# US 10,481,486 B2 · Mask blank, phase shift mask, and method for manufacturing semiconductor device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,481,486 B2 - Document ID: US10481486B2 - Status: Granted - Kind: B2 - Application number: 15/576,937 - Filed: 2016-09-27 - Published: 2018-05-31 - Granted: 2019-11-19 - Earliest claimed: 2015-09-30 - Assignees: Hoya Corporation - Applicants: Hoya Corporation - Inventors: Osamu Nozawa; Takenori Kajiwara; Hiroaki Shishido - Web page: https://patentgrep.com/patent/US10481486B2 ## CPC - G03F 1/32: Attenuating PSM [att-PSM], e.g. halftone PSM or PSM having semi-transparent phase shift portion,; Preparation thereof - G03F 1/54: Absorbers, e.g. of opaque materials - 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 A mask blank with a phase shift film and a light shielding film, laminated on a transparent substrate. The phase shift film transmits ArF exposure light at a transmittance (τ) 2%≥τ≤30% and generates a phase difference (Δϕ) of 150°≥Δϕ≤200°, and is formed from a material containing Si and not substantially containing Cr, and has a lower layer (L) and an upper layer (U) laminated from the transparent substrate side. A refractive index n for layer L is below the transparent substrate while n for layer U is higher, and the layer L has an extinction coefficient k higher than layer U. The light shielding film includes a layer in contact with the phase shift film that is formed from a material containing Cr, has a n lower than layer U, and has an extinction coefficient k higher than layer U. ## Claims ### Claim 1 A mask blank having a structure in which a phase shift film and a light shielding film are laminated in this order on a transparent substrate, wherein the phase shift film has a function to transmit exposure light of an ArF excimer laser at a transmittance of not less than 2% and not more than 30%, and a function to generate a phase difference of not less than 150 degrees and not more than 200 degrees between the exposure light transmitted through the phase shift film and the exposure light transmitted through air for the same distance as a thickness of the phase shift film, wherein the phase shift film is formed from a material containing silicon and not substantially containing chromium, and includes a structure in which a lower layer and an upper layer are laminated from the transparent substrate side, wherein the lower layer has a refractive index n lower than the transparent substrate at a wavelength of the exposure light, wherein the upper layer has a refractive index n higher than the transparent substrate at a wavelength of the exposure light, wherein the lower layer has an extinction coefficient k higher than the upper layer at a wavelength of the exposure light, wherein the light shielding film includes a layer in contact with the phase shift film, and wherein the layer in contact with the phase shift film is formed from a material containing chromium, has a refractive index n lower than the upper layer at a wavelength of the exposure light, and has an extinction coefficient k higher than the upper layer at a wavelength of the exposure light. ### Claim 2 (depends on 1) The mask blank according to claim 1, wherein the upper layer has a thickness greater than the lower layer. ### Claim 3 (depends on 1) The mask blank according to claim 1, wherein the lower layer has a thickness of less than 10 nm. ### Claim 4 (depends on 1) The mask blank according to claim 1, wherein the refractive index n of the lower layer is 1.5 or less. ### Claim 5 (depends on 1) The mask blank according to claim 1, wherein the refractive index n of the upper layer is greater than 2.0. ### Claim 6 (depends on 1) The mask blank according to claim 1, wherein the refractive index n of the layer in contact with the phase shift film is 2.0 or less. ### Claim 7 (depends on 1) The mask blank according to claim 1, wherein the extinction coefficient k of the lower layer is 2.0 or more. ### Claim 8 (depends on 1) The mask blank according to claim 1, wherein an extinction coefficient k of the upper layer is 0.8 or less. ### Claim 9 (depends on 1) The mask blank according to claim 1, wherein the extinction coefficient k of the layer in contact with the phase shift film is 1.0 or more. ### Claim 10 (depends on 1) The mask blank according to claim 1, wherein the lower layer is formed in contact with a surface of the transparent substrate. ### Claim 11 (depends on 1) The mask blank according to claim 1, wherein the upper layer has in its surface layer a layer having an oxygen content higher than in the portion of the upper layer excluding the surface layer. ### Claim 12 (depends on 1) The mask blank according to claim 1, wherein a back-surface reflectance to the exposure light entering from the transparent substrate side is 30% or more. ### Claim 13 A phase shift mask having a structure in which a phase shift film having a transfer pattern formed therein and a light shielding film having a light shielding pattern formed therein are laminated in this order on a transparent substrate, wherein the phase shift film has a function to transmit exposure light of an ArF excimer laser at a transmittance of not less than 2% and not more than 30%, and a function to generate a phase difference of not less than 150 degrees and not more than 200 degrees between the exposure light transmitted through the phase shift film and the exposure light transmitted through air for the same distance as a thickness of the phase shift film, wherein the phase shift film is formed from a material containing silicon and not substantially containing chromium, and includes a structure in which a lower layer and an upper layer are laminated from the transparent substrate side, wherein the lower layer has a refractive index n lower than the transparent substrate at a wavelength of the exposure light, wherein the upper layer has a refractive index n higher than the transparent substrate at a wavelength of the exposure light, wherein the lower layer has an extinction coefficient k higher than the upper layer at a wavelength of the exposure light, wherein the light shielding film includes a layer in contact with the phase shift film, and wherein the layer in contact with the phase shift film is formed from a material containing chromium, has a refractive index n lower than the upper layer at a wavelength of the exposure light, and has an extinction coefficient k higher than the upper layer at a wavelength of the exposure light. ### Claim 14 (depends on 13) The phase shift mask according to claim 13, wherein the upper layer has a thickness greater than the lower layer. ### Claim 15 (depends on 13) The phase shift mask according to claim 13, wherein the lower layer has a thickness of less than 10 nm. ### Claim 16 (depends on 13) The phase shift mask according to claim 13, wherein the refractive index n of the lower layer is 1.5 or less. ### Claim 17 (depends on 13) The phase shift mask according to claim 13, wherein the refractive index n of the upper layer is greater than 2.0. ### Claim 18 (depends on 13) The phase shift mask according to claim 13, wherein the refractive index n of the layer in contact with the phase shift film is 2.0 or less. ### Claim 19 (depends on 13) The phase shift mask according to claim 13, wherein the extinction coefficient k of the lower layer is 2.0 or more. ### Claim 20 (depends on 13) The phase shift mask according to claim 13, wherein an extinction coefficient k of the upper layer is 0.8 or less. ### Claim 21 (depends on 13) The phase shift mask according to claim 13, wherein the extinction coefficient k of the layer in contact with the phase shift film is 1.0 or more. ### Claim 22 (depends on 13) The phase shift mask according to claim 13, wherein the lower layer is formed in contact with a surface of the transparent substrate. ### Claim 23 (depends on 13) The phase shift mask according to claim 13, wherein the upper layer has in its surface layer a layer having an oxygen content higher than in the portion of the upper layer excluding the surface layer. ### Claim 24 (depends on 13) The phase shift mask according to claim 13, wherein a back-surface reflectance to the exposure light entering from the transparent substrate side is 30% or more. ### Claim 25 (depends on 13) A method for manufacturing a semiconductor device comprising the step of using the phase shift mask according to claim 13 and exposure-transferring a transfer pattern to a resist film on a semiconductor substrate.