CN114806394A - A kind of anti-reflection layer coating, anti-reflection layer and preparation method and application thereof - Google Patents

Abstract

The invention discloses an anti-reflection layer coating, an anti-reflection layer, and a preparation method and application thereof. The preparation method of the anti-reflective coating comprises the following steps: firstly, dissolving at least one of a water-soluble polymer and an alcohol-soluble polymer in a solvent to obtain a polymer solution, then adding a perfluorinated compound, a dehydrating agent and a proton capture agent into the polymer solution for reaction, and after the reaction is finished, adding a precipitator into the polymer solution to obtain a precipitate; carrying out the cyclic operation of dissolving, precipitating and washing on the precipitate to obtain a grafted polymer, and preparing the grafted polymer into a grafted polymer solution; and adding a wetting agent, a defoaming agent and an antioxidant into the grafted polymer solution, and uniformly mixing to obtain the anti-reflection layer coating. The anti-reflection coating prepared from the anti-reflection coating has low refractive index, extinction coefficient of 0, good film forming property and easy removal, and has application value in the field of chip manufacturing.

Description

A kind of anti-reflection layer coating, anti-reflection layer and preparation method and application thereof

technical field

The invention belongs to the field of chip manufacturing and chemical materials, and in particular relates to an anti-reflection layer coating, an anti-reflection layer and a preparation method and application thereof.

Background technique

The lithography process used to produce integrated circuit devices is to cast a positive or negative resist composition on a substrate, then bake to remove the solvent in the composition, and then use ultraviolet, far ultraviolet, electron beam or X-ray to remove the solvent. The resist is exposed to radiation; and the exposed resist is developed to form a resist pattern. Note that the substrate used for processing is highly reflective. During exposure, light passing through the resist layer is often reflected by the substrate and then returned to the resist layer, causing those areas that were not expected to be exposed to be exposed by the reflected light, causing pattern defects. In addition, the light reflection will wrinkle the resist layer, resulting in a standing wave effect, which will cause the width of the resist pattern to change, which is uncontrollable. The negative effects of this reflection are more pronounced when shortwave radiation is used to create finer patterns.

In order to solve the above-mentioned problems, various methods have been researched and developed. For example, a dye-in-resist method, a bottom anti-reflective coating (BARC) or top anti-reflective coating (TARC) method, a top surface imaging (TSI) method, and a multi-layer resist (MLR) method. The top surface of the resist layer is coated with a fluoride-containing composition to form a top anti-reflection coating, which reduces interference caused by different thicknesses of the resist layer, thereby forming a fine pattern with a target shape, which is very convenient In an effective method, the fluoride is perfluorooctanoic acid or perfluorooctane sulfonic acid.

When the refractive index of the top anti-reflection coating (n _t ) and the refractive index of the resist layer (n _r ) satisfy the condition of n _t =(n _r ) ^1/2 , the change of the pattern size by multiple interference is minimal. Therefore, there is a need for top antireflection coatings with low refractive index and high light transmittance. Typically, the refractive index of the resist layer is about 1.70, and when the resist layer is treated with a 193 nm ArF excimer laser, it is desirable that the top anti-reflection coating has an optimal refractive index of about 1.30. In many practical cases, top antireflection coatings with relatively low refractive indices are formed from highly fluorinated polymer materials by blending waterborne polymers with perfluorinated compounds to obtain antireflection coatings. However, the two-phase blend will precipitate and become unstable during long-term storage. In addition, after the coating is formed, the small molecule perfluorinated compounds are also prone to migration, resulting in inconsistent refractive index. How to obtain a uniform and stable anti-reflection coating material is a problem existing in the current technology.

SUMMARY OF THE INVENTION

In view of the deficiencies in the prior art, the object of the present invention is to provide an anti-reflection layer coating, an anti-reflection layer and a preparation method and application thereof. The film process is simple, the film-forming property is good, the coating is easy to remove, and the refractive index is low, so it has a strong application prospect.

The object of the present invention is achieved through the following technical solutions:

A preparation method of anti-reflection coating, comprising the following steps:

(1) Dissolve at least one of a water-soluble polymer and an alcohol-soluble polymer in a solvent to obtain a polymer solution, and then add a perfluorinated compound, a dehydrating agent and a proton trapping agent to the polymer solution for reaction , after the reaction is finished, the precipitate is obtained by adding a precipitant;

(2) performing cyclic operations of dissolving, precipitating and washing the precipitate described in step (1) to obtain a grafted polymer, and configuring the grafted polymer into a grafted polymer solution;

(3) A wetting agent, a defoaming agent and an antioxidant are added to the grafted polymer solution in step (2), and the anti-reflection coating is prepared after mixing uniformly.

Preferably, the concentration of the polymer solution in step (1) is 1-30 wt%.

Preferably, the water-soluble polymer and alcohol-soluble polymer in step (1) are one of polyvinyl alcohol, polyvinylpyrrolidone, polyethyleneimine and polyacrylic acid, and the weight average molecular weight is 3,000-200,000.

Preferably, the solvent in step (1) is at least one of water and ethanol.

Preferably, the molar ratio of at least one of the water-soluble polymer and alcohol-soluble polymer described in step (1) to the perfluoro compound is 1-10:10-1.

Preferably, the perfluoro compound in step (1) is at least one of perfluorosulfonic acid, perfluorocarboxylic acid and perfluoroacyl chloride; more preferably, the carbon number of the perfluoro compound in step (1) is 3 to 10.

Preferably, the molar ratio of the dehydrating agent in step (1) to the perfluoro compound is 1-20:20-1.

Preferably, the dehydrating agent in step (1) is one of 1-(3-dimethylaminopropyl)-3-ethyl-carbodiimide hydrochloride and 1,3-dicyclohexylcarbodiimide at least one.

Preferably, the proton capture agent in step (1) is 4-dimethylaminopyridine.

Preferably, the molar ratio of the proton trapping agent and the perfluorinated compound in step (1) is 1-20:20-1.

Preferably, the temperature of the reaction in step (1) is 20-80°C.

Preferably, the reaction time of step (1) is 8-24 h.

Preferably, the precipitating agent in step (1) is n-butanol, and the amount of the precipitating agent added is 2 to 4 times the volume of the polymer solution.

Preferably, the method of washing the precipitate in step (2) is as follows: washing the precipitate with water.

Preferably, the cyclic operation of dissolving, precipitating and washing described in step (2) is as follows: firstly use water to dissolve the precipitate, then use n-butanol to precipitate the grafted polymer, and finally wash with water, that is, to complete a cyclic operation , according to the actual situation, the above-mentioned dissolving-precipitation-washing cycle operation can be repeated many times.

Preferably, the method of configuring the grafted polymer solution in step (2) is: dissolving the grafted polymer in either water or ethanol to configure a solution with a concentration of 0.2-30wt%.

Preferably, the wetting agent in step (3) accounts for 0.1-3 wt% of the grafted polymer.

Preferably, the wetting agent in step (3) is a fluorocarbon surfactant.

Preferably, the fluorocarbon surfactant is at least one of Capstone FS-61, Capstone FS-50 and Capstone FS-10.

Preferably, the defoaming agent in step (3) accounts for 0.1-3 wt % of the grafted polymer.

Preferably, the defoamer in step (3) is polyether-modified silicone oil or polysiloxane.

Preferably, the antioxidant in step (3) accounts for 0.1-3 wt% of the grafted polymer.

Preferably, the antioxidant in step (3) is at least one of ascorbic acid, tea polyphenols and ascorbyl palmitate.

The anti-reflection layer paint prepared by the above-mentioned preparation method of the anti-reflection layer paint.

A preparation method of an anti-reflection layer, comprising the following steps: coating the anti-reflection layer paint on a substrate, and drying at 60-80° C. for 12 hours.

Preferably, the coating method is as follows: use spin coating to coat a clean silicon wafer, and the spin coating parameters used are: first spin coating on the silicon wafer at 1000 r/min for 6-10 s, and then spin at 1400 r/min for 6 to 10 s. min spin coating 10 ~ 20s. After spin coating, a coating with a thickness of 10-100 nm is prepared.

The anti-reflection layer prepared by the above-mentioned method for preparing an anti-reflection layer.

Application of the above anti-reflection layer in the preparation of top anti-reflection coating.

Compared with the prior art, the beneficial effects of the present invention include:

(1) The water-based macromolecule selected by the present invention can be dissolved in water or alcohol-soluble macromolecule is soluble in ethanol, and is environmentally friendly; the polymer used has good film-forming property;

(2) The grafting reaction is simple and controllable and easy to operate;

(3) Compared with the traditional blending method of film-forming substances and low-refractive-index substances, the grafting method enhances the uniform distribution of low-refractive-index components, reduces their mobility as small molecules, and enhances the coating properties. stability. The obtained anti-reflection coating has low refractive index, 0 extinction coefficient, good film-forming property and easy removal, and has application value in the field of chip manufacturing.

Description of drawings

Fig. 1 is the reaction schematic diagram of the graft reaction of polyvinyl alcohol and perfluorosulfonic acid according to the embodiment of the present invention.

FIG. 2 is a schematic diagram of the graft reaction of polyethyleneimine and perfluorocarboxylic acid according to the present invention.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, but not to limit the present invention.

The perfluorocarboxylic acid described in the examples was purchased from Shanghai Maclean Biochemical Technology Co., Ltd., and the number of carbon atoms was 4-8; the perfluorosulfonic acid was purchased from Shanghai Maclean Biochemical Technology Co., Ltd., and the number of carbon atoms was 4 -8.

Example 1

A preparation method of an anti-reflection layer, comprising the steps:

(1) Dissolve polyethyleneimine with a molecular weight of 10,000 in water, and configure it into a 10wt% aqueous solution;

(2) Add perfluorocarboxylic acid to the above solution, the molar ratio of perfluorocarboxylic acid to polyethyleneimine is 1:1, and then, add 1-(3-dimethicone equimolar to perfluorocarboxylic acid) Methylaminopropyl)-3-ethyl-carbodiimide hydrochloride and equimolar 4-dimethylaminopyridine were refluxed at 80°C for 24h. After the reaction is completed, use n-butanol as a precipitant to precipitate the grafted polymer, wash the precipitate with water, dissolve the precipitate with water, then use n-butanol to precipitate the grafted polymer, and finally wash with water to obtain washing. After the grafted polymer.

(3) Dissolving the washed graft polymer obtained in step (2) in water to prepare a polymer solution of 8 wt %.

(4) Add Capstone FS-50 accounting for 0.1wt% of the graft polymer, polyether modified silicone oil accounting for 0.1wt% of the graft polymer, and 0.1wt% of the graft polymer to the polymer solution in step (3). % ascorbic acid, the anti-reflection coating was prepared after mixing evenly, and the film was coated on a clean silicon wafer by spin coating method. Spin coating at 1400r/min for 15s. After spin coating, a coating with a thickness of 40 nm was prepared.

After 6 months, the anti-reflection coating prepared in Example 1 was filtered with a needle filter with a diameter of 13 mm and a pore size of 0.22 μm. No filter residue was observed, and the filter head before and after filtration was dried and weighed. is 0, the solution of the anti-reflection coating was taken six months before and after, and the transmittance of visible light in the range of 380nm to 780nm was observed on the Shimadzu UV-Vis spectrophotometer UV1240. The transmittance half a year ago was 99.0%, and the transmittance after half a year was 99.0%, the coating showed a uniform and stable state in the solvent; the obtained coating was irradiated by 193nm laser, its extinction coefficient was 0, and the refractive index was 1.60; after 6 months, the original solution coating was prepared The anti-reflection coating of 193nm laser irradiation, its extinction coefficient is 0, the refractive index is 1.61.

Example 2

A preparation method of an anti-reflection layer, comprising the steps:

(1) Dissolve polyvinyl alcohol with a molecular weight of 30,000 in water, and configure it into a 10wt% aqueous solution;

(2) Add perfluorocarboxylic acid to the above solution, the molar ratio of perfluorocarboxylic acid to polyvinyl alcohol is 3:1, and then, add 1-(3-dimethylformaldehyde equimolar to perfluorocarboxylic acid) Aminopropyl)-3-ethyl-carbodiimide hydrochloride and equimolar 4-dimethylaminopyridine were refluxed at 80°C for 24h. After the reaction is completed, use n-butanol as a precipitant to precipitate the grafted polymer, wash the precipitate with water, dissolve the precipitate with water, then use n-butanol to precipitate the grafted polymer, and finally wash with water to dissolve in this way. - Precipitation-washing operation three times, the grafted polymer after washing can be obtained.

(3) Dissolving the washed grafted polymer obtained in step (2) in water to prepare a 3 wt% polymer solution.

(4) Adding Capstone FS-61 accounting for 0.2 wt% of the grafted polymer and polysiloxane accounting for 0.2 wt% of the grafted polymer into the polymer solution in step (3) (the embodiment adopts methyl Silicone oil, other types of silicone oil can also be used), tea polyphenols accounting for 0.2wt% of the grafted polymer, after mixing evenly, apply a film on a clean silicon wafer by spin coating. The spin coating parameters used are: Spin coating on silicon wafer at 1000r/min for 8s, and then spin at 1400r/min for 20s. After spin coating, a coating with a thickness of 50 nm was prepared.

After 6 months, the anti-reflection coating prepared in Example 2 was filtered with a needle filter with a diameter of 13 mm and a pore size of 0.22 μm, and no filter residue was observed, and the filter head before and after filtration was dried and weighed. is 0, the solution of the anti-reflection coating was taken six months before and after, and the transmittance of visible light in the range of 380nm to 780nm was observed on the Shimadzu UV-Vis spectrophotometer UV1240. The transmittance half a year ago was 98.8%, and the transmittance after half a year was 98.8%, the coating showed a uniform and stable state in the solvent; the prepared coating was irradiated by 193nm laser, its extinction coefficient was 0, and the refractive index was 1.56; after 6 months, the original solution coating was prepared. The anti-reflection coating of 193nm laser irradiation, its extinction coefficient is 0, the refractive index is 1.55.

Example 3

A preparation method of an anti-reflection layer, comprising the steps:

(1) dissolving polyvinylpyrrolidone K18 in water and configuring it into a 15wt% aqueous solution;

(2) adding perfluorosulfonic acid to the above solution, the molar ratio of perfluorosulfonic acid and polyvinylpyrrolidone K18 is 5:1, then, adding 1-(3-difluorosulfonic acid equimolar to perfluorosulfonic acid) Methylaminopropyl)-3-ethyl-carbodiimide hydrochloride and equimolar 4-dimethylaminopyridine were refluxed for 24h at 80°C. After the reaction is completed, use n-butanol as a precipitant to precipitate the grafted polymer, wash the precipitate with water, dissolve the precipitate with water, then use n-butanol to precipitate the grafted polymer, and finally wash with water to dissolve in this way. - Precipitation-washing operation three times to obtain the grafted polymer after washing.

(3) Dissolving the washed graft polymer obtained in step (2) in water to prepare a 5 wt % polymer solution.

(4) Add Capstone FS-10 accounting for 0.5wt% of the grafted polymer, polyether modified silicone oil accounting for 0.5wt% of the grafted polymer, and 0.5wt% of the grafted polymer to the polymer solution in step (3). % ascorbyl palmitate, after mixing uniformly, apply a film on a clean silicon wafer by spin coating method. Paint 25s. After spin coating, a coating with a thickness of 60 nm was prepared.

After 6 months, the anti-reflection coating prepared in Example 3 was filtered with a needle filter with a diameter of 13 mm and a pore size of 0.22 μm. No filter residue was observed, and the filter head before and after filtration was dried and weighed. is 0, the solution of the anti-reflection coating was taken six months before and after, and the transmittance of visible light in the range of 380nm to 780nm was observed on the Shimadzu UV-Vis spectrophotometer UV1240. The transmittance was 99.1% half a year ago and the transmittance after half a year 99.1%, the coating showed a uniform and stable state in the solvent, the obtained coating was irradiated by 193nm laser, its extinction coefficient was 0, and the refractive index was 1.53; after 6 months, the original solution coating was prepared. The anti-reflection coating of 193nm laser irradiation, its extinction coefficient is 0, the refractive index is 1.52.

The specific embodiments of the present invention described above do not limit the protection scope of the present invention. Any other corresponding changes and modifications made according to the technical concept of the present invention shall be included in the protection scope of the claims of the present invention.

Claims (10)

1. a preparation method of antireflection coating, is characterized in that, comprises the following steps: (1) Dissolve at least one of a water-soluble polymer and an alcohol-soluble polymer in a solvent to obtain a polymer solution, and then add a perfluorinated compound, a dehydrating agent and a proton trapping agent to the polymer solution for reaction , after the reaction is finished, the precipitate is obtained by adding a precipitant; (2) performing cyclic operations of dissolving, precipitating and washing the precipitate described in step (1) to obtain a grafted polymer, and configuring the grafted polymer into a grafted polymer solution; (3) A wetting agent, a defoaming agent and an antioxidant are added to the grafted polymer solution in step (2), and the anti-reflection coating is prepared after mixing uniformly. 2. the preparation method of a kind of antireflection coating according to claim 1, is characterized in that, the mol ratio of at least one in the described water-soluble macromolecule and alcohol-soluble macromolecule of step (1) and perfluorinated compound is 1～10:10～1; The perfluorinated compound in step (1) is at least one of perfluorosulfonic acid, perfluorocarboxylic acid and perfluoroacyl chloride; The concentration of the polymer solution in step (1) is 1-30wt%; The molar ratio of the dehydrating agent and the perfluorinated compound in step (1) is 1-20:20-1; In step (1), the molar ratio of the proton trapping agent and the perfluorinated compound is 1-20:20-1. 3 . The preparation method of an anti-reflection coating according to claim 1 , wherein the carbon number of the perfluorinated compound in step (1) is 3 to 10; 3 . The method of configuring the grafted polymer solution in step (2) is as follows: dissolving the grafted polymer in either water or ethanol to configure a solution with a concentration of 0.2-30 wt%; In step (3), the wetting agent accounts for 0.1-3 wt% of the grafted polymer. 4. The preparation method of an anti-reflection coating according to claim 1, wherein the defoamer in step (3) accounts for 0.1-3wt% of the grafted polymer; In step (3), the antioxidant accounts for 0.1-3wt% of the grafted polymer; The wetting agent described in step (3) is a fluorocarbon surfactant; The defoamer in step (3) is polyether-modified silicone oil or polysiloxane; The water-soluble polymer and alcohol-soluble polymer in step (1) are one of polyvinyl alcohol, polyvinylpyrrolidone, polyethyleneimine and polyacrylic acid, and the weight-average molecular weight is 3,000-200,000; The solvent described in step (1) is at least one of water and ethanol; The dehydrating agent described in step (1) is at least one of 1-(3-dimethylaminopropyl)-3-ethyl-carbodiimide hydrochloride and 1,3-dicyclohexylcarbodiimide ; The proton capture agent in step (1) is 4-dimethylaminopyridine. 5. The preparation method of an anti-reflection coating according to any one of claims 1 to 4, wherein the temperature of the reaction in the step (1) is 20 to 80°C; The time is 8～24h; In step (1), the precipitating agent is n-butanol, and the amount of the precipitating agent added is 2 to 4 times the volume of the polymer solution; The cyclic operation of dissolving, precipitating and washing described in step (2) is as follows: firstly use water to dissolve the precipitate, then use n-butanol to precipitate the grafted polymer, and finally wash with water, that is, a cyclic operation is completed. 6. The anti-reflection layer coating prepared by the method for preparing an anti-reflection layer coating according to any one of claims 1 to 5. 7 . A method for preparing an anti-reflection layer, comprising the following steps: coating the anti-reflection layer coating of claim 6 on a substrate, and drying at 60-80° C. for 12 hours. 8 . 8. the preparation method of a kind of anti-reflection layer according to claim 7, is characterized in that, described coating mode is: adopt spin coating method to coat film on clean silicon wafer, the spin coating parameter adopted is: Spin coating on the silicon wafer at 1000 r/min for 6 to 10 s, and then spin at 1400 r/min for 10 to 20 s; after spin coating, a coating with a thickness of 10 to 100 nm is prepared. 9. The anti-reflection layer prepared by the method for preparing an anti-reflection layer according to any one of claims 7 to 8. 10. The application of the anti-reflection layer of claim 9 in the preparation of a top anti-reflection coating.

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