KR20130113596A - Photoresist composition for forming guide pattern and method for forming fine pattern using the same - Google Patents

Abstract

PURPOSE: A photoresist composition for forming guide patterns, including a photosensitive polymer having the cyanate functional group is provided to be able to form thermally stable guide patterns by self-crosslinking when heating. CONSTITUTION: A photoresist composition for forming guide patterns comprises a photosensitive polymer including 1-60 mol% of the repeating unit represented by Chemical formula 1, and 40-99 mol% of the repeating unit selected from the group consisting of the repeating unit represented by Chemical formula 2, the repeating unit represented by Chemical formula 3 and a mixture thereof; a photo acid generator; and an organic solvent. The photosensitive polymer is selected from the group consisting of polymers represented by Chemical formulas 4a-4b.

Description

Photoresist composition for forming guide pattern and method for forming fine pattern using same {Photoresist composition for forming guide pattern and method for forming fine pattern using the same}

The present invention relates to a photoresist composition for forming a guide pattern, and more particularly, to a photoresist composition for forming a guide pattern used in a direct self assembly (DSA) process using a self-alignment of a block copolymer (BCP). And it relates to a fine pattern forming method using the same.

With the miniaturization and integration of semiconductor devices, the implementation of micropatterns is required. As a method for forming such micropatterns, miniaturization of photoresist patterns through development of exposure equipment or introduction of additional processes is most effective.

Among these additional processes, the direct self assembly (DSA) process using the self-alignment of the block copolymer (BCP) can realize a pattern having a pattern line width of 20 nm or less, which is considered to be a limitation of the optical pattern forming method. It is expected to be.

The DSA process is a method of forming a refined semiconductor pattern by aligning the disordered orientation of the block copolymer with a conventional photoresist pattern process to direct the orientation of the pattern in a predetermined direction. That is, in the DSA process, in order to align the BCP, the BCP is coated and heated on a thin film such as a wafer or ITO glass on which a photoresist pattern is formed, to form a BCP coating film, and then the coated thin film is subjected to the glass transition temperature of the BCP. By heating to a temperature of (Tg) or more and realigning the BCP, a self-aligned pattern having a certain regularity can be obtained.

Therefore, a study is currently being conducted to have a uniform arrangement of patterns using the BCP process (DSA process), and after forming a guide pattern using a conventional photoresist composition, a space between the pattern and the pattern Forming a micropattern by filling BCP in the space and heating it to self-arrangement effectively reduces the cost of developing miniaturized and integrated semiconductors, LCDs, etc. compared to other processes, such as developing new exposure equipment. Can be lowered.

However, in the case of the DSA process, since the heating process must be performed at a temperature higher than the Tg of the BCP (for example, 200 to 250 ° C.) for self-alignment of the BCP, a photoresist composition having poor thermal stability is used. There is a problem in that the guide pattern formed is difficult to apply the DSA process.

Accordingly, an object of the present invention is not to reflow in a heating process for self-alignment of a block copolymer (BCP), and has resistance to a solvent (PGMEA, etc.) used in a BCP coating process, It is to provide a photoresist composition for forming a guide pattern excellent in thermal stability and a micropattern forming method using the same.

In order to achieve the above object, the present invention is from the group consisting of 1 to 60 mol% of repeating units represented by the following formula (1), and repeating units represented by the following formula (2), repeating units represented by the following formula (3) and mixtures thereof A photosensitive polymer comprising 40 to 99 mol% of selected repeating units; Photoacid generators; And it provides a photoresist composition for forming a guide pattern comprising an organic solvent.

[Formula 1]

(2)

(3)

In Chemical Formulas 1 to 3, each R independently represents a hydrogen atom or a methyl group, and R ₁ represents a linear, branched or cyclic hydrocarbon group having 1 to 20 carbon atoms, including or without 1 to 4 heteroatoms (divalent hydrocarbon). Radicals), R ₂ is a linear, branched or cyclic hydrocarbon group having 1 to 20 carbon atoms (monovalent hydrocarbon radical), and R ₃ is linear having 1 to 20 carbon atoms, with or without 1 to 4 heteroatoms, Branched or cyclic hydrocarbon groups (monovalent hydrocarbon radicals).

In addition, the present invention is to form a photoresist film by applying the photoresist composition for forming the guide pattern; And exposing and developing the photoresist film to form a guide pattern (primary pattern).

The photoresist composition for forming a guide pattern according to the present invention includes a photosensitive polymer including a cyanate group in a repeating unit, and when heated, can form a thermally stable guide pattern by self-crosslinking. . Therefore, it is useful as a photoresist composition for forming a guide pattern of a direct self assembly (DSA) process in which self-alignment of a block copolymer (BCP) is performed at a high temperature (for example, 150 to 250 ° C).

1 is a scanning electron micrograph of a guide pattern (photoresist pattern) according to Example 11 of the present invention.

Hereinafter, the present invention will be described in detail.

The photoresist composition for forming a guide pattern according to the present invention is for forming a guide pattern used in a direct self assembly (DSA) process using a self-alignment of a block copolymer (BCP), and a photosensitive polymer and a photoacid generator. And organic solvents.

The photosensitive polymer used in the present invention includes a cyanate group in the repeating unit, 1 to 60 mol%, preferably 3 to 40 mol%, and more preferably 1 to 60 mol% of the repeating unit represented by the following general formula (1). 10 to 30 mole%, most preferably 15 to 30 mole%, and 40 to 99 moles of repeating units selected from the group consisting of a repeating unit represented by the following formula (2), a repeating unit represented by the following formula (3) and mixtures thereof %, Preferably 60 to 97 mol%, more preferably 70 to 90 mol%, most preferably 70 to 85 mol%.

In Chemical Formulas 1 to 3, each R is independently a hydrogen atom or a methyl group, and R ₁ is a linear, branched or cyclic hydrocarbon group having 1 to 20 carbon atoms with or without 1 to 4 heteroatoms (bivalent hydrocarbon) Radical), for example, a linear, branched, or cyclic hydrocarbon group having 1 to 15 carbon atoms with or without containing 1 to 3 heteroatoms such as oxygen atom (O), sulfur atom (S) and the like. R ₂ is a linear, branched or cyclic hydrocarbon group (monovalent hydrocarbon radical) having 1 to 20 carbon atoms, for example, 1 to 15, and R ₃ has 1 to 4 carbon atoms with or without containing 1 to 4 heteroatoms. 20 linear, branched or cyclic hydrocarbon groups (monovalent hydrocarbon radicals), for example, 1 to 15 carbon atoms with or without containing 1 to 3 heteroatoms such as oxygen atom (O), sulfur atom (S) Linear, branched or cyclic hydrocarbon groups (such as lactone groups).

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등을 예시할 수 있고, 상기 R₂의 비한정적인 예로는,

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등을 예시할 수 있으며, 상기 R₃의 비한정적인 예로는,

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등을 예시할 수 있다(상기 화학식에서, *는 결합부위를 나타낸다).
Non-limiting examples of R ₁ ,

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And the like, and non-limiting examples of the above R ₂ ,

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And the like, and non-limiting examples of R ₃ ,

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And the like (in the formula, * represents a binding site).

In the photosensitive polymer, if the content of the repeating unit represented by the formula (1) is less than 1 mol%, when forming the guide pattern, there is a fear that the degree of crosslinking in the polymer may not be sufficient and thermal stability may decrease, and 60 mol% If exceeding, the guide pattern may not be formed or a scum may occur. When the content of the repeating unit selected from the group consisting of the repeating unit represented by the formula (2), the repeating unit represented by the formula (3) and a mixture thereof is less than 40 mol%, after deprotection of the photosensitive polymer, There is a possibility that the guide pattern formed due to the small content of —COOH group may be poor, and when it exceeds 99 mol%, the guide pattern may be difficult to form due to excessive acid diffusion.

Representative examples of the photosensitive polymer may include a polymer represented by the following Chemical Formulas 4a to 4b.

[Chemical Formula 4a]

(4b)

In Chemical Formulas 4a to 4b, R, R ₁ , R _2, and R ₃ are as defined in Chemical Formulas 1 to 3, and a, b, c, d, and e are mole% of repeating units constituting the polymer. And d is 1 to 60 mol%, preferably 3 to 40 mol%, more preferably 10 to 30 mol%, most preferably 15 to 30 mol%, b and c are each independently 1 to 98 mol %, Preferably 2 to 95 mol%, more preferably 5 to 85 mol%, most preferably 10 to 75 mol%, e is 40 to 99 mol%, preferably 60 to 97 mol%, more Preferably it is 70-90 mol%, Most preferably, it is 70-85 mol%.

In the photosensitive polymer, when the range of a, b, c, d, and e is out of the range, when the guide pattern is formed, the degree of crosslinking in the polymer is insufficient, so that the thermal stability is low, or the guide pattern is formed. Or scum may occur.

Representative examples of the polymer represented by Formula 4a may be a polymer represented by the following Formulas 5a to 5j.

[Chemical Formula 5a]

[Chemical Formula 5b]

[Chemical Formula 5c]

[Chemical Formula 5d]

[Chemical Formula 5e]

[Formula 5f]

[Chemical Formula 5g]

[Chemical Formula 5h]

[Formula 5i]

[Formula 5j]

In Chemical Formulas 5a to 5j, R, a, b, and c are as defined in Chemical Formula 4a.

The photosensitive polymer may be prepared using a conventional polymer polymerization method. For example, the cyanate group (-OCN) of the repeating unit represented by Formula 1 may be a hydroxyl group (-OH), as in the following Preparation Example. Substituted monomer and a repeating unit represented by the formula (2), a repeating unit represented by the formula (3) and a monomer of a repeating unit selected from the group consisting of mixtures thereof are polymerized by a conventional polymer polymerization method, the hydroxyl group It can obtain by substituting a nate group.

The content of the photosensitive polymer is 1 to 30% by weight, preferably 3 to 15% by weight, more preferably 5 to 10% by weight, based on the total guide pattern forming composition. When the content of the photosensitive polymer is less than 1% by weight, there is a fear that the guide pattern may not be formed, and the thickness of the formed pattern may be too thin to serve as a guide pattern. It is difficult to obtain a pattern having a desired thickness, and the height of the formed guide pattern is high, making it difficult to form the pattern, or there is a fear that the collapse of the formed pattern may occur. In addition, the weight average molecular weight (Mw) of the photosensitive polymer is, for example, 2,000 to 50,000, preferably 4,000 to 10,000. If the weight average molecular weight of the polymer is less than 2,000, it is difficult to form a uniform guide pattern, there is a fear that the thermal stability is lowered, if it exceeds 50,000, the solubility of the polymer is low during the development process may be long development time.

Photo acid generator (PAG) used in the present invention can be used without limitation, compounds that can generate an acid by light, for example, sulfonium salt compounds, iodonium salt compounds, these Mixtures and the like can be used. Preferably, triphenylsulfonium triflate, phthalimidotrifluoro methanesulfonate, dinitrobenzyltosylate, n-decyl disulfone, naphthylimidotrifluoro Naphthylimidotrifluoro methanesulfonate, diphenylurido salt triflate, diphenylurido salt nonaplate, diphenylurido salt hexafluorophosphate, diphenylurido salt hexafluoroarsenate, diphenylurido salt hexafluoroantimonate, diphenyl Phenylparamethoxyphenylsulfonium triflate, diphenylparatoluenylsulfonium triflate, diphenylparateruylbutylphenylsulfonium triflate, diphenylparaisobutylphenylsulfonium triflate, triphenylsulfonium triflate, Trisparaterylbutylphenylsulfonium triflate, diphenylparamethoxyphenylsulfonium furnace Plate, diphenyl paratoluenyl sulfonium nona plate, diphenyl para butyl phenyl sulphonium nona plate, diphenyl para butyl phenyl sulphonium nona plate, triphenyl sulfonium nona plate, tripara tertiary butyl phenyl sulfonium As nonaplate, hexafluoroarsenate, triphenylsulfonium hexafluoroantimonate, dibutylnaphthylsulfonium triflate, mixtures thereof and the like can be used.

The content of the photoacid generator is 0.5 to 15 parts by weight, preferably 1 to 8 parts by weight, based on 100 parts by weight of the photosensitive polymer. When the content of the photoacid generator is less than 0.5 parts by weight with respect to 100 parts by weight of the photosensitive polymer, the reactivity with respect to the exposure source becomes low and the part to be removed (part remaining in the space portion of the guide pattern) cannot be sufficiently removed. There exists a possibility that when it exceeds 15 weight part, there exists a possibility that adjustment of the sensitivity with respect to an exposure source may not be easy.

The organic solvent used in the present invention is for dissolving the photosensitive polymer, the organic solvent used in the conventional photoresist composition can be used without limitation, for example, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether, Ethylene glycol monoacetate, diethylene glycol, diethylene glycol monoethyl ether, propylene glycol monomethyl ether acetate, propylene glycol, propylene glycol monoacetate, toluene, xylene, methyl ethyl ketone, methyl isoamyl ketone, cyclohexanone, Dioxane, methyl lactate, ethyl lactate, methylpyruvate, ethyl pyruvate, methylmethoxypropionate, ethylethoxypropionate, N, N-dimethylformamide, N, N-dimethylacetamide, N -Methyl 2-pyrrolidone, 3-ethoxyethylpropionate, 2-heptanone, gamma-butyrolactone, 2-hydroxyprop Onethyl, 2-hydroxy ethyl 2-methylpropionate, ethyl ethoxy acetate, ethyl hydroxy acetate, methyl 2-hydroxy 3-methylbutyrate, methyl 3-methoxy 2-methylpropionate, ethyl 3-ethoxypropionate And solvents such as ethyl 3-methoxy 2-methylpropionate, ethyl acetate and butyl acetate may be used alone or in combination of two to four. The content of the organic solvent is the remainder of the entire photoresist composition except for the additives such as the photosensitive polymer and the photoacid generator.

The photoresist composition for forming a guide pattern according to the present invention may further include additives such as a basic acid diffusion regulator (basic compound, quencher) as necessary.

The basic acid diffusion regulator used in the present invention is used to control acid diffusion, and basic acid diffusion regulators used in conventional photoresist compositions can be used without limitation, for example, triethylamine, tri One or more selected from octylamine, triisobutylamine, triisooctylamine, diethanolamine, triethanolamine, 2-piperidine ethanol and the like can be used. When using the basic acid diffusion regulator, the content thereof is 0.5 to 10 parts by weight, preferably 1 to 5 parts by weight based on 100 parts by weight of the photosensitive polymer. When the content of the basic acid diffusion regulator is less than 0.5 parts by weight, it is difficult to control acid diffusion by the exposure source, and when it exceeds 10 parts by weight, the portion to be removed by suppressing excessive acid diffusion (remains in the space portion of the guide pattern) May be impossible to remove.

The micropattern forming method (directed self assembly (DSA) process) according to the present invention may be performed in the same manner as a conventional DSA process. For example, (a) polystyrene-co-methmethylacrylic acid is deposited on a silicon wafer. After applying the self-aligned induction layer composition comprising, bake for 30 to 600 seconds at a temperature of 150 to 250 ℃, for example, for self-aligned induction of block copolymer (BCP) Forming a self-aligned induction layer, (b) applying a photoresist composition for forming a guide pattern according to the present invention onto a wafer on which the self-aligned induction layer is formed, and (c) forming a photoresist film. Exposing and developing to form a guide pattern (primary pattern), (d) a block copolymer such as polystyrene-block-methmethylacrylic acid on the wafer on which the guide pattern is formed; k copolymer: BCP) is coated with a solution of propylene glycol monomethyl ether acetate (PGMEA) and the like to form a block copolymer coating film, (e) a wafer on which the block copolymer coating film is formed Is heated to a temperature higher than the glass transition temperature (Tg) of the block copolymer for 1 to 600 minutes to obtain a self-aligned pattern having a directivity, and (f) dry etching the wafer on which the self-aligned pattern is formed (O _2). Reactive ion etching (RIE) is included.

In the step (e), due to the polarity of the surface of the guide pattern, the polar portion of the BCP is located on the surface of the guide pattern, the low polarity is located far away from the surface of the guide pattern, the self-alignment of the BCP is made In the dry etching step (step (f)), the methacrylacrylic acid site is removed to form a fine pattern.

In the fine pattern forming method (DSA process), when a reflow occurs in the guide pattern, the angle between the guide pattern and the wafer may not be perpendicular to each other, so that the angle of the self-aligned pattern is perpendicular to the wafer. It will not form. Therefore, in order to form a fine pattern using the DSA process, it is necessary to form a guide pattern having excellent thermal stability and no flow phenomenon. In the case of the pattern formed by the conventional photoresist composition, thermal stability is not suitable as a guide pattern, but in the case of the photoresist pattern (guide pattern) formed by the photoresist composition for forming a guide pattern according to the present invention, the thermal stability is Since it is excellent and a flow phenomenon does not generate | occur | produce even at high temperature (for example, 150-250 degreeC), it is suitable as a guide pattern.

Hereinafter, the present invention will be described in more detail with reference to specific examples. The following examples illustrate the present invention and are not intended to limit the scope of the present invention.

Preparation Example 1 Preparation of Photosensitive Polymer Represented by Chemical Formula 5a

12.4 g (0.05 mol) 2-ethyl-2-adamantyl methacrylate, 2-methyl-acrylic acid-2-oxo-tetra hydrofuran-3-yl ester in the reactor 4.25 g (0.03 mol) of (2-methylacrylic acid-2-oxo-tetrahydrofuran-3-yl ester), 5.53 g (0.03 mol) of acetic acid 4-hydroxy-cyclohexyl ester ) And 0.7 g of azobis (isobutyronitrile) (AIBN) were added, the reactant was dissolved in 100 g of anhydrous tetrahydrofuran (THF), and the gas was removed using an ampoule by freezing. The reaction was removed and polymerized at 68 ° C. for 24 hours. After completion of the polymerization reaction, the reaction product was slowly added dropwise to excess diethyl ether and precipitated, and then dissolved in THF. The dissolved reaction product was reprecipitated in diethyl ether to obtain 14.4 g of a copolymer (yield). : 56%). 12.42 g (0.12 mol) of cyanogen bromide was added to a 250 ml three-necked round bottom flask in 14.4 g of the vacuum-dried copolymer, and then dissolved in 50 g of chloroform. After cooling, 11.86 g (0.12 mol) of triethylamine was dissolved in 50 g of chloroform, and slowly added dropwise using a dropping funnel, and then maintained at 0 ° C. for 30 minutes, and then stirred at room temperature for 12 hours. After 12 hours, in order to remove the side reaction product, the reaction product was slowly dropped into methanol, precipitated, filtered, washed three times with methanol, and then vacuum dried for 12 hours using a vacuum oven at 100 ° C. to Chemical Formula 5a. 8.2g of obtained photosensitive polymers (R: methyl group, a: 27.3 mol%, b: 45.4 mol%, c: 27.3 mol%) were obtained (yield: 57.1%). Gel permeation chromatography (GPC) measurement of the photosensitive polymer, the weight average molecular weight (Mw) was 5,760, dispersion degree (PDI) was 2.21.

Preparation Example 2 Preparation of Photosensitive Polymer Represented by Chemical Formula 5b

2-methylacrylic acid-bicyclo [2.2.1] heptan-2-yl ester (2-methylacrylic acid-bicyclo [2.2.1] instead of 5.53 g (0.03 mol) of the acetic acid 4-hydroxy-cyclohexyl ester photosensitive polymer represented by Chemical Formula 5b (R: methyl group, a: 27.3 mol%, b: 45.4 mol%) in the same manner as in Preparation Example 1, except that 6.37 g (0.03 mol) of heptane-2-yl ester) was used , c: 27.3 mol%) (yield: 64.7%, weight average molecular weight (Mw): 4,200, dispersion degree (PDI): 2.32).

Preparation Example 3 Preparation of Photosensitive Polymer Represented by Chemical Formula 5c

2-methylacrylic acid-5-hydroxy-adamantan-2-yl ester instead of 5.53 g (0.03 mol) of the acetic acid 4-hydroxy-cyclohexyl ester (2-methylacrylic acid-5-hydroxy-adamantan- 2-yl ester) Photosensitive polymer represented by Chemical Formula 5c (R: methyl group, a: 27.3 mol%, b: 45.4 mol%, c) except that 7.9 g (0.03 mol) was used. : 27.3 mol%) (yield: 73%, weight average molecular weight (Mw): 4,700, dispersion degree (PDI): 2.16).

Preparation Example 4 Preparation of Photosensitive Polymer Represented by Chemical Formula 5d

2-methylacrylic acid-3-hydroxy-adamantan-2-yl methyl ester (2-methylacrylic acid-3-hydroxy-adamantan instead of 5.53 g (0.03 mol) of the acetic acid 4-hydroxy-cyclohexyl ester -2-yl methyl ester) Photosensitive polymer (R: methyl group, a: 27.3 mol%, b: 45.4 mol%) represented by Chemical Formula 5d by the same procedure as in Preparation Example 1, except that 7.51 g (0.03 mol) was used , c: 27.3 mol%) (yield: 68.6%, weight average molecular weight (Mw): 5,100, dispersion degree (PDI): 2.31).

Preparation Example 5 Preparation of Photosensitive Polymer Represented by Chemical Formula 5e

2-methylacrylic acid-5-hydroxy-adamantan-2-yl-oxycarbonylmethyl ester (2-methylacrylic acid-5) instead of 5.53 g (0.03 mol) of the acetic acid 4-hydroxy-cyclohexyl ester photosensitive polymer represented by Chemical Formula 5e (R: methyl group, a: 27.3 mol%) in the same manner as in Preparation Example 1, except that 8.83 g (0.03 mol) of -hydroxy-adamantan-2-yl-oxycarbonyl methyl ester) was used , b: 45.4 mol%, c: 27.3 mol%) was obtained (yield: 57.7%, weight average molecular weight (Mw): 4,900, dispersion degree (PDI): 2.42).

Preparation Example 6 Preparation of Photosensitive Polymer Represented by Chemical Formula 5f

5.11 g (0.03 mol) of 2-methylacrylic acid-3-hydroxy-cyclopentyl ester instead of 5.53 g (0.03 mol) of the acetic acid 4-hydroxy-cyclohexyl ester A photosensitive polymer (R: methyl group, a: 27.3 mol%, b: 45.4 mol%, c: 27.3 mol%) represented by Chemical Formula 5f was prepared in the same manner as in Preparation Example 1, except that mol) was used. Yield: 63.5%, weight average molecular weight (Mw): 4,200, dispersion (PDI): 2.33).

Preparation Example 7 Preparation of Photosensitive Polymer Represented by Chemical Formula 5g

2-methylacrylic acid octahydro-4,7-methano-inden-5-yl ester (2-methylacrylic acid octahydro-4,7 instead of 5.53 g (0.03 mol) of the acetic acid 4-hydroxy-cyclohexyl ester Except for using 7.57 g (0.03 mol) of -methano-indene-5-yl ester), the photosensitive polymer represented by Chemical Formula 5g was prepared in the same manner as in Preparation Example 1 (R: methyl group, a: 27.3 mol%, b: 45.4 mol%, c: 27.3 mol%) was obtained (yield: 71.1%, weight average molecular weight (Mw): 4,800, dispersion degree (PDI): 2.46).

Preparation Example 8 Preparation of Photosensitive Polymer Represented by Chemical Formula 5h

2-methylacrylic acid decahydro-1,4-methano-naphthalen-2-yl ester (2-methylacrylic acid decahydro-1,4 instead of 5.53 g (0.03 mol) of the acetic acid 4-hydroxy-cyclohexyl ester Except for using 8.44 g (0.03 mol) of -methano-naphthalene-2-yl ester), a photosensitive polymer represented by Chemical Formula 5h (R: methyl group, a: 27.3 mol%, b: 45.4 mol%, c: 27.3 mol%) were obtained (yield: 68.2%, weight average molecular weight (Mw): 4,950, dispersion degree (PDI): 2.52).

Preparation Example 9 Preparation of Photosensitive Polymer Represented by Chemical Formula 5i

2-methylacrylic acid 2-hydroxy-1-methyl-ethyl ester instead of 5.53 g (0.03 mol) of the acetic acid 4-hydroxy-cyclohexyl ester ) Photosensitive polymer represented by Formula 5i (R: methyl group, a: 27.3 mol%, b: 45.4 mol%, c: 27.3 mol%) in the same manner as in Preparation Example 1, except that 3.96 g (0.03 mol) was used ) Was obtained (yield: 77%, weight average molecular weight (Mw): 5,400, dispersion degree (PDI): 1.96).

Preparation Example 10 Preparation of Photosensitive Polymer Represented by Chemical Formula 5j

4.33 g (0.03 mol) of 2-methylacrylic acid-3-hydroxy propyl ester instead of 5.53 g (0.03 mol) of the acetic acid 4-hydroxy-cyclohexyl ester A photosensitive polymer (R: methyl group, a: 27.3 mol%, b: 45.4 mol%, c: 27.3 mol%) represented by Chemical Formula 5j was prepared in the same manner as in Preparation Example 1, except that yield was 81. %, Weight average molecular weight (Mw): 4,590, dispersion (PDI): 1.64).

Examples 1 to 10 and Comparative Example 1 Preparation of Photoresist Composition

According to the composition of Table 1, the photosensitive polymer represented by Formulas 5a to 5j prepared in Preparation Examples 1 to 10 or the photosensitive polymer represented by the following Formula 6 (weight average molecular weight (Mw): 5,010) 2g, basic acid diffusion 0.02 g of triethanolamine as a regulator and 0.08 g of triphenylsulfonium triflate as a photoacid generator were completely dissolved in 17 g of an organic solvent (propylene glycol monomethyl ether acetate (PGMEA)), followed by Filtration with a disk filter produced a photoresist composition for forming a guide pattern.

[Formula 6]

Photosensitive polymer Basic acid diffusion regulators Photoacid generator Organic solvent Example 1 Preparation Example 1 (2 g) Triethanolamine
0.02 g Triphenylsulfonium
Triple rate
0.08g PGMEA 17g Example 2 Preparation Example 2 (2 g) Example 3 Preparation Example 3 (2 g) Example 4 Preparation Example 4 (2 g) Example 5 Preparation Example 5 (2 g) Example 6 Preparation Example 6 (2 g) Example 7 Preparation Example 7 (2 g) Example 8 Preparation Example 8 (2 g) Example 9 Preparation Example 9 (2 g) Example 10 Preparation Example 10 (2 g) Comparative Example 1 Formula 6 (2 g)

[Examples 11 to 20 and Comparative Example 2] Guide Pattern Formation and Evaluation

In order to evaluate the thermal stability of the guide pattern used in the micro pattern formation (DSA process) using the self-alignment of the block copolymer (BCP), guide pattern formation and evaluation was carried out as follows.

An organic antireflective coating composition (product name: DARC-A125, manufacturer: Dongjin Semichem Co., Ltd.) was coated on a silicon wafer, and then baked at 240 ° C. for 60 seconds. After coating the self-aligned induction layer composition (product name: NL-02, manufacturer: Dongjin Semichem Co., Ltd.) for performing the DSA process on the formed organic anti-reflective coating layer, the wafer was baked again at 200 ℃ for 120 seconds. After coating the photoresist composition prepared in Examples 1 to 10 and Comparative Example 1 to a thickness of 130nm on the wafer on which the self-alignment induction layer was formed, and baked at 110 ° C. for 60 seconds, a line and space (L / S) pattern It exposed using the exposure mask which has the inside of a 193 nm ArF exposure apparatus (device name: ASML 1200B), and post-baked at 110 degreeC for 60 second. After post-baking, development was carried out with a 2.38 wt% TMAH (tetramethylammonium hydroxide) aqueous solution to obtain a 50 nm line pattern (guide pattern) having a 150 nm pitch (L / S = 1: 2).

After evaluating the thermal stability of the guide pattern (flood exposure) to the guide pattern (flood exposure), and then hard bake (HB) for 60 seconds at 240 ℃, by measuring the CD change of the guide pattern before and after the process Table 2 shows. In addition, the scanning electron micrograph after hard baking of the guide pattern which concerns on Example 11 is shown in FIG.

HB full pattern CD (nm) Pattern CD after HB (nm) CD variation (nm) Example 11 56.9 49.5 7.4 Example 12 53.8 43.6 10.2 Example 13 56.4 50.6 5.8 Example 14 63.3 57.9 5.4 Example 15 63.7 54.1 9.6 Example 16 56.9 51.4 5.5 Example 17 50.7 46.6 4.1 Example 18 60.3 56.4 3.9 Example 19 55.9 48.2 7.7 Example 20 50.7 45.9 4.8 Comparative Example 2 42.3 reflow 42.3

From the above results, the guide pattern (Comparative Example 2) made of a general ArF photoresist composition (Comparative Example 1) does not maintain the shape of the pattern when heated to a high temperature (240 ° C.) (hard bake process is performed). ), It can be seen that the guide pattern (Examples 11 to 20) for the DSA process prepared using the photoresist composition (Examples 1 to 10) according to the present invention maintains the shape of the pattern even after performing the hard bake process. Can be. Therefore, the photoresist composition according to the present invention, it can be seen that without exposure to other additives, the cyanate group in the photosensitive polymer can be self-crosslinked to form a thermally stable pattern, without high additives, for example, It can be seen that it is useful as a photoresist composition for forming a guide pattern of a direct self assembly (DSA) process in which self-alignment of the block copolymer (BCP) is performed at 150 to 250 ° C.

Claims (8)

1 to 60 mol% of the repeating unit represented by the following Chemical Formula 1, and 40 to 99 mol% of the repeating unit selected from the group consisting of the repeating unit represented by the following Chemical Formula 2, the repeating unit represented by the following Chemical Formula 3, and mixtures thereof Photosensitive polymer containing; Photoacid generators; And Photoresist composition for forming a guide pattern comprising an organic solvent.
[Formula 1]

(2)

(3)

In Chemical Formulas 1 to 3, each R is independently a hydrogen atom or a methyl group, R ₁ is a linear, branched or cyclic hydrocarbon group having 1 to 20 carbon atoms with or without 1 to 4 heteroatoms, and R ₂ Is a linear, branched or cyclic hydrocarbon group having 1 to 20 carbon atoms, and R ₃ is a linear, branched or cyclic hydrocarbon group having 1 to 20 carbon atoms, with or without containing 1 to 4 heteroatoms. The photoresist composition of claim 1, wherein the photosensitive polymer is selected from the group consisting of polymers represented by the following Chemical Formulas 4a to 4b.
[Chemical Formula 4a]

(4b)

In Chemical Formulas 4a to 4b, R, R ₁ , R _2, and R ₃ are as defined in Chemical Formulas 1 to 3, and a, b, c, d, and e are mole% of repeating units constituting the polymer. And d is 1 to 60 mol%, b and c are each independently 1 to 98 mol%, and e is 40 to 99 mol%. The photoresist composition of claim 1, wherein the photosensitive polymer is selected from the group consisting of polymers represented by the following Chemical Formulas 5a to 5j.
[Chemical Formula 5a]

[Chemical Formula 5b]

[Chemical Formula 5c]

[Chemical Formula 5d]

[Chemical Formula 5e]

[Formula 5f]

[Formula 5g]

[Formula 5h]

[Formula 5i]

[Formula 5j]

In Chemical Formulas 5a to 5j, R is as defined in Chemical Formulas 1 to 3, and a, b, and c are. As mole% of the repeating unit which comprises a polymer, a is 1-60 mol%, b and c are 1-98 mol% each independently. According to claim 1, wherein the photoacid generator is selected from the group consisting of sulfonium salt compounds, iodonium salt compounds and mixtures thereof, the organic solvent is ethylene glycol monoethyl ether, ethylene glycol monomethyl ether, ethylene Glycol monoacetate, diethylene glycol, diethylene glycol monoethyl ether, propylene glycol monomethyl ether acetate, propylene glycol, propylene glycol monoacetate, toluene, xylene, methyl ethyl ketone, methyl isoamyl ketone, cyclohexanone, di Oxane, 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-ethoxyethylpropionate, 2-heptanone, gamma-butyrolactone, 2-hydroxypropionethyl, 2-hydrate Ethoxy 2-methylpropionate, ethyl ethoxy acetate, ethyl hydroxyacetate, 2-hydroxy 3-methylbutyrate, 3-methoxy 2-methylpropionate, 3-ethoxypropionate, 3-methoxy 2 A photoresist composition for forming a guide pattern, which is selected from the group consisting of ethyl methyl propionate, ethyl acetate, butyl acetate and mixtures thereof. According to claim 1, wherein the total guide pattern forming composition, the content of the photosensitive polymer is 1 to 30% by weight, the content of the photoacid generator is 0.5 to 15 parts by weight based on 100 parts by weight of the photosensitive polymer, The remainder is the organic solvent, the photoresist composition for forming a guide pattern. The photoresist composition of claim 1, wherein the photoresist composition for forming the guide pattern further includes a basic acid diffusion regulator, and when the basic acid diffusion regulator is included, the content of the basic acid diffusion regulator is 0.5 to 100 parts by weight of the photosensitive polymer. It is to 10 parts by weight, photoresist composition for forming a guide pattern. The method of claim 6, wherein the basic acid diffusion regulator is from the group consisting of triethylamine, trioctylamine, triisobutylamine, triisooctylamine, diethanolamine, triethanolamine, 2-piperidineethanol and mixtures thereof The selected photoresist composition for forming a guide pattern. (a) applying a self-aligned induction layer composition comprising polystyrene-co-methmethylacrylic acid on a silicon wafer to form a self-aligned induction layer;
(b) applying a photoresist composition for forming a guide pattern according to any one of claims 1 to 7, on the wafer on which the self-alignment induction layer is formed to form a photoresist film;
(c) exposing and developing the photoresist film to form a guide pattern (primary pattern);
(d) applying a solution in which the block copolymer is dissolved in a solvent to a wafer on which the guide pattern is formed to form a block copolymer coating film;
(e) heating the wafer on which the block copolymer coating film is formed at a temperature of at least the glass transition temperature (Tg) of the block copolymer for 1 to 600 minutes to obtain a self-aligned pattern having a directivity; And
and (f) dry etching the wafer on which the self-aligned pattern is formed (O ₂ reactive ion etching).

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