KR20090074986A - Basic compound having diphenylhydrazine group and photoresist composition including the same - Google Patents

Abstract

A basic compound having a diphenylhydrazine group is provided to improve resolution of photoresist patterns and line edge roughness by inducing difference of base between exposed portions and unexposed portions. A basic compound represented by chemical formula 1 rearranges a molecular structure by reacting with acids. In chemical formula 1, R1 and R2 are independently hydrogen atom or methyl group(CH3); Ra and Rb are independently hydrogen atom, C1-10 alkyl group or C6-10 aryl group; at least one of Ra and Rb is not a hydrogen atom; and m is 1or 2.

Description

Basic compound having diphenylhydrazine group and photoresist composition including the same}

The present invention relates to a basic compound having a diphenylhydrazine group and a photoresist composition comprising the same. More particularly, the basicity of the exposed portion and the non-exposed portion is increased by reacting with an acid generated in the photoacid generator during the exposure step to increase the basicity. It relates to a basic compound having a diphenylhydrazine group and a photoresist composition comprising the same, which can induce a difference.

In order to manufacture a semiconductor chip or a display element by processing a semiconductor wafer or display glass, a circuit structure of a predetermined pattern must be formed by using a photolithography process. The photosensitive material used in the photolithography process is called a photoresist composition. Recently, as the circuit pattern of a semiconductor or a display device is miniaturized, a photoresist composition having a high resolution is required.

Conventional chemically amplified photoresist compositions include photoresist polymers, photoacid generators (PAGs), organic solvents and basic compounds. In such a chemically amplified photoresist, when a predetermined pattern of light from an exposure source is irradiated onto the photoresist composition, an acid component is generated in the exposed photoacid generator, and a protecting group bonded to the photoresist polymer by the generated acid is chained. Degradation to alter the solubility of the photoresist polymer. Thus, after changing the solubility of a photoresist film according to an exposure pattern, and developing a photoresist film, a desired photoresist pattern can be formed. In the photolithography process using such chemically amplified photoresist, a post exposure bake (PEB) process is usually performed to activate and diffuse an acid component present in the exposed photoresist. In addition, the basic compound contained in the chemically amplified photoresist composition is added to control the diffusion of the acid component.

An object of the present invention is diphenylhydrazine, which can induce a difference in basicity of the exposed portion and the non-exposed portion, thereby improving the resolution of the photoresist pattern and improving the line edge roughness (LER). It is to provide a basic compound having a group and a photoresist composition comprising the same.

Another object of the present invention is to provide a basic compound having a diphenylhydrazine group and a photoresist composition comprising the same, which react with an acid component to increase the basicity.

In order to achieve the above object, the present invention, as one of the components constituting the photoresist composition, the molecular structure is rearranged by reacting with an acid (acid), provides a basic compound represented by the formula (1).

 [Formula 1]

In Formula 1, R ₁ and R ₂ are each independently a hydrogen atom or a methyl group (CH ₃ ); R _a and R _b are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 10 carbon atoms, and at least one of Ra and Rb is not a hydrogen atom; m is 1 or 2.

In addition, the present invention is a basic compound represented by the formula (1) of 0.01 to 10% by weight relative to the total photoresist composition; 0.05 to 20 parts by weight of the photoacid generator based on 100 parts by weight of the photosensitive compound; And it provides a photoresist composition comprising the remaining organic solvent. In addition, the present invention comprises the steps of: a) applying the photoresist composition on the substrate to form a photoresist film; b) exposing the photoresist film in a predetermined pattern; And c) heating the exposed photoresist film after exposure; And d) developing the heated photoresist film to obtain a pattern.

In the photoresist composition of the present invention, the basic compound having a diphenylhydrazine group in the molecule reacts with the acid component of the exposed portion, causing a difference in basicity of the exposed portion and the non-exposed portion, thereby improving the resolution of the photoresist pattern and increasing the line edge Roughness can be improved. In addition, since the basicity of the photoresist composition of the present invention changes with exposure, the post-exposure bake temperature sensitivity (PEB Sensitivity) of the photoresist composition, the sensitivity according to the delay until the post-coating exposure (Post-Coating Delay (PCD)) and There is an advantage in that post exposure delay (PED) may be reduced according to an exposure time difference on the same wafer.

Hereinafter, the present invention will be described in detail.

The basic compound according to the present invention, as one of the components constituting the photoresist composition, has a structure in which a molecular structure is rearranged by reaction with an acid, and is represented by the following Chemical Formula 1.

In Formula 1, R ₁ and R ₂ are each independently a hydrogen atom or a methyl group (CH ₃ ); R _a and R _b are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, preferably having 1 to 3 carbon atoms or an aryl group having 6 to 10 carbon atoms, and at least one of R _a and R _b is not a hydrogen atom, and And R _a and R _b may be linked to each other to form a ring, or may include a ketone group or an ester group; m is 1 or 2.

Representative examples of the basic compound represented by Formula 1 are as follows.

Since the basic compound according to the present invention includes at least one 1,2-diphenylhydrazine group in a molecule, it reacts with an acid generated in a photoacid generator upon exposure, thereby rearranging the molecule (benzidine). rearrangement) to change to a compound containing a benzidine group, the basicity is increased. In general, when a large amount of the basic compound is added to the photoresist composition, the diffusion of the acid component can be controlled to improve the line edge roughness (LER), but in this case, the resolution is lowered and the exposure process speed ( Photo-speed may be slowed down. The basic compound according to the present invention can solve these problems at the same time by changing the basicity by exposure. That is, in the basic compound according to the present invention, since the basic compound molecule is rearranged by an acid catalyst, the structure of the amine changes from the tertiary or secondary amine to the secondary or primary amine, the basicity of the molecule Increases, and may cause a difference in basicity, particularly at the interface between the exposed and non-exposed portions. Therefore, at the interface between the exposed portion and the non-exposed portion, since the acid diffusion length is reduced, the resolution of the pattern is improved and the line edge roughness LER is improved.

The basic compound according to the present invention can be prepared by various conventional organic synthesis methods. For example, as shown in Scheme 1 below, the 1,2-diphenylhydrazine compound and a halogen compound are reacted at a temperature of 0 ° C. or lower, and the reactants are washed with water several times to prepare a basic compound according to the present invention. can do. In addition, a 1,2-diphenylhydrazine compound and an aldehyde compound may be reacted under a temperature of 0 ° C. or below and an acid catalyst to synthesize cyclized basic compounds such as Chemical Formulas 2d and 2e.

로 표시되는 1,2-디페닐히드라진(1,2-Diphenylhydrazine)를 예시할 수 있고, 상기 벤 지딘 화합물과 반응하는 할로겐 화합물 또는 알데하이드 화합물로는,

,

,

,

,

등을 예시할 수 있다.As a raw material for synthesizing the basic compound of the present invention,

1,2-diphenylhydrazine (1,2-Diphenylhydrazine) represented by the above can be exemplified, and as a halogen compound or an aldehyde compound reacting with the benzidine compound,

,

,

,

,

Etc. can be illustrated.

The photoresist composition according to the present invention includes a basic compound represented by the formula (1), a photosensitive compound, a photoacid generator and an organic solvent, and if necessary, other conventional basic compounds, surfactants, etc. as a resist stabilizer (quencher) It may further include. In the photoresist composition according to the present invention, the amount of the basic compound represented by Formula 1 is 0.01 to 10% by weight, preferably 0.1 to 5% by weight, more preferably 0.1 to 3% by weight based on the total photoresist composition. Weight percent. Here, when the content of the basic compound represented by Formula 1 is too small, there is a concern that the resolution of the photoresist pattern, the line edge roughness, etc. may not be sufficient, and when the content of the basic compound is too large, further resolution The improvement effect does not appear, and it is only economically disadvantageous. When a conventional basic compound is used together with the basic compound represented by the formula (1), as the conventional basic compound, triethylamine, trioctylamine, triisobutylamine, triy, which are commonly used in photoresist compositions Organic bases, such as oxoctylamine, diethanolamine, triethanolamine, and mixtures thereof, can be used. Even when the above-mentioned basic basic compound is used, it is preferable that the usage-amount of all basic compounds is 0.01 to 10 weight% with respect to the whole photoresist composition.

In the photoresist composition of the present invention, as the photosensitive compound, a conventional photoresist polymer, a photosensitive monomolecular compound, and the like, which react with an acid and change in solubility in a developer, can be used without limitation. The photoresist polymer may be a block copolymer or a random copolymer having an acid sensitive protecting group, and the weight average molecular weight (Mw) is preferably 3,000 to 20,000. Here, the content of the photosensitive compound is preferably 1 to 30% by weight, more preferably 1 to 20% by weight based on the total photoresist composition. If the content of the photoresist polymer is less than 1% by weight, the resist layer remaining after coating is too thin to form a pattern having a desired thickness, and if it exceeds 30% by weight, coating uniformity may be degraded.

The photoacid generator generates acid by exposure, deprotects the protecting group of the photoresist polymer, or converts the structure of the basic compound, and may generate acid by light. Any compound may be used as long as the compound is present. Preferably, sulfide salt compounds such as organic sulfonic acid, onium salt compounds such as onium salt, and the like may be used alone or in combination. Non-limiting examples of the photoacid generator include phthalimidotrifluoromethane sulfonate, dinitrobenzyl tosylate, n-decyl disulfone, naphthylimidotrifluoro Romethanesulfonate (naphthylimido trifluoromethane sulfonate), diphenylurido salt hexafluorophosphate, diphenylurido salt hexafluoroarsenate, diphenylurido salt hexafluoroantimonate, diphenylparamethoxyphenylsulfonium triflate, Diphenylparatoluenylsulfonium triflate, diphenylparaisobutylphenylsulfonium triflate, triphenylsulfonium hexafluoroarsenate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium triflate, Dibutyl naphthyl sulfonium triflate, mixtures thereof, etc. can be illustrated. The content of the photoacid generator is preferably 0.05 to 20 parts by weight, and more preferably 0.1 to 10 parts by weight based on 100 parts by weight of the photosensitive compound. If the content of the photoacid generator is less than 0.05 part by weight, the sensitivity to light of the photoresist composition may be lowered, thereby making it difficult to deprotect the protective group or to convert the structure of the basic compound. There is a possibility that a large amount of acid is generated in the cross section of the resist pattern to be poor.

As the organic solvent constituting the remaining components of the photoresist composition according to the present invention can be used a wide variety of organic solvents commonly used in the preparation of the photoresist composition, non-limiting examples, ethylene glycol monomethylethyl, ethylene Glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monoacetate, diethylene glycol, diethylene glycol monoethyl ether, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol, propylene glycol monoacetate, toluene, xylene, Methyl ethyl ketone, methyl isoamyl ketone, cyclohexanone, dioxane, methyl lactate, ethyl lactate, methyl pyruvate, ethyl pyruvate, methyl methoxy propionate, ethyl to oxy propionate, N, N Dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, 3-e Methoxy ethylpropionate, 2-heptanone, gamma-butyrolactone, ethyl 2-hydroxypropionate, ethyl 2-hydroxy 2-methylpropionate, ethyl ethoxy acetate, ethyl hydroxy acetate, 2-hydroxy 3- Methyl methyl butyrate, methyl 3-methoxy 2-methylpropionate, ethyl 3-ethoxy propionate, ethyl 3-methoxy 2-methylpropionate, ethyl acetate, butyl acetate, and mixtures thereof. The content of the organic solvent is preferably 300 to 5000 parts by weight based on 100 parts by weight of the total photosensitive compound. If the content of the organic solvent is out of the above range, there is a fear that the photoresist film forming process may not be performed smoothly.

The surfactant contained in the photoresist composition according to the present invention as needed is added for the purpose of improving the uniform mixing of the photoresist composition components, the coatability of the photoresist composition, the developability after exposure of the photoresist film, and the like. As such a surfactant, conventional surfactants used in the photoresist composition can be used without limitation, for example, fluorine-based surfactants, fluorine-silicone-based surfactants and the like can be used. The amount of the surfactant used is 0.001 to 2 parts by weight, preferably 0.01 to 1 part by weight based on 100 parts by weight of the solid content of the photoresist composition, and when the amount is too small, the function as a surfactant cannot be sufficiently expressed. In addition, too much may adversely affect resist characteristics other than applicability | paintability, such as shape stability and storage stability of a composition.

In order to form a photoresist pattern using the photoresist composition of the present invention, (a) first, a photoresist composition is coated on a substrate such as a silicon wafer or an aluminum substrate using a spin coater, and the photoresist. A film is formed, (b) the photoresist film is exposed in a predetermined pattern, (c) the post exposure bake (PEB) is exposed, and (d) the heated photoresist film is developed to develop a pattern. To obtain a conventional photolithography process. The exposure process includes ArF (193 nm), KrF (248 nm), F2 (157 nm), EUV (Extreme Ultra Violet, 13.5 nm), VUV (Vacuum Ultra Violet), E-beam, X-ray, immersion lithography (Immersion lithography) or ion beams. In addition, as the developer used in the developing step, an alkaline aqueous solution in which alkaline compounds such as sodium hydroxide, potassium hydroxide, sodium carbonate and tetramethylammonium hydroxide (TMAH) are dissolved at a concentration of 0.1 to 10% by weight may be used. In accordance with the present invention, an appropriate amount of a water-soluble organic solvent such as methanol or ethanol and a surfactant may be added to the developer. In addition, after the development process, the cleaning process for cleaning the substrate with ultrapure water may be further performed.

Hereinafter, the present invention will be described in more detail with reference to specific examples and comparative examples. The following examples are intended to illustrate the present invention more specifically, but the present invention is not limited by the following examples.

Examples 1-1 to 1-3 Synthesis of Basic Compounds Represented by Chemical Formulas 2a to 2c

) 9.2g (0.05mole)을 용해시킨 후, 유기 염기로서 피리딘 9.5g을 첨가하였다. 반응액의 온도를 0℃로 유지하고, 교반하면서, THF 10mL에 용해시킨, 하기 표 1에 나타낸 바와 같은 성분 및 함량의 할로겐 화합물을 천천히 적가하였다. 상기 할로겐 화합물의 적가가 끝난 후, 반응액의 온도를 상온으로 올리고, 12시간 동안 교반하였다. 반응 종결 후, 반응기에 차가운 증류수 100mL를 넣고, 에틸아세테이트 200mL를 이용하여 3회 추출하였다. 추출한 용액을 무수 마그네슘설페이트로 건조하고, 감압 증류한 다음, 얻어진 화합물을 디에틸에테르로 재결정하여, 각각 화학식 2a 내지 2c로 표시되는 염기성 화합물을 얻었다.To 100 mL of tetrahydrofuran (THF) as a reaction solvent, 1,2-diphenylhydrazine (

) 9.2 g (0.05 mole) was dissolved and 9.5 g of pyridine was added as an organic base. The temperature of the reaction solution was maintained at 0 ° C, and while stirring, a halogen compound having a component and a content as shown in Table 1, dissolved in 10 mL of THF was slowly added dropwise. After the dropwise addition of the halogen compound, the reaction solution was heated to room temperature and stirred for 12 hours. After completion of the reaction, 100 mL of cold distilled water was added to the reactor, and extracted three times using 200 mL of ethyl acetate. The extracted solution was dried over anhydrous magnesium sulfate, distilled under reduced pressure, and the obtained compound was recrystallized with diethyl ether to obtain a basic compound represented by Chemical Formulas 2a to 2c, respectively.

Examples 1-4 to 1-5 Synthesis of Basic Compounds Represented by Chemical Formulas 2d and 2e

) 9.2g (0.05mole)을 용해시킨 후, 상온 및 상압에서, 하기 표 1에 나타낸 바와 같은 성분 및 함량의 알데하이드 화합물을 첨가하였다. 알데하이드 화합물 첨가 후, 반응기의 온도를 40℃로 유지하면서, 6시간 동안 교반하였다. 반응 종료 후, 반응기의 온도를 상온으로 낮추고, 차가운 증류수 100mL를 넣고, 에틸아세테이트 200mL를 이용하여 3회 추출하였다. 추출한 용액을 무수 마그네슘설페이트로 건조하고, 감압 증류한 다음, 얻어진 화합물을 디에틸에테르로 재결정하여, 화학식 2d 및 2e로 표시되는 염기성 화합물을 얻었다.To 100 mL of methylene chloride as a reaction solvent, 1,2-diphenylhydrazine (

) After dissolving 9.2 g (0.05 mole), at room temperature and atmospheric pressure, an aldehyde compound of the component and content as shown in Table 1 was added. After addition of the aldehyde compound, the reactor was stirred for 6 hours while maintaining the temperature at 40 ° C. After the reaction was completed, the temperature of the reactor was lowered to room temperature, 100 mL of cold distilled water was added, and extracted three times using 200 mL of ethyl acetate. The extracted solution was dried over anhydrous magnesium sulfate, distilled under reduced pressure, and the obtained compound was recrystallized with diethyl ether to obtain a basic compound represented by the formulas (2d) and (2e).

Halogen or aldehyde compounds Usage (g) yield(%) Example 1-1

17.0 (0.12mole) 85% Example 1-2

9.4 (0.12mole) 76% Example 1-3

16.8 (0.12 mole) 72% Example 1-4

1.5 (0.05mole) 56% Example 1-5

2.5 (0.05mole) 59%

¹ H-NMR data of the compounds obtained in Examples 1-1 to 1-5 are as follows.

Compound represented by Chemical Formula 2a , ¹H-NMR (CDCl ₃ , internal standard): δ (ppm) 7.20 (CH, 4H), 6.75 (CH, 2H), 6.64 (CH, 4H), 2.67 (CH ₃ , 6H ).

Compound represented by the formula (2b) , ¹H-NMR (CDCl ₃ , internal standard): δ (ppm) 7.19 (CH, 4H), 6.75 (CH, 2H), 6.63 (CH, 4H), 1.98 (CH ₃ , 6H) ).

Compound represented by the formula 2c , ¹H-NMR (CDCl ₃ , internal standard): δ (ppm) 7.89 (CH, 4H), 7.52 (CH, 2H), 7.43 (CH, 4H), 7.18 (CH, 2H) , 6.72 (CH, 4H), 6.56 (CH, 4H).

Compound represented by the formula (2d) , ¹H-NMR (CDCl ₃ , internal standard): δ (ppm) 7.25 (CH, 8H), 6.73 (CH, 4H), 6.66 (CH, 8H), 5.12 (CH ₂ , 4H) ).

Compound represented by the formula (2e) , ¹H-NMR (CDCl ₃ , internal standard): δ (ppm) 7.28 (CH, 4H), 7.20 (CH, 2H), 7.12 (CH, 2H), 6.71 (CH, 2H) , 6.65 (CH, 1H), 6.61 (CH, 1H), 6.58 (CH, 4H), 6.54 (CH, 2H), 6.50 (CH, 2H), 4.65 (NH, 1H), 3.84 (CH, 1H), 3.09 (CH, 1 H), 1.98 (CH ₂ , 2H), 1.27 (CH ₃ , 3H).

[Production Example] Photoresist represented by Chemical Formula 3 Preparation of Polymer

In the reactor, 8.89 g (0.04 mol) of 9-methacryloyl oxy-4-oxa-tricyclo [5.2.1.02,6] decane-3-one, 23.4 g of 2-methyl-2-adamantyl methacrylate (0.1 mol), 11.8 g (0.05 mol) of 1-methacryloyloxy-3-hydroxy adamantane and 0.7 g of azobis (isobutyronitrile) (AIBN) were added and the reaction was dissolved in 100 g of anhydrous THF. After the degassing, the gas was removed using an ampoule as a freezing method, and the degassed reactant was polymerized at 68 ° C. for 24 hours. After the polymerization was completed, the reactant was slowly added dropwise to excess diethyl ether, followed by precipitation, and the precipitate was dissolved again with THF. The dissolved reactant was reprecipitated in diethyl ether, and the following formula (3) wherein a, b and c are the mole% of each repeating unit with respect to the total repeating units constituting the polymer, and each monomer used in the polymerization reaction. Is proportional to the amount of the polymer used. The synthesized polymer was analyzed by gel permeation chromatography (GPC). As a result, the weight average molecular weight (Mw) was 9,201, the number average molecular weight (Mn) was 5,124, and the dispersion degree (PD: Polydispersity) was 1.80.

[Examples 2-1 to 2-5, Comparative Example 1] Preparation of Photoresist Composition

Basic compounds synthesized in Examples 1-1 to 1-5 (Formula 2a to 2e), 2.0 g of photoresist polymer (Formula 3) synthesized in Preparation Example and 0.08 g of triphenylsulfonium triflate were prepared in propylene glycol monomethyl. After completely dissolved in 17 g of ether acetate (PGMEA), it was filtered through a 0.2 μm disk filter to prepare photoresist compositions (Examples 2-1 to 2-5). A photoresist composition was prepared in the same manner as in Example 2-1, except that triethanol amine was used instead of the basic compound synthesized in Examples 1-1 to 1-5 (Comparative Example 1). The types and contents of the photoresist composition components used in the Examples and Comparative Examples are shown in Table 2 below.

division Photoresist Polymer (Formula 3) Photoacid generator (triphenylsulfonium triflate) Basic compound (usage) Organic Solvents (PGMEA) Example 2-1 2.0 g 0.08 g Formula 2a (0.021 g) 17 g Example 2-2 2.0 g 0.08 g Formula 2b (0.026 g) 17 g Example 2-3 2.0 g 0.08 g Formula 2c (0.038 g) 17 g Example 2-4 2.0 g 0.08 g Formula 2d (0.041 g) 17 g Example 2-5 2.0 g 0.08 g Formula 2e (0.038 g) 17 g Comparative Example 1 2.0 g 0.08 g Triethanol amine (0.014 g) 17 g

[Examples 3-1 to 3-5, Comparative Example 2] Photoresist Pattern Formation

The photoresist composition prepared in Examples 2-1 to 2-5 and Comparative Example 1 was spin-coated on the etching target layer of the silicon wafer treated with hexamethyldisilazane (HMDS), and the photoresist having a thickness of 0.02 μm. After the thin film was formed, soft heat treatment was performed for 90 seconds in an oven or hot plate at 120 ° C., exposed using an ISI Stepper, an ArF laser exposure apparatus having a numerical aperture of 0.6, and then heated again at 120 ° C. for 90 seconds. It was. The heated wafer was immersed in a 2.38 wt% tetramethylammonium hydroxide (TMAH) aqueous solution for 30 seconds and developed to form an identical line and space pattern with a line width of 120 nm. The line width change and the optimum exposure energy (EOP) of the formed photoresist pattern were investigated, and the results are shown in Table 3 below.

Resolution (nm) Line width change size (nm) Optimal energy (mJ / cm ² ) Example 3-1 (Formula 2a) 120 3.0 36 Example 3-2 (Formula 2b) 120 3.6 40 Example 3-3 (Formula 2c) 120 3.2 38 Example 3-4 (Formula 2d) 120 2.8 39 Example 3-5 (Formula 2e) 120 3.2 41 Comparative Example 2 120 4.6 32

From Table 3, the photoresist composition (Examples 2-1 to 2-5) containing the basic compound according to the present invention has a line width compared with the photoresist composition (Comparative Example 1) containing a conventional organic base. It is understood that the magnitude of change is small and the line width stability is excellent. In addition, the photoresist compositions prepared in Examples 2-1 to 2-5 were exposed to light by contacting a mask and a wafer using an AIXUV device and a light source having a wavelength of 13.5 nm (EUV), and the same lines having a line width of 50 nm. And since the space pattern was successfully formed, when using the photoresist composition according to the invention, it can be confirmed that the resolution of the photoresist pattern is excellent.

Claims (5)

As one of the components constituting the photoresist composition, the basic compound represented by the following formula (1), the molecular structure is rearranged by reaction with an acid (acid).  [Formula 1]

In Formula 1, R ₁ and R ₂ are each independently a hydrogen atom or a methyl group (CH ₃ ); R _a and R _b are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 10 carbon atoms, and at least one of R _a and R _b is not a hydrogen atom; m is 1 or 2. The basic compound according to claim 1, wherein R _a and R _b are each independently an alkyl group having 1 to 3 carbon atoms, and m is 2. The method of claim 1, wherein the basic compound

,

,

,

And

Basic compound which is any one compound selected from the group consisting of. 0.01 to 10% by weight of the basic compound represented by Chemical Formula 1, based on the total photoresist composition, [Formula 1]

In Formula 1, R ₁ and R ₂ are each independently a hydrogen atom or a methyl group (CH ₃ ); R _a and R _b are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 10 carbon atoms, and at least one of R _a and R _b is not a hydrogen atom; m is 1 or 2; 1 to 30% by weight of the photosensitive compound based on the total photoresist composition; 0.05 to 20 parts by weight of the photoacid generator based on 100 parts by weight of the photosensitive compound; And Photoresist composition comprising the remaining organic solvent. a) 0.01 to 10% by weight of the basic compound represented by the following Chemical Formula 1 based on the total photoresist composition, and 1 to 30% by weight of the photosensitive compound based on the total photoresist composition; 0.05 to 20 parts by weight of the photoacid generator based on 100 parts by weight of the photosensitive compound; And applying a photoresist composition including the remaining organic solvent on the substrate to form a photoresist film. [Formula 1]

In Formula 1, R ₁ and R ₂ are each independently a hydrogen atom or a methyl group (CH ₃ ); R _a and R _b are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 10 carbon atoms, and at least one of R _a and R _b is not a hydrogen atom; m is 1 or 2; b) exposing the photoresist film in a predetermined pattern; And c) heating the exposed photoresist film after exposure; And d) developing the heated photoresist film to obtain a pattern.