Preparation method of 193nm photoresist resin

Abstract

The application discloses a preparation method of 193nm photoresist resin, which comprises the following steps: resin synthesis to obtain a synthetic resin solution; during the synthesis, the synthesized monomers comprise the following raw materials in terms of molar percentage: 99.9-99.99% etch-resistant methacrylate monomers and 0.01-0.1% epoxy-containing methacrylate monomers; removing impurities and unreacted monomers in the synthetic resin solution to obtain a first resin solution; removing metal impurities in the first resin solution to obtain a second resin solution; replacing the solvent in the second resin solution with electronic-grade solvent to obtain a third resin solution; adding an electronic-grade secondary tertiary amine group resin solution in the third resin solution, and the molar amount of the electronic-grade secondary amine compound is 95-100% of the molar amount of the epoxy groups in the epoxy-containing methacrylate monomers. In the application, the epoxy group monomers introduced in the resin synthesis process are methacrylate, which does not affect the basic structure, etch resistance, light transmittance and the like of the resin, and the tertiary amine group is synthesized on the resin, and will not volatilize during later use.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of photoresist, in particular to a preparation method of 193nm photoresist resin. BACKGROUND

[0002] The polymethacrylate resin has good light transmittance and excellent etching resistance, and is used as a film-forming resin in a semiconductor photoresist composition. The 193nm photoresist uses a 193nm light source, and the benzene ring has absorption at this wavelength, which competes with the photoacid for light absorption, so the 193nm photoresist resin cannot use benzene ring monomers, and in order to make the photoresist have good etching resistance, rigid groups such as cyclic structures need to be used.

[0003] High-precision integrated circuits have high requirements for the metal impurity content of semiconductor photoresist, which requires the metal impurity content of the film-forming resin in the corresponding composition to be as low as possible, with a single metal impurity content requirement of <1ppb and a total metal impurity content requirement of <10ppb.

[0004] After the conventional 193nm resin is prepared, it is configured with other resins, photoacid generators, auxiliaries, solvents, etc. to form a photoresist solution, which is used in the photoetching process. The photoacid generator is generally added at 0.1% to 2%, and under the condition of light, it produces super strong protonic acid to acidolyze the acidolyzable groups in the photoresist resin, improve the alkali solubility of the resin, achieve the difference in solubility between the exposed and unexposed areas, and achieve the purpose of etching. However, the photoacid will diffuse in the film after decomposition under light, which will reduce the precision of the boundary between the exposed and unexposed areas. For photoetching processes with high etching precision requirements, a small amount of organic amine is added to neutralize a small amount of diffused acid, thereby inhibiting this side effect. However, the front process of the photoresist includes coating, baking, exposure, development, post-baking, etc., which will cause the volatilization of small organic amine molecules, affecting the equipment and environment in the photoetching process. SUMMARY

[0005] The purpose of the present application is to provide a preparation method of 193nm photoresist resin.

[0006] The innovation of the present application lies in the introduction of an epoxy group monomer in the resin synthesis process, which is a methacrylate and will not affect the basic structure, etching resistance and light transmittance of the resin. Since the tertiary amine is synthesized on the resin, it will not volatilize in the later stage.

[0007] To achieve the above-mentioned purpose of the application, the technical solution of the present application is as follows:

[0008] A preparation method of 193nm photoresist resin, comprising the following steps:

[0009] (1) resin synthesis to obtain a synthetic resin solution, the monomers synthesized during the synthesis include the following molar percentage of raw materials: 99.9~99.99% anti-etching methacrylate monomer, 0.01~0.1% epoxy-containing methacrylate monomer;

[0010] (2) remove impurities and unreacted monomers in the synthetic resin solution to obtain a No. 1 resin solution;

[0011] (3) remove metal impurities in the No. 1 resin solution to obtain a No. 2 resin solution;

[0012] (4) replace the solvent in the No. 2 resin solution with an electronic grade solvent to obtain a No. 3 resin solution;

[0013] (5) add an electronic grade secondary amine group resin solution to the No. 3 resin solution, the molar amount of the electronic grade secondary amine compound is 95~100% of the molar amount of the epoxy group in the epoxy-containing methacrylate monomer.

[0014] Further, the anti-etching methacrylate monomer is 3~8 of 1-methylcyclopentyl methacrylate, 1-ethylcyclopentyl methacrylate, 1-isopropylcyclopentyl methacrylate, 1-methylcyclohexyl methacrylate, 1-ethylcyclohexyl methacrylate, 1-isopropylcyclohexyl methacrylate, 2-methyl-2-adamantanol methacrylate, 2-ethyl-2-adamantanol methacrylate, 1-(1-adamantane)-1-methyl ethyl methacrylate, 2-isopropyl-2-methyladamanol methacrylate, 3-hydroxy-1-adamantanol methacrylate, 2-carboxy-4-norbornolactone-5-methacrylate, 2-carboxy-4-norbornolactone-5-acetyloxymethyl methacrylate, perfluorobutyl ethyl methacrylate, perfluorohexyl ethyl methacrylate.

[0015] Further, the epoxy-containing methacrylate monomer is one of 3-ethyl-3-(methacryloyloxymethyl) oxetane, glycidyl methacrylate, 3,4-epoxycyclohexyl methyl methacrylate.

[0016] Further, the electronic grade secondary amine compound is one of morpholine, 3-piperidine formic acid ethyl ester, imino diethyl adipate, 3-hydroxymethyl piperidine, N-methyl-3-fluorobenzyl amine, etc.

[0017] Further, in step (1), the synthetic resin solution is obtained by free radical polymerization during resin synthesis.

[0018] Further, in step (4), the electronic grade solvent is one of propylene glycol methyl ether acetate, propylene glycol monomethyl ether, ethyl lactate, diethylene glycol methyl ethyl ether, cyclohexanone.

[0019] The beneficial effects of the present application are:

[0020] 1、The epoxy group monomer introduced in the resin synthesis process in the present application is methyl methacrylate, which does not affect the basic structure, etching resistance, light transmittance, etc. of the resin. Since the tertiary amine group is synthesized on the resin, it will not volatilize during later use.

[0021] 2、The epoxy reaction in the present application through the electronic grade secondary amine and the resin does not increase the metal ion content in the resin.

[0022] 3、The introduction of tertiary amine in the present application is in the last process of resin production, and the reaction is carried out under mild conditions, which does not affect the synthesis of the resin; and avoids the early introduction of amine group in the resin synthesis process, such as oxidation yellowing. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the present application will be described clearly and completely below.

[0024] Example 1: A preparation method of a 193nm photoresist resin, comprising the following steps: resin synthesis to obtain a synthetic resin solution, the monomers synthesized during synthesis include the following molar percentage of raw materials: 99.9% etch-resistant methyl methacrylate monomer, 0.1% epoxy-containing methyl methacrylate monomer; removing impurities and unreacted monomers in the synthetic resin solution to obtain a first resin solution; removing metal impurities in the first resin solution to obtain a second resin solution; replacing the solvent in the second resin solution with an electronic grade solvent to obtain a third resin solution; reacting in the third resin solution by adding an electronic grade secondary amine compound to generate a resin solution with a tertiary amine group, and the molar amount of the electronic grade secondary amine compound is 95% of the molar amount of the epoxy group in the epoxy-containing methyl methacrylate monomer.

[0025] The etch-resistant methyl methacrylate monomer is 1-methylcyclopentyl methacrylate, 1-ethylcyclopentyl methacrylate, or 1-isopropylcyclopentyl methacrylate.

[0026] The epoxy-containing methyl methacrylate monomer is 3-ethyl-3-(methacryloyloxymethyl) oxetane.

[0027] The electronic grade secondary amine compound is morpholine.

[0028] The free radical polymerization method is used for resin synthesis to obtain a synthetic resin solution.

[0029] The electronic grade solvent is propylene glycol methyl ether acetate.

[0030] Embodiment 2: a preparation method of a 193nm photoresist resin, comprising the following steps: resin synthesis to obtain a synthetic resin solution, the monomers synthesized during the synthesis include the following raw materials in terms of molar percentage: 99.99% etch-resistant methacrylate monomer, 0.01% epoxy-containing methacrylate monomer; removing impurities and unreacted monomers in the synthetic resin solution to obtain a first resin solution; removing metal impurities in the first resin solution to obtain a second resin solution; replacing the solvent in the second resin solution with an electronic-grade solvent to obtain a third resin solution; reacting in the third resin solution by adding an electronic-grade secondary amine compound to generate a resin solution containing a tertiary amine group, the molar amount of the electronic-grade secondary amine compound being 96% of the molar amount of the epoxy groups in the epoxy-containing methacrylate monomer.

[0031] The etch-resistant methacrylate monomer is 1-methylcyclohexyl methacrylate, 1-ethylcyclohexyl methacrylate, or 1-isopropylcyclohexyl methacrylate.

[0032] The epoxy-containing methacrylate monomer is glycidyl methacrylate.

[0033] The electronic-grade secondary amine compound is ethyl 3-piperidinecarboxylate.

[0034] The electronic-grade solvent is propylene glycol monomethyl ether.

[0035] Embodiment 3: a preparation method of a 193nm photoresist resin, comprising the following steps: resin synthesis to obtain a synthetic resin solution, the monomers synthesized during the synthesis include the following raw materials in terms of molar percentage: 99.95% etch-resistant methacrylate monomer, 0.05% epoxy-containing methacrylate monomer; removing impurities and unreacted monomers in the synthetic resin solution to obtain a first resin solution; removing metal impurities in the first resin solution to obtain a second resin solution; replacing the solvent in the second resin solution with an electronic-grade solvent to obtain a third resin solution; reacting in the third resin solution by adding an electronic-grade secondary amine compound to generate a resin solution containing a tertiary amine group, the molar amount of the electronic-grade secondary amine compound being 98% of the molar amount of the epoxy groups in the epoxy-containing methacrylate monomer.

[0036] The etch-resistant methacrylate monomer is 2-methyl-2-adamantanol methacrylate, 2-ethyl-2-adamantanol methacrylate, or 1-(1-adamantyl)-1-methyl ethyl methacrylate.

[0037] The epoxy-containing methacrylate monomer is one of 4-epoxycyclohexylmethyl methacrylate.

[0038] The electronic-grade secondary amine compound is diethyl iminodiacetate.

[0039] The resin synthesis solution is obtained by using a free radical polymerization method.

[0040] The electronic grade solvent is ethyl lactate.

[0041] The preparation method of the 193nm photoresist resin of the embodiment 4 comprises the following steps: resin synthesis to obtain a synthesis resin solution, the monomers synthesized during the synthesis comprise the following raw materials in terms of molar percentage: 99.92% of etch-resistant methacrylate monomer, 0.08% of epoxy-containing methacrylate monomer; removing impurities and unreacted monomers in the synthesis resin solution to obtain a first resin solution; removing metal impurities in the first resin solution to obtain a second resin solution; replacing the solvent in the second resin solution with an electronic grade solvent to obtain a third resin solution; reacting to generate a resin solution containing a tertiary amine group in the third resin solution by adding an electronic grade secondary amine compound, and the molar amount of the electronic grade secondary amine compound is 100% of the molar amount of the epoxy group in the epoxy-containing methacrylate monomer.

[0042] The etch-resistant methacrylate monomer is 3-8 kinds of 2-carboxy-4-norbornenol-5-acetyloxymethyl acrylate, perfluorobutyl ethyl methacrylate, and perfluorohexyl ethyl methacrylate.

[0043] The epoxy-containing methacrylate monomer is 3-ethyl-3-(methacryloyloxymethyl) oxetane.

[0044] The electronic grade secondary amine compound is diethyl iminodiacetate.

[0045] The electronic grade solvent is diethylene glycol methyl ethyl ether.

[0046] In the embodiment 5, the etch-resistant methacrylate monomer is 3-8 kinds of 1-methylcyclopentyl methacrylate, 1-ethylcyclopentyl methacrylate, 1-isopropylcyclopentyl methacrylate, 1-methylcyclohexyl methacrylate, 1-ethylcyclohexyl methacrylate, 1-isopropylcyclohexyl methacrylate, 2-methyl-2-adamantanol methacrylate, 2-ethyl-2-adamantanol methacrylate, 1-(1-adamantane)-1-methyl ethyl methacrylate, 2-isopropyl-2-methyladamanol methacrylate, 3-hydroxy-1-adamantanol methacrylate, 2-carboxy-4-norbornenol-5-methacrylate, 2-carboxy-4-norbornenol-5-acetyloxymethyl acrylate, perfluorobutyl ethyl methacrylate, and perfluorohexyl ethyl methacrylate.

[0047] The epoxy-containing methacrylate monomer is one of 3-ethyl-3-(methacryloyloxymethyl) oxetane, glycidyl methacrylate, and 3,4-epoxycyclohexylmethyl methacrylate.

[0048] The electronic grade secondary amine compound is one of morpholine, 3-piperidine formic acid ethyl ester, imino diacetic acid diethyl ester, 3-hydroxymethyl piperidine, N-methyl-3-fluorobenzyl amine, etc.

[0049] The electronic grade solvent is one of propylene glycol methyl ether acetate, propylene glycol monomethyl ether, ethyl lactate, diethylene glycol methyl ethyl ether, cyclohexanone.

[0050] Example 6: Reference to Example 1:

[0051] S1: When synthesizing the resin, 100 parts of monomer, 2-8 parts of initiator, and 200 parts of propylene glycol methyl ether acetate are uniformly mixed; drop at a constant speed into a reaction bottle at 70-90°C, stop after 3h of drop and maintain the temperature to continue to react for 2h to synthesize the resin solution;

[0052] S2: Remove impurities and unreacted monomers in the synthesized resin solution: add 600 parts of n-hexane to the synthesized resin solution, pour out the upper liquid after precipitation, and add ethyl acetate to dissolve to 300 parts; repeat this step 3 times to obtain a first resin solution;

[0053] S3: When removing metal impurities, precipitate the first resin solution in 400 parts of ultrapure water, pour out the upper liquid, and add electronic grade THF to dissolve to 200 parts in the precipitate; repeat this step 5 times to obtain a second resin solution;

[0054] S4: When replacing the solvent, vacuum dry the second resin solution at 60°C for 48h, and dissolve with an electronic grade solvent to obtain a third resin;

[0055] S5: Introduce tertiary amine: add an electronic grade secondary amine compound to the third resin to generate a resin solution with a tertiary amine group after reaction, the molar amount of the electronic grade secondary amine compound is 95% of the molar amount of the epoxy-containing methacrylate monomer, and the temperature is raised to 30-60°C to react for 8h to obtain the finished product.

[0056] The described embodiments are only a part of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor belong to the scope of protection of the present application.

Claims

1. A method for producing a 193 nm photoresist resin, characterized by, The method comprises the following steps: (1) obtaining a synthetic resin solution by resin synthesis, wherein the monomers synthesized during the synthesis comprise the following raw materials in terms of molar percentage: 99.9-99.99% of etch-resistant methacrylate monomers, 0.01-0.1% of 3-ethyl-3-(methacryloyloxymethyl) oxetane or epoxy-containing methacrylate monomers, and the etch-resistant methacrylate monomers are 1-methylcyclopentyl methacrylate, 1-ethylcyclopentyl methacrylate, 1-isopropylcyclopentyl methacrylate, 1-methylcyclohexyl methacrylate, 1-ethylcyclohexyl methacrylate, 1-isopropylcyclohexyl methacrylate, 2-methyl-2-adamantanol methacrylate, 2-ethyl-2-adamantanol methacrylate, 1-(1-adamantane)-1-methyl ethyl methacrylate, 2-isopropyl-2-methyladamanol methacrylate, 3-hydroxy-1-adamantanol methacrylate, 2-carboxy-4-norbornolactone-5-methacrylate, 2-carboxy-4-norbornolactone-5-acetyloxymethyl methacrylate, perfluorobutyl ethyl methacrylate, and 3-8 kinds of perfluorohexyl ethyl methacrylate; the epoxy-containing methacrylate monomers are one of glycidyl methacrylate and 3,4-epoxycyclohexylmethyl methacrylate; (2) adding 600 parts of n-hexane to the synthetic resin solution, pouring out the upper liquid after precipitation, and adding ethyl acetate to dissolve the precipitate into 300 parts; The step is repeated three times to obtain a first resin solution; (3) removing metal impurities from the first resin solution to obtain a second resin solution; (4) vacuum drying the second resin solution at 60°C for 48h to obtain a dried product, and dissolving the dried product with an electronic-grade solvent to obtain a third resin solution; (5) adding an electronic-grade secondary amine compound to the third resin solution to generate a resin solution containing a tertiary amine group, and the molar amount of the electronic-grade secondary amine compound is 95-100% of the molar amount of the oxygen-containing heterocyclic ring in 3-ethyl-3-(methacryloyloxymethyl) oxetane or the molar amount of the epoxy group in the epoxy-containing methacrylate monomer; the electronic-grade secondary amine compound is one of morpholine, 3-piperidine formate ethyl, imino diacetic acid diethyl ester, 3-hydroxymethyl piperidine, and N-methyl-3-fluorobenzyl amine.

2. The method for preparing the 193nm photoresist resin according to claim 1, characterized in that, In the step (1), the synthetic resin solution is obtained by free radical polymerization during resin synthesis.

3. The method for preparing the 193nm photoresist resin according to claim 1, characterized in that, In the step (4), the electronic-grade solvent is one of propylene glycol methyl ether acetate, propylene glycol monomethyl ether, ethyl lactate, diethylene glycol methyl ethyl ether, and cyclohexanone.