KR100263911B1 - Photosensitive polymer for chemically amplified photoresist and chemically amplified photoresist compositon having the same - Google Patents

Abstract

A photosensitive polymer for chemically amplified photoresist and a composition comprising the same are disclosed. The photosensitive polymer for chemically amplified photoresist according to the present invention is represented by the following formula (1). The photoresist composition comprising the photosensitive polymer for chemically amplified photoresist according to the present invention has high etching resistance.

Description

Photosensitive polymer for chemically amplified photoresist and chemically amplified photoresist composition comprising same

The present invention relates to a photosensitive polymer for chemically amplified photoresist and a chemically amplified photoresist composition comprising the same.

As the degree of integration of semiconductor devices increases, forming a fine pattern in a photolithography process has become an essential problem. In addition, a photolithography technique using an ArF excimer laser (193 nm), which is shorter than the conventional KrF excimer laser (248 nm), as an exposure source is proposed because a pattern of sub-quarter micron size must be formed in a device of 1 giga-bit or more. It became. Therefore, development of a photosensitive polymer and photoresist composition for a chemically amplified photoresist suitable for an ArF excimer laser has started to be required.

In general, chemically amplified photoresist compositions for ArF excimer lasers must satisfy the following requirements. (1) be transparent at a wavelength of 193 nm, (2) have good thermal properties (e.g. high glass transition temperature), (3) have good adhesion to film quality, and (4) have high resistance to dry etching (5) During development, it should be able to be easily developed with a developer (for example, 2.38 wt% tetramethyl ammonium hydroxide (TMAH)) widely used in the manufacturing process of semiconductor devices.

However, ternary polymers composed of methylmethacrylic acid, t-butyl methacrylic acid and methacrylic acid monomers, which are widely known as polymers for chemically amplified photoresists for ArF excimer lasers, do not satisfy all of the above requirements. In particular, it has a disadvantage in that the resistance to etching is very weak and the adhesion to the membrane is weak.

Therefore, in recent years, attempts have been made to introduce alicyclic compounds such as isobornyl, adamantyl, tricyclodecanyl groups, etc. into the polymer skeleton to form photosensitive polymers for ArF excimer lasers having increased etching resistance. come. However, these polymers also have the disadvantage that dry etching resistance is still not satisfactory.

SUMMARY OF THE INVENTION The present invention has been made in an effort to provide a photosensitive polymer for chemically amplified photoresist that can be exposed with an ArF excimer laser and has high resistance to dry etching.

Another object of the present invention is to provide a chemically amplified photoresist composition comprising the photosensitive polymer.

The photosensitive polymer for chemically amplified photoresist according to an aspect of the present invention for achieving the above technical problem is a ternary polymer in which norbornene dicarboxylic acid mono alkyl ester monomer, norbornene alkyl ester monomer and maleic anhydride monomer are polymerized to be.

In particular, the alkyl groups of the norbornene dicarboxylic acid mono alkyl ester monomers are aliphatic ring hydrocarbons having 6 to 20 carbon atoms, such as adamantyl, adamantanemethyl, adamantaneethyl, norbornyl, norbornylmethyl, isobonyl Or naphthyl.

The chemically amplified photoresist composition according to the present invention for achieving the above another technical problem is a ternary polymer in which norbornene dicarboxylic acid mono alkyl ester monomer, norbornene alkyl ester monomer and maleic anhydride monomer are polymerized; It includes a photoacid generator mixed in a ratio of 1 to 15% by weight based on the weight of the original polymer.

As the photoacid generator, triallyl sulfonium salt, diaryl iodonium salt or sulfonate may be used.

The chemically amplified photoresist composition according to the present invention may further include 1 to 50% by weight dissolution inhibitor based on the weight of the photosensitive polymer. In addition, the base may further include 0.01 to 2.0% by weight of an organic base based on the weight of the photosensitive polymer.

The dissolution inhibitor may be a compound in which a dialkyl group having a chemical reaction by an acid to a hydrocarbon compound having 1 to 40 carbon atoms is bonded with a functional group, or a tricyclodecane derivative in which a group having a chemical reaction by an acid is bonded to a functional group. It is preferable.

Triethylamine, triisobutylamine, triisooctylamine, diethanolamine or triethanolamine may be used as the organic base.

In the photosensitive polymer for chemically amplified photoresist according to the present invention, the backbone of the polymer has a ring structure. Therefore, the etching resistance of the photoresist composition including the same is large. In particular, since the aliphatic ring hydrocarbon group is bonded to the side chain group, the etching resistance is further increased.

Hereinafter, a photosensitive polymer for chemically amplified photoresist and a chemically amplified photoresist composition including the same will be described. Moreover, the preferable photolithography process using a chemically amplified photoresist composition is also demonstrated. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various forms, and only the embodiments are intended to complete the disclosure of the present invention, and to those skilled in the art to fully understand the scope of the invention. It is provided to inform you.

Photosensitive Polymer for Chemically Amplified Photoresist

The photosensitive polymer for chemically amplified photoresist according to an embodiment of the present invention is a ternary polymer in which norbornene dicarboxylic acid mono alkyl ester monomer, norbornene alkyl ester monomer and maleic anhydride monomer are polymerized.

When the polymer is represented by the formula, it is represented by the following formula (1).

<Formula 1>

Wherein R 1 is an aliphatic ring hydrocarbon group having 6 to 20 carbon atoms, R 2 is a t-butyl, tetrahydropyranyl group, l, m and n are integers, and l / (l + m + n) is 0.01 to 0.5, m / (l + m + n) is 0.5, n / (l + m + n) is 0.1 to 0.5 and the weight average molecular weight of the polymer is 3,000 to 100,000.

The weight average molecular weight of the polymer is preferably 5,000 to 50,000.

The backbone of the photosensitive polymer according to the invention is composed of norbornane, which is a cyclic structure. Therefore, the etching resistance is large. In particular, since aliphatic ring hydrocarbon groups are bonded side chains to norbornane, etching resistance is further increased.

Chemically Amplified Photoresist Compositions

The chemically amplified photoresist composition according to the present invention is composed of the photosensitive terpolymer and the photoacid generator described above.

The photoacid generator is preferably mixed at a ratio of 1 to 15% by weight based on the weight of the photosensitive polymer. As the photoacid generator, a material having high thermal stability is preferably used. Thus, triarylsulfonium salts, diaryliodonium salts or sulfonates can be used. For example, triphenylsulfonium triflate, triphenylsulfonium antimonate, diphenyliodonium triflate, diphenylidonium antimonate, methoxy di Methoxydiphenyliodonium triflate, di-t-butyldiphenyliodonium triflate, 2,6-dinitrobenzyl sulfonate, fatigue Pyrogallol tris (alkylsulfonates), or N-hydroxysuccinimide triflate may be used as the photoacid generator.

In addition, the photoresist composition according to the present invention preferably further comprises a dissolution inhibitor of 1 to 50% by weight based on the weight of the photosensitive polymer.

The dissolution inhibitor may be represented by the following Chemical Formula 2, and a compound in which a dialkylmalonate group having a chemical reaction by an acid is bonded to a hydrocarbon compound having 1 to 40 carbon atoms may be used.

Wherein R3 is cyclohexyl, dimethylcyclohexyl, xylenyl or naphthalenyl methyl, and R2 is t-butyl or tetrahydropyranyl (tetrahydropyranyl) group, k being 1 or 2.

The dissolution inhibitor shows very low solubility due to the bulky dialkyl group, which is a functional group before exposure, but after exposure the solubility is greatly increased since the dialkyl group is hydrolyzed by acid to form malonic acid groups. In addition, since the dialkyl group is stable to heat, it has stable thermal properties even above the glass transition temperature.

As another dissolution inhibitor, a tricyclodecane derivative in which a group in which a chemical reaction is caused by an acid is bonded to a functional group may be used.

The tricyclodecane derivative may be represented by the following formula (3).

In the above formula, R 4 is preferably a t-butoxycarbonyl or tetrahydropyranyl group, respectively.

Since the dissolution inhibitors are cyclic structures, they are highly etch resistant. In addition, due to the bulky alkoxy group, which is a functional group, the solubility is low, but after exposure, the solubility increases because the alkoxy group is hydrolyzed by an acid to form a hydroxy group.

By including the above-described dissolution inhibitor, there is an advantage in that the difference in solubility before and after exposure of the photoresist film can be increased to significantly increase the contrast.

More preferably, the photoresist composition according to the present invention further comprises 0.01 to 2.0% by weight of organic base additive based on the total weight of the photosensitive polymer or the photosensitive polymer mixture. As the organic base additive, triethylamine, triisobutylamine, triisooctylamine, diethanolamine or triethanolamine is used. After exposure, the organic base additive is added to prevent the problem that the acid generated in the exposed portion diffuses into the non-exposed portion and thus the photoresist composition constituting the non-exposed portion is also hydrolyzed (acidolysis) to deform the pattern.

As described above, the photoresist composition according to the present invention comprises a photosensitive polymer composed of norbornane whose skeleton is a cyclic structure and in which aliphatic ring hydrocarbons are bonded side chains. Therefore, the etching resistance of the photoresist composition is large. And before exposure, since it exists in the bulky state, but the maleic anhydride which forms a carboxyl group by ester acid and the ester group are couple | bonded, the polarity of the photoresist film of the exposed part and the polarity of the photoresist film of the unexposed part are remarkable. Makes a difference.

In addition, the inclusion of a dissolution inhibitor having a cyclic structure to which a bulky alkoxy group is bonded significantly increases the etching resistance of the photoresist composition. In addition, the dissolution inhibitor has an alkoxy group or a malonic acid dialkyl group which is hydrolyzed by an acid to form a hydroxy group or malonic acid group, so that the solubility of the photoresist composition is significantly different before and after exposure. Greatly increases.

Method of Making Photosensitive Polymer

1. Preparation of monomer

1-1. Preparation of 5-norbornene-2,3-dicarboxylic acid mono-1-alkyl ester (compound III) monomer

5-norbornene-2,3-dicarboxylic acid anhydride (compound I) and an alcohol like compound II are reacted to react 5-norbornene-2,3-dicarboxylic acid mono-1- as in Scheme 1 below. Prepare the alkyl ester (Compound III).

Wherein R 1 is an aliphatic ring hydrocarbon group having 6 to 20 carbon atoms.

R1 is adamantyl, adamantanemethyl, adamantaneethyl, adamantaneethyl, norbornyl, norbornylmethyl, norbornylmethyl, isobornyl and naphthyl It is preferably any one selected from the group consisting of.

1-2. Preparation of Norbornene Alkyl Ester (Compound VI) Monomer

As in Scheme 2, cyclopentadiene (Compound IV) is dissolved in an organic solvent, and then alkyl acrylate (Compound V) is added to prepare norbornene alkyl ester (Compound VI).

Wherein R 2 is a t-butyl or tetrahydropyranyl group.

2. Preparation of Terpolymer

A polymer in which 5-norbornene-2,3-dicarboxylic acid mono-1-alkyl ester (III) monomer, norbornene alkyl ester (VI) monomer and maleic anhydride (VII) monomer are polymerized and represented by formula (1) Preparation of VIII)

Polymerization is carried out as in Scheme 3 below to form polymer (VIII).

Wherein R 1 is an aliphatic ring compound group having 6 to 20 carbon atoms, R 2 is a t-butyl, tetrahydropyranyl group, l, m and n are integers, and l / (l + m + n) is 0.01 to 0.5, m / (l + m + n) is 0.5, n / (l + m + n) is 0.1 to 0.5 and the weight average molecular weight of the polymer is 3,000 to 100,000.

That is, 5-norbornene-2,3-dicarboxylic acid mono-1-alkyl ester (III) monomer, norbornene alkyl ester (VI) monomer and maleic anhydride (VII) monomer are dissolved in an organic solvent such as toluene. After the polymerization, a polymerization initiator such as azobisisobutyronitrile (AIBN) is added to the polymerization reaction to prepare a polymer (VIII).

Method for preparing chemically amplified photoresist composition and photolithography method using the same

The chemically amplified photoresist composition of the present invention is prepared by dissolving the photosensitive polymer represented by the formula (1) and the photoacid generator prepared according to the above-described preparation in a suitable solvent.

At this time, the photoacid generator is mixed at a ratio of 1 to 15% by weight based on the weight of the polymer. It is preferable to use thermally stable triarylsulfonium salt, diaryl iodonium salt, or sulfonate as a photo-acid generator.

Further, 1 to 50% by weight of the dissolution inhibitor based on the weight of the polymer is further mixed. In this case, as the dissolution inhibitor, any one selected from the dissolution inhibitors represented by Formulas 2 and 3 may be used.

In addition, it is preferable to further dissolve 0.01 to 2.0% by weight of the organic base additive based on the weight of the polymer to complete the photoresist composition. As the organic base additive, it is preferable to use triethylamine, triisobutylamine, triisooctylamine, diethanolamine or triethanolamine.

Chemically amplified photoresist compositions prepared according to the methods described above can be used in general photolithography processes. In particular, the ArF excimer laser is used as an exposure source, and is suitable for forming a fine pattern with a design rule of 0.20 µm or less.

First, the photoresist composition described above is applied onto a substrate on which an object to be patterned is formed to form a photoresist film having a predetermined thickness. Subsequently, pre-baking is performed on the photoresist film. After the pre-exposure bake step, the photoresist film is exposed using a mask in which a predetermined pattern is formed using an ArF excimer laser as the exposure source. By exposure, an acid is generated from the photoacid generator in the photoresist film, and the generated acid catalyzes to hydrolyze the photosensitive polymer as shown in Scheme 4 to form a large amount of carboxy groups. In addition, as shown in Scheme 5 or 6, the dissolution inhibitor is hydrolyzed by the acid to form a hydroxy group.

Therefore, the polarity of the photoresist film of the exposed portion and the polarity of the photoresist film of the unexposed portion are remarkably different. In other words, the contrast is significantly increased.

After the exposure is completed, before the development, the photoresist film is heat-treated again for a short time (post-exposure-thermal treatment). The post-exposure heat treatment is performed to further activate the acidolysis reaction by the acid catalyst in the exposed portion. In other words, all the ester groups or acid anhydrides of the photosensitive polymer in the exposed portion are hydrolyzed to carboxyl groups, and the alkoxy groups of the dissolution inhibitor are hydrolyzed to be converted to hydroxy groups to increase the contrast.

Next, depending on whether the photoresist film is used for positive or negative use, a developing process is performed using an appropriate developer to complete the photoresist pattern. At this time, the developer used is a developer at a concentration used in a conventional process, such as 2.38% by weight of TMAH.

After forming the photoresist pattern, the film to be patterned is etched to form a desired pattern. Since the photoresist pattern according to the present invention is formed of a photoresist film made of a photosensitive polymer having a skeleton having a ring structure and having an aliphatic ring hydrocarbon side chain bonded thereto, the photoresist pattern is highly resistant during etching. Thus, it is possible to form a pattern of good profile with accurate critical dimensions.

The invention is described in more detail with reference to the following Examples, which are not intended to limit the invention.

Experimental Example 1: Preparation of Monomer

Experimental Example 1-1 Preparation of 5-norbornene-2,3-dicarboxylic acid mono-1-adamantanemethyl ester

16.2 g of 5-norbornene-2,3-dicarboxylic anhydride (0.1 mol) and 25 g of 1-adamantanemethanol (0.15 mol) were dissolved in tetrahydrofuran (THF) in a round bottom flask. After adding a small amount of and p-toluene sulfonic acid, it was made to react for about 12 hours at reflux conditions.

After the reaction was completed, the reactant was dissolved in excess water to filter out the precipitate, and the reaction product was separated by recrystallization using methylene chloride n-hexane (yield 40%).

Experimental Example 1-2: Preparation of t-butyl 5-norbornenecarboxylic acid

After dissolving 6.6 g of cyclopentadiene (0.1 mol) obtained by distillation from dicyclopentadiene into 50 mL of methylene chloride in a round bottom flask, 14 g of t-butyl acrylic acid (0.11 mol) was slowly added at 0 ° C., and then room temperature The reaction was carried out for about 12 hours.

After the reaction was completed, the reaction product was separated by vacuum distillation (yield 70%).

Experimental Example 1-3: Preparation of Tetrahydropyranyl 5-norbornenecarboxylic Acid

The reaction product was separated by vacuum distillation in the same manner as in Example 1-2, except that 17.2 g of tetrahydropyranyl acrylic acid (0.11 mol) was used instead of t-butyl acrylic acid (0.11 mol). 60%)

Experimental Example 2: Preparation of Ternary Polymer

Experimental Example 2-1 Poly (5-norbornene-2,3-dicarboxylic acid mono-1-adamantanemethyl ester-maleic anhydride-t-butyl 5-norbornenecarboxylic acid) terpolymer Manufacturing of>

The monomer synthesized in Experimental Example 1-1 (0.05 mol), the monomer synthesized in Experimental Example 1-2 (0.05mol) and the maleic anhydride monomer (0.1mol) were dissolved in THF anhydride. AIBN (4 mmol) was added thereto, purged with nitrogen gas for about 2 hours, and then polymerized under reflux for about 24 hours.

After completion of the polymerization reaction, the reactant was precipitated in excess n-hexane, and then the precipitate was dissolved in THF again and then re-precipitated in n-hexane. The precipitate was filtered using a glass filter and then dried in a vacuum oven at 50 ° C. for about 24 hours to separate the reaction product.

The weight average molecular weight of the obtained reaction product was 7,860, and polydispersity was 2.2.

Experimental Example 2-2 Poly (5-norbornene-2,3-dicarboxylic acid mono-1-adamantanemethyl ester-maleic anhydride-tetrahydropyranyl 5-norbornenecarboxylic acid) Preparation of Polymer>

The tetrahydropyranyl 5-norbornenecarboxylic acid monomer (0.05 mol) synthesized in Experimental Example 1-3 was used instead of the t-butyl 5-norbornenecarboxylic acid monomer synthesized in Experimental Example 1-2. A reaction product was obtained in the same manner as in Experimental Example 2-1 except for the following.

The weight average molecular weight of the obtained reaction product was 7,550, and polydispersity was 2.1.

Experimental Example 3: Preparation of Dissolution Inhibitor

Experimental Example 3-1 Preparation of Bis (t-Butoxy Carbonyloxymethyl) Tricyclodecane>

Into a round bottom flask, 20 g of 4,8-bis (hydroxymethyl) tricyclodecane (0.1 mol) and 22 g of triethylamine (0.22 mol) were added and dissolved in 400 mL of THF. After adding 65 g of di-t-butyl dicarbonate (0.3 mol) to this solution, it reacted at the temperature of about 60 degreeC.

After the reaction was completed, excess THF was evaporated and the reaction was then poured into excess water and neutralized with hydrochloric acid. Finally, the mixture was extracted with diethyl ether, and then the reaction product was separated using column chromatography. (Yield 65%)

Experimental Example 3-2: Preparation of 1,4-bis (di-t-butylmalonyl) cyclohexane

Sodium hydride (0.2 mol) was added to a round bottom flask and dissolved in THF (250 mL). Malonic acid di-t-butyl (0.2 mol) was slowly added thereto, followed by reaction for about 1 hour. Thereafter, 1,4-dibromocyclohexane (0.05 mol) was slowly dropped at 0 ° C, and reacted at 45 ° C for about 12 hours.

After completion of the reaction, excess THF was evaporated from the reaction, and then dissolved in excess water. Then, the mixture was neutralized with hydrochloric acid, and then extracted with diethyl ether.

The precipitate obtained was dried over magnesium sulfate, and then the reaction product was separated using column chromatography (yield 55%).

Experimental Example 4: Preparation of Photoresist Composition and Photolithographic Etching Process Using the Same

Experimental Example 4-1 Poly (5-norbornene-2,3-dicarboxylic acid mono-1-adamantanemethyl ester-maleic anhydride-t-butyl 5-norbornenecarboxylic acid) terpolymer Preparation of Photoresist Composition Using Photo etch Process>

1.0 g of the terpolymer prepared in Experimental Example 2-1 was dissolved in 6.0 g of propylene glycol monomethyl ether acetate, and then 0.02 g of triphenylsulfonium triflate was added thereto as a photoacid generator. Stirred. The mixture was then filtered using a 0.2 μm filter to obtain a photoresist composition.

The obtained photoresist composition was spin coated to a thickness of about 0.5 μm on the wafer on which the material layer to be patterned was formed. The wafer coated with the photoresist composition was soft baked at a temperature of about 130 ° C. for about 90 seconds, exposed using a ArF excimer laser as an exposure source and a mask defining a pattern of 0.30 μm line width, and then exposed to about 140 ° C. Post bake for about 90 seconds at temperature. Thereafter, the film was developed with 2.38 wt% of TMAH for 60 seconds to form a photoresist pattern.

An excellent photoresist pattern having a 0.30 µm line width could be formed with an exposure energy of 20 mJ / cm 2 dose. In addition, it was possible to form a material layer pattern having an excellent pattern profile.

Experimental Example 4-2 Poly (5-norbornene-2,3-dicarboxylic acid mono-1-adamantanemethyl ester-maleic anhydride-t-butyl 5-norbornenecarboxylic acid) terpolymer And photoresist composition using dissolution inhibitor and photolithography process using the same>

Bis (t-butoxy carbonyloxymethyl) tree prepared in Experimental Example 3-1 using 0.01 g of triphenylsulfonium triflate and 0.01 g of N-hydroxy succinimide triflate as a photoacid generator, and a dissolution inhibitor A photoresist composition was prepared in the same manner as Experimental Example 4-1 except that 0.1 g of cyclodecane was further added, and a photolithography process was performed.

As a result, a photoresist pattern having an excellent profile having a 0.30 µm line width could be formed with an exposure energy of 33 mJ / cm 2 dose.

Experimental Example 4-3 Poly (5-norbornene-2,3-dicarboxylic acid mono-1-adamantanemethyl ester-maleic anhydride-t-butyl 5-norbornenecarboxylic acid) terpolymer Of Photoresist Composition Using Chemical, Dissolution Inhibitor and Organic Base and Photolithography Process Using the Same>

A photoresist composition was prepared in the same manner as Experimental Example 4-2 except that 2 mg of triisobutylamine was further added as an organic base, and a photolithography process was performed.

As a result, a photoresist pattern having an excellent profile having a 0.30 µm line width could be formed with an exposure energy of 43 mJ / cm 2 dose.

Experimental Example 4-3 Poly (5-norbornene-2,3-dicarboxylic acid mono-1-adamantanemethyl ester-maleic anhydride-tetrahydropyranyl 5-norbornenecarboxylic acid) Preparation of Photoresist Composition Using Polymer and Dissolution Inhibitor and Photolithography Process Using the Same>

The ternary polymer formed in Experimental Example 2-2 was used as the photosensitive polymer, and 0.2 g of 1,4-bis (di-t-butylmalonyl) cyclohexane prepared in Experimental Example 3-2 was further added as a dissolution inhibitor. Except that, a photoresist composition was prepared in the same manner as in Experimental Example 4-1, and a photolithography process was performed.

As a result, a photoresist pattern having an excellent profile having a 0.30 µm line width was formed at an exposure energy of 23 mJ / cm 2 dose.

The backbone of the photosensitive polymer according to the invention is composed of norbornane, which is a cyclic structure. Therefore, the etching resistance is large. In particular, the etch resistance is further increased when the alicyclic hydrocarbon group is linked to the side chain in norbornane.

The dissolution inhibitor constituting the photoresist composition together with the photosensitive polymer according to the present invention also has a cyclic structure and thus has high etching resistance. The dissolution inhibitor has a very low solubility before exposure due to the bulky alkoxy group which is a functional group, but after exposure the solubility is greatly increased because the alkoxy group is hydrolyzed by acid to form a hydroxy group.

Therefore, when the photoresist composition is formed using the photosensitive polymer and the dissolution inhibitor according to the present invention, the etching resistance of the photoresist composition is increased, and the polarity of the photoresist film in the exposed portion and the polarity of the photoresist film in the unexposed portion are remarkable. This makes a difference and increases the contrast.

Claims (11)

A photosensitive polymer for chemically amplified photoresists, characterized in that the ternary polymer represented by the formula (1). <Formula 1> Wherein R 1 is an aliphatic ring hydrocarbon group having 6 to 20 carbon atoms, R 2 is a t-butyl or tetrahydropyranyl group, l, m and n are integers, and l / (l + m + n) is 0.01 to 0.5, m / (l + m + n) is 0.5, n / (l + m + n) is 0.1 to 0.5, and the weight average molecular weight of the polymer is 3,000 to 100,000. According to claim 1, wherein R1 is adamantyl (adamantyl), adamantanemethyl (adamantanemethyl), adamantaneethyl (adamantaneethyl), norbornyl (norbornyl), norbornylmethyl (norbornylmethyl, isobornyl) And naphthyl, any one selected from the group consisting of photosensitive polymers for chemically amplified photoresists. Ternary polymer represented by the formula (1); And Chemically amplified photoresist composition comprising a photoacid generator mixed in a ratio of 1 to 15% by weight based on the weight of the photosensitive polymer. <Formula 1> Wherein R 1 is an aliphatic ring hydrocarbon group having 6 to 20 carbon atoms, R 2 is a t-butyl or tetrahydropyranyl group, l, m and n are integers, and l / (l + m + n) is 0.01 to 0.5, m / (l + m + n) is 0.5, n / (l + m + n) is 0.1 to 0.5, and the weight average molecular weight of the polymer is 3,000 to 100,000. According to claim 3, wherein R1 is adamantyl, adamantanemethyl, adamantaneethyl, adamantaneethyl, norbornyl, norbornylmethyl, norbornylmethyl, isobornyl ) And any one selected from the group consisting of naphthyl (chemical) amplification type photoresist composition 4. The photosensitive polymer according to claim 3, wherein the photoacid generator is triarylsulfonium salts, diaryliodonium salts or sulfonates. The chemically amplified photoresist composition of claim 3, further comprising 1 to 50 wt% of a dissolution inhibitor based on the weight of the photosensitive polymer. The method according to claim 6, wherein the dissolution inhibitor is a group in which a chemical reaction is performed by a compound or acid in which a dialkylmalonate group having a chemical reaction with an acid to a hydrocarbon compound having 1 to 40 carbon atoms is bonded with a functional group ( Acid-labile group) is a tricyclodecane derivatives (tricyclodecane derivatives) bonded to a functional group, characterized in that the chemically amplified photoresist composition. The chemically amplified photoresist composition according to claim 7, wherein the compound having a functional group of a dialkyl group of malonic acid which causes a chemical reaction with an acid to a hydrocarbon compound having 1 to 40 carbon atoms is represented by Formula 2 below. . <Formula 2> Wherein k is 1 or 2, R 2 is a t-butyl, tetrahydropyranyl or trimethylsilyl group and R 3 is a cyclohexyl, dimethylcyclohexyl, xylenyl or naphthalenylmethyl group. 8. The chemically amplified photoresist composition of claim 7, wherein the tricyclodecane derivative is bis (t-butoxy carbonyloxymethyl) tricyclodecane or bis (tetrahydropyranyloxymethyl) tricyclodecane. . The photoresist composition of claim 3, further comprising 0.01 to 2.0% by weight of an organic base based on the weight of the photosensitive polymer. The method of claim 10, wherein the organic base is triethylamine, triisobutylamine, triisooctylamine, diethanolamine, or triethanolamine, Photoresist composition.