KR100638957B1 - Photoresist Polymer and Photoresist Composition Containing it - Google Patents

Abstract

The present invention relates to a photoresist polymer and a photoresist composition, and more particularly, to a compound of formula 1 used as a photoresist monomer, a photoresist polymer comprising the same, and a photoresist composition of the present invention containing the polymer. Since the film has transmittance, etching resistance, heat resistance, adhesion, and low light absorption at wavelengths of nm and 157 nm, and has high affinity for a developer, line edge roughness (LER) can be improved.

[Formula 1]

Where

R, R ', R'', R ₁ , R ₂ , R ₃ , R ₄ , R ₅ and m are as defined in the specification.

Description

Photoresist polymer and photoresist composition containing same {Photoresist Polymer and Photoresist Composition Containing it}

1 is a photoresist pattern photo formed by Example 13. FIG.

2 is a photoresist pattern photo formed by Example 14.

3 is a photoresist pattern photo formed by Example 15.

4 is a photoresist pattern photo formed by Example 16.

5 is a photoresist pattern photo formed by Example 17. FIG.

6 is a photoresist pattern photo formed by Example 18. FIG.

The present invention relates to a photoresist polymer and a photoresist composition, and more particularly, to a compound of formula 1 used as a photoresist monomer, a photoresist polymer comprising the same, and a photoresist composition of the present invention containing the polymer is 1938. It is possible to improve line edge roughness (LER) because of excellent transmittance, etching resistance, heat resistance and adhesion at wavelengths of nm and 157 nm, low light absorption, and high affinity for a developer.

In general, in order to be used as photoresist for ArF and vacuum ultraviolet light (VUV), the light absorption at the wavelength of 193nm and 157nm should be low, the etching resistance and the adhesion to the substrate should be excellent, and the 2.38wt% and 2.6wt% Many requirements must be met, such as developing with an aqueous tetramethyl ammonium hydroxide (TMAH) solution.

The main research direction to date has been to search for resins with high transparency at 248 nm and 193 nm with the same etching resistance as novolak resin.

However, most of these resists are not suitable as resists for 157nm, as the circuit of the device becomes smaller and the thickness of the resist becomes lower, which makes it difficult to improve the LER of the pattern and also shows strong absorbance in the wavelength region of 157nm.

In order to solve the above problems, polyethylene and polyacrylate-based resins containing fluorine have been used, but polyethylene and polyacrylate-based resins containing fluorine have weak etching resistance and There is a disadvantage that the adhesion is greatly reduced.

In addition, the polyethylene and polyacrylate-based resins are not suitable for commercial use due to the difficulty in mass production and high price. In case of the pattern forming process using the conventional chemically amplified photoresist, after exposure, the acid-sensitive protecting group is broken during the baking process, the glass is released, and the outgassing of the gas is generated, which damages the lens. .

The present invention is a polymer for photoresist having a transmittance, etching resistance, heat resistance, adhesion and low light absorbance, and low light absorbance at a wavelength of 157 nm in order to obtain an improved pattern of LER and a photoresist composition containing the polymer. The purpose is to provide.

In order to achieve the above object, the present invention provides a sultone compound used as a photoresist monomer, a photoresist polymer including the compound, a composition containing the polymer, and a method of forming a photoresist pattern using the same.

In the present invention below

To prepare a compound of formula 1 used as a photoresist monomer.

[Formula 1]

Where

R is CH ₂ , CHCH ₂ or C (CH ₂ ) ₂ ,

R 'and R''are H or CH ₃ ,

R ₁ , R ₂ , R ₃ , R ₄ and R ₅ are each H, F, C ₁ -C ₂₀ alkyl, C ₁ -C ₂₀ perfluoroalkyl, ether containing ether group (-O-) _1, containing the ~C ₂₀ alkyl, an ether group (-O-) C ₁ ~C ₂₀ alkyl, perfluoroalkyl, containing a part of the alkyl ether or F-substituted C ₁ ~C ₂₀ group in part F Is substituted C ₁ -C ₂₀ alkyl,

m is an integer of 0-3.

In this case, the compound of Formula 1 is Tetrahedron. 33, pp 1113-1118 (1977) and J. Am. Chem. Synthesis by the method of SOC. 82, 6181 (1960).

Preferred examples of the compound of formula 1 used as the photoresist monomer of the present invention are as follows. That is, when m is 0, the compound is preferably the following Formulas 1a to 1f.

[Formula 1a]

[Formula 1b]

[Formula 1c]

[Formula 1d]

[Formula 1e]

[Formula 1f]

In addition, when R is CH ₂ and m is 1, the compound of Formula 1 is preferably 1g to 1l.

[Formula 1g]

[Formula 1h]

Formula 1i]

[Formula 1j]

[Formula 1k]

[Formula 1l]

In addition, the present invention prepares a polymer comprising a polymerization repeating unit of the formula (2).

[Formula 2]

Where

R is CH ₂ , CHCH ₂ or C (CH ₂ ) ₂ ,

R 'and R''are H or CH ₃ ,

R ₁ , R ₂ , R ₃ , R ₄ and R ₅ are each H, F, C ₁ -C ₂₀ alkyl, C ₁ -C ₂₀ perfluoroalkyl, ether containing ether group (-O-) _1, containing the ~C ₂₀ alkyl, an ether group (-O-) C ₁ ~C ₂₀ alkyl, perfluoroalkyl, containing a part of the alkyl ether or F-substituted C ₁ ~C ₂₀ group in part F Is substituted C ₁ -C ₂₀ alkyl,

m is an integer of 0-3, n is an integer of 10-150.

Thus, since the polymer of the present invention contains sultone, it has a high adhesion to the silicon substrate, has a low absorbance at wavelengths of 193 nm and 157 nm, and is also caused by an acid generated during exposure during the baking process. Since a mechanism such as the following Equation 1 is generated, a degassing reaction such as a problem of the conventional chemically amplified resist does not occur and damage to the lens can be prevented. In addition, since the product of the exposed portion including sulfuric acid produced by this mechanism is easily dissolved in the developer, the line edge roughness (LER) of the pattern can be improved.

Scheme 1

Preferred examples of the polymerization repeating unit of Chemical Formula 2 are as shown in Chemical Formulas 2a to 2l.

[Formula 2a]

[Formula 2b]

[Formula 2c]

[Formula 2d]

[Formula 2e]

[Formula 2f]

[Formula 2g]

[Formula 2h]

[Formula 2i]

[Formula 2j]

[Formula 2k]

[Formula 2l]

In the formula 2a to 2l,

n is an integer of 10-150.

In the present invention,

(a) reacting a compound of formula 3 with a compound of formula 4 in the presence of a salt to obtain a compound of formula 1; And

(b) polymerizing the compound of Chemical Formula 1 in the presence of a polymerization initiator to prepare a polymer of Chemical Formula 2.

[Formula 3]

[Formula 4]

In Chemical Formulas 3 and 4,

R is CH ₂ , CHCH ₂ or C (CH ₂ ) ₂ ,

R 'and R''are H or CH ₃ ,

R ₁ , R ₂ , R ₃ , R ₄ and R ₅ are each H, F, C ₁ -C ₂₀ alkyl, C ₁ -C ₂₀ perfluoroalkyl, ether containing ether group (-O-) _1, containing the ~C ₂₀ alkyl, an ether group (-O-) C ₁ ~C ₂₀ alkyl, perfluoroalkyl, containing a part of the alkyl ether or F-substituted C ₁ ~C ₂₀ group in part F Is substituted C ₁ -C ₂₀ alkyl,

X is F, Cl or Br,

m is an integer of 0-3.

The polymerization reaction is carried out by radical polymerization, bulk polymerization or solution polymerization, or the like, and may be formed using a metal catalyst as disclosed in WO 96/37526 (Nov. 28, 1996).

The salt of step (a) is preferably selected from sodium hydride (NaH), butyl lithium (n-BuLi), lithium diisopropylamine (LDA) and lithium hydride (LiH).

The polymerization of step (b) is solution polymerization, selected from the group consisting of cyclohexanone, cyclopentanone, tetrahydrofuran, dimethylformamide, dimethylsulfoxide, dioxane, methylethylketone, benzene, toluene and xylene A single solvent or a mixed solvent is used.

In addition, the polymerization initiator of step (b) is benzoyl peroxide, 2,2'-azobisisobutyronitrile (AIBN), acetyl peroxide, lauryl peroxide, t- butyl per acetate, t- butyl hydroper Preference is given to using those selected from the group consisting of oxides and di-t-butylperoxides.

The polymer prepared by the above method is preferably crystallized using a lower alcohol or water containing diethyl ether, petroleum ether, methanol, ethanol or isopropanol alone or as a mixed solvent.

In the present invention, a photoresist composition is prepared by including the polymer, a photoacid generator, and an organic solvent. In this case, the composition may further include a vinylene-based or acrylic polymer.

The photoacid generator may be used as long as the compound can generate an acid by light, US 5,212,043 (May 18, 1993), WO 97/33198 (September 12, 1997), WO 96/37526 (1996. 11.28), EP 0794458 (September 10, 1997), EP 0789278 (August 13, 1997), US 5,750,680 (May 12, 1998), US 6,051,678 (April 18, 2000), GB 2,345,286 A (2000) 7. 5), US 6,132,926 (October 17, 2000), US 6,143,463 (11/7/2000), US 6,150,069 (11/21/2000), US 6.180.316 B1 (January 30, 2001), US 6,225,020 B1 (May 1, 2001), US 6,235,448 B1 (May 22, 2001), and US 6,235,447 B1 (May 22, 2001) and the like, and mainly sulfur-based or onium salt-based compounds are used. In particular, low absorbance phthalimidotrifluoromethane sulfonate, dinitrobenzyltosylate, n-decyl disulfone and naphthylimidotrifluoromethane at 157 nm and 193 nm Preference is given to using those selected from the group consisting of naphthylimido trifluoromethane sulfonate, together with diphenylurodoxyl hexafluorophosphate, diphenylurodoxyl hexafluoro arsenate, diphenylurodoxyl hexafluoro antimonate, Diphenylparamethoxyphenylsulfonium triflate, diphenylparatol ruenylsulfonium triflate, diphenylparaisobutylphenylsulfonium triflate, triphenylsulfonium hexafluoro arsenate, triphenylsulfonium hexafluor Rho antimonate, triphenylsulfonium triflate and dibutylnaphthylsulfonium It can also be used for the photo acid generator selected from the group consisting of a plate, is preferably used in a ratio of 0.05 to 10wt% with respect to the photoresist polymer. When the photoacid generator is used in an amount of 0.05wt% or less, the sensitivity of the photoresist to light is weak. When the photoacid generator is used at 10wt% or more, the photoacid generator absorbs a lot of ultraviolet rays and generates a large amount of acid, thereby obtaining a pattern having a bad cross section.

In addition, the organic solvent can be used in any one, US 5,212,043 (May 18, 1993), WO 97/33198 (September 12, 1997), WO 96/37526 (Nov. 28, 1996), EP 0 794 458 (October 10, 1997) EP 0 789 278 (August 13, 1997), US 5,750,680 (May 12, 1998), US 6,051,678 (April 18, 2000), GB 2,345,286 A (2000. 7. 5), US 6,132,926 (October 17, 2000), US 6,143,463 (11/7/2000), US 6,150,069 (11/21/2000), US 6.180.316 B1 (January 30, 2001), US 6,225,020 B1 (2001. 5) 1), US 6,235,448 B1 (May 22, 2001) and US 6,235,447 B1 (May 22, 2001) and the like, preferably diethylene glycol diethyl ether, methyl 3- Methoxy propionate (methyl 3-methoxypropionate), ethyl 3-ethoxypropionate, propylene glycol methyl ether acetate, cyclohexanon (cyclohexanon), 2-heptanone (n-heptanone) or ethyl lactate alone Can be used in combination or in combination with It is used in a ratio of 2000 wt% to obtain a photoresist film having a desired thickness, for example, the thickness of the photoresist when the organic solvent is used is 1000wt% with respect to the photoresist polymer.

The present invention also provides a method of forming a photoresist pattern consisting of the following steps:

(a) applying the above-described photoresist composition of the present invention on the etched layer to form a photoresist film;

(b) exposing the photoresist film;

(c) baking the exposed photoresist film; And

(d) developing the resultant to obtain a desired pattern.

In the above process, it may further comprise the step of performing a baking process before exposure, this baking process is carried out at 70 to 200 ℃.

The exposure process is performed using an exposure energy of 1 to 100 mJ / cm ² using Ar, as well as KrF, Extreme Ultra Violet (EUV), Vacuum Ultra Violet (VUV), E-beam, X-ray or ion beam. desirable.

On the other hand, the development of step (d) is preferably carried out using an alkaline developer, for example 0.01 to 5wt% TMAH aqueous solution.

The present invention also provides a semiconductor device manufactured using the pattern formation method described above.

Hereinafter, the present invention will be described in detail by examples. However, the examples are only to illustrate the invention and the present invention is not limited by the following examples.

I. Preparation of Photoresist Monomer

Example 1 Synthesis of Formula 1b

2,3,3-trimethyl-1,3-propane sultone (0.1 M) was dissolved in anhydrous tetrahydrofuran under a nitrogen atmosphere, followed by NaH (0.1 M). ) Was added. Then, after stirring for 10 minutes, vinyl bromide (vinyl bromide) (0.11M) was added, and further reacted for 3 hours while adding the temperature to room temperature. After completion of the reaction, the reaction mixture was filtered to remove NaBr, and then crystallized in a dimethyl ether / pentane mixed solution to obtain a pure compound of formula 1b (92%).

Example 2. Synthesis of Formula 1c

Same as Example 1 except that 2,2,3,3-tetramethyl-1,3-propane sultone is used instead of 2,3,3-trimethyl-1,3-propane sultone of Example 1 Synthesis was carried out to give a compound of formula 1c (96%).

Example 3. Synthesis of Formula 1e

Example 1, except that 1,2,3,3-tetramethyl-1,3-propane sultone is used instead of 2,3,3-trimethyl-1,3-propane sultone of Example 1 Synthesis was carried out to give a compound of formula 1e (92%).

Example 4. Synthesis of Formula 1h

Except for using allyl bromide (allyl bromide) instead of the vinyl bromide of Example 1 was synthesized in the same manner as in Example 1 to obtain a compound of formula 1h (86%).

Example 5 Synthesis of Formula 1i

Except for using allyl bromide instead of the vinyl bromide of Example 2 was synthesized in the same manner as in Example 2 to obtain a compound of Formula 1i (89%).

Example 6 Synthesis of Chemical Formula 1k

Except for using allyl bromide instead of the vinyl bromide of Example 3 was synthesized in the same manner as in Example 3 to obtain a compound of formula (1k) (87%).

II. Preparation of Photoresist Polymer

Example 7. Synthesis of Polymer of Formula 2b

Compound (0.05M) and AIBN (0.20 g) of Formula 1b prepared in Example 1 were dissolved in tetrahydrofuran (30 ml), and then reacted at 65 ° C. for 6 hours. After completion of the reaction, the solid obtained by adding hexane to the reaction mixture was dried in vacuo to give a polymer of formula 2b (53%).

Example 8. Synthesis of Polymer of Formula 2c

The compound of Formula 1c (0.05M) and AIBN (0.20g) prepared in Example 2 were dissolved in tetrahydrofuran (30ml), and then reacted at 65 ° C for 6 hours. After completion of the reaction, the solid obtained by adding hexane to the reaction mixture was dried in vacuo to obtain a polymer of formula 2c (52%).

Example 9 Synthesis of Polymer of Formula 2e

Compound (0.05M) and AIBN (0.20 g) of Formula 1e prepared in Example 3 were dissolved in tetrahydrofuran (30 ml), and then reacted at 65 ° C. for 6 hours. After completion of the reaction, the solid obtained by adding hexane to the reaction mixture was dried in vacuo to give a polymer of formula 2e (53%).

Example 10 Synthesis of Polymer of Formula 2h

The compound of Formula 1h prepared in Example 4 (0.05M) and AIBN (0.20g) were dissolved in tetrahydrofuran (30ml), and then reacted at 65 ° C for 6 hours. After completion of the reaction, the solid obtained by adding hexane to the reaction mixture was dried in vacuo to obtain a polymer of formula 2h (50%).

Example 11 Synthesis of Polymer of Formula 2i

The compound of Formula 1i prepared in Example 5 (0.05M) and AIBN (0.20g) were dissolved in tetrahydrofuran (30ml), and then reacted at 65 ° C for 6 hours. After completion of the reaction, the solid obtained by adding hexane to the reaction mixture was dried in vacuo to obtain a polymer of formula 2i (50%).

Example 12. Synthesis of Polymer of Formula 2k

The compound of Formula 1k (0.05M) and AIBN (0.20g) prepared in Example 6 were dissolved in tetrahydrofuran (30ml), and then reacted at 65 ° C for 6 hours. After completion of the reaction, the solid obtained by adding hexane to the reaction mixture was dried in vacuo to obtain a polymer of formula 2k (50%).

III. Preparation and Pattern Formation of Photoresist Composition

Example 13.

The polymer (2 g) prepared in Example 7, phthalimidotrifluoromethanesulfonate (0.024 g) and triphenylsulfonium triflate (0.06 g), which are photoacid generators, were propylene glycol methyl ethyl acetate (PGMEA) (30 g). It was dissolved in and filtered through a 0.20 μm filter to obtain a photoresist composition.

The photoresist composition thus obtained was spin-coated on the etching target layer of the silicon wafer to prepare a photoresist thin film, followed by soft baking for 90 seconds in an oven or hot plate at 130 ° C., and then exposed to light using an ArF laser exposure apparatus, followed by 90 ° at 130 ° C. Bake again for a second. The baked wafer was immersed in a 2.38 wt% TMAH aqueous solution for 40 seconds to develop an L / S pattern of 0.08 μm (see FIG. 1).

Example 14.

A photoresist composition was prepared in the same manner as in Example 13, except that the polymer (2 g) prepared in Example 8 was used instead of the polymer prepared in Example 7, and L / S of 0.08 μm was used using the composition. An S pattern was formed (see FIG. 2).

Example 15.

A photoresist composition was prepared in the same manner as in Example 13, except that the polymer (2 g) prepared in Example 9 was used instead of the polymer prepared in Example 7. An S pattern was formed (see FIG. 3).

Example 16.

A photoresist composition was prepared in the same manner as in Example 13, except that the polymer (2 g) prepared in Example 10 was used instead of the polymer prepared in Example 7. An S pattern was formed (see FIG. 4).

Example 17.

A photoresist composition was prepared in the same manner as in Example 13, except that the polymer (2 g) prepared in Example 11 was used instead of the polymer prepared in Example 7, and the L / S of 0.08 μm was used. An S pattern was formed (see FIG. 5).

Example 18.

A photoresist composition was prepared in the same manner as in Example 13, except that the polymer (2 g) prepared in Example 12 was used instead of the polymer prepared in Example 7. An S pattern was formed (see FIG. 6).

As described above, since the polymer of the present invention includes sultone, it has high adhesion to the silicon substrate, low absorption at wavelengths of 193 nm and 157 nm, and does not generate a degassing reaction during the post-exposure baking process. This prevents damage to the lens, has low absorbance in the 193nm and 157nm range, and also has excellent durability, etching resistance, reproducibility and resolution, and can form ultra-fine patterns of 4G and 16G DRAMs as well as DRAMs of 1G or less. have.

Claims (22)

Compound of formula 1, characterized in that used as a photoresist monomer. [Formula 1]

Where R is CH ₂ , CHCH ₂ or C (CH ₂ ) ₂ , R 'and R''are H or CH ₃ , R ₁ , R ₂ , R ₃ , R ₄ and R ₅ are each H, F, C ₁ -C ₂₀ alkyl, C ₁ -C ₂₀ perfluoroalkyl, ether containing ether group (-O-) _1, containing the ~C ₂₀ alkyl, an ether group (-O-) C ₁ ~C ₂₀ alkyl, perfluoroalkyl, containing a part of the alkyl ether or F-substituted C ₁ ~C ₂₀ group in part F Is substituted C ₁ -C ₂₀ alkyl, m is an integer of 0-3. The method of claim 1, The compound is characterized in that selected from the group consisting of the formula 1a to 1f. [Formula 1a]

[Formula 1b]

[Formula 1c]

[Formula 1d]

[Formula 1e]

[Formula 1f]

The method of claim 1, The compound is selected from the group consisting of the formula 1g to 1l. [Formula 1g]

[Formula 1h]

Formula 1i] [Formula 1j]

[Formula 1k]

[Formula 1l]

A photoresist polymer comprising a polymer repeating unit of the formula (2). [Formula 2]

Where R is CH ₂ , CHCH ₂ or C (CH ₂ ) ₂ , R 'and R''are H or CH ₃ , R ₁ , R ₂ , R ₃ , R ₄ and R ₅ are each H, F, C ₁ -C ₂₀ alkyl, C ₁ -C ₂₀ perfluoroalkyl, ether containing ether group (-O-) _1, containing the ~C ₂₀ alkyl, an ether group (-O-) C ₁ ~C ₂₀ alkyl, perfluoroalkyl, containing a part of the alkyl ether or F-substituted C ₁ ~C ₂₀ group in part F Is substituted C ₁ -C ₂₀ alkyl, m is an integer of 0-3, n is an integer of 10-150. The method of claim 4, wherein The polymer is a photoresist polymer, characterized in that selected from the group consisting of the formula 2a to 2l. [Formula 2a]

[Formula 2b]

[Formula 2c]

[Formula 2d]

[Formula 2e]

[Formula 2f]

[Formula 2g]

[Formula 2h]

[Formula 2i]

[Formula 2j]

[Formula 2k]

[Formula 2l]

In the formula 2a to 2l, n is an integer of 10-150. (a) reacting a compound of formula 3 with a compound of formula 4 in the presence of a salt to obtain a compound of formula 1; And (b) preparing a polymer of Formula 2, comprising the step of polymerizing the compound of Formula 1 in the presence of a polymerization initiator. [Formula 1]

[Formula 2]

[Formula 3]

[Formula 4]

In Chemical Formulas 1 to 4, R is CH ₂ , CHCH ₂ or C (CH ₂ ) ₂ , R 'and R''are H or CH ₃ , R ₁ , R ₂ , R ₃ , R ₄ and R ₅ are each H, F, C ₁ -C ₂₀ alkyl, C ₁ -C ₂₀ perfluoroalkyl, ether containing ether group (-O-) _1, containing the ~C ₂₀ alkyl, an ether group (-O-) C ₁ ~C ₂₀ alkyl, perfluoroalkyl, containing a part of the alkyl ether or F-substituted C ₁ ~C ₂₀ group in part F Is substituted C ₁ -C ₂₀ alkyl, X is F, Cl or Br, m is an integer of 0-3, n is an integer of 10-150. The method of claim 6, The salt of step (a) is selected from the group consisting of sodium hydride (NaH), butyl lithium (n-BuLi), lithium diisopropylamine (LDA) and lithium hydride (LiH) Method of Making Photoresist Polymer. The method of claim 6, The polymerization of step (b) is a single solvent or mixed selected from the group consisting of cyclohexanone, cyclopentanone, tetrahydrofuran, dimethylformamide, dimethyl sulfoxide, dioxane, methyl ethyl ketone, benzene, toluene and xylene A process for producing a photoresist polymer, characterized by using a solvent. The method of claim 6, The polymerization initiator of step (b) is benzoyl peroxide, 2,2'- azobisisobutyronitrile (AIBN), acetyl peroxide, lauryl peroxide, t- butyl per acetate, t- butyl hydroperoxide and A method for producing a photoresist polymer, characterized by using a compound selected from the group consisting of di-t-butylperoxide. The method of claim 6, The polymer is a method of producing a photoresist polymer, characterized in that the crystallization using a single or mixed solvent selected from the group consisting of diethyl ether, petroleum ether, lower alcohols including methanol, ethanol or isopropanol and water. . A photoresist composition comprising a photoresist polymer according to claim 4, a photoacid generator and an organic solvent. The method of claim 11, The photoacid generators are phthalimidotrifluoromethane sulfonate, dinitrobenzyltosylate, n-decyl disulfone, and naphthylimidotrifluoromethanesulfonate (naphthylimido). trifluoromethane sulfonate) photoresist composition, characterized in that selected from the group consisting of. The method of claim 12, In addition to the photoacid generator, diphenyl iodo hexafluorophosphate, diphenyl iodo hexafluoro arsenate, diphenyl iodo hexafluoro antimonate, diphenyl paramethoxyphenylsulfonium triflate, diphenyl paratoluene Nylsulfonium triflate, diphenylparaisobutylphenylsulfonium triflate, triphenylsulfonium hexafluoro arsenate, triphenylsulfonium hexafluoro antimonate, triphenylsulfonium triflate and dibutylnaphthylsulfonium Photoresist composition, characterized in that used together with the one selected from the group consisting of triflate. The method of claim 11, A photoresist composition, characterized in that the photoacid generator is used in a proportion of 0.05 to 10 wt% based on the photoresist polymer. The method of claim 11, The organic solvent is diethylene glycol diethyl ether, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, propylene glycol methyl ether acetate, cyclohexanone (cyclohexanon), n-heptanone (n-heptanone) and the photoresist composition, characterized in that selected from the group consisting of ethyl lactate. The method of claim 11, The organic solvent is a photoresist composition, characterized in that used in 500 to 2000wt% relative to the photoresist polymer. (a) applying the photoresist composition of claim 11 over the etched layer to form a photoresist film; (b) exposing the photoresist film; (c) baking the exposed photoresist film; And (d) developing the resultant to obtain a desired pattern. The method of claim 17, A method of forming a photoresist pattern, characterized by further comprising the step of performing a baking process before the exposure of step (b). The method of claim 17 or 18, The baking process is a photoresist pattern forming method, characterized in that performed at 70 to 200 ℃. The method of claim 17, The exposing process is performed using ArF, KrF and EUV (Extreme Ultra Violet), VUV (Vacuum Ultra Violet), E-beam, X-ray or ion beam. The method of claim 17, The exposure process is a photoresist pattern forming method, characterized in that performed with an exposure energy of 0.1 to 100mJ / cm ² . The method of claim 17, The development of the step (d) is a photoresist pattern forming method, characterized in that carried out using an alkaline developer.

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