KR20090055894A - Acid- diffusion buffering compound and photoresist composition including the same - Google Patents

Abstract

An acid-diffusion buffering compound and a photoresist composition including the same are provided to improve line edge roughness and resolution of a resist and to realize vertical patterns by uniformly distributing and maintaining acids on the upper and lower sides of an exposure part. An acid-diffusion buffering compound has any one structure selected from the group consisting of chemical formula 1 and 2. In chemical formula 1, R1 ~ R3 are independently hydrogen atom, hydroxy group or C1-10 aliphatic hydrocarbon group, wherein at least one of R1 ~ R3 is C1-10 aliphatic hydrocarbon group substituted with a carboxyl group, sulfonyl group or phosphate group. In chemical formula 2, R1 ~ R6 are independently hydrogen atom, hydroxy group or C1-10 aliphatic hydrocarbon group, wherein at least one of R1 ~ R6 C1-10 aliphatic hydrocarbon group substituted with a carboxyl group, sulfonyl group or phosphate group.

Description

Acid-diffusion buffering compound and photoresist composition including the same

The present invention relates to an acid-diffusion buffer compound, and more particularly, an acid generated in a photoacid generator of a chemically amplified resist is formed on an exposed portion of the resist. The present invention relates to an acid-diffusion buffer compound and a photoresist composition comprising the same, which can be uniformly distributed in the lower portion to improve resolution, thereby forming a fine pattern at a high resolution.

In recent years, with the high integration of semiconductor devices, the formation of ultrafine patterns having a line width of 80 nm or less has been achieved using chemically amplified photoresists. Generally, the positive chemically amplified photoresist includes a photosensitive polymer having a photoacid generator that generates an acid component upon exposure and a protecting group that is decomposed by the acid component. When the chemically amplified photoresist is exposed, an acid component is generated from the photoacid generator, and the produced acid decomposes the protecting group bound to the backbone of the polymer in series, thereby changing the solubility of the high molecule, thereby resulting in high contrast after development. A pattern having a contrast is formed. In the photolithography process using the chemically amplified photoresist, a post exposure bake (PEB) process is performed to activate and diffuse an acid component present in the exposed photoresist.

Since the resolution of the chemically amplified resist is determined by the amount of acid generated from the photoacid generator and the acid degree, the resolution of the resist can be controlled by adjusting the amount of photoacid generator used. However, if the photoacid generator is excessively used, not only by-products are generated from the photoacid generator, but also other problems may occur due to the high absorbance of the photoacid generator, and the upper part of the pattern may be weakened as a whole, resulting in a slope pattern. Obtained. On the other hand, if the amount of the photo-acid generator is insufficient, there is a disadvantage in that a pattern in which only the upper portion of the pattern is reinforced (T-Top) is obtained or the resolution is lowered so that the resolution of the bottom portion is reduced. In order to solve this problem, a method of improving the resolution of the resist by adding an acid-diffusion buffer has been attempted. With acid-diffusion buffers, during the post-exposure heating process, the acid acts as a base to inhibit acid-diffusion at the top of the excess, and on the contrary, as the acid to promote acid-diffusion at the bottom of the acid-deficient, By making the acid distribution of Y uniform, effects of enhancement of resolution, improvement of line edge roughness and removal of bottom residue can be obtained.

It is an object of the present invention to provide an acid-diffusion buffer compound and a photoresist composition comprising the same, which buffers the amplification of an acid generated in a photoacid generator to induce a uniform acid dispersion action.

Another object of the present invention is to provide an acid-diffusion buffer compound and the same, which are capable of uniformly distributing acid on and under the resist exposed portion to remove residues from the resist bottom portion and improve line edge roughness properties. It is to provide a photoresist composition.

Another object of the present invention is to provide a novel acid-diffusion buffer compound having a base functional group and an acid functional group in a molecule, and a photoresist composition comprising the same.

In order to achieve the above object, the present invention provides an acid-diffusion buffer compound having any one structure selected from the group consisting of the following formula (1) and (2).

 [Formula 1]

Wherein R ₁ to R ₃ are each independently a hydrogen atom, a hydroxyl group or an aliphatic hydrocarbon group having 1 to 10 carbon atoms, and at least one of R ₁ to R ₃ is an aliphatic carbon having 1 to 10 carbon atoms substituted with a carboxyl group, sulfonyl group or phosphoric acid group It is a hydrocarbon group.

[Formula 2]

Wherein R ₁ to R ₆ are each independently a hydrogen atom, a hydroxyl group or an aliphatic hydrocarbon group having 1 to 10 carbon atoms, and at least one of R ₁ to R ₆ is an aliphatic carbon having 1 to 10 carbon atoms substituted with a carboxyl group, sulfonyl group or phosphoric acid group It is a hydrocarbon group.

In addition, the present invention, the photosensitive polymer 1 to 30% by weight; 0.05 to 20 parts by weight of a photoacid generator based on 100 parts by weight of the photosensitive polymer; 1 to 50 moles of the acid-diffusion buffer compound relative to 100 moles of the photoacid generator; And it provides a photoresist composition comprising the remaining organic solvent. The present invention also includes the step of applying the photoresist composition on the substrate, to form a photoresist film; Exposing the photoresist film in a predetermined pattern; And heating and developing the exposed photoresist film after exposure.

The acid-diffusion buffer compound according to the present invention buffers the diffusion and amplification of the acid generated in the photoacid generator, thereby uniformly dispersing and maintaining the acid on the upper and lower portions of the resist film, thereby improving the resolution of the resist and improving the vertical pattern. Can be implemented. In addition, the acid-diffusion buffer compound according to the present invention can easily remove residues under the resist pattern to maximize resolution and improve line edge roughness characteristics. Acid-diffusion buffer compounds of the invention are particularly useful for the formation of low thickness and fine patterns.

Hereinafter, the present invention will be described in detail.

The acid-diffusion buffer compound according to the present invention is used in a photoresist composition and has a structure of any one of the following Chemical Formulas 1 and 2.

In Formula 1, R ₁ to R ₃ are each independently a hydrogen atom, a hydroxyl group or an aliphatic hydrocarbon group having 1 to 10 carbon atoms, preferably an alkyl group having 1 to 5 carbon atoms, at least one of R ₁ to R ₃ is a carboxyl group, An aliphatic hydrocarbon group having 1 to 10 carbon atoms substituted with a sulfonyl group or a phosphoric acid group. When R ₁ to R ₃ are aliphatic hydrocarbon groups, they may be substituted with a hydroxy group, a halogen group (for example, a fluorine group), or the like, and are connected to each other to be mono-cyclic or multi-cyclic ) May also form a ring structure.

In Formula 2, R ₁ to R ₆ are each independently a hydrogen atom, a hydroxy group or an aliphatic hydrocarbon group of 1 to 10 carbon atoms, preferably an alkyl group of 1 to 5 carbon atoms, at least one of R ₁ to R ₆ is a carboxyl group, An aliphatic hydrocarbon group having 1 to 10 carbon atoms substituted with a sulfonyl group or a phosphoric acid group. When R ₁ to R ₆ are aliphatic hydrocarbon groups, they may be substituted with a hydroxy group, a halogen group (for example, a fluorine group), or the like, and are connected to each other to be mono-cyclic or multi-cyclic ) May also form a ring structure.

)일 수 있으며, 바람직하게는, 상기 화학식 2에 있어서, R₁ 및 R₂ 모두가 카르복실기, 설포닐기 또는 인산기로 치환된 탄소수 1 내지 10의 지방족 탄화수소기이다.In Formulas 1 and 2, the phosphate group is a phosphoric acid group substituted with a lower alkyl group (R) having 1 to 4 carbon atoms (

), Preferably, in Formula 2, both R ₁ and R ₂ is an aliphatic hydrocarbon group having 1 to 10 carbon atoms substituted with a carboxyl group, a sulfonyl group or a phosphoric acid group.

Specific examples of the acid-diffusion buffer compound represented by Chemical Formula 1 are as follows.

Specific examples of the acid-diffusion buffer compound represented by Chemical Formula 2 are as follows.

In addition, as another specific example of the acid-diffusion buffer compound represented by Chemical Formula 2, examples of forming a mono-cyclic or multi-cyclic ring structure are as follows (where Me is a methyl group) ).

The acid-diffusion buffer compound according to the present invention has a base which simultaneously inhibits acid-diffusion in an acid-based upper part during exposure and / or heating of a positive photoresist film or pattern by simultaneously having an acid-base. On the other hand, at the bottom of the acid-deficient floor, it acts as an acid-promoting acid-diffusion, which makes the acid distribution in the upper and lower portions uniform, and buffers the diffusion of the acid to maintain the acid distribution uniformly. This improves line edge roughness performance.

The photoresist composition according to the present invention includes an acid-diffusion buffer compound, a photosensitive polymer, a photoacid generator and an organic solvent represented by any one of Formulas 1 to 3, and, if necessary, a basic compound as a resist stabilizer. And surfactants may be further included. In the photoresist composition of the present invention, the content of the acid-diffusion buffer compound is 1 to 50 mol (mol), preferably 20 to 100 mol (mol) of the photoacid generator to be added. To 40 mol. If the content of the acid-diffusion buffer compound is too small, there is no uniform diffusion of acid, so that the improvement of the line edge roughness performance is insufficient, and if the content of the acid-diffusion buffer compound is too large, the resolution Low has the disadvantage of requiring excessive energy.

As the photosensitive polymer, an ordinary photosensitive polymer for photoresist which reacts with an acid and changes in solubility in a developing solution can be used without particular limitation, and is preferably an acid sensitive protecting group that is desorbed by an acid. Eggplant may use a photosensitive polymer. The photosensitive polymer may be a block copolymer or a random copolymer, and the weight average molecular weight (Mw) is preferably 3,000 to 20,000. In the photoresist composition of the present invention, the content of the photosensitive polymer is 1 to 30% by weight, preferably 3 to 20% by weight. If the content of the photosensitive polymer is too small, the resist layer remaining after the coating is too thin to form a pattern having a desired thickness. If the content of the photosensitive polymer is too large, coating uniformity of the resist film formed on the wafer may be deteriorated. An example of the photosensitive polymer that can be used in the present invention may be represented by the following Chemical Formula 3.

In Formula 3, R ₁ is a hydrogen atom, a methyl group, an ethyl group or an isopropyl group, and l, m and n are mole% of each repeating unit with respect to all repeating units constituting the photosensitive polymer, and each 1 to 60 mol. %, 1-60 mol%, 1-50 mol%.

The photoacid generator generates an acid upon exposure and serves to deprotect the protecting group of the photosensitive polymer, and any photoacid generator may be used as long as the compound can generate an acid by light. Sulfur salt compounds, such as phonic acid, Onium salt compounds, such as an onium salt, etc. can be used individually or in mixture. Non-limiting examples of the photoacid generator, phthalimidotrifluoromethane sulfonate (dinitrobenzyl tosylate), n-decyl disulfone (n) having a low absorbance at 157 nm and 193 nm -decyl disulfone), naphthylimido trifluoromethane sulfonate, diphenylurodoxyl hexafluorophosphate, diphenylurodoxyl hexafluoroarsenate, diphenylurodoxyl hexafluoroantimonate, diphenyl Paramethoxyphenylsulfonium triflate, diphenylparatoluenylsulfonium triflate, diphenylparaisobutylphenylsulfonium triflate, triphenylsulfonium hexafluoroarsenate, triphenylsulfonium hexafluoroantimo Nate, triphenylsulfonium triflate, dibutylnaphthylsulfonium triflate, mixtures thereof, etc. can be illustrated. . The content of the photoacid generator is preferably 0.05 to 20 parts by weight based on 100 parts by weight of the photosensitive polymer. If the content of the photoacid generator is less than 0.05 part by weight, the sensitivity of the photoresist composition to light may be lowered, which may make it difficult to deprotect the protective group. When the amount of the photoacid generator exceeds 20 parts by weight, a large amount of acid may be generated from the photoacid generator. There exists a possibility that the cross-sectional shape of a resist pattern may become bad.

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 ethoxy 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.

In addition, the photoresist composition according to the present invention, if necessary, may further include an organic base as a reaction inhibitor (quencher), non-limiting examples of the organic base is triethylamine, triisobutylamine, triisoocta Tylamine, diethanolamine, triethanolamine, a mixture thereof, etc. can be illustrated. The content of the organic base is preferably 0.01 to 10% by weight based on the total photoresist composition. Here, when the amount of the basic compound is too small, the diffusion of acid generated during exposure may not be easily controlled, and the cross-sectional shape of the pattern may be uneven. If the amount of the basic compound is too high, the diffusion of the generated acid may be excessively suppressed and It is not easy to implement. 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, (i) first, a photoresist composition is coated on a substrate such as a silicon wafer or aluminum using a spin coater to form a photoresist film. A conventional photolithography process is performed, wherein (ii) the photoresist film is exposed in a predetermined pattern, and (iii) post exposure bake (PEB) is developed and developed. The exposure process includes ArF (193 nm), KrF (248 nm), F ₂ (157 nm), EUV (Extreme Ultra Violet, 13.5 nm), VUV (Vacuum Ultra Violet), E-beam, X-ray It may be performed using immersion lithography or ion beam, and is preferably performed with an exposure energy of 1 to 100 mJ / cm ² . 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 and a surfactant such as methanol and ethanol 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 Examples and Comparative Examples. The following examples are intended to illustrate the invention, and the invention is not limited by the following examples.

Example 1-1 Synthesis of Photosensitive Compound Represented by Chemical Formula 4a

Sodium hydroxyethanesulfonate (5 g, 37.3 mmol) was added to a 250 mL round bottom flask, and 100 mL of distilled water was added thereto to dissolve. Diethanolamine (3.9 g, 37.3 mmol) was added dropwise and stirred at room temperature for 5 hours. It was. After 5 hours of reaction, concentrated hydrochloric acid was slowly added dropwise to acidify, and the resulting white precipitate was filtered to give 6.5 g (yield: 82.4%) of the photosensitive compound represented by the formula (4a). The elemental analysis of the obtained compound was as follows: C ₆ H ₁₅ NO ₅ S, Calcd: C, 33.79; H, 7.09; N, 6.57; 0, 37.51; S, 15.04 Found: C, 33.53; H, 6. 82; N, 6.07; O, 36.98, S, 14.86

Example 1-2 Synthesis of Photosensitive Compound Represented by Chemical Formula 4b

In the same manner as in Example 2-1, except for using sodium-3-chloro-2-hydroxypropane sulfonate (10 g, 50.1 mmol) and diethanolamine (5.3 g, 50.1 mmol), to Formula 4b 9.7 g (yield: 79.5%) of photosensitive compounds were obtained. Elemental analysis of the obtained compound was as follows: C ₇ H ₁₇ NO ₆ S, calculated: C, 34.56; H, 7.04; N, 5.76; 0, 39.46; S, 13.18 Found: C, 34.42; H, 6.56; N, 5.27; O, 38.78, S, 12.67

Example 1-3 Synthesis of Photosensitive Compound Represented by Chemical Formula 4c

To a 100 mL two necked round bottom flask was placed N, N'-bis (2-hydroxyethyl) ethyl diamine (4.1 g, 27.6 mmol), 50 mL of distilled water was added, followed by 3-chloropropionic acid (6 g , 55.2 mmol) was added, and then a cooling tube was connected and stirred at 65 ° C. for 10 hours. After 10 hours of reaction, concentrated hydrochloric acid was slowly added dropwise to acidify the resulting white precipitate, which was filtered and dried to obtain 6.6 g (yield: 81.8%) of the photosensitive compound represented by Chemical Formula 4c. Elemental analysis of the obtained compound was as follows: C ₁₂ H ₂₄ N ₂ O ₆ , calculated value: C, 49.30; H, 8. 28; N, 9.58; 0, 32.84 Found: C, 48.82; H, 7.56; N, 8.77; O, 31.87

Example 1-4 Synthesis of Photosensitive Compound Represented by Chemical Formula 4d

Example 1-1, except that sodium hydroxyethanesulfonate (10 g, 74.6 mmol) and N, N'-bis (2-hydroxy ethyl) ethyldiamine (5.52g, 37.3 mmol) were used In the same manner, 10.5 g (yield: 77.2%) of the photosensitive compound represented by Chemical Formula 4d was obtained. Elemental analysis of the obtained compound was as follows: C ₁₀ H ₂₄ N ₂ O ₈ S ₂ , calculated: C, 32.96; H, 6. 64; N, 7.69; 0, 35.12; S, 17.60. Found: C, 32.52; H, 6. 42; N, 5.79; O, 34.26, S, 17.01

Example 1-5 Synthesis of Photosensitive Compound Represented by Chemical Formula 4e

, 10.4 g, 74.6 mmol)을 적가하고, 30분간 교반하였다. 30분 후, 포름알데하이드(2.3g, 74.6 mmol)을 가한 후, 2시간 동안 교반하였으며, 1시간 후 온도를 120℃로 올려 2시간 반응 후, 부생성물을 감압 증류하여 제거하였다. 다음으로, 반응액에 무수 에테르 60 mL를 가하여, 반응물을 녹인 후, N,N'-비스(2-하이드록시에틸)에틸 다이아민(8.3 g, 56 mmol)을 적가하고, 상온에서 10시간 동안 교반하였다. 10시간 반응 후, 진한 염산을 천천히 적가하여 산성화하고, 생성된 흰색 침전물을 여과한 후 건조하여, 화학식 4e로 표시되는 감광성 화합물 5.7g(수율: 39.0%)을 얻었다. 얻어진 화합물의 원소분석 결과는 다음과 같다: C₁₂H₃₀N₂O₈P₂, 계산값: C, 36.74; H, 7.71; N, 7.14; O, 32.62; P, 15.79 측정값: C, 36.02; H, 7.24; N, 6.46; O, 31.67; P, 15.12N, N'-bis (2-hydroxyethyl) ethyl diamine (5.52 g, 37.3 mmol) was added to a 100 mL round bottom flask, and the temperature was maintained at 0 ° C, followed by distilled dimethyl phosphite (Dimethyl phosphite (C ₂ H ₇ O ₃ P),

, 10.4 g, 74.6 mmol) was added dropwise and stirred for 30 minutes. After 30 minutes, formaldehyde (2.3 g, 74.6 mmol) was added thereto, followed by stirring for 2 hours. After 1 hour, the temperature was raised to 120 ° C. and the reaction was distilled off under reduced pressure for 2 hours. Next, 60 mL of anhydrous ether was added to the reaction solution, and the reactant was dissolved. Then, N, N'-bis (2-hydroxyethyl) ethyl diamine (8.3 g, 56 mmol) was added dropwise, and at room temperature for 10 hours. Stirred. After 10 hours of reaction, concentrated hydrochloric acid was slowly added dropwise to acidify the resulting white precipitate, which was filtered and dried to obtain 5.7 g (yield: 39.0%) of the photosensitive compound represented by the formula (4e). Elemental analysis of the obtained compound was as follows: C ₁₂ H ₃₀ N ₂ O ₈ P ₂ , calculated: C, 36.74; H, 7.71; N, 7.14; 0, 32.62; P, 15.79 Found: C, 36.02; H, 7.24; N, 6.46; 0, 31.67; P, 15.12

Example 1-6 Synthesis of Photosensitive Compound Represented by Chemical Formula 4f

Except for using sodium-3-chloro-2-hydroxypropane sulfonate (12 g, 61.0 mmol) and N, N'-bis (2-hydroxyethyl) ethyldiamine (3.8 g, 25.4 mmol) In the same manner as in Example 1-1, 8.2g (yield: 76%) of the photosensitive compound represented by the formula (4f) was obtained. Elemental analysis of the obtained compound was as follows: C ₁₂ H ₂₈ N ₂ O ₁₀ S ₂ , calculated: C, 33.95; H, 6.65; N, 6. 60; 0, 37.69; S, 15.11. Found: C, 33.42; H, 6. 13; N, 6.04; O, 36.76, S, 14.42

Example 1-7 Synthesis of Photosensitive Compound Represented by Chemical Formula 4g

In the same manner as in Example 1-1, except for using sodium-3-chloro-2-hydroxypropane sulfonate (12 g, 61.0 mmol) and deca hydronaphthyridine diol (5.2 g, 30.3 mmol). , 10.2 g (yield: 75.1%) of the photosensitive compound represented by the formula (4g) were obtained. Elemental analysis of the obtained compound was as follows: C ₁₄ H ₂₈ N ₂ O ₁₀ S ₂ , calculated: C, 37.49; H, 6. 29; N, 6.25; 0, 35.67; S, 14.30. Found: C, 36.87; H, 5.85; N, 5.71; 0, 34.78; S, 13.85

[Examples 2-1 to 2-7, Comparative Example 1] Preparation of Photoresist Composition and Formation of Exposure Pattern

As shown in Table 1, 1.5 g of the photosensitive polymer represented by Formula 3 (R ₁ is an ethyl group, l, m and n are the mole% of each repeating unit with respect to the total repeating units constituting the photosensitive polymer, 25 mole%, 30 mole%, and 45 mole% each), 0.04 g of triphenylsulfonium triflate as a photoacid generator, each of the acid-diffusion buffer compounds synthesized in Examples 1-1 to 1-7 ( 0.003 g to 0.005 g of the compound of Formulas 4a to 4g and 20 g of propylene glycol monomethyl ether acetate (PGMEA) as an organic solvent were mixed and filtered by a filter to prepare each photoresist composition (Examples 2-1 to 1). 2-7). A photoresist composition was also prepared in the same manner as in Example, except that no acid-diffusion buffer compound was used (Comparative Example 1).

The prepared photoresist composition was spin coated to a thickness of 0.20 μm on the silicon wafer coated with an organic antireflection film to form a photoresist thin film, followed by soft baking at 110 ° C. for 60 seconds, and numerical aperture (Numerical Aperture) 0.75 ArF ASML 1100 equipment was exposed, and then post-baked (PEB, Post exposure bake) for 60 seconds at 110 ℃. The thus baked wafer was developed with a 2.38% by weight aqueous tetramethylammonium hydroxide (TMAH) solution for 30 seconds to obtain the same line and space (L / S) pattern having a rectangular thickness of 0.20 mu m and a line width of 80 nm. The performance of the photoresist pattern thus formed was evaluated and shown in Table 1 below. In addition, an electron micrograph of a photoresist pattern formed using the photoresist composition of the present invention (Example 2-6), FE-SEM showing a CD-SEM (Critical Dimension Scanning Electron Microscope) photograph and a cut section (Field Emission Scanning Electron Microscope) Photographs are shown in FIGS. 1 and 2, respectively. In addition, as an electron micrograph of the photoresist pattern formed using the photoresist composition of the comparative example, the CD-SEM photograph and the FE-SEM photograph showing the cut cross section are shown in FIGS. 3 and 4, respectively.

Polymer resin Mine generator Acid diffusion buffer 20 g organic solvent EOP (mJ / cm ² ) FCCD (nm) LER (nm) Example 2-1 1.5 g 0.04 g Formula 4a, 3.0 mg PGMEA 26 58.2 5.4 Example 2-2 1.5 g 0.04 g Formula 4b, 3.0 mg PGMEA 25 61.2 5.1 Example 2-3 1.5 g 0.04 g Formula 4c, 3.2 mg PGMEA 27 56.7 4.9 Example 2-4 1.5 g 0.04 g Formula 4d, 3.4 mg PGMEA 24 58.6 5.6 Example 2-5 1.5 g 0.04 g Formula 4e, 3.5 mg PGMEA 23 55.6 4.7 Example 2-6 1.5 g 0.04 g Formula 4f, 4.0 mg PGMEA 25 61.6 4.8 Example 2-7 1.5 g 0.04 g Formula 4g, 5.0 mg PGMEA 26 59.7 5.2 Comparative Example 1 1.5 g 0.04 g 0 PGMEA 42 76.4 7.4

In Table 1, EOP is the exposure energy when the mask pattern size and the actual implemented pattern size are the same, First collapse critical dimension (FCCD) means the critical dimension that the pattern falls first, LER is line edge roughness Indicates. From Table 1, it can be seen that the photoresist composition comprising the acid-diffusion buffer compound according to the present invention not only has excellent resist resolution and strength of the formed pattern, but also improves line edge roughness characteristics of the resist.

1 and 2 are electron micrographs of a photoresist pattern formed using a photoresist composition according to an embodiment of the present invention, each showing a CD-SEM (Critical Dimension Scanning Electron Microscope) photograph and a FE showing a cut section -Field Emission Scanning Electron Microscope (SEM) photo.

3 and 4 are electron micrographs of the photoresist pattern formed using the photoresist composition according to the comparative example, FE-SEM photograph showing a CD-SEM photograph and a cut section, respectively, viewed from above.

Claims (6)

An acid-diffusion buffer compound having any one structure selected from the group consisting of the following Chemical Formulas 1 and 2. [Formula 1]

Wherein R ₁ to R ₃ are each independently a hydrogen atom, a hydroxyl group or an aliphatic hydrocarbon group having 1 to 10 carbon atoms, and at least one of R ₁ to R ₃ is an aliphatic carbon having 1 to 10 carbon atoms substituted with a carboxyl group, sulfonyl group or phosphoric acid group It is a hydrocarbon group. [Formula 2]

Wherein R ₁ to R ₆ are each independently a hydrogen atom, a hydroxyl group or an aliphatic hydrocarbon group having 1 to 10 carbon atoms, and at least one of R ₁ to R ₆ is an aliphatic carbon having 1 to 10 carbon atoms substituted with a carboxyl group, sulfonyl group or phosphoric acid group It is a hydrocarbon group. According to claim 1, wherein both R ₁ and R ₂ in the general formula (2) is a carboxyl group, a sulfonyl group or a carbon number of from 1 to 10 aliphatic hydrocarbon group that is substituted by a phosphoric acid in-diffusion buffer compound. The acid-diffusion buffer according to claim 1, wherein R ₁ to R ₆ of Formula 2 are aliphatic hydrocarbon groups and they are linked to each other to form a mono-cyclic or multi-cyclic ring structure. compound. 1 to 30% by weight of the photosensitive polymer; 0.05 to 20 parts by weight of a photoacid generator based on 100 parts by weight of the photosensitive polymer; With respect to 100 moles of the photoacid generator, 1 to 50 moles of acid-diffusion buffer compound having any structure selected from the group consisting of [Formula 1]

Wherein R ₁ to R ₃ are each independently a hydrogen atom, a hydroxyl group or an aliphatic hydrocarbon group having 1 to 10 carbon atoms, and at least one of R ₁ to R ₃ is an aliphatic carbon having 1 to 10 carbon atoms substituted with a carboxyl group, sulfonyl group or phosphoric acid group A hydrocarbon group, [Formula 2]

Wherein R ₁ to R ₆ are each independently a hydrogen atom, a hydroxyl group or an aliphatic hydrocarbon group having 1 to 10 carbon atoms, and at least one of R ₁ to R ₆ is an aliphatic carbon having 1 to 10 carbon atoms substituted with a carboxyl group, sulfonyl group or phosphoric acid group A hydrocarbon group; And Photoresist composition comprising the remaining organic solvent. The photoresist composition of claim 4, further comprising 0.01 to 10% by weight of organic base based on the total photoresist composition. 1 to 30% by weight of the photosensitive polymer; 0.05 to 20 parts by weight of a photoacid generator based on 100 parts by weight of the photosensitive polymer; An acid-diffusion buffer compound having any one structure selected from the group consisting of 1 to 50 moles of the following Chemical Formula 1 to 100 moles of the photoacid generator; And applying a photoresist composition comprising the remaining organic solvent on the substrate to form a photoresist film. [Formula 1]

Wherein R ₁ to R ₃ are each independently a hydrogen atom, a hydroxyl group or an aliphatic hydrocarbon group having 1 to 10 carbon atoms, and at least one of R ₁ to R ₃ is an aliphatic carbon having 1 to 10 carbon atoms substituted with a carboxyl group, sulfonyl group or phosphoric acid group A hydrocarbon group, [Formula 2]

Wherein R ₁ to R ₆ are each independently a hydrogen atom, a hydroxyl group or an aliphatic hydrocarbon group having 1 to 10 carbon atoms, and at least one of R ₁ to R ₆ is an aliphatic carbon having 1 to 10 carbon atoms substituted with a carboxyl group, sulfonyl group or phosphoric acid group A hydrocarbon group; Exposing the photoresist film in a predetermined pattern; And A method of forming a photoresist pattern comprising the step of heating and developing an exposed photoresist film after exposure.

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