# US 11,906,896 B2 · Reflective photomask blank and reflective photomask > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,906,896 B2 - Document ID: US11906896B2 - Status: Granted - Kind: B2 - Application number: 17/292,409 - Filed: 2019-11-01 - Published: 2022-01-13 - Granted: 2024-02-20 - Earliest claimed: 2018-11-15 - Assignees: Toppan Photomask Co., Ltd. - Applicants: Toppan Printing Co., Ltd. - Inventors: Toru Komizo; Norihito Fukugami; Genta Watanabe; Eisuke Narita - Web page: https://patentgrep.com/patent/US11906896B2 ## CPC - G03F 1/24: Reflection masks; 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 There is provided a reflective photomask blank and a reflective photomask having good irradiation resistance and capable of obtaining good transfer performance. A reflective photomask blank (10) contains a reflective layer (2) reflecting incident light and an absorption layer (4) absorbing incident light, which are formed in this order on one surface side of a substrate (1). The absorption layer (4) contains a first material selected from the group consisting of tin, indium, and tellurium and a second material containing one or two or more kinds of materials selected from the group consisting of transition metals, bismuth (Bi), and silicon (Si) at least in the outermost layer. The content of the second material is more than 20 at and less than 50 at % in the same laver. ## Claims ### Claim 1 A reflective photomask blank comprising: a reflective layer configured to reflect incident light; and an absorption layer configured to absorb incident light, the reflective layer and the absorption layer being formed in this order on one surface side of a substrate, wherein the absorption layer contains a first material selected from the group consisting of tin, indium, and tellurium and a second material containing one or two or more of materials selected from the group consisting of transition metals, bismuth (Bi), and silicon (Si) at least in an outermost layer, and a content of the second material is more than 20 at % and less than 50 at % in a same layer. ### Claim 2 (depends on 1) The reflective photomask blank according to claim 1, wherein the absorption layer further contains oxygen at least in the outermost layer, and a ratio (B/A) of a number of atoms of the second material (B) to a total number of atoms of the first material and the oxygen (A) is in a range of more than ¼ and less than 1. ### Claim 3 (depends on 1) The reflective photomask blank according to claim 1, wherein the transition metals include one or two or more selected from the group consisting of tantalum, gold, osmium, hafnium, tungsten, platinum, iridium, rhenium, and zirconium. ### Claim 4 (depends on 1) The reflective photomask blank according to claim 1, wherein when intensity of reflected light from the reflective layer is defined as Rm, intensity of reflected light from the absorption layer is defined as Ra, and an optical density OD based on the reflective layer and the absorption layer is defined by Equation (1) below, a value of the optical density OD is 1 or more, OD=−log(Ra/Rm) (1). ### Claim 5 (depends on 1) The reflective photomask blank according to claim 1, wherein a film thickness of the absorption layer is 18 nm or more and less than 45 nm. ### Claim 6 (depends on 1) The reflective photomask blank according to claim 1, wherein the reflective layer contains a multilayer reflective layer containing a multilayer structure and an intermediate layer formed on the multilayer reflective layer. ### Claim 7 (depends on 2) The reflective photomask blank according to claim 2, wherein the transition metals include one or two or more selected from the group consisting of tantalum, gold, osmium, hafnium, tungsten, platinum, iridium, rhenium, and zirconium. ### Claim 8 (depends on 2) The reflective photomask blank according to claim 2, wherein when intensity of reflected light from the reflective layer is defined as Rm, intensity of reflected light from the absorption layer is defined as Ra, and an optical density OD based on the reflective layer and the absorption layer is defined by Equation (1) below, a value of the optical density OD is 1 or more, OD=−log(Ra/Rm) (1). ### Claim 9 (depends on 3) The reflective photomask blank according to claim 3, wherein when intensity of reflected light from the reflective layer is defined as Rm, intensity of reflected light from the absorption layer is defined as Ra, and an optical density OD based on the reflective layer and the absorption layer is defined by Equation (1) below, a value of the optical density OD is 1 or more, OD=−log(Ra/Rm) (1). ### Claim 10 (depends on 2) The reflective photomask blank according to claim 2, wherein a film thickness of the absorption layer is 18 nm or more and less than 45 nm. ### Claim 11 (depends on 3) The reflective photomask blank according to claim 3, wherein a film thickness of the absorption layer is 18 nm or more and less than 45 nm. ### Claim 12 (depends on 4) The reflective photomask blank according to claim 4, wherein a film thickness of the absorption layer is 18 nm or more and less than 45 nm. ### Claim 13 (depends on 2) The reflective photomask blank according to claim 2, wherein the reflective layer contains a multilayer reflective layer containing a multilayer structure and an intermediate layer formed on the multilayer reflective layer. ### Claim 14 (depends on 3) The reflective photomask blank according to claim 3, wherein the reflective layer contains a multilayer reflective layer containing a multilayer structure and an intermediate layer formed on the multilayer reflective layer. ### Claim 15 (depends on 4) The reflective photomask blank according to claim 4, wherein the reflective layer contains a multilayer reflective layer containing a multilayer structure and an intermediate layer formed on the multilayer reflective layer. ### Claim 16 (depends on 5) The reflective photomask blank according to claim 5, wherein the reflective layer contains a multilayer reflective layer containing a multilayer structure and an intermediate layer formed on the multilayer reflective layer. ### Claim 17 A reflective photomask comprising: a reflective layer formed on one surface side of a substrate and configured to reflect incident light; and an absorption layer formed by a predetermined pattern on the reflective layer and configured to absorb incident light, wherein at least an outermost layer of the absorption layer contains a first material selected from the group consisting of tin, indium, and tellurium and a second material containing one or two or more of materials selected from the group consisting of transition metals, bismuth (Bi), and silicon (Si), and a content of the second material is more than 20 at % and less than 50 at % in a same layer.