# US 10,120,274 B2 · Method of manufacturing photomask blank and photomask blank > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,120,274 B2 - Document ID: US10120274B2 - Status: Granted - Kind: B2 - Application number: 15/404,755 - Filed: 2017-01-12 - Published: 2017-05-04 - Granted: 2018-11-06 - Earliest claimed: 2013-07-03 - Assignees: Shin-Etsu Chemical Co., Ltd. - Applicants: Shin-Etsu Chemical Co., Ltd. - Inventors: Souichi Fukaya; Yukio Inazuki - Web page: https://patentgrep.com/patent/US10120274B2 ## CPC - G03F 1/32: Attenuating PSM [att-PSM], e.g. halftone PSM or PSM having semi-transparent phase shift portion,; Preparation thereof - G03F 1/26: Phase shift masks [PSM]; PSM blanks; Preparation thereof - 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) ## Abstract In a chamber (50), a quartz substrate (10) having a main surface on which an optical film (20) is formed is put on a susceptor (30). A flash lamp (60) is housed in a lamp house (90), and the optical film (20) is irradiated with flash light through two quartz plates (70a and 70b). A transmittance adjustment region (80) is formed on a surface of the quartz plate (70b) of the two quartz plates (70a and 70b), and the amount of light with which the optical film (20) is irradiated has in-plane distribution. If the optical film (20) is irradiated with the flash light, optical characteristics of the optical film (20) change depending on the received irradiation energy. Hence, for example, the characteristics of the optical film are not uniform, the optical film is irradiated with flash light having such irradiation energy distribution that cancels the in-plane distribution. ## Claims ### Claim 1 A method of manufacturing a photomask blank, comprising: forming an optical film on a quartz substrate transparent to exposure light; and irradiating said optical film with flash lamp light, wherein said optical film is irradiated with the flash lamp light through a quartz plate on which a region with a different transmittance to the flash lamp light is formed, and wherein the flash light irradiation energy is set to a predetermined amount of 41.5 J/cm2 or less. ### Claim 2 (depends on 1) The method of manufacturing a photomask blank according to claim 1, further comprising laminating one or more films on said optical film after the flash lamp light irradiation. ### Claim 3 (depends on 2) The method of manufacturing a photomask blank according to claim 2, wherein said one or more films are selected from other optical films different from the optical film and functional films. ### Claim 4 (depends on 1) The method of manufacturing a photomask blank according to claim 1, wherein said quartz plate includes a light shielding film on a surface thereof, and said light shielding film has a thickness that is different correspondingly to the region with a different transmittance. ### Claim 5 (depends on 4) The method of manufacturing a photomask blank according to claim 4, further comprising laminating one or more films on said optical film after the flash lamp light irradiation. ### Claim 6 (depends on 5) The method of manufacturing a photomask blank according to claim 5, wherein said one or more films are selected from other optical films different from the optical film and functional films. ### Claim 7 (depends on 4) The method of manufacturing a photomask blank according to claim 4, wherein said irradiating said optical film includes a sub-step of forming the light shielding film having the thickness that is different correspondingly to the region with a different transmittance, on a transparent quartz plate, by: forming a light shielding film on an entire surface of a second quartz plate; then irradiating the second quartz plate with flash light having in-plane intensity distribution; and sublimating the light shielding film in accordance with irradiation intensity of the flash light, to thereby deposit the sublimated light shielding film onto the transparent quartz plate. ### Claim 8 (depends on 7) The method of manufacturing a photomask blank according to claim 7, further comprising laminating one or more films on said optical film after the flash lamp light irradiation. ### Claim 9 (depends on 8) The method of manufacturing a photomask blank according to claim 8, wherein said one or more films are selected from other optical films different from the optical film and functional films. ### Claim 10 (depends on 4) The method of manufacturing a photomask blank according to claim 4, wherein said quartz plate is formed by: irradiating a substrate on which a light shielding film is formed, with flash light; and sublimating the light shielding film, to thereby deposit the sublimated light shielding film onto a transparent quartz plate. ### Claim 11 (depends on 10) The method of manufacturing a photomask blank according to claim 10, further comprising laminating one or more films on said optical film after the flash lamp light irradiation. ### Claim 12 (depends on 11) The method of manufacturing a photomask blank according to claim 11, wherein said one or more films are selected from other optical films different from the optical film and functional films. ### Claim 13 (depends on 1) The method of manufacturing a photomask blank according to claim 1, wherein said quartz plate has a surface roughness that is different correspondingly to the region with a different transmittance. ### Claim 14 (depends on 13) The method of manufacturing a photomask blank according to claim 13, further comprising laminating one or more films on said optical film after the flash lamp light irradiation. ### Claim 15 (depends on 14) The method of manufacturing a photomask blank according to claim 14, wherein said one or more films are selected from other optical films different from the optical film and functional films. ### Claim 16 (depends on 1) The method of manufacturing a photomask blank according to claim 1, wherein said optical film is a halftone phase shift film. ### Claim 17 (depends on 1) A photomask blank manufactured using the method according to claim 1.