, a blank mask, a III-V group compound semiconductor wafer such as GaAs, AlGaAs, chromium or chromium oxide A vapor deposition mask, an aluminum vapor deposition substrate, an IBPSG coated substrate, a PSG coated substrate, an SOG coated substrate, a carbon film sputtering 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 surface of the resist film 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, deep UV light such as KrF or ArF excimer laser light, synchrotron orbital radiation (SOR), electron beam (EB), gamma ray, ion beam, etc. It is possible to use.

  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 by infrared irradiation. Thereafter, the resist film is developed by an immersion method, a spray method or the like, and the resist film in the exposed or unexposed area is selectively dissolved and removed in an alkaline solution to form a desired pattern. In this case, specific examples of the alkaline solution include organic alkaline aqueous solutions such as tetramethylammonium hydroxide aqueous solution and choline aqueous solution, inorganic alkaline aqueous solutions such as potassium hydroxide and sodium hydroxide, and alcohols and surfactants added thereto. A solution. The concentration of the alkali solution here is preferably 15% by weight or less from the viewpoint of sufficient difference in dissolution rate between the exposed part and the unexposed part.

  Thus, the resist pattern formed using the photosensitive composition of the present invention has extremely good resolution and adhesion. For example, by dry etching using this resist pattern as an etching mask, a sub-quarter is formed on an exposed substrate. An ultra-fine pattern of about a micron can be faithfully transferred. The resist pattern obtained here has high dry etching resistance.

  In addition, there is no problem even if other processes other than the processes described above are added, for example, a planarization layer forming process as a resist film base, a pretreatment process for improving the adhesion between the resist film and the base, After the development of the resist film, a rinsing process for removing the developer with water or the like, and an ultraviolet re-irradiation process before dry etching can be appropriately performed.

(Example 1 to Example 9, Comparative Example 1 to Comparative Example 4)
<Synthesis of Raw Material (> Adamantane Compound (Monomer) Having C═O)>
[Synthesis of Compound (A) and Compound (B)]
1 mol of 2-adamantyl ketone was heated and stirred in an acetic acid-acetic anhydride solution of CrO ₃ as an oxidizing agent, and after reacting for 8 hours, the reaction solution was neutralized to obtain a polyhydroxylated compound mixture of adamantyl ketone. . When this mixture was fractionated by high performance liquid chromatography, 1-hydroxy-4-adamantanone (compound (A)) and 1,3-dihydroxy-6-adamantanone (compound (B)) were obtained.
[Synthesis of Compound (C)]
1,3-Dicarboxyadamantane is oxidized and fractionated in the same manner as in the synthesis of Compound (A) or Compound (B) to obtain 1,3-dicarboxy-6-adamantacinone (Compound (C)). It was.
[Synthesis of Compound (D)]
Compound (C) was dissolved in THF, an excess amount of thionyl chloride was refluxed for 4 hours, and excess thionyl chloride and the solvent were distilled off to obtain an acid chloride compound (compound (D)) of compound (C).
[Synthesis of Compound (E)]
Compound (A) was dissolved in THF, stirred with an equimolar amount of acrylic acid chloride, an excess amount of triethylamine was added dropwise at room temperature, and the mixture was stirred for 3 hours. The precipitated salt was separated by filtration, and the solution was concentrated to obtain an acrylic ester of compound (A) (compound (E), R = acryloyl of general formula (1)). A ¹ HNMR chart of this compound is shown in FIG.
[Synthesis of Compound (F)]
The compound (E) is stirred with equimolar 2,2′-dimethyl-1,3-dioxane-4,6-dione in pyridine at room temperature for 1 week, and the reaction product is added dropwise to water. -Acryloyloxylation, -4- (5-adamantylidene) -2,2, -dimethyl-1,3-dioxane-4,6-dione (compound (F)), R in the general formula (2) is acryloyl , R ₁ and R ₂ were crosslinked with a dimethylmethylene structure). A ¹ HNMR chart of this compound is shown in FIG.
[Synthesis of Compound (G)]
Dihydropyran was added to methacrylic acid with an acid catalyst to obtain tetrahydropyranyl methacrylate (compound (G)).
[Synthesis of Compound (H)]
1-adamantanol and acrylic acid chloride were desalted with a basic catalyst to obtain adamantyl acrylate (compound (H)).

化合物（Ｆ）を０．６モル、化合物（Ｇ）を０．４モル、テトラヒドロフラン（ＴＨＦ）２００ｇに混合した。続いて、アゾイソブチルニトリル（ＡＩＢＮ）２ｇを添加して６０℃で３６時間加熱し、反応液をヘキサンに滴下することで、平均分子量約８０００の共重合体２を得た。共重合体２の構造式は以下に示す通りである。

化合物（Ｅ）を０．６モル、化合物（Ｉ）を０．４モル、テトラヒドロフラン（ＴＨＦ）２００ｇに混合した。続いて、アゾイソブチルニトリル（ＡＩＢＮ）２ｇを添加して６０℃で３６時間加熱し、反応液をヘキサンに滴下することで、平均分子量約５０００の共重合体３を得た、共重合体３の構造式は以下に示す通りである。

化合物（Ｂ）を０．０４モルをＴＨＦに溶解し、化合物（Ｄ）を０．０５モルをこれに加え、さらに化合物（Ｃ）を０．０１０モル加えた。温度を室温に保ち、攪拌し、０．１モルのトリエチルアミンのＴＨＦ溶液を徐々に滴下した。２時間攪拌し、その後、室温でさらに２時間撹杵した後、反応液を炉別した。水中に徐々に反応液を滴下し、析出した沈殿をさらに、再沈し、エステルオリゴマー（ポリ酸無水物合む）４を得た、平均分子量４０００であった。エステルオリゴマー４の構造式を以下に示す。

化合物（Ｄ）を０．０５モルをＴＨＦに溶解し．メンタンジオールを０．０４０モルをこれに加え、さらに化合物（Ｃ）を０．０１０モル加えた。温度を室温に保ち、攪拌し、０．１モルのトリエチルアミンのＴＨＦ溶液を徐々に滴下した。２時間撹伴し、その後、室温でさらに２時間撹伴した後、反応液を濾別した。水中に徐々に反応液を滴下し、析出した沈殿をさらに、再沈し、エステルオリゴマー（ポリ酸無水物合む）５を得た。平均分子量は３５００であった。エステルオリゴマー５の構造式を以下に示す。

化合物（Ｄ）を０．０５モルをＴＨＦに溶解し、メンタンジオールを０．０５０モルをこれに加えた。温度を室温に保ち、撹拌し、０．１モルのトリエチルアミンのＴＨＦ溶液を徐々に滴下した。２時間撹拌し、その後、室温でさらに４時間撹拌した後、反応液を濾別した。水中に徐々に反応液を滴下し、析出した沈殿をさらに、再沈し、エステルオリゴマー６を得た。平均分子量は３０００であった。エステルオリゴマー６の構造式を以下に示す。

＜比較アクリレートポリマーの合成＞
アダマンチルアクリレート（化合物（Ｈ））を０．６モル、テトラヒドロピラニルメタクリレート（化合物（Ｇ））を０．４モルをＴＨＦ中で、ＡＩＢＮ（１０モル％）を開始剤として、４０時間反応し、ヘキサン中に滴下して、比較アクリレートポリマーＡを得た。比較アクリレートポリマーＡの構造式を以下に示す。

化合物（Ｊ）を０．６モル、化合物（Ｇ）を０．４モル、テトラヒドロフラン（ＴＨＦ）２００ｇに混合した。続いて、アゾイソブチルニトリル（ＡＩＢＮ）２ｇを添加して６０℃で３６時間加熱し、反応液をヘキサンに滴下することで、平均分子量約１００００の比較アクリレートポリマーＢを得た。比較アクリレートポリマーＢの構造式を以下に示す。

化合物（Ｅ）を０．５モル、化合物（Ｇ）を０．４モル、メタクリル酸０．１モルをテトラヒドロフラン（ＴＨＦ）２００ｇに混合した。続いて、アゾイソブチルニトリル（ＡＩＢＮ）２ｇを添加して６０℃で３６時間加熱し、反応液をヘキサンに滴下することで、比較アクリレートポリマーＣ（平均分子量約８０００）を得た。比較アクリレートポリマーＣの構造式を以下に示す。

＜比較エステルポリマーの合成＞
アダマンタンジカルボニルクロリド０．０５モルをＴＨＦに溶解し．メンタンジオール０．０５モルをこれに加えた。温度を室温に保ち、撹拌し、０．１モルのトリエチルアミンのＴＨＦ溶液を徐々に滴下した。２時間撹拌し、その後、室温でさらに２時間撹拌した後、反応液を濾別した。水中に徐々に反応液を滴下し、析出した沈殿をさらに水−アセトン系溶媒で、再沈し、比較エステルオリゴマーＤを得た。比較エステルポリマーＤの構造式を以下に示す。

＜溶解抑止剤の合成＞
０．１モルナフトール当量のβ−ナフトールノボラックをＴＨＦに溶解し、水素化ナトリウム０．１モルの存在下、充分な量のジ−ｔ−ブチル２炭酸エステルと室温で６時間攪拌した後、反応液を水と混合して酢酸エチルで抽出することで、分子量３０００のｔ−ブトキシカルボニル化ナフトールノボラック（ｔＢｏｃＮＮ）を合成した。なお、ここでｔＢｏｃＮＮにおけるｔ−ブトキシカルボニルの導入率は、全水酸基の１００モル％であった。 As methacrylic acid, menthanediol, and 1,3-dicarboxyl adamantane, reagents made by Aldrich were used as they were.
[Synthesis of Compound (I)]
2-Methyl-2-adamantanol was dissolved in methylene chloride, stirred with an equimolar amount of acrylic acid chloride, an excess amount of triethylamine was added dropwise at room temperature, and the mixture was stirred for 3H. The precipitated salt was filtered off, and the solution was concentrated to obtain 2-methyl-2-adamantanol acrylic ester (compound (I)).
[Synthesis of Compound (J)]
Hydroxypinanone was dissolved in THF, stirred with an equimolar amount of acrylic acid chloride, an excess amount of triethylamine was added dropwise at room temperature, and the mixture was stirred for 3H. The precipitated salt was filtered off, and the solution was concentrated to obtain an acrylic ester of human roxypinanone (comparative monomer J).
<Resin synthesis>
Compound (E) was mixed in 0.6 mol, compound (G) in 0.4 mol, and tetrahydrofuran (THF) in 200 g. Subsequently, 2 g of azoisobutyl nitrile (AIBN) was added and heated at 60 ° C. for 36 hours, and the reaction solution was added dropwise to hexane to obtain a copolymer 1 having an average molecular weight of about 7000. The structural formula of the copolymer 1 is as shown below.

Compound (F) (0.6 mol), compound (G) (0.4 mol), and tetrahydrofuran (THF) 200 g were mixed. Subsequently, 2 g of azoisobutyl nitrile (AIBN) was added and heated at 60 ° C. for 36 hours, and the reaction solution was dropped into hexane to obtain a copolymer 2 having an average molecular weight of about 8000. The structural formula of the copolymer 2 is as shown below.

Compound (E) was mixed in 0.6 mol, compound (I) in 0.4 mol, and tetrahydrofuran (THF) in 200 g. Subsequently, 2 g of azoisobutyl nitrile (AIBN) was added and heated at 60 ° C. for 36 hours, and the reaction solution was dropped into hexane to obtain a copolymer 3 having an average molecular weight of about 5000. The structural formula is as shown below.

0.04 mol of compound (B) was dissolved in THF, 0.05 mol of compound (D) was added thereto, and 0.010 mol of compound (C) was further added. The temperature was kept at room temperature and the mixture was stirred, and 0.1 mol of triethylamine in THF was gradually added dropwise. The mixture was stirred for 2 hours and then stirred for another 2 hours at room temperature, and then the reaction solution was separated in a furnace. The reaction solution was gradually dropped into water, and the deposited precipitate was further re-precipitated to obtain an ester oligomer (polyacid anhydride combined) 4 having an average molecular weight of 4000. The structural formula of the ester oligomer 4 is shown below.

0.05 mol of compound (D) was dissolved in THF. 0.040 mol of mentanediol was added thereto, and 0.010 mol of compound (C) was further added. The temperature was kept at room temperature and the mixture was stirred, and 0.1 mol of triethylamine in THF was gradually added dropwise. After stirring for 2 hours and further stirring at room temperature for 2 hours, the reaction solution was filtered off. The reaction solution was gradually dropped into water, and the deposited precipitate was further reprecipitated to obtain an ester oligomer (polyacid anhydride combined) 5. The average molecular weight was 3500. The structural formula of the ester oligomer 5 is shown below.

0.05 mol of compound (D) was dissolved in THF, and 0.050 mol of menthanediol was added thereto. The temperature was kept at room temperature and stirred, and 0.1 mol of triethylamine in THF was gradually added dropwise. After stirring for 2 hours and further stirring at room temperature for 4 hours, the reaction solution was filtered off. The reaction solution was gradually dropped into water, and the deposited precipitate was further reprecipitated to obtain an ester oligomer 6. The average molecular weight was 3000. The structural formula of the ester oligomer 6 is shown below.

<Synthesis of comparative acrylate polymer>
The reaction is carried out for 40 hours using 0.6 mol of adamantyl acrylate (compound (H)), 0.4 mol of tetrahydropyranyl methacrylate (compound (G)) in THF and AIBN (10 mol%) as an initiator, By dropping into hexane, a comparative acrylate polymer A was obtained. The structural formula of comparative acrylate polymer A is shown below.

Compound (J) (0.6 mol), compound (G) (0.4 mol), and tetrahydrofuran (THF) 200 g were mixed. Subsequently, 2 g of azoisobutyl nitrile (AIBN) was added and heated at 60 ° C. for 36 hours, and the reaction solution was dropped into hexane to obtain a comparative acrylate polymer B having an average molecular weight of about 10,000. It is shown in below the structural formulas of the comparative acrylate polymer B.

0.5 mol of compound (E), 0.4 mol of compound (G), and 0.1 mol of methacrylic acid were mixed with 200 g of tetrahydrofuran (THF). Subsequently, 2 g of azoisobutyl nitrile (AIBN) was added and heated at 60 ° C. for 36 hours, and the reaction solution was added dropwise to hexane to obtain comparative acrylate polymer C (average molecular weight of about 8000). The structural formula of comparative acrylate polymer C is shown below.

<Synthesis of comparative ester polymer>
Dissolve 0.05 mol of adamantane dicarbonyl chloride in THF. To this was added 0.05 mole of menthanediol. The temperature was kept at room temperature and stirred, and 0.1 mol of triethylamine in THF was gradually added dropwise. After stirring for 2 hours and further stirring at room temperature for 2 hours, the reaction solution was filtered off. The reaction solution was gradually dropped into water, and the deposited precipitate was further reprecipitated with a water-acetone solvent to obtain comparative ester oligomer D. The structural formula of the comparative ester polymer D is shown below.

<Synthesis of dissolution inhibitor>
A β - naphthol novolak of 0.1 mol naphthol equivalent was dissolved in THF and 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, and then reacted. The liquid was mixed with water and extracted with ethyl acetate to synthesize t-butoxycarbonylated naphthol novolak (tBocNN) having a molecular weight of 3000. Here, the introduction rate of t-butoxycarbonyl in tBocNN was 100 mol% of the total hydroxyl groups.

  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 generated salt was filtered off and the solution was concentrated to obtain ditertbutyl 2-((1-adamantyl) carbonylmethyl) malonate (ADTB).

一方、比較レジストとして光酸発生剤としてＴＰＳ−１０５を配合したレジストのワニスを併せて表２のように比較例１〜４のワニスを調製した。

次いで、これらのレジストのワニスをそれぞれシリコンウエハ上に回転塗布して厚さ０．３μｍのレジスト膜を成膜し、波長１９３ｎｍのＡｒＦエキシマレーザー光を光源としたＮＡ０．５５のステッパを使用してレジスト膜表面に所定のパターン光を露光した。続いて１１０℃で２分のぺ一キング処理を施した後、２．３８％のテトラメチルアンモニウムハイドロキシド水溶液（ＴＭＡＨ）ＭＡＨとイソプロピルアルコールの混合溶液で露光部を選択的に溶解・除去して、ポジ型のレジストパターンを形成した。このときの現像液濃度及び感度、解像度を表３に示す。

表３に示される通り、実施例１〜９のレジストにおいては、いずれも高い感度で解像性の良好なレジストパターンが形成されており、波長１９３ｎｍの光に対する透明性、アルカリ現像性とも優れていることがわかる。一方比較例１〜３のレジストでは、解像性の良好なレジストパターンが形成されていないこともわかり、さらに剥がれやすい等の問題があることがわかった。 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>
A polymer compound synthesized as described above, TPS-105, or NAI-105 manufactured by Midori Chemical as a dissolution inhibitor and photoacid generator is added to cyclohexanone (polyester) or PGMEA (in accordance with the formulations shown in Tables 1 and 2). The resist varnishes of Examples 1 to 9 were prepared.

On the other hand, varnishes of Comparative Examples 1 to 4 were prepared as shown in Table 2 together with a resist varnish containing TPS-105 as a photoacid generator as a comparative resist.

Next, each of these resist varnishes is spin-coated on a silicon wafer to form a resist film having a thickness of 0.3 μm, and an NA 0.55 stepper using an ArF excimer laser beam having a wavelength of 193 nm as a light source is used. The resist film surface was exposed to a predetermined pattern light. Subsequently, after performing a peaking treatment at 110 ° C. for 2 minutes, the exposed area was selectively dissolved and removed with a 2.38% tetramethylammonium hydroxide aqueous solution (TMAH) MAH and isopropyl alcohol mixed solution. A positive resist pattern was formed. Table 3 shows the developer concentration, sensitivity, and resolution at this time.

As shown in Table 3, in each of the resists of Examples 1 to 9, a resist pattern having high sensitivity and good resolution was formed, and both transparency to light with a wavelength of 193 nm and alkali developability were excellent. I understand that. On the other hand, in the resists of Comparative Examples 1 to 3, it was also found that a resist pattern with good resolution was not formed, and it was found that there were problems such as easy peeling.

Furthermore, the dry etching resistance of these resists was measured by measuring the etching rate using CF4 plasma. As a result, when the resist etch rate to base over scan resin polyhydroxystyrene resin and 1.0, the etching rate of Comparative Examples 1 and 4 is usually 1.0-1.3, Comparative Examples 2 and 3 The resist etching rate of Examples 1 and 9 is 0.9 to 1.2, which is high in dry etching resistance. It was confirmed that
(Reference Example 10 to Reference Example 18 Comparative Example 5 to Comparative Example 9)
<Synthesis of Raw Material (Adamantane Compound (Monomer) Having Lactonyl Group)>
[Synthesis of Compound (a) and Compound (b)]
1 mol of 2-adamantyl ketone was heated and stirred in an acetic acid-acetic anhydride solution of CrO3 as an oxidizing agent, and after reacting for 8 hours, the reaction solution was neutralized to obtain a polyhydroxylated compound mixture of adamantyl ketone. When this mixture was fractionated by high performance liquid chromatography, 1-hydroxy-4-adamantanone (compound (a)) and 1,3 dihydroxy-6-adamantanone (compound (b)) were obtained.
[Synthesis of Compound (c)]
1,3-Dicarboxyadamantane was oxidized and fractionated in the same manner to obtain 1,3-dicarboxy-6-adamantanone (C).
[Synthesis of Compound (d)]
Compound (c) was dissolved in THF, an excess amount of thionyl chloride was refluxed for 4 hours, and excess thionyl chloride and the solvent were distilled off to obtain an acid chloride compound (compound (d)) of compound (c).
[Synthesis of Compound (a ′)]
Compound (a) was dissolved in dichloromethane, metachloroperbenzoic acid was added, and the mixture was stirred at room temperature for 1 hour. Treatment with diazomethane gave a lactone (compound (a ′)) .
[ Synthesis of Compound (b ′) ]
Compound (b) was dissolved in dichloromethane, metachloroperbenzoic acid was added, and the mixture was stirred at room temperature for 1 hour. Treatment with diazomethane gave a lactone (compound (b ′)).
[Synthesis of Compound (c ′)]
1,3-Dicarboxyadamantane was oxidized and fractionated in the same manner to obtain a lactone (compound (c ′)).

[Synthesis of Compound (d ′)]
Compound (c ′) is dissolved in THF, an excess amount of thionyl chloride is refluxed for 4 hours, and excess thionyl chloride and the solvent are distilled off to obtain an acid chloride compound (compound (d ′)) of compound (c ′). Obtained.
[Synthesis of Compound e]
Compound (a ′) was dissolved in THF, stirred with an equimolar amount of acrylic acid chloride, an excess amount of triethylamine was added dropwise at room temperature, and the mixture was stirred for 3H. The precipitated salt was filtered off and the solution was concentrated to obtain an acrylate ester of the compound (a ′) (compound (e), R = acryloyl group of the general formula (3)).
[Synthesis of Compound (f)]
The compound (b ′) was dissolved in THF, stirred with an equimolar amount of acrylic acid chloride, an excess amount of triethylamine was added dropwise at room temperature, and the mixture was stirred for 3H. The precipitated salt was separated by filtration, and the solution was concentrated to obtain an acrylate ester of compound (b ′) (compound f, R = acryloyl group of general formula (4)).
[Synthesis of Compound (g)]
Dihydropyran was added to methacrylic acid with an acid catalyst to obtain tetrahydropyranyl methacrylate (compound (g)) .
[ Synthesis of Compound (h) ]
1-adamantanol and acrylic acid chloride were desalted with a basic catalyst to obtain adamantyl acrylate (compound (h)).

化合物（ｆ）を０．６モル、化合物（ｇ）を０．４モル、テトラヒドロフラン（ＴＨＦ）２００ｇに混合した。続いて、アゾイソブチルニトリル（ＡＩＢＮ）２ｇを添加して６０℃で３６時間加熱し、反応液をヘキサンに滴下することで、平均分子量約８０００の共重合体８を得た。共重合体８の構造式は以下に示す通りである。

化合物（ｅ）を０．６モル、化合物（ｉ）を０．４モル、テトラヒドロフラン（ＴＨＦ）２００ｇに混合した。続いて、アゾイソブチルニトリル（ＡＩＢＮ）２ｇを添加して６０℃で３６時間加熱し、反応液をヘキサンに滴下することで、平均分子量約５０００の共重合体９を得た。共重合体９の構造式は以下に示す通りである。

化合物（ｂ′）を０．０５モルをＴＨＦに溶解し、化合物（ｄ）を０．０４０モルをこれに加え、さらに化合物（ｃ）を０．０１０モル加えた。温度を室温に保ち、攪拌し、０．１モルのトリエチルアミンのＴＨＦ溶液を徐々に滴下した。２時間撹拌し、その後、室温でさらに２時間撹拌した後、反応液を濾別した。水中に徐々に反応液を滴下し、析出した沈殿をさらに、再沈し、エステルオリゴマー（ポリ酸無水物含む）１０を得た。平均分子量４０００であった。エステルオリゴマー１０の構造式を以下に示す。

化合物（ｄ′）を０．０５モルをＴＨＦに溶解し、メンタンジオールを０．０４０モルをこれに加え、さらに化合物（Ｃ）を０．０１０モル加えた。温度を室温に保ち、攪拌し、０．１モルのトリエチルアミンのＴＨＦ溶液を徐々に滴下した。２時間撹拌し、その後、室温でさらに２時間撹拌した後、反応液を濾別した。水中に徐々に反応液を滴下し、析出した沈殿をさらに、再沈し、エステルオリゴマー（ポリ酸無水物含む）１１を得た。平均分子量は３５００であった。エステルオリゴマー１１の構造式を以下に示す。

化合物（ｄ′）を０．０５モルをＴＨＦに溶解し、メンタンジオールを０．０５０モルをこれに加えた。温度を室温に保ち、攪拌し、０．１モルのトリエチルアミンのＴＨＦ溶液を徐々に滴下した。２時間撹拌し、その後、室温でさらに４時間撹拌した後、反応液を濾別した。水中に徐々に反応液を滴下し、析出した沈殿をさらに、再沈し、エステルオリゴマー１２を得た。平均分子量は３０００であった。エステルオリゴマー１２の構造式を以下に示す。

［比較アクリレートポリマーの合成］
アダマンチルアクリレート（化合物（Ｈ））を０．６モル、テトラヒドロピラニルメタクリレート（化合物（Ｇ））を０．４モルをＴＨＦ中で、ＡＩＢＮ（１０モル％）を開始剤として、４０時間反応し、ヘキサン中に滴下して、比較アクリレートポリマーＥを得た。比較アクリレートポリマーＥの構造式を以下に示す。

［比較エステルオリゴマーの合成］
アダマンタンジカルボニルクロリド０．０５モルをＴＨＦに溶解し、メンタンジオール０．０５モルをこれに加えた。温度を室温に保ち、攪拌し、０．１モルのトリエチルアミンのＴＨＦ溶液を徐々に滴下した。２時間撹拌し、その後、室温でさらに２時間撹拌した後、反応液を濾別した。水中に徐々に反応液を滴下し、析出した沈殿をさらに水−アセトン系溶媒で、再沈し、比較エステルオリゴマーＦを得た。比較エステルポリマーＦの構造式を以下に示す。

［比較アクリレートポリマー］
特開平１０―３１６９号公報に記載される、下記構造式で示される比較アクリレートポリマーＧ及び比較アクリレートポリマーＨ、比較アクリレートポリマーＩを用意した。

［レジストの調製及びレジストパターンの形成］
上述した通り合成した高分子化合物、溶解抑止剤及び光酸発生剤としてみどり化学製ＴＰＳ−１０５、またははＮＡＩ−１０５を、表４に示す処方にしたがってシクロヘキサノン（ポリエステル系）又はＰＧＭＥＡ（アクリル酸エステル系）に溶解させ、参考例１０〜１８のレジストのワニスを調製した。

一方、比較レジストとして光酸発生剤としてＴＰＳ−１０５を配合したレジストのワニスを併せて表５のように比較例５〜９のワニスを調製した。

次いで、これらのレジストのワニスをそれぞれシリコンウェハ上に回転塗布して厚さ０．３μｍのレジスト膜を成膜し、波長１９３ｎｍのＡｒＦエキシマレーザー光を光源としたＮＡ０．５５のステッパを使用してレジスト膜表面に所定のパターン光を露光した。続いて１１０℃で２分のベーキング処理を施した後、２．３８％のテトラメチルアンモニウムハイドロキシド水溶液（ＴＭＡＨ）ＭＡＨとイソプロピルアルコールの混合溶液で露光部を選択的に溶解・除去して、ポジ型のレジストパターンを形成した。このときの現像液濃度及び感度、解像度を表６に示す。

表６に示される通り、参考例１０〜１８のレジストにおいては、いずれも高い感度で解像性の良好なレジストパターンが形成されており、波長１９３ｎｍの光に対する透明性、アルカリ現像性とも優れていることが判る。一方比較例５〜９のレジストでは、解像性の良好なレジストパターンが形成されていないこともわかり、さらに剥がれやすい等の問題があることがわかった。 As methacrylic acid, menthanediol, and 1,3 dicarboxyl adamantane, reagents made by Aldrich were used as they were.
[Synthesis of Compound (i)]
2-Methyl-2-adamantanol was dissolved in methylene chloride, stirred with an equimolar amount of acrylic acid chloride, an excess amount of triethylamine was added dropwise at room temperature, and the mixture was stirred for 3H. The precipitated salt was separated by filtration, and the solution was concentrated to obtain 2-methyl 2-adamantanol acrylic acid ester (compound (i)).
[Synthesis of Compound (j)]
Hydroxypinanone was dissolved in THF, stirred with an equimolar amount of acrylic acid chloride, an excess amount of triethylamine was added dropwise at room temperature, and the mixture was stirred for 3H. The precipitated salt was filtered off, and the solution was concentrated to obtain hydroxypinanone acrylic acid ester (comparative monomer j).
<Resin synthesis>
Compound (e) was mixed in 0.6 mol, compound (g) in 0.4 mol, and tetrahydrofuran (THF) in 200 g. Subsequently, 2 g of azoisobutyl nitrile (AIBN) was added and heated at 60 ° C. for 36 hours, and the reaction solution was dropped into hexane to obtain a copolymer 7 having an average molecular weight of about 7000. The structural formula of the copolymer 7 is as shown below.

Compound (f) was mixed in 0.6 mol, compound (g) in 0.4 mol, and tetrahydrofuran (THF) in 200 g. Subsequently, 2 g of azoisobutyl nitrile (AIBN) was added and heated at 60 ° C. for 36 hours, and the reaction solution was dropped into hexane to obtain a copolymer 8 having an average molecular weight of about 8000. The structural formula of the copolymer 8 is as shown below.

Compound (e) was mixed with 0.6 mol, compound (i) with 0.4 mol, and tetrahydrofuran (THF) 200 g. Subsequently, 2 g of azoisobutyl nitrile (AIBN) was added and heated at 60 ° C. for 36 hours, and the reaction solution was dropped into hexane to obtain a copolymer 9 having an average molecular weight of about 5000. The structural formula of the copolymer 9 is as shown below.

0.05 mol of compound (b ′) was dissolved in THF, 0.040 mol of compound (d) was added thereto, and 0.010 mol of compound (c) was further added. The temperature was kept at room temperature and the mixture was stirred, and 0.1 mol of triethylamine in THF was gradually added dropwise. After stirring for 2 hours and further stirring at room temperature for 2 hours, the reaction solution was filtered off. The reaction solution was gradually dropped into water, and the deposited precipitate was further reprecipitated to obtain an ester oligomer (including polyacid anhydride) 10. The average molecular weight was 4000. The structural formula of the ester oligomer 10 is shown below.

0.05 mol of compound (d ′) was dissolved in THF, 0.040 mol of menthanediol was added thereto, and 0.010 mol of compound (C) was further added. The temperature was kept at room temperature and the mixture was stirred, and 0.1 mol of triethylamine in THF was gradually added dropwise. After stirring for 2 hours and further stirring at room temperature for 2 hours, the reaction solution was filtered off. The reaction solution was gradually dropped into water, and the deposited precipitate was further reprecipitated to obtain an ester oligomer (including polyacid anhydride) 11. The average molecular weight was 3500. The structural formula of the ester oligomer 11 is shown below.

0.05 mol of compound (d ′) was dissolved in THF, and 0.050 mol of menthanediol was added thereto. The temperature was kept at room temperature and the mixture was stirred, and 0.1 mol of triethylamine in THF was gradually added dropwise. After stirring for 2 hours and further stirring at room temperature for 4 hours, the reaction solution was filtered off. The reaction solution was gradually dropped into water, and the deposited precipitate was further reprecipitated to obtain an ester oligomer 12. The average molecular weight was 3000. The structural formula of the ester oligomer 12 is shown below.

[Synthesis of comparative acrylate polymer]
The reaction is carried out for 40 hours using 0.6 mol of adamantyl acrylate (compound (H)), 0.4 mol of tetrahydropyranyl methacrylate (compound (G)) in THF and AIBN (10 mol%) as an initiator, By dropping into hexane, a comparative acrylate polymer E was obtained. The structural formula of comparative acrylate polymer E is shown below.

[Synthesis of comparative ester oligomer]
0.05 mol of adamantane dicarbonyl chloride was dissolved in THF, and 0.05 mol of menthanediol was added thereto. The temperature was kept at room temperature and the mixture was stirred, and 0.1 mol of triethylamine in THF was gradually added dropwise. After stirring for 2 hours and further stirring at room temperature for 2 hours, the reaction solution was filtered off. The reaction solution was gradually dropped into water, and the deposited precipitate was further reprecipitated with a water-acetone solvent to obtain comparative ester oligomer F. The structural formula of the comparative ester polymer F is shown below.

[Comparative acrylate polymer]
Comparative acrylate polymer G, comparative acrylate polymer H, and comparative acrylate polymer I represented by the following structural formula described in JP-A-10-3169 were prepared.

[Preparation of resist and formation of resist pattern]
The polymer compound synthesized as described above, TPS-105, or NAI-105 made by Midori Chemical as a dissolution inhibitor and photoacid generator, cyclohexanone (polyester) or PGMEA (acrylic ester) according to the formulation shown in Table 4 The resist varnish of Reference Examples 10 to 18 was prepared.

On the other hand, varnishes of Comparative Examples 5 to 9 were prepared as shown in Table 5 together with a resist varnish containing TPS-105 as a photoacid generator as a comparative resist.

Next, each of these resist varnishes was spin-coated on a silicon wafer to form a resist film having a thickness of 0.3 μm, and using a NA0.55 stepper using ArF excimer laser light having a wavelength of 193 nm as a light source. The resist film surface was exposed to a predetermined pattern light. Subsequently, after baking at 110 ° C. for 2 minutes, the exposed area was selectively dissolved and removed with a 2.38% solution of tetramethylammonium hydroxide aqueous solution (TMAH) MAH and isopropyl alcohol. A mold resist pattern was formed. Table 6 shows the developer concentration, sensitivity, and resolution at this time.

As shown in Table 6, in each of the resists of Reference Examples 10 to 18, a resist pattern with high sensitivity and good resolution is formed, and both transparency to light with a wavelength of 193 nm and alkali developability are excellent. I know that. On the other hand, in the resists of Comparative Examples 5 to 9, it was also found that a resist pattern with good resolution was not formed, and it was found that there were problems such as easy peeling.

  Furthermore, the dry etching resistance of these resists was measured by measuring the etching rate using CF4 plasma. As a result, when the etching rate of the resist having a polyhydroxystyrene resin as a base resin is 1.0, the etching rates of Comparative Examples 5 and 6 are generally 1.0 to 1.3, and Comparative Examples 7, 8, and 9 are used. The etching rate of the resist is about 1.4 to 1.6, whereas the etching rate of the resists of Reference Examples 10 to 18 is 0.9 to 1.2, both having high dry etching resistance. It was confirmed that

¹ HNMR chart of Compound E ¹ HNMR chart of Compound F

Claims (1)

Monomer compound represented by any one of the following general formulas A to C

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