KR20060002051A - Photoresist composition and method for forming photoresist pattern using the same - Google Patents

Abstract

The present invention relates to a photoresist composition and a method of forming a photoresist pattern using the same, and specifically, to a photoresist composition comprising (a) a photoresist resin, (b) a photoacid generator, and (c) an organic solvent. It relates to a photoresist composition further comprising a compound of formula 1 as a dissolution inhibitor and a pattern forming method using the same.

Such a photoresist composition of the present invention can improve the difference in dissolution rate of the developer in the exposure region and the non-exposed region in the light source of the general exposure process, including KrF and ArF light source to form a pattern having excellent line edge roughness (LER) Can be.

[Formula 1]

Wherein R is C ₁ to C ₂₀ alkyl, C ₁ to C ₂₀ alkyl comprising an ether group and an ester group.

Description

Photoresist composition and method for forming photoresist pattern using the same {Photoresist Composition and Method for Forming Photoresist Pattern Using the Same}

1 is a photoresist pattern photo formed by Example 1.

2 is a photoresist pattern photo formed by Example 2.

3 is a photoresist pattern photo formed by Example 3.

4 is a photoresist pattern photo formed by Comparative Example 1.

The present invention relates to a photoresist composition and a method of forming a photoresist pattern using the same, and more specifically, a compound used as a dissolution inhibitor in a photoresist composition including a photoresist resin, a photoacid generator, and an organic solvent. It relates to a photoresist composition comprising and a pattern forming method using the same.

At present, as semiconductor devices have become increasingly integrated, lithography process technology incorporating a chemically amplified deep ultra violet (DUV) light source capable of forming sub-micron fine patterns has been applied.

At this time, the lithography technique incorporating the light source in the DUV region uses short wavelengths of KrF (248 nm), ArF (193 nm), and VUV (vacuum ultraviolet light; 157 nm) instead of conventional g-line (436 nm) and i-line (365 nm) light sources. Or by applying a light source in a DUV region such as Extreme Ultraviolet (13 nm), thereby developing a chemically amplified photoresist (CAP) material having high sensitivity and resolution for the light source. in need.

The chemically amplified photoresist is a material capable of forming a pattern while maintaining high transparency by using H ⁺ (proton) generated by exposure as a catalyst to cause diffusion and decomposition of H ^{+ in} a chain. Not only should it be the same as this novolak resin, it should have low light absorption, high heat resistance and adhesion to light sources in the DUV region, such as ArF and VUV light sources, and 2.38 wt% and 2.6 wt% tetramethyl ammonium hydroxide. It should be possible to develop with an alkaline developer such as aqueous solution of TMAH and meet many requirements such as excellent etching resistance and adhesion to substrate.

The chemically amplified photoresist generally includes a base resin having a dissolution inhibiting group and a photoacid generator, in order to maximize the difference in dissolution rates of the exposed and non-exposed portions of the base resin with respect to the alkaline solution. It may further include a dissolution inhibitor in the resist.                         

However, as the pattern density of the semiconductor device becomes higher and higher, the thickness of the chemically amplified photoresist formed on the etched layer becomes thinner, so that the difference in the dissolution rate between the exposed portion and the non-exposed portion of the base resin is reduced, thereby providing excellent LER (line). It has become difficult to form a pattern having edge roughness.

Therefore, the inventors of the present invention have studied a photoresist composition including a new concept of a dissolution inhibitor capable of forming an improved pattern of the LER by maximizing the dissolution rate difference between the exposed portion and the non-exposed portion of the base resin. Developed to complete the present invention.

It is an object of the present invention to provide a photoresist composition comprising a compound having an excellent contrast ratio of solubility between an exposed area and a non-exposed area, and a pattern forming method using the same.

In order to achieve the above object, the present invention provides a photoresist composition comprising a compound used as (a) photoresist resin, (b) photoacid generator, (c) organic solvent and (d) dissolution inhibitor.

Hereinafter, the present invention will be described in detail.

The compound used as the dissolution inhibitor is a compound having a molecular weight of 1000 or less, can be represented by the following formula (1).                     

[Formula 1]

Where

R is alkyl of C ₁ ~C ₂₀ alkyl and ester containing groups of the C ₁ ~C ₂₀ alkyl containing an ether group in the C ₁ ~C _20.

At this time, the alkyl containing the ether group is C ₂ H ₅ OC ₂ H _4- , CH ₃ OCH ₂ CH _2- , CH ₃ OCH _2- Or cyclic ethers such as tetrahydrofuran are also possible.

The compound of Chemical Formula 1 may be preferably represented by the following Chemical Formulas 1a to 1c.

[Formula 1a]

[Formula 1b]

[Formula 1c]

The compound of Formula 1 is included in a ratio of 0.1 to 3wt%, preferably 0.5 to 2wt% with respect to the total weight of the photoresist composition.

When the compound of Chemical Formula 1 is mixed in the photoresist composition, the compound of Chemical Formula 1 coexists with an acid generated by the photoacid generator in the photoresist composition upon exposure, followed by a post-exposure bake (PEB) process. In Reaction with an acid as shown in Scheme 1 will be changed to a material soluble in the developer. Then, the contrast ratio of the dissolution rate with respect to the developing solution is improved between the exposure region and the non-exposure region, so that the LER of the pattern is improved, so that an excellent pattern can be formed.                     

Scheme 1

In addition, since the compound of Formula 1 fills the gaps between the photoresist resins well, the etching resistance of the pattern is improved, and the subsequent etching is performed in the etching process using the photoresist composition of the present invention rather than the etching process using the general photoresist composition. Significantly improves the process margin for the process.

In addition, since the compound of Formula 1 has excellent transmittance, heat resistance, and adhesion in light sources in general DUV region including KrF and ArF light sources, there is no problem even when used as an additive in a photoresist composition.

The photoresist resin, which is the base of the photoresist composition, may use all existing photoresist resins including cycloolefin-based, acrylate-based, methacrylate-based, poly (hydroxystyrene) -based, and novolak-based compounds. Preferably (i) a cycloolefin moiety having a protecting group sensitive to acid, (ii) a cycloolefin moiety having a hydroxyalkyl group, (iii) a cycloolefin moiety having a carboxy or carboxyalkyl group and (iv) It is a resin containing a repeating unit consisting of maleic anhydride, and more preferably poly (t-butyl bicyclo [2.2] in which cycloolefin-based comonomers are polymerized by addition to maintain a ring structure without breaking the ring structure. .1] hept-5-ene-2-carboxylate / 2-hydroxyethyl bicyclo [2.2.1] hept-5-ene-2-carboxylate / bi Cyclo [2.2.1] hept-5-ene-2-carboxylic acid / maleic hydride) or poly (t-butyl bicyclo [2.2.1] hept-5-ene-2 to improve substrate adhesion -Carboxylate / 2-hydroxyethyl bicyclo [2.2.2] oct-5-ene-2-carboxylate /bicyclo[2.2.1]hept-5-ene-2-carboxylic acid / maleicane Hydride) and the like.

In addition, the photoresist resin is included in a ratio of 5 to 20 wt%, preferably 8 to 15 wt% with respect to the total weight of the photoresist composition.

Further, the photoacid generator may be used as long as it is a compound capable of generating an acid by light, US 5,212,043 (May 18, 1993), WO 97/33198 (September 12, 1997), WO 96/37526 ( Nov. 28, 1996, EP 0 794 458 (October 10, 1997) EP 0 789 278 (August 13, 1997), US 5,750,680 (May 12, 1998), US 6,051,678 (April 18, 2000), GB 2,345,286 A (July 5, 2000), US 6,132,926 (October 17, 2000), US 6,143,463 (Nov. 7, 2000), and US 6,150,069 (November 21, 2000), and the like, and are mainly sulfur sulfide systems Or onium salt compounds. In particular, low absorbance at 157 nm and 193 nm phthalimidotrifluoromethane sulfonate, dinitrobenzyltosylate, n-decyl disulfone and naphthylimidotrifluoromethane Preference is given to using those selected from the group consisting of naphthylimido trifluoromethane sulfonate, together with diphenylurodoxyl hexafluorophosphate, diphenylurodoxyl hexafluoro arsenate, diphenylurodoxyl hexafluoro antimonate, Diphenylparamethoxyphenylsulfonium triflate, diphenylparatoluenylsulfonium triflate, diphenylparaisobutylphenylsulfonium triflate, triphenylsulfonium hexafluoro arsenate, triphenylsulfonium hexafluoro Antimonate, triphenylsulfonium triflate and dibutylnaphthylsulfonium It can also be used for the photo acid generator selected from the group consisting of a plate, and is used in a proportion of 0.1 to 10 parts by weight based on 100 parts by weight of the photoresist resin.

In this case, when the photoacid generator is used at 0.1 parts by weight or less, the sensitivity of the photoresist to light is weak. When the photoacid generator is used at 10 parts by weight or more, the photoacid generator absorbs a lot of ultraviolet rays and a large amount of acid is generated to obtain a pattern having a bad cross section. do.

The organic solvent can be any one commonly used, US 5,212,043 (May 18, 1993), WO 97/33198 (September 12, 1997), WO 96/37526 (Nov. 28, 1996), EP 0 794 458 (September 10, 1997) EP 0 789 278 (August 13, 1997), US 5,750,680 (May 12, 1998), US 6,051,678 (April 18, 2000), GB 2,345,286 A (2000. 7. 5), US 6,132,926 (October 17, 2000), US 6,143,463 (11/7/2000) and US 6,150,069 (11/21/2000) and the like, preferably propylene glycol methyl ether acetate, diethylene Diethylene glycol diethyl ether, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, cyclohexanone, or 2-heptanone may be used alone or in combination. It is used in the ratio of 100-2000 weight part with respect to 100 weight part of resist resins, in order to obtain the photoresist film of desired thickness.

In addition, the present invention provides a method of forming a photoresist pattern consisting of the following steps:

(a) forming a photoresist film by applying the photoresist composition of the present invention further comprising the compound of Formula 1 on the etched layer;

(b) exposing the photoresist film;

(c) baking the exposed photoresist film; And

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

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

In addition, the exposure process may use any light source, such as KrF, ArF, VUV, EUV, E-beam, X-rays or ion beam, preferably using a KrF or ArF light source of 1 to 100 mJ / cm ² It is carried out with exposure energy.

In addition, the present invention provides a semiconductor device manufactured using the photoresist composition of the present invention.                     

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

I. Preparation of Dissolution Inhibitor Compounds

Preparation Example 1 Preparation of Compound of Formula 1a

1,2: 5,6-di-o-cyclopentylidene-α-D-glucofuranose [1,2: 5,6-di-o-cyclopentylidene-α-D-glucofuranose] (0.05M) Di-tert-butyl-dicarbonate (0.055M) was dissolved in benzene solution (50ml) and triethylamine (0.055M) was added slowly while stirring at room temperature. After 6 hours of reaction, 1M NaOH aqueous solution (100 ml) was added to the reaction mixture, which was stirred for another 5 minutes, and then the aqueous layer was removed. Water (100 ml) was added to the remaining benzene solution, and the benzene solution obtained by extraction was dehydrated with magnesium sulfate (MgSO ₄ ), filtered and distilled to obtain the compound of Formula 1a (91%).

Preparation Example 2 Preparation of Compound of Formula 1b

1,2: 5,6-di-o-cyclopentylidene-α-D-glucofuranose (0.05M) was dissolved in tetrahydrofuran and then n-butyl lithium (2.5M solution in hexane 20ml at 0 ° C). ) (0.055M) and bromomethyl-tert-butyl-carboxylate (0.055M) were added. After stirring the resulting solution at room temperature for 10 hours, the reaction mixture was distilled to remove tetrahydrofuran, and then benzene (100 ml) and water (100 ml x 2) were added, and the extracted benzene solution was dehydrated, filtered and Distillation to yield the compound of Formula 1b (84%)

Preparation Example 3 Preparation of Compound of Formula 1c

1,2: 5,6-di-o-cyclopentylidene-α-D-glucofuranose (0.05M) was dissolved in tetrahydrofuran and then n-butyl lithium (2.5M solution in hexane at 0 ° C). 20 ml) (0.055 M) and chloromethyl ethyl ether (0.055 M) were added. After stirring the resulting solution at room temperature for 10 hours, the reaction mixture was distilled to remove tetrahydrofuran, and then benzene (100 ml) and water (100 ml x 2) were added, and the extracted benzene solution was dehydrated, filtered and Distillation gave the compound of Formula 1c (92%).

II. Preparation of Photoresist Composition and Forming Photoresist Pattern

Example 1.

After dissolving the compound (4 g) of Formula 1a of Preparation Example 1 in a photoresist photosensitive agent (H200D4; Dongjin Semichem Co., Ltd.) (20 ml), a photoresist composition was prepared by filtration with a 0.20 μm filter.

The composition was spin coated onto a silicon wafer at 3000 rpm and baked at 130 ° C. for 90 seconds. Then, it was exposed with an ArF exposure apparatus and then baked again for 90 seconds at 130 ° C. and developed for 40 seconds in a 2.38 wt% TMAH developer to obtain a pattern of 0.075 μm L / S with improved LER (see FIG. 1).

Example 2.

After dissolving the compound (4 g) of Chemical Formula 1b of Preparation Example 2 in a photoresist composition (H200D4) (20 ml), a photoresist composition was prepared by filtration with a 0.20 μm filter.

The composition was spin coated onto a silicon wafer at 3000 rpm and baked at 130 ° C. for 90 seconds. Then, it was exposed with an ArF exposure apparatus and then baked again at 130 ° C. for 90 seconds and developed for 40 seconds in a 2.38 wt% TMAH developer to obtain a pattern of 0.075 μm L / S with improved LER (see FIG. 2).

Example 3.

After dissolving compound (4 g) of Chemical Formula 1c of Preparation Example 3 in photoresist composition (H200D4) (20 ml), a photoresist composition was prepared by filtration with a 0.20 μm filter.

The composition was spin coated onto a silicon wafer at 3000 rpm and baked at 130 ° C. for 90 seconds. Then, the resultant was exposed with an ArF exposure apparatus and subsequently baked again at 130 ° C. for 90 seconds and developed in 2.38 wt% TMAH developer for 40 seconds to obtain a pattern of 0.075 μm L / S with improved LER (see FIG. 3).

Comparative Example 1. Conventional Photoresist Composition and Pattern Formation Using the Same

Photoresist composition (H200D4) (20 ml) was spin coated onto a silicon wafer at 3000 rpm and baked at 130 ° C. for 90 seconds. After baking, the resultant was exposed with an ArF exposure apparatus and then baked again at 130 ° C. for 90 seconds and developed for 40 seconds in a 2.38 wt% TMAH developer to obtain a pattern of 0.08 μm L / S (see FIG. 4).

 As described above, the photoresist composition including the compound of Chemical Formula 1 has a superior pattern of improved LER due to an improved dissolution rate difference between the developer and the non-exposure region in the developer in a general exposure light source including KrF and ArF light sources. Can be formed.

In addition, since the photoresist composition of the present invention fills the voids between the polymers well, the etching resistance is improved, thereby greatly improving the process margin for the subsequent etching process.

Claims (15)

A photoresist composition comprising (a) a photoresist resin, (b) a photoacid generator, (c) an organic solvent, and (d) a compound of formula (1): [Formula 1]

(Wherein R is a C ₁ ~C ₂₀ alkyl) ester group, including alkyl and the C ₁ ~C ₂₀ alkyl containing an ether group in the C ₁ ~C _20. The method of claim 1, The compound of Formula 1 is a photoresist composition, characterized in that selected from the group consisting of the formula 1a to 1c. [Formula 1a]

[Formula 1b]

[Formula 1c]

The method according to claim 1 or 2, The compound is a photoresist composition, characterized in that contained in a ratio of 0.1 to 3wt% relative to the total weight of the photoresist composition. The method of claim 3, wherein The compound is a photoresist composition, characterized in that contained in a ratio of 0.5 to 2wt% relative to the total weight of the photoresist composition. The method of claim 1, The photoresist resin is a photoresist composition, characterized in that selected from the group consisting of cycloolefin-based, acrylate-based, methacrylate-based, poly (hydroxy styrene) and novolak-based compound. The method of claim 5, The photoresist resin comprises a repeating unit comprising a cycloolefin moiety having an acid-sensitive protecting group, a cycloolefin moiety having a hydroxyalkyl group, a cycloolefin moiety having a carboxy or carboxyalkyl group, and a maleic anhydride. Photoresist composition comprising a. The method of claim 1, The photoresist resin is a photoresist composition, characterized in that contained in a ratio of 5 to 20wt% relative to the total weight of the photoresist composition. The method of claim 7, wherein The photoresist resin is a photoresist composition, characterized in that contained in a ratio of 8 to 15wt% relative to the total weight of the photoresist composition. The method of claim 1, The photoacid generators include phthalimidotrifluoromethane sulfonate, dinitrobenzyltosylate, n-decyl disulfone, and naphthylimidotrifluoromethanesulfonate. trifluoromethane sulfonate) photoresist composition, characterized in that selected from the group consisting of. The method of claim 9, The photoacid generator is diphenyl iodo hexafluorophosphate, diphenyl iodo hexafluoro arsenate, diphenyl iodo hexafluoro antimonate, diphenyl paramethoxyphenylsulfonium triflate, diphenyl paratoluenyl sulphate Phosphonium triflate, diphenylparaisobutylphenylsulfonium triflate, triphenylsulfonium hexafluoro arsenate, triphenylsulfonium hexafluoro antimonate, triphenylsulfonium triflate and dibutylnaphthylsulfonium tri A photoresist composition further comprising a compound selected from the group consisting of plates. The method of claim 1, The photoresist is a photoresist composition, characterized in that contained in a ratio of 0.1 to 10 parts by weight based on 100 parts by weight of the photoresist resin. The method of claim 1, The organic solvent is propylene glycol methyl ether acetate, diethylene glycol diethyl ether, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, cyclohexanone, 2-heptanone and Photoresist composition, characterized in that selected from the group consisting of a mixture thereof. The method of claim 1, The organic solvent is a photoresist composition, characterized in that contained in a ratio of 100 to 2000 parts by weight based on 100 parts by weight of the photoresist resin. (a) applying the photoresist composition of claim 1 over the etched layer to form a photoresist film; (b) exposing the photoresist film; (c) baking the exposed photoresist film; And (d) developing the resultant to obtain a desired pattern. A semiconductor device manufactured by the method of claim 14.

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