KR0124950B1 - Chemical amplification type resist composition - Google Patents

Abstract

A chemical amplification type resist composition comprising : naphto quinone diazide group as light absorbing material ; sulponyl group as acid generating material; and tert-butyloxy carbonyl novolac and poly which aren't soluble to alkali as matrix resin; is disclosed. Thereby, it is possible to solve the residue generating problem according to heavy metal, to enhance the solubility against resist solution and to generate the acid in response to the i-line.

Description

Resist composition for chemical amplification

The present invention relates to photoresist compositions used in semiconductor manufacturing processes.

In recent years, as the integration of semiconductor devices has accelerated, the micro image forming technology used in semiconductor device manufacturing has gradually required high precision and high resolution. In particular, the demand characteristics of microfabricated circuits for the most critical sectors of microimaging forming technology are increasing every year.

Generally, g-line (wavelength 436nm) light source using a mercury lamp has been used as a micro-image forming technology in general, but according to the trend of micromachining, it is changing to an exposure technology using a light source of i-line (wavelength 365nm). have. Other next-generation exposure technologies include excimer lasers (KrF, wavelength 248 nm), X-rays, and electron beams.

The present invention allows the photoresist using a photoacid generator, which has been developed as a resist for an excimer laser, to be used for i-rays. In order to use the excimer resist which has been used conventionally for i line | wire, there exists a method of adding the dye (dye) which can absorb i line | wire, The example is as follows. U.S. Patent No. 4,491,628 describes an example in which onium salt is added to polystyrene having a tertiary butoxy carbonyl protecting group and then perylene or pyrene is added as a dye. In addition, nonionic photoacid generators (Proc. SPIE Adv. Resist Technol. In addition, poly (tert-butoxycarbonyloxy styrene) is widely used as the resin used as the matrix resin of the excimer resist.

Onium salt, a photoacid generator mainly used in conventional chemically amplified resists, has problems such as the presence of residues due to heavy metals and only light of short wavelength (224 nm, 232 nm), and long reaction time and complexity in synthesis. Perylene or pyrene added to make it sensitive to i-rays has many problems, such as the poor dissolution in the solvent used for preparing the resist.

Therefore, in order to solve this problem, the present invention is sensitive to i-rays and may also act as a photoacid generator, and synthesizes a photosensitive agent that is well dissolved in a resist solvent, and has excellent heat resistance as a matrix resin, and an alkaline solvent. The resist was prepared using the polymeric material which does not melt | dissolve in. As a result, not only the problem with heavy metals was solved, but also the solubility in the resist solvent was greatly improved.

The feature of this patent is that tert-butyloxy carbonyl novolac represented by the general formula (I) is introduced as a matrix polymer, and it also increases acid suppression effect and absorbs ultraviolet rays in the near ultraviolet region to generate acid. As a photoacid generator, a photoacid generator represented by formula (II) was introduced as a photosensitive agent. Naphthoquinone diazide was introduced as a substance that absorbs near ultraviolet rays and enhances dissolution inhibiting effect.

Where R is

Hereinafter, the present invention will be described in detail.

Cresol novolac (1) was reacted with di-tert-butyldicarbonate (2) to synthesize tert-butyloxy carbonyl novolac (3). Potassium carbonate, sodium hydroxide, etc. are used as a basic substance used for synthesis | combination, and also a phase transfer catalyst is used. Among these, it is preferable to use potassium carbonate and 18-crown-6-.

Characterization of tert-butyloxy carbonyl novolac was carried out by nuclear magnetic resonance spectroscopy, infrared spectroscopy, gel permeation chromatography and the like. The tert-butyloxy carbonyl novolak resin used in the present invention has a molecular weight of 2,000 to 15,000 g / mol and an injection degree (Mw / Mn) of 1.5 to 3.5.

In addition, poly (tert-butoxy carbonyloxy styrene) was used as the matrix resin, and the material will be described in detail as follows.

Synthesis of poly (tert-butoxy carbonyloxy styrene) was polymerized p-tert-butoxy carbonyloxy styrene under azobis isobutylonitrile catalyst and molecular weight was determined using gel permeation chromatography It was. The molecular weight of (tert-butoxy carbonyloxy styrene) used in the present invention is 1,000 to 500,000 g / mol, of which 3,000 to 50,000 g / mol is preferably used.

The synthetic route of the photosensitizer is as follows.

Here, X is a halogen group, M is -CH ₃ , -CF ₃ , R ₁ , R ₃ is a 1, 2-naphthoquitone-2-diazide-5-sulfonyl group, R ₂ , R ₄ is is SO ₃ M, is a, c = 0~2, b, d = 1~2.

Reaction of hydroxy benzophenone (4) with 1, 2-naphthoquinone-2-diazide-5-sulfonyl halide (5) and alkyl sulfonyl halide (6) under basic catalyst , 2-naphthoquinone-2-diazide-5-sulfonyl benzophenone (II) was synthesized.

The basic catalysts used in the synthesis of alkylsulfonyl 1, 2-naphthoquinone-2-diazide-5-sulfonyl benzophenone (7) are pyridine, triethylamine, sodium hydroxy carbonate, sodium carbonate and the like. Among these, triethylamine, pyridine and the like are preferable.

Characterization of alkylsulfonyl 1, 2-naphthoquinone-2-diazide-5-sulfonyl benzophenone (7) was carried out by ultraviolet spectroscopy, liquid chromatography and the like.

Preparation of the resist was prepared by dissolving alkylsulfonyl 1, 2-naphthoquinone-2-diazide-5-sulfonyl benzophenone (7) and tert-butyloxy carbonyl novolak (3) in an organic solvent. In this case, the organic solvent used for preparing the resist is ethylene glycol, cyclohexanone, ethylene glycol monoalkyl ether, acetates thereof, ethyl lactate, and the like. Generally, the solvent is preferably used alone, and if necessary, You may mix and use 2 or more types.

The chemically amplified resist composition of the present invention is 10-50 parts by weight of alkylsulfonyl 1, 2-naphthoquinone-2-diazide-5-sulfonyl benzophenone based on 100 parts by weight of tert-butyloxy carbonyl novolac resin. Consists of.

Hereinafter, the present invention will be described in detail with reference to Examples. However, the present invention is not limited to the examples.

Example 1

A mixture of cresol compounds having a weight ratio of m-cresol and p-cresol of 60:40 was condensed with formalin under an oxalic acid catalyst to prepare a phenol novolak resin by a conventional method. Was dissolved in 20 ml of ethyl acetate, 3.5 g of potassium carbonate and 4.55 g of di-tert-butyldicarbonate were added at room temperature, followed by reaction for 24 hours to synthesize tert-butyloxy carbonyl novolac. This compound was purified using a filter, distillation, precipitation and extraction, in that order. The contents are as follows.

After removing the solid material by the filter, the ethyl acetate was removed by evaporation from the liquid material, dissolved in a minimum of tetrahydrofuran solvent, precipitated and dried in a mixed solvent of water and methyl alcohol (6: 4), It was dissolved in methylene chloride solvent again and the unreacted product was removed using water. Distillation gave a solid tert-butyloxy carbonyl novolak.

The substitution rate was analyzed by nuclear magnetic resonance spectroscopy. As a result, the substitution rate was 50%.

Example 2

tert-butyloxy carbonyl furnace by the same method as [Example 1] while changing the weight ratio of m-cresol and p-cresol to 65:35, 70:30, 75:25, 80:20, 90:10 Volacs were synthesized. The analysis was performed by nuclear magnetic resonance spectroscopy, and the substitution rate was 50 to 100%.

Example 3

The cresol compounds consisting of m-cresol, p-cresol and o-cresol having a weight ratio of 64: 35: 1, 65: 30: 5, 60:30:10 were tert- by the same method as in [Example 1]. Butyloxy carbonyl novolac was synthesized and the substitution rate was 50 to 100%.

Example 4

2.46 g of 2, 3, 4, 4'-hydroxy benzophenone was dissolved in 100 ml of tetrahydrofuran, followed by 5.37 g of 1, 2-naphthoquinone-2-diazide-5-sulfonyl chloride (NAC-5) and catalyst. 2.02 g of phosphorus triethanamine was reacted at 0 to 10 ° C. for 2 hours, and 2.173 g of methane sulfonyl chloride and 2.02 g of triethylamine as a catalyst were added thereto and reacted at 0 to 10 ° C. for 2 hours. . The mixture was precipitated in water, washed several times with methyl alcohol and purified. As a result of analysis through liquid chromatography, it was found that the material was composed of a mixture of 2, 3, 4, and 4'-NAC-metal sulfonyl groups. Infrared absorption spectrometer shows that the infrared absorption is reduced by more than 1/3 compared to the existing 2, 3, 4, 4'-NAC system.

Example 5

2, 3, 4, 4'-hydroxy benzophenone and 1, 2-naphthoquinone-2-diazide-5-sulfonyl chloride (NAC-5), by the same method as in [Example 4] The ratio of methane sulfonyl chloride was synthesized by switching to 1: 05.: 3.5, 1: 1: 3, 1: 1.5: 2.5, 1: 3: 1, 1: 3.5: 0.5, etc. Analysis via absorption spectrometer.

Example 6

Example 5 2, 3, 4, 4'-hydroxy benzophenone and 1, 2-naphthoquinone-2-diazide-4-sulfonyl chloride (NAC-4) and methane sulfide The ratio of ponyl chloride was synthesized by changing to 1: 0.5: 3.5, 1: 1: 3, 1: 1.5: 2.5, 1: 2: 1, 1: 3: 1, 1: 3.5: 0.5 and so on.

Example 7

2, 4, 2 ', 4'-hydroxy benzophenone was prepared in the same manner as in [Example 5], and 2, 4, 2', 4'-hydroxy benzophenone, 1, 2-naphthoquinone-2- The ratio of diazide-5-sulfonyl chloride (NAC-5) and methane sulfonyl chloride was 1: 0.5: 3.5, 1: 1: 1: 3, 1: 1.5: 2.5, 1: 2: 2: 2, 1: 2.5: 1.5. , 1: 3: 1, 1: 3.5: 0.5, and the like were synthesized. The analysis was performed using liquid chromatography and infrared absorption spectrometer.

Example 8

This example is a detailed description of the resist preparation.

5 g of tert-butyloxy carbonyl novolac with 50% substitution and alkylsulfonyl 1,2-naphthoquinone-2-diazide-5-sulfonyl benzophenone (2,3,4,4'-hydroxy benzo Phenone: 1,2-naphthoquinone-2-diazide-5-sulfonyl chloride: methanesulfonyl chloride = 1: 2: 2) 1.0 g was dissolved in 15.6 g of ethylene glycol monoethyl acetate solvent and filtered A resist was prepared. After the prepared solution was filtered, it was coated on a silicon wafer with a thickness of 1 μm using a spin coater, followed by electrothermal treatment at 100 ° C. for 1 minute.

After exposing to 150 mJ / cm <2> in i line | wire (wavelength 365nm), heat processing was performed at 140 to 150 degreeC for 30 to 50 second. The infrared absorption spectrometer and the ultraviolet absorption spectrometer showed that the tert-butyloxy carbonyl group, which is a substituent attached to the polymer resin, was completely broken, and was dissolved in a basic solvent.

The development was carried out in a basic solvent, resulting in a high resolution forge pattern.

Example 9

5 g of tert-butyloxy carbonyl novolac with 75% substitution and alkylsulfonyl 1,2-naphthoquinone-2-diazide-5-sulfonyl benzophenone (2,3,3,4'-hydroxy benzo Phenone: 1,2-naphthoquinone-2-diazide-5-sulfonyl chloride: methanesulfonyl chloride = 1: 1.5: 2.5) 10 g was dissolved in 13.2 g of ethylene glycol monoethyl acetate solvent, and then filtered Was prepared. After the prepared solution was filtered, it was coated on a silicon wafer with a thickness of 1 μm using a spin coater and then preheated at 100 ° C. for 1 minute.

After exposing to 200 mJ / cm <2> in i line | wire (wavelength 365nm), heat processing was performed at 140 to 150 degreeC for 30 to 50 second. The development was carried out in a basic solvent, resulting in a high resolution forge pattern.

Example 10

Tert-butyloxy carbonyl novolac and alkylsulfonyl 1,2-naphthoquinone-2-diazide-5-sulfonyl benzophenone with 75% substitution rate (2,3,4,4'-hydroxy benzophenone : 1,2-naphthoquinone-2-diazide-5-sulfonyl chloride: methanesulfonyl chloride ratio = 1: 2: 2 and 1: 1: 3, 1: 1.5: 2.5) After the resist solution was prepared as described above, the resist properties were evaluated by the same method.

Example 11

Tert-Butyloxy carbonyl novolac and alkylsulfonyl 1,2-naphthoquinone-2-diazide-4-sulfonyl benzophenone with 75% substitution rate (2,3,4,4'-hydroxy benzophenone : 1,2-naphtuquinone-2-diazide-4-sulfonyl chloride: methanesulfonyl chloride ratio = 1: 2: 2 and 1: 1: 3, 1: 1.5: 2.5) After the resist solution was prepared as described above, the resist properties were evaluated by the same method.

Example 12

Poly (tert-butoxy carbonyloxy styrene) and alkylsulfonyl 1,2-naphthoquinone-2-diazide-5-sulfonyl benzophenone (2,3,4,4'-hydroxy benzophenone: 1,2-naphthoquinone-2-diazide-5-sulfonyl chloride to methanesulfonyl chloride ratio = 1: 1: 3 and 1: 1.5: 2.5, 1: 2.5, 1: 2: 2,1: 2.5 : 1.5) was evaluated in the same manner as in Example 8), and the resulting resistive pattern was obtained with high resolution.

Claims (4)

In the resist composition, 100 parts by weight of a tert-butyloxy carbonyl novolak resin represented by the following general formula (I) and having a molecular weight of 2,000 to 15,000 g / mol and a dispersion degree (Mw / Mn) of 1.5 to 3.5, A chemically amplified resist composition comprising 10 to 50 parts by weight of alkylsulfonyl 1, 2-naphthoquinone-2-diazide-5-sulfonyl benzophenone represented by the following general formula (II). Here, m = 10-100 or n = 0-90, Wherein R ₁ , R ₃ = 1, 2-naphthoquinone-2-diazide-5-sulfonyl group or 1, 2-naphthoquinone-2-diazide-4-sulfonyl group, R ₃ , R ₄ = SO ₃ M, M = CH ₃ , CF ₃ , a, c = 0 to 2, b, d = 1 to 2; The chemically amplified resist composition according to claim 1, wherein the substitution rate of tert-butyloxy carbonyl group is 40 to 100%. The chemically amplified resist composition according to claim 1, wherein the tert-butyloxy carbonyl novolak resin is poly (tert-butoxy carbonyloxy styrene). The method according to claim 2, wherein the tert- butyloxy carbonyl group is substituted with a molecular weight of 3,000 to 50,000 g / mol and the degree of dispersion (Mw / Mn) of 1.8 to 3.0, and poly (tert-butoxy carbonyloxy styrene) and And chemically amplified resist composition containing 1 to 99 wt% of a compound of the general formula (II).