KR19990085664A - Resist Compositions Containing Silicon - Google Patents

Abstract

The present invention

(a) a polymer having the following formula for use in chemically amplified resists,

Wherein R ₁ is —CH ₂ Si (CH ₃ ) ₃ , R ₂ , R ₄ and R ₅ are —H or —CH ₃ , and R ₃ and R ₆ are —CH ₃ , t-butyl or tetrahydropyra Nyl group, k / (k + l + m + n) = 0.1-0.7, l / (k + l + m + n) = 0.0-0.4, m / (k + l + m + n) = 0.1 -0.4 and n / (k + l + m + n) = 0.0-0.4.

(b) provides a resist composition composed of a photoacid generator (PAG).

Description

Resist Compositions Containing Silicon

TECHNICAL FIELD This invention relates to a resist composition. Specifically, It is related with the chemically amplified resist composition which consists of a high molecular compound containing silicone.

As the semiconductor manufacturing process becomes complicated and the degree of integration increases, fine pattern formation is required, and thus, the development of new resists is also essential in lithography technology. Moreover, as the capacity of semiconductor devices has increased to more than 1G bit, there is a need for a new resist material capable of acting in the wavelength region of ArF excimer laser (193 nm).

ArF resists can be divided into single-layer resist (SLR) and bi-layer resist (BLR) during the semiconductor process. In general, in the case of using SLR, the resist pattern forming process is simpler than in the case of using BLR. However, when forming a resist pattern using the SLR it is not possible to sufficiently ensure the dry etch resistance (dry etch resistance). In addition, when the aspect ratio becomes large, the resist pattern is inclined to fall while being inclined, resulting in many difficulties in forming the resist pattern.

BLR is a resist containing silicon. In the case of forming a resist pattern using BLR, the resist pattern forming process is more complicated than in the case of SLR. However, silicon atoms in the resist material are glassed during dry etching with O ₂ plasma to form a cured layer on the surface of the resist layer, and the cured layer thus formed acts as an etching mask in a subsequent dry etching process. When the fact ratio is large, it is easy to form a resist pattern.

On the other hand, when manufacturing BLR, a polymer containing silicon is mainly used. At this time, since the content of silicon contained in the polymer depends on the resistance to dry etching, the content of silicon in the BLR acts as an important factor. In addition, it is necessary to secure the adhesive properties to the film quality.

It is an object of the present invention to provide a resist composition having good adhesion properties while having a sufficient silicon content for use as a BLR.

In order to achieve the above object, the present invention (a) a polymer having the following formula used in the chemically amplified resist,

Wherein R ₁ is —CH ₂ Si (CH ₃ ) ₃ , R ₂ , R ₄ and R ₅ are —H or —CH ₃ , and R ₃ and R ₆ are —CH ₃ , t-butyl or tetrahydropyra Nyl group, k / (k + l + m + n) = 0.1-0.7, l / (k + l + m + n) = 0.0-0.4, m / (k + l + m + n) = 0.1 -0.4 and n / (k + l + m + n) = 0.0-0.4.

(b) provides a resist composition composed of a photoacid generator (PAG).

The polymer has a weight average molecular weight of 5,000 to 100,000.

The resist composition comprises 1-10% PAG based on the weight of the polymer.

The PAG is selected from the group consisting of triarylsulfonium salts, diaryliodonium salts, sulfonates and mixtures thereof.

Next, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

Example 1

Synthesis of Bis (trimethylsilylmethyl) fumarate

The synthesis reaction of bis (trimethylsilylmethyl) fumarate (I) can be represented by the following formula.

In a round flask, trimethylsilylmethanol (0.11 mole) and triethylamine (TEA) (0.11 mole) were dissolved in THF, and fumaric acid dichloride (0.05 mole) was slowly dropped therein, and the reaction temperature was 45 deg. The reaction was carried out for about 12 hours.

After the reaction was completed, excess THF in the reaction was distilled off, and the reaction was introduced into excess water, which was then neutralized with HCl.

Thereafter, the mixture was extracted using diethyl ether and dried using MgSO ₄ . The obtained product was separated and purified by distillation under reduced pressure (yield 70%).

Example 2

Synthesis of Terpolymer

Wherein, R is _{-CH 2 Si (CH 3) 3} .

Bis (trimethylsilylmethyl) fumarate (50 mmol) synthesized in Example 1 was dissolved in THF solution with t-butyl methacrylate (30 mmol) and methacrylic acid (20 mmol), and then AIBN (azobisisobutyronitrile) was added thereto. (4 mmol) was added and purged with nitrogen gas for about 2 hours.

After the reaction was polymerized at reflux for about 24 hours, the reaction was slowly dropped in excess of n-hexane to precipitate, and the precipitate was dissolved in THF again and then re-precipitated in n-hexane.

The precipitate obtained was filtered using a glass filter and then dried in a vacuum oven maintained at about 50 ° C. for about 24 hours to recover the desired product (yield 70%).

At this time, the weight average molecular weight of the obtained product was 13,500, and polydispersity was 2.1.

Example 3

Synthesis of Tetrapolymer

Bis (trimethylsilylmethyl) fumarate (40 mmol) synthesized in Example 1 was combined with t-butyl methacrylate (20 mmol), methyl methacrylate (20 mmol) and methacrylic acid (20 mmol) in THF solution. After dissolving in, AIBN (azobisisobutyronitrile) (4 mmol) was added thereto and purged with nitrogen gas for about 2 hours.

After the reaction was polymerized at reflux for about 24 hours, the reaction was slowly dropped in excess of n-hexane to precipitate, and the precipitate was dissolved in THF again and then re-precipitated in n-hexane.

The precipitate obtained was dried in a vacuum oven maintained at about 50 ° C. for about 24 hours to recover the desired product (yield 75%).

At this time, the weight average molecular weight of the obtained product was 12,350, and the polydispersity was 2.17.

Example 4

Synthesis of Terpolymer

Bis (trimethylsilylmethyl) fumarate (50 mmol) synthesized in Example 1 was dissolved in THF solution with t-butyl methacrylate (20 mmol) and 2-hydroxyethyl methacrylate (30 mmol), AIBN (azobisisobutyronitrile) (4 mmol) was added thereto and purged with nitrogen gas for about 2 hours.

After the reaction was polymerized at reflux for about 24 hours, the reaction was slowly dropped in excess of n-hexane to precipitate, and the precipitate was dissolved in THF again and then re-precipitated in n-hexane.

The precipitate obtained was dried in a vacuum oven maintained at about 50 ° C. for about 24 hours to recover the desired product (yield 75%).

At this time, the weight average molecular weight of the obtained product was 13,200, and polydispersity was 2.2.

Example 5

The terpolymer (1 g) synthesized in Example 2 was completely dissolved in propylene glycol monomethyl ether acetate (PGMEA) (7 g) together with triphenyl sulfonium triflate (0.02 g), PAG. Thereafter, the solution was filtered using a 0.2 μm filter to obtain a resist composition. This resist composition was then coated to a thickness of about 0.3 μm on a silicon wafer treated with hexamethyldisilazane (HMDS).

The wafer coated with the resist composition was pre-baked at a temperature of about 130 ° C. for about 90 seconds and exposed using a stepper using a KrF excimer laser having a numerical aperture (NA) of 0.45. Post-exposure baking (PEB) was performed at a temperature of about 130 ° C. for about 90 seconds.

Thereafter, development was performed using a tetramethylammonium hydroxide (TMAH) solution. As a result, when the exposure dose amount was set to about 23 mJ / cm ² , it was confirmed that a clear 0.3 μm line and space pattern was obtained.

Example 6

The tetrapolymer (1 g) synthesized in Example 3 was completely dissolved in propylene glycol monomethyl ether acetate (PGMEA) (7 g) together with triphenyl sulfonium triflate (0.02 g), PAG. Thereafter, the solution was filtered using a 0.2 μm filter to obtain a resist composition. This resist composition was then coated to a thickness of about 0.3 μm on a silicon wafer treated with hexamethyldisilazane (HMDS).

The wafer coated with the resist composition was pre-baked at a temperature of about 130 ° C. for about 90 seconds and exposed using a stepper using a KrF excimer laser having a numerical aperture (NA) of 0.45. Post-exposure baking (PEB) was performed at a temperature of about 130 ° C. for about 90 seconds.

Thereafter, it was developed using a 2.38 wt% tetramethylammonium hydroxide (TMAH) solution. As a result, when the exposure dose amount was about 21 mJ / cm ² , it was confirmed that a clear 0.3 μm line and space pattern was obtained.

Example 7

The terpolymer (1 g) synthesized in Example 4 was completely dissolved in propylene glycol monomethyl ether acetate (PGMEA) (7 g) together with triphenyl sulfonium triflate (0.02 g), PAG. Thereafter, the solution was filtered using a 0.2 μm filter to obtain a resist composition. This resist composition was then coated to a thickness of about 0.3 μm on a silicon wafer treated with hexamethyldisilazane (HMDS).

The wafer coated with the resist composition was pre-baked at a temperature of about 130 ° C. for about 90 seconds and exposed using a stepper using a KrF excimer laser having a numerical aperture (NA) of 0.45. Post-exposure baking (PEB) was performed at a temperature of about 130 ° C. for about 90 seconds.

Thereafter, the solution was developed for 60 seconds using a 2.38 wt% tetramethylammonium hydroxide (TMAH) solution. As a result, when the exposure dose amount was set to about 23 mJ / cm ² , it was confirmed that a clear 0.3 μm line and space pattern was obtained.

As described above, according to the present invention, it is possible to provide a resist composition having a silicon content sufficient for use as a BLR and having excellent adhesive properties.

The present invention has been described in detail with reference to preferred embodiments, but the present invention is not limited to the above embodiments, and various modifications can be made by those skilled in the art within the scope of the technical idea of the present invention. Do.

Claims (4)

(a) a polymer having the following formula for use in chemically amplified resists, Wherein R ₁ is —CH ₂ Si (CH ₃ ) ₃ , R ₂ , R ₄ and R ₅ are —H or —CH ₃ , and R ₃ and R ₆ are —CH ₃ , t-butyl or tetrahydropyra Nyl group, k / (k + l + m + n) = 0.1-0.7, l / (k + l + m + n) = 0.0-0.4, m / (k + l + m + n) = 0.1 -0.4 and n / (k + l + m + n) = 0.0-0.4. (b) a resist composition composed of a photoacid generator (PAG). The resist composition of claim 1, wherein the polymer has a weight average molecular weight of 5,000 to 100,000. The resist composition of claim 1, comprising 1-10% PAG based on the weight of the polymer. The resist composition of claim 1, wherein the PAG is selected from the group consisting of triarylsulfonium salts, diaryliodonium salts, sulfonates, and mixtures thereof.