KR20020047865A - Photosensitive polymer with protecting group and photoresist composition comprising the same - Google Patents

Abstract

PURPOSE: Provided are a photosensitive polymer having a protective group, which has a low Tg, and a photoresist composition comprising the photosensitive polymer. CONSTITUTION: The photosensitive polymer has a protective group represented by formula 1(wherein R represents a methyl group, an ethyl group, a propyl group or a butyl group, n is an integer of 0-10, and m is an integer of 1-5). The photosensitive polymer is represented by formulae 2-5. In the formulae 2-5, n and m are defined as the above. Also, in the formula 3, p+q=1, p/(p+q)=0.5, q/(p+q)=0.5, and in the formulae 4 and 5, p+q+r=1, p/(p+q+r)=0-0.5, q/(p+q+r)=0.5, r/(p+q+r)=0-0.5. The photoresist composition comprises (a) the photosensitive polymer having protective group of formula 1, and (b) photoacid generator.

Description

Photosensitive polymer with protecting group and photoresist composition comprising the same

The present invention relates to a photoresist, and more particularly, to a photosensitive polymer having a protecting group and a photoresist composition comprising the same.

As the semiconductor manufacturing process is complicated and the integration of semiconductor devices is dramatically increased, the formation of subquarter-micron-class fine patterns in the lithography process is urgently required. In addition, as the capacity of the device becomes more than 1 giga bit, the size of the pattern in which the lithography design rule is 0.2 µm or less is required. Accordingly, a new resist material using ArF excimer laser (193 nm), which is shorter than DUV (deep UV: 248 nm), needs to be developed urgently.

In general, the conditions for ArF resists are as follows: 1) high optical transmittance in the region of 193 nm, 2) strong resistance to etching process, 3) good adhesion, 4) alkaline Developer should be well developed, for example 2.38 wt% TetraMethyl Ammonium Hydride (TMAH), 5) high contrast, 6) easy to manufacture.

On the other hand, the photoresist for ArF excimer laser known so far is a chemical amplification type, among which back-bone (Acrylate), COMA (CycloOlefin Maleic An-hydride), polynorbornene (Polynorbornene) A photoresist having a bone is typical. However, these photoresists are applied and undergo a constant heat treatment process after the exposure is completed. For example, it is heated to remove the free volume inherent in the coated photoresist film or subjected to a heat treatment such as post-exposure bake (hereinafter referred to as PEB). However, since the glass transition temperature (Tg) of the chemically amplified photoresist is high, there is a problem such as causing a T-top phenomenon.

Accordingly, the technical problem to be achieved by the present invention is to provide a photosensitive polymer having a low Tg.

Another technical object of the present invention is to provide a photoresist composition using a photosensitive polymer having a low Tg.

The photosensitive polymer according to the present invention for achieving the above technical problem, has a protecting group of the formula (1).

In formula, R is a methyl group, an ethyl group, a propyl group, or a butyl group, n is an integer of 0-10 and m is an integer of 1-5.

In addition, it is preferable that the photosensitive polymer includes the following Chemical Formula 2,

Furthermore, it is more preferable that the photosensitive polymer consists of the following Chemical Formula 3, Chemical Formula 4 or Chemical Formula 5.

Wherein n and m satisfy the definition of Chemical Formula 1, and p + q = 1, p / (p + q) = 0.5, q / (p + q) = 0.5.

Wherein n and m satisfy the definition of Formula 1 above, p + q + r = 1, p / (p + q + r) = 0-0.3, q / (p + q + r) = 0.5, r / (p + q + r) = 0 to 0.5.

Wherein n and m satisfy the definition of Formula 1 above, p + q + r = 1, p / (p + q + r) = 0-0.5, q / (p + q + r) = 0.5, r / (p + q + r) = 0 to 0.5.

The photoresist composition for achieving another technical problem to be achieved by the present invention, a photosensitive polymer comprising a protecting group of the formula (1) and a photo-acid generator.

In addition, the photosensitive polymer is preferably composed of Formula 2, Formula 3, Formula 4 or Formula 5.

Furthermore, it is preferable that the said photo-acid generator is a triarylsulfonium salt, a diaryl iodonium salt, or sulfonic acid, and has 1-15 weight% based on the weight of the photosensitive polymer.

In addition, the photoresist composition preferably further comprises an organic base of triethylamine, triisobutylamine, trisutylamine, diethanolamine or triethanolamine by 0.01 to 2.0% by weight based on the weight of the photosensitive polymer.

On the other hand, the present invention obtains a photosensitive polymer and a photoresist composition having a low Tg by adjusting the length of the carbon chain present in the protecting group to be long.

Hereinafter, a preferred embodiment of the photosensitive polymer for photoresist and the photoresist composition including the same according to the present invention will be described in detail. Moreover, the preferable manufacturing method for manufacturing a photoresist composition and the preferable photolithography process using the photoresist composition of this invention are demonstrated. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in different forms, only the embodiments are intended to complete the disclosure of the present invention, and to those skilled in the art to fully understand the scope of the invention. It is provided to inform you.

Example 1

Methyl-2-n-hexyl cyclopentanyl norbornene carboxylate (Methyl-2-n-

Hexylcyclopentanyl Norbornene Carboxylate; MHCPNC) Synthesis

Wherein R is a methyl group or an ethyl group.

0.1 mol (14.22 g) of 2-n-hexylcyclopentanone was dissolved in dried ether, and Grignard solution was slowly dropped. At this time, since the reaction heat is generated it was cooled using an ice bath (bath). The solution was dropped completely and stirred for 24 hours. After confirming that the reaction proceeded completely, deionized water was added to the reaction solution to stop the reaction, and neutralized by adding dilute sulfuric acid. The ether layer was then extracted and the ether was removed under reduced pressure. Here, the ether was removed and the remaining filtrate was alcohol, which was dissolved in dried Methylene Chloride (MC), and 0.1 mol (10.21 g) of triethylamine was added thereto to form a mixture. . Acid chloride was slowly added to the mixture using a dropping funnel. At this time, too, since strong heat was generated, it was cooled by using an ice bath. After the addition was complete, the mixture was stirred for 24 hours, and then the salts produced were filtered and the remaining filtrate was extracted. Then, the solvent MC was completely removed. The resulting product is Methyl-2-n-HexylCycloPentanyl Acrylate (MHCPA). This was dissolved in tetrahydrofuran (TetraHydroFuran; THF), and 0.1 mol (6.6 g) of cyclopentadiene, which was previously cracked, was slowly added. After the addition, the mixture was stirred at about 50 ° C. for 24 hours and then the reaction was terminated by gas chromatography (Thin Chromatography) or TLC (Thin Layer Chromatography). Next, the solvent, THF, was removed under reduced pressure and then separated by vacuum distillation. At this time, the yield of the reaction product MHCPNC was about 93%.

<Example 2>

Methyl-4-n-pentylcyclohexyl norbornene carboxylate (Methyl-4-n-

Pentyl Cyclo Hexyl Norbornene Carboxylate; Synthesis of MPCHNC)

MPCHNC was synthesized using 4-n-pentylcyclohexanone in the same manner as in Example 1.

Wherein R is a methyl group or an ethyl group.

At this time, the yield of the reaction product was 90%.

<Example 3>

Polymerization of Poly [MHCPNC-Maleic Anhydride]

Wherein R is a methyl group or an ethyl group.

0.1 mol (26.14 g) of MHCPNC and 0.1 mol (9.81 g) of MA, which were synthesized in Example 1, were dissolved in 9.4 g of ethyl acetate (EA) as a polymerization solution. Subsequently, 5 mole% (1.64 g) of azobisisobutyronitrile (AlBN) as a polymerization initiator was added. Next, degassing was repeated three times to extract the gas under vacuum using a rotary pump and to dissolve the frozen reactant. Then, the polymerization was carried out at 65 ° C. for 48 hours. Subsequently, the reaction was completely dissolved in THF and then precipitated twice using isopropyl alcohol (IPA). Next, the precipitate was filtered and then dissolved in THF and precipitated twice using n-hexane. After that, the mixture was filtered again and dried at low pressure and room temperature. In this case, the weight average molecular weight of the polymer was 12000, polydiversity (PD) was 1.9, and the yield was 68%.

Example 4

Polymerization of Poly [MPCHNC-MA]

Wherein R is a methyl group or an ethyl group.

0.1 mol (26.14 g) of MPCHNC and 0.1 mol (9.81 g) of MA, which were the monomers synthesized in Example 2, were dissolved in 9.4 g of the polymerization solution, EA. Next, 5 mol% (1.64 g) of AlBN which is a polymerization initiator was added. Next, degassing was repeated three times to extract the gas under vacuum using a rotary pump and to dissolve the frozen reactant. Then, the polymerization was carried out at 65 ° C. for 48 hours. The reaction was then completely dissolved in THF and then precipitated twice using IPA. The precipitate was then filtered off and dissolved in THF again and precipitated twice with n-hexane. After that, the mixture was filtered again and dried at low pressure and room temperature. At this time, the weight average molecular weight of the polymer was 11500, PD was 1.4, and the yield was 63%.

Example 5

Poly [MHCPNC-MA-ethyltricyclodecylnorbornene carbonate

(Ethyl TriCyclo Decyl Norbornene Carbonate; ETCDNC)

Wherein R is a methyl group or an ethyl group.

0.1 mol (26.14 g) of MHCPNC synthesized in Example 1, 0.1 mol (19.62 g) of MA and 0.1 mol (30.04 g) of ETCDNC were dissolved in 19 g of EA, a polymerization solution. Next, 5 mol% (1.64 g) of AlBN which is a polymerization initiator was added. Next, degassing was repeated three times to extract the gas under vacuum using a rotary pump and to dissolve the frozen reactant. Then, the polymerization was carried out at 65 ° C. for 48 hours. The reaction was then completely dissolved in THF and then precipitated twice using IPA. The precipitate was then filtered off and dissolved in THF again and precipitated twice with n-hexane. After that, the mixture was filtered again and dried at low pressure and room temperature. At this time, the weight average molecular weight of the polymer was 12500, PD was 2.04, the yield was 70%.

<Example 6>

Poly [MPCHNC-MA-methyladamantylnorbornene carbonate (Methyl Adamantyl

Norbornene Carboxylate; MAdNC)] polymerization

Wherein R is a methyl group or an ethyl group.

0.1 mol (27.54 g) of monomer, 0.1 mol (19.62 g) of MA and 0.1 mol (28.8 g) of MAdNC, synthesized in Example 2, were dissolved in 19 g of EA, a polymerization solution. Next, 5 mol% (1.64 g) of AlBN which is a polymerization initiator was added. Next, degassing was repeated three times to extract the gas under vacuum using a rotary pump and to dissolve the frozen reactant. Then, the polymerization was carried out at 65 ° C. for 48 hours. The reaction was then completely dissolved in THF and then precipitated twice using IPA. The precipitate was then filtered off and dissolved in THF again and precipitated twice with n-hexane. After that, the mixture was filtered again and dried at low pressure and room temperature. At this time, the weight average molecular weight of the polymer was 12300, PD was 2.01, the yield was 65%.

<Example 7>

Polymerization of Poly [MHCPA-MA-ETCDNC]

Wherein R is a methyl group or an ethyl group.

0.1 mol (19.5 g) of MHCPA, 0.1 mol (9.81 g) of MA and 0.1 mol (30.04 g) of ETCDNC synthesized in Example 1 were dissolved in 15 g of EA, a polymerization solution. Next, 5 mol% (1.64 g) of AlBN which is a polymerization initiator was added. Next, degassing was repeated three times to extract the gas under vacuum using a rotary pump and to dissolve the frozen reactant. Then, the polymerization was carried out at 65 ° C. for 48 hours. The reaction was then completely dissolved in THF and then precipitated twice using IPA. The precipitate was then filtered off and dissolved in THF again and precipitated twice with n-hexane. After that, the mixture was filtered again and dried at low pressure and room temperature. At this time, the weight average molecular weight of the polymer was 11700, PD was 1.97, the yield was 67%.

<Example 8>

1.0 g of the copolymer (weight average molecular weight 12000) synthesized in Example 3 was mixed with 0.02 g of triphenylsulfonium triflate, a photoacid generator, and 8.0 g of Propylene Gglycol Monomethyl EtherAcetate (PGMEA). A photoresist composition dissolved in a solution was formed. Next, the photoresist composition was filtered using a 0.2 μm membrane filter, and the composition was applied to a silicon wafer treated with hexamethyldisilazane (HMDS) to a thickness of about 0.3 μm. At this time, triarylsulfonium salts, diaryliodonium salts or sulfonic acids are preferable as the photoacid generator. Then, soft-baking was performed at 120 ° C. for about 90 sec, followed by exposure using an ArF excimer laser (NA 0.60). Post-exposure bake (PEB) was performed at 130 ° C. for 90 sec after exposure and developed for about 60 sec with a 2.38 wt% TMAH solution. As a result, a line and space (L / S) pattern of about 0.30 μm was confirmed at an irradiation dose of about 27 mJ / cm ² .

Example 9

1.0 g of the copolymer (weight average molecular weight 12000) synthesized in Example 4 was dissolved in 8.0 g of PGMEA solution with 0.02 g of triphenylsulfonium triplate, and 2 mg of triethanolamine as an organic base was added thereto to completely dissolve it. The photoresist composition was formed. Here, triethylamine, triiso-butylamine, diethanolamine or triethanol-amine is preferable as the organic base. Next, the photoresist composition was filtered using a 0.2 μm membrane filter, and the composition was applied to a silicon wafer treated with HMDS to a thickness of about 0.3 μm. Then, soft baking was performed at 130 ° C. for about 90 sec, and then exposed using an ArF excimer laser (NA 0.60). After exposure, PEB was carried out at 130 ° C. for 90 sec and developed with 2.38 wt% of TMAH solution for about 60 sec. As a result, an L / S pattern of about 0.30 µm was confirmed at an irradiation dose of about 23 mJ / cm ² .

<Example 10>

1.0 g of the terpolymer synthesized in Example 5 was dissolved in 8.0 g of PGMEA solution together with 0.02 g of triphenylsulfonium triflate, and 2 mg of triethanolamine was added thereto to completely dissolve the photoresist. The composition was formed. Next, the photoresist composition was filtered using a 0.2 μm membrane filter, and the composition was applied to a silicon wafer treated with HMDS to a thickness of about 0.3 μm. Then, soft baking was performed at 120 ° C. for about 90 sec, and then exposed using an ArF excimer laser (NA 0.60). After exposure, PEB was carried out at 130 ° C. for 90 sec and developed with 2.38 wt% of TMAH solution for about 60 sec. As a result, an L / S pattern of about 0.30 µm was confirmed at an irradiation dose of about 23 mJ / cm ² .

<Example 11>

1.0 g of the terpolymer synthesized in Example 6 was dissolved in 8.0 g of PGMEA solution with 0.01 g of triphenylsulfonium triflate and 0.02 g of n-hydroxysuccinimide triflate. 2 mg of triethanolamine was added thereto to form a fully dissolved photoresist composition. Next, the photoresist composition was filtered using a 0.2 μm membrane filter, and the composition was applied to a silicon wafer treated with HMDS to a thickness of about 0.3 μm. Then, soft baking was performed at 120 ° C. for about 90 sec, and then exposed using an ArF excimer laser (NA 0.60). After exposure, PEB was carried out at 130 ° C. for 90 sec and developed with 2.38 wt% of TMAH solution for about 60 sec. As a result, an L / S pattern of about 0.30 µm was confirmed at an irradiation dose of about 31 mJ / cm ² .

<Example 12>

1.0 g of the copolymer synthesized in Example 7 was dissolved in 8.0 g of PGMEA solution together with 0.02 g of triphenylsulfonium triplate, and 2 mg of triethanolamine was added thereto to form a completely dissolved photoresist composition. Next, the photoresist composition was filtered using a 0.2 μm membrane filter, and the composition was applied to a silicon wafer treated with HMDS to a thickness of about 0.3 μm. Then, soft baking was performed at 130 ° C. for about 90 sec, and then exposed using an ArF excimer laser (NA 0.60). After exposure, PEB was carried out at 130 ° C. for 90 sec and developed with 2.38 wt% of TMAH solution for about 60 sec. As a result, the L / S pattern of about 0.30 micrometer was confirmed at the irradiation amount of about 26 mJ / cm <^2> .

Although the present invention has been described in detail above, the present invention is not limited to the above embodiments, and many modifications and improvements can be made by those skilled in the art. For example, in Examples 8 to 12, exposure was performed using an ArF excimer laser, but exposure can be performed using a KrF excimer laser.

The above-described photosensitive polymer according to the present invention can lower the Tg of the polymer by lengthening the length of the chain present in the protecting group with tertiary alcohol. In addition, when the pattern is formed using the photoresist composition in which the photosensitive polymer according to the present invention is used, a pattern such as T-top may not be formed because Tg is low.

Claims (10)

A photosensitive polymer having a protecting group of the formula [Formula 1] Wherein R is a methyl group, an ethyl group, a propyl group or a butyl group, n is an integer of 0-10 and m is an integer of 1-5. The photosensitive polymer according to claim 1, wherein the photosensitive polymer is formed of the following Chemical Formula 2. [Formula 2] Wherein n and m satisfy the definition of Chemical Formula 1. The photosensitive polymer according to claim 1, wherein the photosensitive polymer is formed of the following Chemical Formula 3. [Formula 3 Wherein n and m satisfy the definition of Formula 1 above, and p + q = 1, p / (p + q) = 0.5, q / (p + q) = 0.5. According to claim 1, wherein the photosensitive polymer, characterized in that consisting of the formula (4). [Formula 4] Wherein n and m satisfy the definition of Formula 1 above, p + q + r = 1, p / (p + q + r) = 0-0.5, q / (p + q + r) = 0.5, r /(p+q+r)=0-0.5 According to claim 1, wherein the photosensitive polymer, characterized in that consisting of the formula (5). [Formula 5] Wherein n and m satisfy the definition of Formula 1 above, p + q + r = 1, p / (p + q + r) = 0-0.5, q / (p + q + r) = 0.5, r /(p+q+r)=0.5. (a) a photosensitive polymer having a protecting group of the formula [Formula 1] Wherein R is a methyl group, an ethyl group, a propyl group or a butyl group, n is an integer of 0-10 and m is an integer of 1-5. (b) using a photoacid generator Photoresist composition comprising a. The photoresist composition of claim 6, wherein the photosensitive polymer is formed of the following Chemical Formula 2. 8. [Formula 2] Wherein n and m satisfy the definition of Chemical Formula 1. 7. The photoresist composition of claim 6, wherein the photosensitive polymer is composed of the following Chemical Formula 3. [Formula 3] Wherein n and m satisfy the definition of Formula 1 above, p + q = 1, p / (p + q) = 0.5, q / (p + q) = 0.5. The photoresist composition of claim 6, wherein the photosensitive polymer is formed of the following Chemical Formula 4. [Formula 4] Wherein n and m satisfy the definition of Formula 1 above, p + q + r = 1, p / (p + q + r) = 0-0.5, q / (p + q + r) = 0.5, r /(p+q+r)=0-0.5 7. The photoresist composition of claim 6, wherein the photosensitive polymer is composed of the following Chemical Formula 5. [Formula 5] Wherein n and m satisfy the definition of Formula 1 above, p + q + r = 1, p / (p + q + r) = 0-0.5, q / (p + q + r) = 0.5, r /(p+q+r)=0-0.5