KR20090119262A - Chemically Amplified Positive Resist Composition - Google Patents

Abstract

The present invention comprises (A) a compound represented by the following general formula (1), a compound represented by the following general formula (2), and an m-cresol / p-cresol novolak resin, and the protection rate of the compound represented by the following general formulas (1) and (2) 30 to 34% resin; (B) photoacid generator; And (C) relates to a chemically amplified positive photoresist composition comprising a quencher.

The chemically amplified positive resist composition exhibits less unevenness due to standing waves in basic characteristics such as sensitivity and resolution, and can improve pattern profiles, especially line edge roughness, and manufacturing costs. Can reduce the cost.

Description

Chemically Amplified Positive Resist Composition {CHEMICAL AMPLIFICATION TYPE POSITIVE RESIST COMPOSITION}

TECHNICAL FIELD The present invention relates to a chemically amplified positive resist composition, and in particular, to a resist composition suitable for photolithography or the like acting by high energy radiation such as far ultraviolet rays (including excimer lasers, etc.), electron beams, X-rays or radiated light. It is about.

In recent years, as the degree of integration of integrated circuits has increased, submicron pattern formation has been required. In particular, photolithography using an excimer laser from fluoride krypton (KrF) or argon fluoride (ArF) has been noted in that it enables the production of 64M DRAM to 1G DRAM. As a resist suitable for a photolithography process using such an excimer laser, a so-called chemically amplified resist using an acid catalyst and a chemical amplification effect is adopted. When a chemically amplified resist is used, the acid generated from the photoacid generator in the irradiation section of the radiation is diffused by subsequent heat treatment, and the solubility in the alkaline developer of the irradiation section is changed by a reaction using the generated acid as a catalyst. Or a negative pattern is obtained.

Chemically amplified positive type resists, particularly positive type resists for KrF excimer laser photolithography, are poly (hydroxystyrene) resins in which some of their phenolic hydroxyl groups are dissociated by the action of an acid. Protected resins are often used in combination with photoacid generators. Moreover, as a group dissociated by the action of such an acid, forming an acetal bond between oxygen atoms derived from phenolic hydroxy groups from the viewpoint of resolution and sensitivity, for example, tetrahydro-2-pyranyl Attention is drawn to resins in which tetrahydro-2-furyl or 1-ethoxyethyl are bonded to an oxygen atom.

However, even when such a resin is used, there is a limit in the profile in forming a good pattern under conditions with a high film thickness and high sensitivity when used for a metal process and an ion implantation process. The unit price is high. In addition, when the chemically amplified resist composition increases the protection ratio of an unstable group to an acid in the resin which becomes soluble in the aqueous alkali solution due to insoluble or poorly soluble in the aqueous alkali solution or the action of acid, the resolution is generally improved, but it is normal. Unevenness due to the corrugated pattern is increased, and the linearity of the pattern profile, specifically, the pattern profile is lowered, resulting in an increase in irregularities in the process dimensions. In addition, when the permeability of the photoresist is reduced to reduce the unevenness and line edge roughness due to the steady wave pattern, the resolution is inferior.

The present invention solves the problems of the prior art as described above, and various performances such as resolution and applicability are good, and in particular, the pattern under high film sensitivity and film thickness condition in which a scum or reverse taper appears. It is an object of the present invention to provide a chemically amplified positive resist composition having an improved profile and having a low cost effect by developing a resist composition used for high sensitivity.

The present invention comprises (A) a compound represented by the following formula (1), a compound represented by the following formula (2), and m-cresol / p-cresol novolak resin, the protection rate of the compound represented by the formula (1) and 30 to 34% resin; (B) photoacid generator; And (C) provides a chemically amplified positive photoresist composition comprising a quencher.

<Formula 1>

<Formula 2>

In Formulas 1 and 2, R ₁ , R ₂ are each independently hydrogen, a substituted or unsubstituted linear or branched alkyl group having 1 to 10 carbon atoms; A substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms; Or a substituted or unsubstituted heterocycloalkyl group having 3 to 10 carbon atoms, R ₃ is a substituted or unsubstituted straight or branched chain alkyl group having 1 to 10 carbon atoms; A substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms; Or a substituted or unsubstituted linear or branched alkoxy group having 1 to 10 carbon atoms, a1, a2, b, and c are each a molar ratio of each monomer. Each is independently a real number of 0 to 1.

The chemically amplified positive resist composition of the present invention maintains basic characteristics such as sensitivity, resolution, and the like, and can reduce costs. It has an improved profile when forming a pattern under the film thickness condition where scum or reverse taper appears and high sensitivity. In addition, less unevenness due to standing waves appears, and pattern profiles, especially line edge roughness, can be improved.

Hereinafter, the present invention will be described in detail.

The chemically amplified positive photoresist composition of the present invention contains (A) resin, (B) photoacid generator, and (C) quencher.

I. (A) resin

The resin (A) forms a pattern and maintains the pattern, and is inherently insoluble or poorly soluble in aqueous alkali solution, but is soluble in aqueous alkali solution after dissociation of a functional group unstable with acid by the action of acid. Becomes The resin (A) includes a compound represented by the following formula (1), a compound represented by the following formula (2), and an m-cresol / p-cresol novolak resin, and the protection rate of the compound represented by the following formulas (1) and (2) is 30 to 34%.

<Formula 1>

<Formula 2>

In Formulas 1 and 2, R ₁ , R ₂ are each independently hydrogen, a substituted or unsubstituted linear or branched alkyl group having 1 to 10 carbon atoms; A substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms; Or a substituted or unsubstituted heterocycloalkyl group having 3 to 10 carbon atoms, R ₃ is a substituted or unsubstituted linear or branched alkyl group having 1 to 10 carbon atoms; A substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms; Or a substituted or unsubstituted linear or branched alkoxy group having 1 to 10 carbon atoms, a1, a2, b, and c are each a molar ratio of each monomer. Each is independently a real number of 0 to 1.

It is preferable that said R <_1> , R <_2> and R <_3> are a C1-C10 linear or branched alkyl group, or a C3-C10 cycloalkyl group.

When the carbon number of the alkyl group satisfies the above-mentioned range, there is an advantage in that the solubility in the solvent is excellent and no residue is generated during the desorption reaction after exposure.

The protection rate of the compounds represented by Formulas 1 and 2 is 30% to 34%. If the above range is satisfied, an excellent pattern can be obtained under high sensitivity. Here, the method of calculating the protection rate will be described with an example. When the a1 = 0.70 and b = 0.30 of the compound represented by the formula (1) and the a2 = 0.80 and c = 0.2 of the compound represented by the formula (2), the protection rate is { b × (parts by weight of the compound represented by Formula 1) + c × (parts by weight of the compound represented by Formula 2)} / {(parts by weight of the compound represented by Formula 1) + (compounds of the compound represented by Formula 2) Parts by weight)} × 100.

When the value of c / (a1 + a2 + b + c) is 0.01 to 0.2, there is an advantage in that the dissolution rate in the developer is excellent and the contrast is improved.

The compound represented by Chemical Formula 1 and the compound represented by Chemical Formula 2 are preferably included in the resin (A) in a weight ratio of 9: 1 to 5: 5. If the above range is satisfied, there is an advantage of maintaining an excellent pattern profile.

The weight average molecular weight of the compound represented by Formula 1 and the compound represented by Formula 2 is preferably 9,000 to 14,000, respectively. When the above-mentioned range is satisfied, the pattern can be easily formed, an appropriate dissolution rate can be realized with respect to the developer, and the development of residue after development can be prevented.

The compounds represented by the formulas (1) and (2) are obtained by introducing a protecting group that can be dissociated by the action of an acid into a resin that is soluble in an aqueous alkali solution. For example, a resin having a hydroxystyrene skeleton in which a part of the hydroxy group is protected by a protecting group which is dissociated by the action of an acid and / or a part of the hydroxy group is protected by a protecting group which is not dissociated by the action of an acid. It is resin which has frame | skeleton.

The protecting group is not particularly limited, and may include one or two or more selected from quaternary carbon-bonded oxygen atoms, acetal-type groups, and non-aromatic cyclic compounds. Examples of the group in which the quaternary carbon is bonded to an oxygen atom include t-butyl, t-butoxycarbonyl and t-butoxycarbonylmethyl. Examples of the acetal group include tetrahydro-2-pyranyl, tetrahydro-2-furyl, 1-ethoxyethyl, 1- (2-methylpropoxy) ethyl, 1- (2-methoxyethoxy) ethyl, 1 -(2-acetoxyethoxy) ethyl, 1- [2- (1-adamantyloxy) ethyl] ethyl, 1- [2- (1-adamantanecarbonyloxy) ethoxy] ethyl, and the like. Can be. The nonaromatic cyclic compounds include 3-oxocyclohexyl, 4-methyltetrahydro-2-pyron-4-yl (derived from mevalonic acid lactone), 2-methyl-2-adamantyl and 2-ethyl-2 -Adamantyl etc. are mentioned. Among them, it is particularly preferable to include a 1-ethoxyethyl group having high stability against delay after exposure. Accordingly, the compounds represented by Chemical Formulas 1 and 2 partially have a structure formed by protecting a hydroxy group of hydroxystyrene with a 1-ethoxyethyl group, and partially form a structure formed by protecting a pivalolate group. It is desirable to have.

The m-cresol / p-cresol novolak resins of the present invention are very inexpensive compared to resins commonly used in chemically amplified resist compositions, effectively reducing the manufacturing cost of the resist composition. The m-cresol and p-cresol in the m-cresol / p-cresol novolak resin are preferably included in a molar ratio of 3: 7 to 5: 5. If included in the above-described range, there is an advantage that scum and reverse taper do not occur.

The m-cresol / p-cresol novolak resin has a weight average molecular weight of 1,000 to 7000 when measured by gel permeation chromatography (GPC).

The m-cresol / p-cresol novolak resin is generally obtained by condensation of a phenolic compound with an aldehyde in the presence of an acid catalyst. The phenolic compound is m-cresol and p-cresol.

Examples of aldehydes that can be used to prepare the novolak resin include aliphatic aldehydes such as formaldehyde, acetaldehyde, propionaldehyde, n-butylaldehyde, isobutylaldehyde, acrolein or crotonaldehyde; Aliphatic ring aldehydes such as cyclohexanealdehyde, cyclopentanealdehyde, furfural or furyl acrolein; Aromatic aldehydes such as benzaldehyde, o-, m- or p-methylbenzaldehyde, p-ethylbenzaldehyde, 2,4-, 2,5-, 3,4- or 3,5-dimethylbenzaldehyde or o-, m Or p-hydroxybenzaldehyde; Aromatic aliphatic aldehydes such as phenylacetaldehyde or cinnamic aldehyde. Moreover, these aldehydes can also be used independently and can also use 2 or more types together. Of these aldehydes, formaldehyde is preferably used because it can be easily obtained commercially. Examples of the acid catalyst include inorganic acids such as hydrochloric acid, sulfuric acid, perchloric acid or phosphoric acid; Organic acids such as formic acid, acetic acid, oxalic acid, trichloroacetic acid or p-toluenesulfonic acid; Divalent metal salts such as zinc acetate, zinc chloride or magnesium acetate. In addition, these acid catalysts may be used independently and may use 2 or more types together. The condensation reaction can be carried out in a conventional manner. For example, when carried out at a temperature of 60 ° C to 120 ° C for about 2 to 30 hours, it is possible to obtain the m-cresol / p-cresol novolak resin of the present invention having a molecular weight of 1,000 to 7,000 or less.

The m-cresol / p-cresol novolak resin is preferably included in 10 to 15% based on the total weight of the resin (A). If included in the above-described range, the resolution and pattern profile are improved.

It is preferable that the dispersion degree of said (A) resin is 1.1-1.5. If the above range is satisfied, it may indicate that the resin having physical properties necessary for forming the pattern is precisely synthesized.

II. (B) Photoacid generator

The photoacid generator (B) is a compound that generates an acid by the action of light or radiation, and has a high energy such as ultraviolet ray, far ultraviolet ray, electron beam, X-ray or radiation to the material itself or a resist composition comprising such material. It is a substance that generates acid by irradiating radiation. The acid generated from the photoacid generator (B) acts on the resin to dissociate the functional group unstable to the acid present in the resin.

It is preferable that the said (B) photo-acid generator contains the compound represented by following formula (3).

<Formula 3>

In Formula 3, R ₄ and R ₅ are each independently a hydroxy group, an amino group or a C 1 to C 10 straight or branched alkyl group unsubstituted or substituted with an alkoxy group having 1 to 6 carbon atoms; A cycloalkyl group having 3 to 10 carbon atoms unsubstituted or substituted with a hydroxy group, an amino group or an alkoxy group having 1 to 6 carbon atoms; Or a C6-C11 aryl group unsubstituted or substituted with a C1-C20 alkyl group, a C1-C6 alkoxy or halogen atom.

Preferably, in Formula 3, R ₄ and R ₅ are each independently n-propyl group, n-butyl group, n-octyl group, toluyl group, 2,4,6-trimethylphenyl group, 2,4,6- Triisopropylphenyl group, 4-dodecylphenyl group, 4-methoxyphenyl group, 2-naphthyl group or benzyl group. More preferably, in Formula 3, R ₄ and R ₅ are each independently n-propyl group and n-butyl group.

The photoacid generator (B) is more preferably used by mixing the compound represented by the formula (3) and other photoacid generators having high acidity and high transmittance. The other photoacid generator can maintain a high resolution in a thick film because the transmittance is greater than the conventional photoacid generator.

The other photoacid generators include onium salt compounds, s-triazine-based organic halogen compounds, sulfone compounds, sulfonate compounds, and the like, and these may be used alone or in combination of two or more thereof. Specific examples of the other photoacid generators include diphenyl iodonium trifluoromethanesulfonate, 4-methoxyphenylphenyl iodonium hexafluoroantimonate, 4-methoxyphenylphenyl iodonium trifluoromethanesulfonate , Bis (4-t-butylphenyl) iodonium tetrafluoroborate, bis (4-t-butylphenyl) iodonium hexafluorophosphate, bis (4-t-butylphenyl) iodonium hexafluoroantimonate , Bis (4-t-butylphenyl) iodonium trifluoromethanesulfonate, triphenylsulfonium hexafluorophosphate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium trifluoromethanesulfonate, 4-methylphenyldiphenylsulfonium perfluorobutanesulfonate, 4-methylphenyldiphenylsulfonium perfluorooctanesulfonate, 4-methoxyphenyldiphenylsulfonium hexafluoroantimonate, 4-methoxyphenyldi Phenylsulfonium trifluorome Tansulfonate, p-tolyldiphenylsulfonium trifluoromethanesulfonate, 2,4,6-trimethylphenyldiphenylsulfonium trifluoromethanesulfonate, 4-t-butylphenyldiphenylsulfonium trifluoro Methanesulfonate, 4-phenylthiophenyldiphenylsulfonium hexafluorophosphate, 4-phenylthiophenyldiphenylsulfonium hexafluoroantimonate, 1- (2-naphtolylmethyl) thiolanium hexafluoroanti Monate, 1- (2-naphtolylmethyl) thiolanium trifluoromethanesulfonate, 4-hydroxy-1-naphthyldimethylsulfonium hexafluoroantimonate, 4-hydroxy-1-naphthyl Dimethylsulfonium trifluoromethanesulfonate, N- (trifluoromethylsulfonyloxy) -5-norbornene-2,3-dicarboxyimide, N- (trifluoromethylsulfonyloxy) naphthali Mead etc. are mentioned. Among them, triphenylsulfonium hexafluorophosphate, triphenylsulfonium hexafluoroantimonate, and triphenylsulfonium trifluoric acid having a cationic group of triphenylsulfonium and containing a fluorine group as an anionic group and having high acidity and high lipophilic properties Romethanesulfonate, triphenylsulfonium 2,4,6-triisopropylbenzenesulfonate, 4-methylphenyldiphenylsulfonium perfluorobutanesulfonate, 4-methylphenyldiphenylsulfonium perfluorooctanesulfonate, 4-methoxyphenyldiphenylsulfonium hexafluoroantimonate, 4-methoxyphenyldiphenylsulfonium trifluoromethanesulfonate, p-tolyldiphenylsulfonium trifluoromethanesulfonate, 2,4, 6-trimethylphenyldiphenylsulfonium trifluoromethanesulfonate, 4-t-butylphenyldiphenylsulfonium trifluoromethanesulfonate, 4-phenylthiophenyldiphenylsulfonium hexafluorophosphate The antimonate is preferably 4-phenylthio-phenyl diphenyl sulfonium hexafluoro.

The photoacid generator (B) preferably contains from 0.1 to 5 parts by weight (in terms of solids) based on 100 parts by weight of the (A) resin (in terms of solids). When the (B) photoacid generator is included in an amount of 0.1 to 5 parts by weight, the development defect does not occur, so the resolution is excellent and the shape of the pattern is excellent.

When the (B) photoacid generator is used by mixing the compound represented by Chemical Formula 3 with the other photoacid generator, the mixing ratio (weight%) of the compound represented by Chemical Formula 3 with another photoacid generator is 50:50 to 90:10 is preferred. When included in the above range, the profile of the photoresist is excellent, there is an advantage that can prevent the development failure.

III. (C) Quencher

The (C) Quencher is a synthesized nitrogen-containing basic organic compound. Specific examples of the quencher include tetramethylammonium hydroxide, tetra-n-butylammonium hydroxide, tetra-n-hexylammonium hydroxide, tetra-n-octylammonium hydroxide, phenyltrimethylammonium hydroxide , 3- (trifluoromethyl) -phenyltrimethylammonium hydroxide, (2-hydroxyethyl) trimethylammonium hydroxide, dicyclohexylmethylamine, 2,6-diisopropylaniline, tris (2- ( 2-methoxyethoxy) ethyl) amine etc. are mentioned. In addition, a hindered amine compound having a piperidine backbone as described in JP-A-11-52575 can also be used as a quencher. In addition, dicyclohexylmethylamine, 2,6-diisopropylaniline and tris (2- (2-methoxyethoxy) ethyl) amine are used to form a good pattern under conditions of high film thickness and high sensitivity. It is desirable to.

The quencher is preferably 100 parts by weight of the resin (A) (in terms of solid content), and 0.001 to 10 parts by weight (in terms of solid content). When included in the above-described range, the acid is not diffused in an area other than the exposure area, so that the profile can be kept constant, and the sensitivity is excellent and the development defect can be suppressed.

Ⅳ. (D) organic solvent

The chemically amplified positive photoresist composition of the present invention may further include (D) an organic solvent to provide the resist composition in solution. The organic solvent (D) dissolves the respective components, has a suitable drying rate, and provides a smooth film after evaporation of the organic solvent (D). In addition, the (C) organic solvent is not particularly limited, and conventional organic solvents used in the technical field of the present invention can be used.

The organic solvent (D) may include one or two selected from the group consisting of glycol ether esters, esters, ketones, cyclic esters and alcohols. Examples of the glycol ether esters include ethyl cellosolve acetate, methyl cellosolve acetate, propylene glycol monomethyl ether acetate, and the like. Ethyl lactate, butyl acetate, amyl acetate, ethyl pyruvate, etc. are mentioned as said ester. Acetone, methyl isobutyl ketone, 2-heptanone, cyclohexanone, etc. are mentioned as said ketone. (Gamma) -butyrolactone etc. are mentioned as said cyclic ester. Moreover, 3-methoxy-1- butanol etc. are mentioned as said alcohol.

The organic solvent (D) may be included in an amount of 250 to 450 parts by weight based on 100 parts by weight of the (A) resin. If included in the above range, each component is sufficiently dissolved, there is an advantage that can be uniformly mixed, there is an advantage that can maintain a smooth surface even if the solvent is dried during the photoresist patterning process.

In addition, the resist compositions of the present invention may also contain small amounts of various additives such as sensitizers, dissolution inhibitors, other resins, surfactants, stabilizers, dyes, and the like.

Using the chemically amplified positive photoresist composition according to the present invention, a resist pattern can be formed by the following method.

The chemically amplified positive photoresist composition according to the present invention is formed on the etching target layer of the substrate by spin coating to form a photoresist film. Soft baking may be performed to form the photoresist film into a solid resist. After the electron beam is injected into the photoresist film as an exposure source, a post exposure bake is performed on the exposed resist film as necessary to promote the protecting group removal reaction. The baked resist film is developed with an alkaline developer to form a resist pattern.

The alkaline developer used in the present invention is sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, ammonia water, ethylamine, n-propylamine, triethylamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide And (2-hydroxyethyl) trimethylammonium hydroxide, and may be one or two or more selected from among them, among which tetramethylammonium hydroxide and (2-hydroxyethyl) trimethylammonium hydroxide (Usually called choline) is preferred.

Hereinafter, preferred embodiments of the present invention are provided to aid in understanding the present invention. However, the following specific examples are provided only for easier understanding of the present invention, and the contents of the present invention are not limited thereto.

Synthesis Example 1 : One- Ethoxyethyl group  partially Etherified Poly (hydroxystyrene) phosphorus  Synthesis of A-1

40 g of poly (p-hydroxystyrene) [weight average molecular weight; 11,000, dispersion: 1.1] (333 mmol calculated using the molecular weight of the p-hydroxystyrene structural unit) and 47 mg (0.25 mmol) of p-toluenesulfonic acid monohydrate were added to 720 g of propylene glycol monomethyl ether acetate. Dissolved. This solution was distilled under reduced pressure under the condition of a temperature of 60 ° C. and a pressure of 10 Torr (1,333 Pa) or less, followed by azeotropic dehydration. The weight of the solution after distillation was 337 g. This solution was transferred to a 500 ml four neck flask purged with nitrogen, and thereto was added dropwise 13.3 g (184 mmol) of ethyl vinyl ether, and they were reacted at 25 ° C. for 5 hours. To the reaction solution was added 62.3 g of propylene glycol monomethyl ether acetate and 320 g of methyl isobutyl ketone, additionally 240 mL of ion exchanged water was added and the mixture was stirred. Subsequently, the mixture was allowed to stand and the organic layer portion was taken out. 240 mL of ion-exchanged water was added to the organic layer again, the mixture was stirred and washed, and then left to stand to allow the liquid to separate. After performing washing with this on-exchanged water and liquid separation again, the organic layer was taken out and distilled under reduced pressure to remove water and methyl isobutyl ketone by azeotropic distillation with propylene glycol monomethyl ether acetate, and propylene glycol monomethyl An ether acetate solution was obtained. A solution of poly (p-hydroxystyrene) partially etherified with the resulting 1-ethoxyethyl group was obtained and the polymer was analyzed by 1 H-NMR. 40% of the hydroxyl groups in poly (p-hydroxystyrene) were etherified with 1-ethoxyethyl groups. This polymer is referred to as A-1, A-1 is represented by the formula (1), and has a molecular weight of 12,500, a degree of dispersion of 1.45, a R ₁ : methyl group, a R ₂ : ethyl group, a1 = 0.60, b = 0.40.

Synthesis Example 2 : One- Ethoxyethyl group  partially Etherified Poly (hydroxystyrene) phosphorus  Synthesis of A-2 Resin

Reaction, post-treatment in the same manner as in Synthesis Example 1, except that the amount of ethyl vinyl ether was changed to 10 g (138 mmol) to obtain a solution of poly (hydroxystyrene) partially etherified with 1-ethoxyethyl group. And analysis was performed. 30% of the hydroxyl groups in the poly (hydroxystyrene) were etherified with 1-ethoxyethyl groups. This polymer is referred to as number A-2, wherein A-2 is represented by Formula 1 and has a molecular weight of 12,300, a dispersity of 1.45, a R ₁ : methyl group, a R ₂ : ethyl group, a1 = 0.70, and b = 0.30.

Synthesis Example 3 : One- With pivalo diary  partially Esterified Poly (hydroxystyrene) phosphorus  Synthesis of A-3

650 g of poly (p-hydroxystyrene) [＇VP-8000 ', manufactured by Nippon Soda KK, weight average molecular weight: 8000, dispersion degree: 1.2] (5.41 mol calculated using the molecular weight of the p-hydroxystyrene structural unit) ) And 6.5 kg of acetone were added and stirred to dissolve them, and then 246 g (2.43 mol) of triethylamine were added thereto, and the mixture was heated at 35 deg. 130.6 g of pivaloyl chloride (1.62 mol, 0.30 equiv based on the hydroxyl group of poly (p-hydroxystyrene)) was added dropwise into this resin solution over about 30 minutes. After the mixture was stirred at 35 ° C. for 3 hours, 6.5 kg of methyl isobutyl ketone was added and the mixture was washed three times with 2% aqueous oxalic acid solution. The resulting organic layer was further washed with ion exchanged water to separate the liquid and this process was repeated five times. From this organic layer, the solvent was distilled off and concentrated until the resin solution content became 2.0 kg. 6.0 kg of propylene glycol monomethyl ether acetate were then added and the mixture was further concentrated to 2.5 kg to give a solution of poly (p-hydroxystyrene) partially esterified with 1-pivaloyl group. The resulting polymer was analyzed by 13 C-NMR. 20% of the hydroxyl groups in the poly (hydroxystyrene) were esterified with pivaloyl groups. This polymer is referred to as A-3, wherein A-3 is represented by the formula (2) and has a molecular weight of 10,000, a dispersity of 1.4, a R ₃ : t-butyl group, a2 = 0.80, and c = 0.20.

Synthesis Example  4: Low molecular weight  M-cresol except Novolac  Synthesis of Resin A-4

 A 1 liter four-necked flask equipped with a reflux tube, a stirrer and a thermometer was charged with 10.2 g of oxalic acid dihydrate, 68.7 g of 90% acetic acid and 203 g of methyl isobutyl ketone, and the mixture was heated to 80 ° C. and the mixture 37 143.2 g of% aqueous formaldehyde solution was added dropwise over 1 hour. The mixture was then heated to reflux and held at the same temperature for 12 hours. The resulting reaction solution was diluted with methyl isobutyl ketone, diluted with water and dehydrated to obtain a 36.8% methyl isobutyl ketone solution of novolac resin. 612 g of the resin solution was charged to a 5-liter bottom-drain flask, diluted with 1,119 g of methyl isobutyl ketone, charged with 1,232 g of n-heptane, and the mixture was separated by stirring and standing at 60 ° C. to form a novolak resin in the lower layer. A solution was obtained. This novolak resin solution was diluted with propylene glycol methyl ether acetate and then concentrated to give a propylene glycol methyl ether acetate solution of novolak resin. This resin is called A-4. The A-4 was measured by gel permeation chromatography (GPC) using polystyrene as a standard material, and it was confirmed that the area ratio of components having a molecular weight of 1,000 or less was 4.8% based on the total pattern area excluding unreacted monomers. The weight average molecular weight of the resin was 8,699.

Synthesis Example  5: Low molecular weight  M-cresol / p-cresol (= 40/60) excluded Novolac  Synthesis of Resin A-5

A 1 liter four-necked flask equipped with a reflux tube, stirring device and thermometer was charged with 87.3 g of m-cresol, 131.0 g of p-cresol, 6.1 g of oxalic acid dihydrate, 59.3 g of 90% acetic acid and 203 g of methyl isobutyl ketone. The mixture was heated to 80 ° C. To the mixture was added dropwise 94.2 g of aqueous 37% formaldehyde solution over 1 hour. The mixture was then heated to reflux and held at the same temperature for 12 hours. The resulting reaction solution was diluted with methyl isobutyl ketone, washed with water and dehydrated to obtain a 38.0% methyl isobutyl ketone solution of novolac resin. 384 g of the resin solution was charged into a 5-liter low-emission flask, diluted with 574 g of methyl isobutyl ketone, and filled with 764 g of n-heptane, the mixture was stirred and left at 60 ° C. to separate the novolak resin solution into the lower layer. Got it. Subsequently, the novolak resin solution was diluted with propylene glycol methyl ether acetate, and then concentrated to obtain a propylene glycol methyl ether acetate solution of novolak resin. The resin is called A-5. The A-5 was measured by gel permeation chromatography (GPC) using polystyrene as a standard material, and it was confirmed that the area ratio of components having a molecular weight of 1,000 or less was 5.3% based on the total pattern area excluding unreacted monomers. The weight average molecular weight of the resin was 6,846.

Synthesis Example  6: Low molecular weight  Except m-cresol / 2,5- Xylenol (= 100/40) Novolac  Synthesis of Resin A-6

15-liter m-cresol, 67.9 g of 2,5-xylenol, 10.0 g of oxalic acid dihydrate, 66.3 g of 90% acetic acid and 218 g of methyl isobutyl ketone Was charged and the mixture was heated to 80 ° C. To the mixture was added dropwise 142.2 g of 37% aqueous formaldehyde solution over 1 hour. The mixture was then heated to reflux and held at the same temperature for 12 hours. The resulting reaction solution was diluted with methyl isobutyl ketone, washed with water and dehydrated to obtain a 38.0% methyl isobutyl ketone solution of novolac resin. 644 g of the resin solution was charged to a 5-liter bottom discharge flask and diluted with 411 g of methyl isobutyl ketone. There, 715 g of n-heptane was charged, and the mixture was stirred at 60 degreeC, left still, and it isolate | separated, and obtained the novolak resin solution in the lower layer. Then, the novolak resin solution was diluted with propylene glycol methyl ether acetate, and then concentrated to obtain a propylene glycon methyl ether acetate solution of novolak resin. The resin is called A-6. The A-6 was measured by gel permeation chromatography (GPC) using polystyrene as a standard material, and it was confirmed that the area ratio of components having a molecular weight of 1000 or less was 11.9% based on the total pattern area excluding unreacted monomers. The weight average molecular weight of the resin was 6,119.

Synthesis Example  7: 2-ethyl-2- Adamantyl Methacrylate  And p- Acetoxystyrene  Synthesis of Copolymer (30:70)

In the flask 59.6 g (0.24 mol) of 2-ethyl-2-adamantyl methacrylate, 90.8 g (0.56 mol) of p-acetoxystyrene and 279 g of isopropanol were charged, and the atmosphere in the flask was washed with nitrogen. The mixture was then heated to 75 ° C. To the solution was added dropwise a solution prepared by dissolving 11.05 g (0.048 mol) of dimethyl-2,2'-azobis (2-methylpropionate) in 22.11 g of isopropanol. The mixture was aged at 75 ° C. for about 0.3 hours, refluxed for 12 hours, diluted with acetone, and charged in methanol to crystallize. The resulting crystals were removed by filtration. The weight of the crude crystal of the resulting copolymer of 2-ethyl-2-adamantylmethacrylate and p-acetoxystyrene was 250 g.

Synthesis Example  8: 2-ethyl-2- Adamantyl Methacrylate  And p- Hydroxystyrene  Synthesis of A-7 as Copolymer (30:70)

250 g of crude crystals of a copolymer of 2-ethyl-2-adamantyl methacrylate and p-acetoxystyrene (30:70) obtained in Synthesis Example 7 in a flask and 10.8 g (0.088 mol) of 4-dimethylaminopyridine And 239 g of methanol and aged for 20 hours under reflux. After cooling, the mixture was neutralized with 8.0 g (0.133 mol) of glacial acetic acid, crystallized by filling with water, and the crystals were removed by filtration. The crystals were then dissolved in acetone, filled with water to crystallize, and the crystals removed by filtration. This operation was repeated three times. The resulting crystals were then dried. The weight of the resulting copolymer of 2-ethyl-2-adamantyl methacrylate and p-hydroxystyrene was 102.8 g. The weight average molecular weight was about 8,200, the dispersity was 1.68 (reduced by GPC method: polystyrene), and the copolymerization ratio was about 30:70 when analyzed by nuclear magnetic resonance (13 C-NMR) spectrophotometer. This resin is called A-7.

Example 1  To 6 and Comparative Example 1  To 6: chemically amplified positive Photoresist  Preparation of the composition

The components shown in Table 1 were mixed at the indicated composition ratios (in terms of solids), and filtered through a fluorine resin filter having a pore diameter of 0.2 μm to prepare a resist solution.

Resin (part by weight) Photoacid Generator (parts by weight) Quencher (parts by weight) Solvent (part by weight) Example 1 A-1 / A-2 / A-3 / A-5 Protection Rate: 31.18% 35/25/25/15 = 100 B-1 / B-2 2.2 / 0.74 = 2.94 C-1 / C-2 0.148 / 0.074 = 0.222 D-1 377 Example 2 A-1 / A-2 / A-3 / A-5 Protection Rate: 31.89% 38/31/21/10 = 100 B-1 / B-3 2.2 / 0.74 = 2.94 C-1 / C-2 0.148 / 0.074 = 0.222 D-1 377 Example 3 A-1 / A-3 / A-5 protection rate: 33.78% 62/28/10 = 100 B-1 / B-2 2.2 / 0.74 = 2.94 C-1 / C-2 0.148 / 0.074 = 0.222 D-1 377 Example 4 A-1 / A-2 / A-3 / A-5 Protection Rate: 30.59% 30/30/25/15 = 100 B-1 / B-2 3.3 / 0.74 = 4.04 C-1 / C-2 0.148 / 0.074 = 0.222 D-1 377 Comparative Example 1 A-1 / A-2 / A-3 / A-4 Protection Rate: 31.18% 35/25/25/15 = 100 B-1 / B-2 2.2 / 0.74 = 2.94 C-1 / C-2 0.148 / 0.074 = 0.222 D-1 377 Comparative Example 2 A-1 / A-2 / A-3 / A-6 protection rate: 31.18% 35/25/25/15 = 100 B-1 / B-2 2.2 / 0.74 = 2.94 C-1 / C-2 0.148 / 0.074 = 0.222 D-1 377 Comparative Example 3 A-1 / A-5 protection rate: 80% 75/25 = 100 B-1 / B-2 2.2 / 0.74 = 2.94 C-1 / C-2 0.148 / 0.074 = 0.222 D-1 377 Comparative Example 4 A-1 / A-4 protection rate: 40% 50/50 = 100 B-1 / B-2 2.2 / 0.74 = 2.94 C-1 / C-2 0.148 / 0.074 = 0.222 D-1 377 Comparative Example 5 A-5 / A-7 25/75 = 100 B-1 / B-2 2.2 / 0.74 = 2.94 C-1 / C-2 0.148 / 0.074 = 0.222 D-1 377 Comparative Example 6 A-5 / A-7 50/50 = 100 B-1 / B-2 2.2 / 0.74 = 2.94 C-1 / C-2 0.148 / 0.074 = 0.222 D-1 377

A-1: Resin with a molecular weight of 12,500 containing 1-ethoxyethyl group protecting group and a dispersity of 1.45 with respect to the hydroxy group of hydroxystyrene, a1 = 0.60, b = 0.40

A-2: A1 = 0.70 and b = 0.30 with a resin having a molecular weight of 12,300 and a dispersity of 1.45 containing a 1-ethoxyethyl protecting group relative to the hydroxy group of hydroxystyrene.

A-3: Resin with a molecular weight of 10,000 containing a pivaloyl protecting group and a dispersity of 1.4 with respect to the hydroxy group of hydroxystyrene, a2 = 0.80, c = 0.20

A-4: m-cresol novolak resin except low molecular weight.

A-5: m-cresol / p-cresol (= 40/60) novolak resin except low molecular weight.

A-6: m-cresol / 2,5-xylenol (= 100/40) novolak resin except low molecular weight.

A-7: 2-ethyl-2-adamantyl methacrylate and p-acetoxystyrene copolymer (30:70).

B-1: Diazodisulfone type photoacid generator in which R ₄ and R ₅ in Formula 2 are each a butyl group,

B-2: 4-methylphenyldiphenylsulfonium perfluorobutanesulfonate

B-3: triphenylsulfonium 2,4,6-triisopropylbenzenesulfonate

C-1: dicyclohexylmethylamine

C-2: tris (2- (2-methoxyethoxy) ethyl) amine

D-1: Propylene Glycol Monomethyl Ether Acetate

Test Example ; Chemically Amplified Positive Resist  Evaluation of the properties of the composition

The resist solutions of Examples 1 to 4 and Comparative Examples 1 and 2 were applied onto a silicon wafer substrate treated with hexamethyldisilazane using a spin coater, and the thickness of the resist film after drying was 0.57 μm. The substrate on which the dried resist film was formed was subjected to preheat treatment for 60 seconds on a hot plate at 100 ° C. The wafer substrate having the resist film thus formed was gradually exposed to light using a scanning exposure apparatus ('NSR-S203B' manufactured by Nikon Corp., NA = 0.55, sigma = 0.55) having an exposure wavelength of 248 nm (KrF). Exposure was performed to form line and space patterns. Subsequently, in the hot plate, post-exposure heat treatment was performed at 110 ° C. for 60 seconds. In addition, paddle development was performed for 60 seconds using an aqueous 2.38% tetramethylammonium hydroxide solution. The pattern after development was observed with a scanning electron microscope, and the effective sensitivity, resolution and profile were examined by the method described below, and the test results are shown in Table 2 below.

※ Effective Sensitivity: This is described as the exposure amount when the 0.25 μm line and space pattern is 1: 1.

Resolution: This is described as the minimum size of the line and space pattern separated by the exposure dose at effective sensitivity.

profile Sensitivity (mJ / ㎠) Resolution (μm) Example 1 ◎ 30 0.18 Example 2 ○ 33 0.20 Example 3 ○ 30 0.20 Example 4 ◎ 30 0.18 Comparative Example 1 × 33 > 0.25 Comparative Example 2 × 33 > 0.25 Comparative Example 3 × 30 > 0.25 Comparative Example 4 × 30 > 0.25 Comparative Example 5 × 34 > 0.25 Comparative Example 6 × 33 > 0.25

◎: very good, ○: excellent, ×: poor

As shown in Table 2, it can be seen that the profile and resolution are excellent when the resist compositions of Examples 1 to 4 according to the present invention are compared with the resist compositions of Comparative Examples 1 to 6. This suggests that resists with a range of m-cresol / p-cresol novolak resins for ethoxyethyl / pivaloyl protecting groups on ethoxyethyl / pivaloyl protecting groups under thick film conditions or conditions requiring fast sensitivity are effective in showing good profiles. Can be.

Claims (13)

(A) a compound represented by the following formula (1), a compound represented by the following formula (2), and m-cresol / p-cresol novolak resin, the protection rate of the compound represented by the formula (1) and 2 is 30 to 34 Resin which is%; (B) photoacid generator; And (C) a chemically amplified positive photoresist composition comprising a quencher: <Formula 1>

<Formula 2>

In Chemical Formulas 1 and 2, R ₁ and R ₂ are each independently hydrogen, a substituted or unsubstituted linear or branched alkyl group having 1 to 10 carbon atoms; A substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms; Or a substituted or unsubstituted heterocycloalkyl group having 3 to 10 carbon atoms, R ₃ is a substituted or unsubstituted linear or branched alkyl group having 1 to 10 carbon atoms; A substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms; Or a substituted or unsubstituted linear or branched alkoxy group having 1 to 10 carbon atoms, a1, a2, b and c are the molar ratios of each monomer Each is independently a real number of 0 to 1. The method according to claim 1, Based on 100 parts by weight of the (A) resin, 0.1 to 5 parts by weight of the photoacid generator (B); And The chemically amplified positive photoresist composition comprising (C) 0.001 to 10 parts by weight of the quencher. The method according to claim 1, Dispersion degree of the resin (A) is 1.1 to 1.5, the chemically amplified positive photoresist composition. The method according to claim 1, The compound represented by the formula (1) and the compound represented by the formula (2) is a chemically amplified positive photoresist composition, characterized in that included in the (A) resin in a weight ratio of 9: 1 to 5: 5. The method according to claim 1, Some of the hydroxyl groups of the compound represented by Formula 1 and the compound represented by Formula 2 are each protected with a protecting group capable of dissociation by an acid. The method according to claim 1, Chemical amplification-type positive photoresist composition, characterized in that the weight average molecular weight of the compound represented by Formula 1 and the compound represented by Formula 2 are 9,000 to 14,000, respectively. The method according to claim 5, The protecting group is a chemically amplified positive resist composition, characterized in that the quaternary carbon is one or two or more selected from a group bonded to an oxygen atom, an acetal-type group and a non-aromatic cyclic compound. The method according to claim 1, The m-cresol and p-cresol in the m- cresol / p- cresol novolak resin is a chemically amplified resist composition, characterized in that contained in a molar ratio of 3: 7 to 5: 5. The method according to claim 1, The m-cresol / p-cresol novolak resin is a chemically amplified resist composition, characterized in that contained in 10 to 15% by weight based on the total weight of the resin (A). The method according to claim 1, The weight-average molecular weight of the m-cresol / p-cresol novolak resin is 1,000 to 7,000, characterized in that the chemically amplified positive resist composition. The method according to claim 1, (B) the photoacid generator is a chemically amplified positive photoresist composition characterized in that it comprises a compound represented by the formula <Formula 3>

In Chemical Formula 3, R ₄ and R ₅ are each independently a hydroxy group, an amino group or a C 1-10 straight or branched chain alkyl group unsubstituted or substituted with an alkoxy group having 1 to 6 carbon atoms; A cycloalkyl group having 3 to 10 carbon atoms unsubstituted or substituted with a hydroxy group, an amino group or an alkoxy group having 1 to 6 carbon atoms; Or an aryl group having 6 to 11 carbon atoms unsubstituted or substituted with an alkyl group having 1 to 20 carbon atoms, alkoxy having 1 to 6 carbon atoms or a halogen atom. The method according to claim 11, R ₄ and R _{5 in} Formula 3 are each independently n-propyl group, n-butyl group, n-octyl group, toluyl group, 2,4,6-trimethylphenyl group, 2,4,6-triisopropylphenyl group And 4-dodecylphenyl group, 4-methoxyphenyl group, 2-naphthyl group and benzyl group. The method according to claim 11, (B) the photoacid generator is a chemical amplification type, characterized in that it further comprises one or two or more selected from the group consisting of onium salt compound, s-triazine-based organic halogen compound, sulfone compound, and sulfonate compound Positive photoresist composition.