KR20020047866A - 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 can be easily deprotected, and has strong resistance to dry etching, and which is economically advantageous in its manufacturing cost. 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, and n is an integer of 3-8). The photosensitive polymer is represented by formulae 2-5. In the formula 2, n is defined as the above, in the formula 3, p+q=1, p/(p+q)=0.5, q/(p+q)=0.5, in the formula 4, R1 represents hydrogen or a methyl group, in the formula 5, R2 represents hydrogen or a methyl group, p+q=1, p/(p+q)=0.3-0.7, q/(p+q)=0.3-0.7. 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 Developers, for example 2.38% by weight TetraMethyl Ammonium Hydride (TMAH) should be well developed, 5) high contrast, 6) easy to manufacture.

On the other hand, none of the above-mentioned ArF excimer laser photoresists satisfy all of the above conditions. In particular, a photoresist having a high resistance to dry etching and easy deprotection is urgently needed. Adamantane, a protection group recently developed by Fujitsu, has high dry etching resistance and good resolution. However, this protecting group is very expensive in monomers, and is very disadvantageous in terms of manufacturing cost for practical application to the device.

Accordingly, the technical problem to be achieved by the present invention is to provide a photosensitive polymer having easy deprotection, high resistance to dry etching, and economical in terms of manufacturing cost of the device.

Another object of the present invention is to provide a photoresist composition that is easy to deprotect, has a high resistance to dry etching, and is economical in terms of manufacturing cost of the device.

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 3-8.

In addition, the photosensitive polymer is preferably composed of Formula (2),

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

Wherein p + q = 1, p / (p + q) = 0.5, q / (p + q) = 0.5.

In formula, R <_1> is hydrogen or a methyl group.

In formula, R <_2> is hydrogen or a methyl group, p + q = 1, p / (p + q) = 0.3-0.7, q / (p + q) = 0.3-0.7.

A photoresist composition for achieving another technical problem to be achieved in the present invention, the 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.

Further, the photoacid generator is a triarylsulfonium salt, a diaryl iodonium salt or a sulfonic acid, and preferably has 1 to 15% by weight based on the weight of the photosensitive polymer.

Furthermore, it is preferable that the photoresist composition 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.

The protecting group according to the present invention has a large number of places that can be combined with protons and a large number of protons generated after deprotection, so that the deprotection is easy, the structure is dense, and the dry etching property is excellent, and the manufacturing cost of the device is economical.

Hereinafter, a preferred embodiment of the photosensitive polymer of the present invention and a photoresist composition including the same will be described in detail. In addition, a preferable manufacturing method for producing a photoresist composition and a preferable photolithography process using the photoresist composition of the present invention will be described. However, the present invention is not limited to the embodiments disclosed below but may be embodied in different forms, only these embodiments are to make the disclosure of the present invention complete, and complete the scope of the invention to those skilled in the art. It is provided to inform you.

Example 1

Methyl DiCycloPropyl

Norbornene Carboxylate; Synthesis of MDCPNC

1.0 mol (110.15 g) of dicyclopropyl ketone was dissolved in purified ether, and then 330 ml of 3M 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 stirred for 24 hours after the addition was complete. Subsequently, the reaction mixture was slowly dropped into excess water and neutralized with dilute sulfuric acid. Next, the solvent was extracted with ether, and then the solvent ether was removed. Methyl DiCyclopropyl alcohol (MDCol) was dissolved in dried methyl chloride (MC) and triethylamine, and 1.0 mol (90.51 g) of acid chloride was slowly added. It was. Since heat is also generated at this time, it is cooled using an ice bath. After the addition was completed, the mixture was stirred for 24 hours. Next, the salts generated during the reaction were filtered and then extracted several times with deionized water. Subsequently, the solvent MC was removed and then separated by distillation. At this time, the resultant product was methyldicyclopropyl acrylate (MDCPA). This was dissolved in excess of TetraHydroFuran (THF) and slowly added 1 mol (66 g) of cyclopentadiene cracked at high temperature in advance. After the addition, the mixture was stirred at about 65 ° C. for 24 hours, and then confirmed that the reaction was terminated by using gas chromatography (Gas Chromatography). Finally, the solvent, THF, was removed and separated by distillation.

<Example 2>

Methyl Dicyclohexylnorbornenecarboxylate (Methyl DiCycloHexyl)

Norbornene Carboxylate; Synthesis of MDCHNC)

Methyldicyclohexyl acrylate (MDCHA) and MDCHNC were synthesized using the same method as in Example 1 using 1 mole of dicyclohexyl ketone (194.31 g).

<Example 3>

Polymerization of Poly [MDCPNC-Maleic Anhydride (MA)]

0.1 mol (24.63 g) of MDCPNC and 0.1 mol (9.81 g) of MA, which were synthesized in Example 1, were dissolved in 8.5 g of ethyl acetate (EA) as a polymerization solution. Subsequently, 5 mol% (1.64 g) of azobisisobutyronitrile (AlBN) as a polymerization initiator was added. Thereafter, the resulting reaction was completely dissolved and then completely frozen in liquid nitrogen. 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 dissolved in THF, and then precipitated twice using n-hexane. Subsequently, the resultant was filtered again and dried at low pressure and room temperature. In this case, the weight average molecular weight of the polymer was 12000, polydispersity (PD) was 1.9 and the yield was 68%.

Example 4

Polymerization of Poly [MDCHNC-MA]

0.1 mol (33.05 g) of MDCHNC and 0.1 mol (9.81 g) of MA, which were synthesized in Example 2, were dissolved in 10.75 g of EA, which is a polymerization solution. Next, 5 mol% (1.64 g) of AlBN which is a polymerization initiator was added. Thereafter, the resulting reaction was completely dissolved and then completely frozen in liquid nitrogen. 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 twice precipitated using IPA. Next, the precipitate was filtered and dissolved in THF, and then precipitated twice using n-hexane. Subsequently, the resultant was filtered again and dried at low pressure and room temperature. In this case, the weight average molecular weight of the polymer was 11500, PD was 1.92, and the yield was 68%.

Example 5

Polymerization of Poly [Norbornene-MA-MDCPA]

0.1 mol (90.12 g) of MDCPA synthesized in Example 1, 0.1 mol (9.42 g) of norbornene (Nb) and 0.1 mol (9.81 g) of MA were dissolved in EA (200 g) as a polymerization solution. Next, 5 mol% (1.64 g) of AlBN which is a polymerization initiator was added. Thereafter, the resulting reaction was completely dissolved and then completely frozen in liquid nitrogen. 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 twice precipitated using IPA. Next, the precipitate was filtered and dissolved in THF, and then precipitated twice using IPA. Subsequently, the resultant was filtered again and dried at low pressure and room temperature. In this case, the weight average molecular weight of the polymer was 12500, PD was 2.04, and the yield was 70%.

<Example 6>

Polymerization of Poly [Nb-MA-MDCHA]

It was polymerized in the same manner as in Example 5 using 0.1 mol of MDCHA synthesized in Example 2.

<Example 7>

Poly [methyldicyclopropyl methacrylate (MethylDiCycloPropyl)

MethAcrylate; MDCPMA)-Pantolactone Methacrylate (PanToLactone)

MethAcrylate; PTLMA)]

MDCPMA was synthesized as in Example 1 using methacryloyl chloride instead of acryloyl chloride. Next, 0.10 mol (19.43 g) of MDCPMA and 0.1 mol (19.8 g) of PTLMA were dissolved in 20.0 g of THF as a polymerization solution. Next, 5 mol% (1.64 g) of AlBN which is a polymerization initiator was added. The reaction was completely dissolved and then completely frozen in liquid nitrogen. 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 formed twice with methanol. Next, the precipitate was filtered and dissolved in THF, and then precipitated twice using n-hexane. Subsequently, the resultant was filtered again and dried at low pressure and room temperature. In this case, the weight average molecular weight of the polymer was 10500, PD was 2.02, and the yield was 70%.

<Example 8>

Poly [methyldihexyl methacrylate (MethylDiCycloHexyl)

MethaAcrylate; MDCHMA) -PTLMA)]

In Example 2, MDCHMA was synthesized using methacryloyl chloride instead of acryloyl chloride. Subsequently, MDCHMA and PTLMA were polymerized in the same manner as in Example 7. In this case, the weight average molecular weight of the polymer was 10300, PD was 2.08 and the yield was 70%.

Example 9

1.0 g of the copolymer (weight average molecular weight 12000) synthesized in Example 3 with 0.02 g of triphenylsulfonium triflate as a photoacid generator, 8.0 g of Propylene Glycol Monomethyl Ether Acetate; PGMEA) to form a photoresist composition dissolved in a solution. 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 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 10>

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 triflate, a photoacid generator, and triethanolamine, which is an organic base. 2 mg of triethanolamine was added to form a fully dissolved photoresist composition. As the organic base, triethylamine, triisobutylamine, diethanolamine or triethanolamine is preferable. 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 for about 60 sec with 2.38 wt% of TMAH solution. As a result, an L / S pattern of about 0.30 µm was confirmed at an irradiation dose of about 26 mJ / cm ² .

<Example 11>

1.0 g of the copolymer (weight average molecular weight 12000) synthesized in Example 5 was dissolved in 8.0 g of PGMEA solution with 0.02 g of triphenylsulfonium triflate, a photoacid generator, and triisobutyl, an organic base. 2 mg of amine was added to form a fully dissolved poin 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 for about 60 sec with 2.38 wt% of TMAH solution. 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 12>

1.0 g of the terpolymer synthesized in Example 6 was dissolved in 0.01 g of triphenylsulfonium triflate and 0.02 g of n-hydroxysuccinimide triflate, and 8.0 g of PGMEA was dissolved in a solution. 2 mg of amine was added 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 for about 60 sec with 2.38 wt% of TMAH solution. As a result, the L / S pattern of about 0.30 micrometer was confirmed at the irradiation amount of about 31 mJ / cm <^2> .

Example 13

1.0 g of the copolymer (weight average molecular weight 12000) synthesized in Examples 7 and 8 was dissolved in 8.0 g of PGMEA solution with 0.02 g of triphenylsulfonium triflate, a photoacid generator, and an organic base. 2 mg of phosphorus triethanolamine was added 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 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 for about 60 sec with 2.38 wt% of TMAH solution. 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 Example 9-13, although exposure was performed using ArF excimer laser, exposure can be performed using KrF excimer laser.

The photosensitive polymer according to the present invention and the composition comprising the same have an alicyclic ring in which a protecting group is identically substituted on the left and right side, so that the number of places that can be combined with protons increases compared to carbon number, and the protons generated after deprotection. As the number of s increases, the de-protection becomes easy and the structure is dense, so the dry etching resistance is excellent.

In addition, the photosensitive polymer according to the present invention and the photoresist composition including the same have excellent economical efficiency in terms of production cost.

Claims (10)

A photosensitive polymer having a protecting group of formula (1). [Formula 1] In formula, R is a methyl group, an ethyl group, a propyl group, or a butyl group, n is an integer of 3-8. The photosensitive polymer of claim 1, wherein the photosensitive polymer is formed of Chemical Formula 2. [Formula 2] The photosensitive polymer according to claim 1, wherein the photosensitive polymer is formed of Chemical Formula 3. [Formula 3] Wherein p + q = 1, p / (p + q) = 0.5 and q / (p + q) = 0.5. The photosensitive polymer according to claim 1, wherein the photosensitive polymer is formed of Formula 4. [Formula 4] Wherein R ₁ is hydrogen or a methyl group. The photosensitive polymer according to claim 1, wherein the photosensitive polymer is formed of Formula 5. [Formula 5] Wherein R ₂ is hydrogen or a methyl group, p + q = 1, p / (p + q) = 0.7, q / (p + q) = 0.3. (a) a photosensitive polymer having a protecting group of formula (1) [Formula 1] In formula, R is a methyl group, an ethyl group, a propyl group, or a butyl group, n is an integer of 3-8. (b) using a photoacid generator Photoresist composition comprising a. The photoresist composition of claim 6, wherein the photosensitive polymer is composed of Chemical Formula 2. [Formula 2] The photoresist composition of claim 6, wherein the photosensitive polymer is composed of Chemical Formula 3. [Formula 3] Wherein p + q = 1, p / (p + q) = 0.5 and q / (p + q) = 0.5. The photoresist composition of claim 6, wherein the photosensitive polymer is composed of Chemical Formula 4. [Formula 4] Wherein R ₁ is hydrogen or a methyl group. The photoresist composition of claim 6, wherein the photosensitive polymer is formed of Chemical Formula 5. 8. [Formula 5] In formula, R <_2> is hydrogen or a methyl group, p + q = 1, p / (p + q) = 0.3-0.7, q / (p + q) = 0.3-0.7.