# US 10,310,373 B2 · Method for manufacturing mask blank substrate, method for manufacturing mask blank and method for manufacturing transfer mask > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,310,373 B2 - Document ID: US10310373B2 - Status: Granted - Kind: B2 - Application number: 14/760,506 - Filed: 2014-01-08 - Published: 2015-12-10 - Granted: 2019-06-04 - Earliest claimed: 2013-01-18 - Assignees: Hoya Corporation - Applicants: Hoya Corporation - Inventors: Takeyuki Yamada; Takahito Nishimura - Web page: https://patentgrep.com/patent/US10310373B2 ## CPC - G03F 1/60: Substrates - B24B 37/04: designed for working plane surfaces - C23C 14/0036: {Reactive sputtering} - C23C 14/0641: {Nitrides (C23C14/0617 takes precedence)} - C23C 14/0676: {Oxynitrides} - C23C 14/14: Metallic material, boron or silicon - G03F 1/32: Attenuating PSM [att-PSM], e.g. halftone PSM or PSM having semi-transparent phase shift portion,; Preparation thereof - G03F 1/50: Mask blanks not covered by G03F1/20 - G03F1/34; Preparation thereof - G03F 1/80: Etching - G03F: PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR; (phototypographic composing devices B41B; photosensitive materials or processes for photographic purposes G03C; electrophotography, sensitive layers or processes therefor G03G) - B24B: MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING (grinding of gear teeth B23F, of screw-threads B23G1/36; by electro-erosion B23H; abrasive or related blasting B24C; tools for grinding, buffing or sharpening B24D; polishing compositions C09G1/00; abrasives C09K3/14; electrolytic etching or polishing C25F3/00; grinding arrangements for use on assembled railway tracks E01B31/17); DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS - C23C: COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL (making metal-coated products by extrusion B21C23/22; covering with metal by connecting pre-existing layers to articles, see the relevant places, e.g. B21D39/00, B23K; metallising of glass C03C; metallising mortars, concrete, artificial stone, ceramics or natural stone C04B41/00; enamelling of, or applying a vitreous layer to, metals C23D; treating metal surfaces or coating of metals by electrolysis or electrophoresis C25D; single-crystal film growth C30B; by metallising textiles D06M11/83; decorating textiles by locally metallising D06Q1/04) ## Abstract A method for manufacturing a low-defect and high-quality mask blank substrate with minimized transfer pattern defects and high mechanical strength, particularly such that the occurrence of a phenomenon where a portion of a transfer pattern and a principal surface of the substrate therebeneath are broken off together is minimized such that there is little pattern loss. The mask blank is manufactured by preparing a mask blank substrate (X) having a substrate principal surface (X1) polished using a polishing solution containing abrasive grains, etching the substrate principal surface (X1) using catalyst-referred etching so as to remove damaged portions from the principal surface (X1), and then depositing a thin film that forms a transfer pattern on the substrate principal surface (X1) of the substrate (X) by sputtering. ## Claims ### Claim 1 A method for manufacturing a mask blank substrate for creating a transfer pattern forming thin film on a principal surface of the mask blank substrate, the method comprising the steps of: polishing the mask blank substrate using a polishing solution containing abrasive grains, wherein the abrasive grains are chemically modified colloidal silica, or wherein the polishing solution contains colloidal silica, an additive, and alkali compound, the additive being at least one selected from the group consisting of hydroxyethyl cellulose, hydroxypropyl cellulose, polyvinyl alcohol, polyvinylpyrrolidone, and prolan; and conducting a Catalyst Referred Etching subsequent to the polishing, including contacting a processing fluid that under normal conditions does not show solubility to the principal surface of the substrate, and under condition of making a processing reference surface of a catalytic surface plate to be in contact with or to be in close proximity to the principal surface, causing the substrate and the processing reference surface to move relative to each other so as to subject the principal surface to Catalyst Referred Etching to remove machining-affected portions of the principal surface, wherein the processing reference surface is placed above the principal surface of the substrate so as to face the principal surface, wherein the processing reference surface is formed by creating a film of catalyst on a pad including foaming resin, and wherein the machining-affected portions are generated by the polishing. ### Claim 2 (depends on 1) The method for manufacturing a mask blank substrate according to claim 1, comprising the step of cleaning for removing foreign matters attached to the principal surface, the cleaning being conducted after removal of the polishing solution attached to the principal surface during the polishing and before the Catalyst Referred Etching. ### Claim 3 (depends on 1) The method for manufacturing a mask blank substrate according to claim 1, wherein the substrate comprises a glass material. ### Claim 4 A method for manufacturing a mask blank by creating a transfer pattern forming thin film on a principal surface of a mask blank substrate polished using a polishing solution containing abrasive grains, the method comprising the steps of: preparing a mask blank substrate polished using a polishing solution containing abrasive grains, wherein the abrasive grains are chemically modified colloidal silica, or wherein the polishing solution contains colloidal silica, an additive, and alkali compound, the additive being at least one selected from the group consisting of hydroxyethyl cellulose, hydroxypropyl cellulose, polyvinyl alcohol, polyvinylpyrrolidone, and prolan; conducting a Catalyst Referred Etching including contacting a processing fluid that under normal conditions does not show solubility to the principal surface of the substrate, and under condition of making a processing reference surface of a catalytic surface plate to be in contact with or to be in close proximity to the principal surface, causing the substrate and the processing reference surface to move relative to each other to subject the principal surface to Catalyst Referred Etching to remove machining-affected portions of the principal surface, wherein the processing reference surface is placed above the principal surface of the substrate so as to face the principal surface, wherein the processing reference surface is formed by creating a film of catalyst on a pad including foaming resin, and wherein the machining-affected portions are generated by the polishing of the mask blank substrate; and creating a transfer pattern forming thin film wherein, after the Catalyst Referred Etching, a transfer pattern forming thin film is created on the principal surface by a sputtering method. ### Claim 5 (depends on 4) The method for manufacturing a mask blank according to claim 4, wherein the substrate comprises a glass material. ### Claim 6 (depends on 4) The method for manufacturing a mask blank according to claim 4, wherein at least the processing reference surface of the catalytic surface plate comprises at least one material selected from the group consisting of a transition metal selected from aluminum, scandium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, yttrium, zirconium, niobium, molybdenum, technetium, ruthenium, rhodium, palladium, hafnium, tantalum, tungsten, rhenium, osmium, iridium, platinum, and gold, and an alloy including at least one of the transition metals. ### Claim 7 (depends on 4) The method for manufacturing a mask blank according to claim 4, wherein the processing fluid is pure water. ### Claim 8 (depends on 4) The method for manufacturing a mask blank according to claim 4, wherein the substrate comprises a glass material, the processing reference surface comprises platinum, and the processing fluid is pure water. ### Claim 9 (depends on 5) The method for manufacturing a mask blank according to claim 5, wherein the glass material is a synthetic quartz glass. ### Claim 10 (depends on 4) The method for manufacturing a mask blank according to claim 4, comprising the step of cleaning for removing foreign matters attached to the principal surface, the cleaning being conducted after removal of the polishing solution attached to the principal surface during the polishing and before the Catalyst Referred Etching. ### Claim 11 (depends on 4) The method for manufacturing a mask blank according to claim 4, wherein the transfer pattern forming thin film comprises a material comprising silicon. ### Claim 12 (depends on 4) A method for manufacturing a transfer mask, wherein the transfer pattern forming thin film of a mask blank obtained by the method for manufacturing a mask blank according to claim 4 is patterned to form a transfer pattern on the principal surface. ### Claim 13 (depends on 12) A method for manufacturing a transfer mask according to claim 12 comprising the step of physical cleaning after forming the transfer pattern. ### Claim 14 (depends on 12) A method for manufacturing a transfer mask according to claim 12, wherein the transfer mask comprises a transfer pattern with a pattern line width of 100 nm or less. ### Claim 15 (depends on 1) The method for manufacturing a mask blank substrate according to claim 1, wherein the machining-affected portions are removed by removing the principal surface up to the depth based on the polishing. ### Claim 16 (depends on 1) The method for manufacturing a mask blank substrate according to claim 1, wherein the relative movement is conducted by rotating the catalytic surface plate against the substrate. ### Claim 17 (depends on 4) The method for manufacturing a mask blank according to claim 4, wherein the machining-affected portions are removed by removing the principal surface up to the depth based on the polishing. ### Claim 18 (depends on 4) The method for manufacturing a mask blank according to claim 4, wherein the relative movement is conducted by rotating the catalytic surface plate against the substrate. ### Claim 19 (depends on 1) The method according to claim 1, wherein the abrasive grains are chemically modified colloidal silica. ### Claim 20 (depends on 4) The method according to claim 4, wherein the abrasive grains are chemically modified colloidal silica.