CN-118460074-B - Preparation method of photoetching coating

Abstract

The invention discloses a preparation method of a photoetching coating, which comprises the steps of S1, mixing titanium dioxide and cesium carbonate, calcining to obtain a solid, S2, carrying out acid leaching and solid-liquid separation on the solid, adding the obtained solid phase into a tetramethyl ammonium hydroxide solution, stirring, stripping to obtain a titanium dioxide dispersion liquid, S3, adding a coupling agent into the titanium dioxide dispersion liquid for modification, carrying out solid-liquid separation, ball milling to obtain modified titanium dioxide, S4, dissolving hydroxyl-terminated hyperbranched polyester into a solvent, adding the modified titanium dioxide, carrying out ultrasonic dispersion, adding a vinyl-terminated compound, mixing to obtain a mixed solution, S5, coating the mixed solution on a substrate, and carrying out heating curing to obtain the photoetching coating. The prepared photoetching coating has high refractive index, is easy to remove by development, and can be used for preparing a photomask.

Inventors

• Li Gezhou
• DUAN CONG
• Zhong Xuanfei

Assignees

• 长沙韶光芯材科技有限公司

Dates

Publication Date

20260512

Application Date

20240527

Claims (10)

1. 1. A preparation method of a photoetching coating is characterized by comprising the following steps: s1, mixing titanium dioxide and cesium carbonate, and calcining to obtain a solid; S2, carrying out acid leaching on the solid, carrying out solid-liquid separation, adding the obtained solid phase into a tetramethyl ammonium hydroxide solution, stirring, and stripping to obtain a titanium dioxide dispersion liquid; S3, adding a coupling agent into the titanium dioxide dispersion liquid for modification, carrying out solid-liquid separation, and carrying out ball milling to obtain modified titanium dioxide; S4, dissolving the hydroxyl-terminated hyperbranched polyester in a solvent, adding the modified titanium dioxide, performing ultrasonic dispersion, adding a vinyl-terminated compound, and mixing to obtain a mixed solution; S5, coating the mixed solution on a substrate, and heating and curing to obtain the photoetching coating.
2. 2. The method for preparing a photolithographic coating according to claim 1, wherein in step S1, the molar ratio of titanium pigment to cesium carbonate is 4.5-5:1, and/or the calcination temperature is 800-830 ℃ and the calcination time is 10-15 hours.
3. 3. A method for producing a photolithographic coating according to claim 1, characterized in that in step S2, hydrochloric acid is used in a concentration of 1-2M, and/or the acid leaching time is 80-100h, and/or the solid-to-liquid ratio of the acid leaching is 0.8-1.5g/100mL, and/or the concentration of the tetramethyl ammonium hydroxide solution is 0.1-0.15M, and/or the mass-to-volume ratio of the solid phase to the tetramethyl ammonium hydroxide solution is 1-2g/100mL, and/or the stirring time is 70-80h.
4. 4. The method according to claim 1, wherein in the step S3, the coupling agent is trimethoxy (3-methoxypropyl) silane, and/or the mass volume ratio of the coupling agent to the titanium dioxide dispersion is 0.05-0.3g/100mL, and/or the modification temperature is 40-50 ℃ and the modification time is 5-10h, and/or the ball milling adopts ball milling ball gradation of 8-10mm, 4-5mm, and the gradation ratio is 1:2-3, and/or the ball milling rotational speed is 80-120rpm, the ball milling time is 2-5h, the ball material ratio is 4-8:1, and/or the ball milling medium is ethylene glycol, and the mass ratio of the ball milling medium to the solid phase material to be milled is 1-2:1.
5. 5. The method for producing a photolithographic coating according to claim 1, characterized in that in step S4 the hydroxyl-terminated hyperbranched polyester has a functionality of 5-7, a hydroxyl value of 500-700mgKOH/g, a molecular weight of 500-600g/mol, and/or the ratio of the total mass of the hydroxyl-terminated hyperbranched polyester, the vinyl-terminated compound to the mass of the modified titanium dioxide is 1.8-2:1, and/or the vinyl-terminated compound is triethylene glycol divinyl ether or diethylene glycol divinyl ether, and/or the molar ratio of the hydroxyl-terminated hyperbranched polyester to the vinyl-terminated compound is 1:8-12, and/or the solvent is an alcohol ether solvent, and/or the ratio of the mass of the hydroxyl-terminated hyperbranched polyester to the solvent is 0.2-0.5:98-100, and/or the time of the ultrasonic dispersion is 0.5-1h.
6. 6. The method of claim 1, wherein the step S4 further comprises adding at least one of a photoacid generator and a quencher to the mixture.
7. 7. The method of claim 1, wherein in step S5, the heating temperature is 200-210 ℃ and the heating time is 90-150S, and/or the coating mode is spin coating.
8. 8. A photolithographic coating, characterized in that it is produced by the process according to any one of claims 1 to 7.
9. 9. A photoresist coating according to claim 8, where the thickness of the photoresist coating is 100-150nm.
10. 10. Use of a lithographic coating according to any of claims 8-9 for the preparation of a photomask.

Description

Preparation method of photoetching coating Technical Field The invention relates to the technical field of photomask materials, in particular to a preparation method of a photoetching coating. Background The photomask is also called a photomask, generally quartz glass with low thermal expansion rate and high light transmittance is selected as a substrate, and metal Cr is used for forming patterns (circuit pattern template) on the surface of the substrate as a shading layer. In the photoetching technology, patterns on a photomask are reduced and transferred to a silicon substrate in an equal proportion by utilizing processes such as exposure, development, etching and the like to form a circuit pattern. Along with the development trend of miniaturization of the microelectronics industry, the requirements on resolution of integrated circuits are higher and higher, and in order to reduce the influence of manufacturing defects and errors on the photomask on the quality of chips, it is necessary to improve the quality of the photomask so as to meet the high-definition processing requirements of the integrated circuits. The basic steps for forming the pattern on the photomask are similar to those of a silicon wafer, and the basic steps also need to be subjected to processes such as exposure, development, etching and the like, and because of the optical reflection effect, reflected light and incident light interfere, a standing wave effect and multiple exposure are formed inside the photoresist, so that the deviation of the pattern size occurs, such as the problems of contour deformation, contrast reduction, edge blurring, rounding and the like. The anti-reflection coating can reduce interference of light in the photoresist and reduce processing errors. The existing anti-reflection coating comprises an organic anti-reflection coating and an inorganic anti-reflection coating, wherein the forming process and the removing process of the inorganic anti-reflection coating are complex, the organic anti-reflection coating mainly utilizes a dyeing group in a polymer to absorb ultraviolet light so as to reduce light reflection, and most of the organic anti-reflection coating needs to introduce a light absorption group through a complex synthesis process and has the problem of difficult removal through a developing process. Disclosure of Invention The present invention aims to solve at least one of the technical problems existing in the prior art. Therefore, the invention provides a preparation method of the photoetching coating, and the prepared photoetching coating has high refractive index and is easy to remove by development. The invention also provides the photoetching coating prepared by the preparation method. The invention also provides a preparation method or application of the photoetching coating in preparation of a photomask. Specifically, an embodiment of the first aspect of the present invention relates to a method for preparing a photolithographic coating, comprising the steps of: s1, mixing titanium dioxide and cesium carbonate, and calcining to obtain a solid; S2, carrying out acid leaching on the solid, carrying out solid-liquid separation, adding the obtained solid phase into a tetramethyl ammonium hydroxide solution, stirring, and stripping to obtain a titanium dioxide dispersion liquid; S3, adding a coupling agent into the titanium dioxide dispersion liquid for modification, carrying out solid-liquid separation, and carrying out ball milling to obtain modified titanium dioxide; S4, dissolving the hydroxyl-terminated hyperbranched polyester in a solvent, adding the modified titanium dioxide, performing ultrasonic dispersion, adding a vinyl-terminated compound, and mixing to obtain a mixed solution; S5, coating the mixed solution on a substrate, and heating and curing to obtain the photoetching coating. The preparation method of the photoetching coating according to the embodiment of the first aspect of the invention has at least the following beneficial effects: And calcining titanium dioxide and cesium carbonate to form cesium titanate with a layered structure, carrying out proton exchange by acid leaching to replace cesium, and carrying out expansion stripping by tetramethyl ammonium hydroxide to obtain platy titanium dioxide. After the surface of the flaky titanium dioxide is modified by a coupling agent, the dispersibility is improved, and the flaky titanium dioxide is subjected to ball milling and refining to obtain a two-dimensional flaky structure with smaller size. The two-dimensional sheet structure can form a multi-layer surface structure, so that incident light is refracted, scattered and interfered among different layers, the reflection of the incident light is reduced, and the photoetching precision is improved. The hydroxyl-terminated hyperbranched polyester and the titanium dioxide sheet layer can form hydrogen bond interaction, so that the dispersibility of the titanium dioxide is improved