# US 12,001,133 B2 · Reflective mask blank, reflective mask, method of manufacturing reflective mask blank, and method of manufacturing reflective mask > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,001,133 B2 - Document ID: US12001133B2 - Status: Granted - Kind: B2 - Application number: 18/382,356 - Filed: 2023-10-20 - Published: 2024-02-08 - Granted: 2024-06-04 - Earliest claimed: 2022-04-01 - Assignees: AGC Inc. - Applicants: AGC Inc. - Inventors: Takuma Kato; Daijiro Akagi; Takeshi Okato; Ryusuke Oishi; Yusuke Ono - Web page: https://patentgrep.com/patent/US12001133B2 ## CPC - G03F 1/24: Reflection masks; Preparation thereof - G03F 1/48: Protective coatings - G03F 1/52: Reflectors - G03F 1/54: Absorbers, e.g. of opaque materials - G03F 1/78: by charged particle beam [CPB], e.g. electron beam patterning of masks - 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) ## Abstract A reflective mask blank includes a substrate; a multilayer reflective film that reflects EUV light; a protection film that protects the multilayer reflective film; and an absorption film that absorbs the EUV light, in this order. The protection film contains 50 at % or more of Rh. When a band-shaped gray scale image parallel to an interface between the protection film and the multilayer reflective film is obtained by imaging a cross section of the protection film with a transmission electron microscope (TEM) and a luminance profile of the gray scale image in a longitudinal direction of the gray scale image is created, a number of peaks of the luminance profile per 100 nm in the longitudinal direction of the gray scale image is 50 or more. ## Claims ### Claim 1 A reflective r cask blank rising: a substrate; a multilayer reflective film that reflects EUV light; a protection film that protects the multilayer reflective film; and an absorption film that absorbs the EUV light, the substrate, the multilayer reflective film, the protect on film, and the absorption film being arranged in this order, wherein the protection film contains 50 at % or more of Rh, and when a hand-shaped gray scale image parallel to an interface between the protection film and the multilayer reflective film is obtained by imaging a cross section of the protection film with a transmission electron microscope (TEM) and a luminance profile of the gray scale image in a longitudinal direction of the gray scale image is created, a number of peaks of the luminance profile per 100 nm in the longitudinal direction of the gray scale image is 50 or more. ### Claim 2 (depends on 1) The reflective mask blank according to claim 1, wherein, the multilayer reflective film includes a Si film having a content of oxygen atoms of 15 at % or less as an uppermost layer in contact with the protection film. ### Claim 3 (depends on 1) The reflective mask blank according to claim 1, wherein the protection film contains, as a metal element, only Rh, or contains, as metal elements, Rh and an element selected from the group consisting of Ru, Pd, Ir, Pt, Zr, Nb, Ta, and Ti. ### Claim 4 (depends on 1) The reflective mask blank according to claim 1, wherein the protection film contains, as metal elements, Rh and an element X, selected from the group consisting of Ru, Pd, Ir, Pt, Zr, Nb, Ta, and Ti in addition to Rh, and an element ratio of Rh to X (Rh:X) in the protection film is 50:50 to 99:1. ### Claim 5 (depends on 1) The reflective mask blank according to claim 1, wherein the protection film includes an upper layer containing 50 at % or more of Rh, and a lower layer containing 50 at % or more of Ru, Pd, Ir, Pt, Zr, Nb, Ta, or Ti, and the lower layer is provided between the upper layer and the multilayer reflective film. ### Claim 6 (depends on 5) The reflective mask blank according to claim 5, wherein in the protection film, a thickness of the lower layer is 0.5 nm or more and 2.0 nm or less, and a thickness of the upper layer is 0.5 nm or more and 4.0 nm or less. ### Claim 7 (depends on 1) The reflective mask blank according to claim 1, wherein the protection film is composed of a single layer containing 50 at % or more of Rh. ### Claim 8 (depends on 1) The reflective mask blank according to claim 1, wherein a thickness of the protection film is 1.5 am or more and 4.0 am or less. ### Claim 9 (depends on 1) The reflective mask blank according to claim 1, wherein a film density of the protection film is 10.0 g/cm3 or more and 14.0 g/cm3 or less. ### Claim 10 (depends on 1) The reflective mask. blank according to claim 1, wherein a root mean square (RMS) roughness of a surface of the protection film on which the absorption film is formed is 0.300 nm or less. ### Claim 11 (depends on 1) The reflective mask blank according to claim 1, wherein the absorption film contains a metal element selected from the group consisting of Ru, Ta, Cr, Nb, Pt, Ir, Re, W, Mn, Au, Si, and Al. ### Claim 12 (depends on 11) The reflective mask blank according to claim 11, wherein the absorption film further contains a non-metal element selected from the group consisting of O, N, C, and B. ### Claim 13 (depends on 1) The reflective mask blank according to claim 1 further comprising an etching mask film on the absorption film opposite to where the protection film is provided, wherein the etching mask film contains a metal element selected from the group consisting of Cr Nb, Ti, Mo, Ta, and Si. ### Claim 14 (depends on 13) The reflective mask blank according to claim 13, wherein the etching mask film further contains a non-metal element selected from the group consisting of O, N, C, and B. ### Claim 15 (depends on 1) A reflective mask comprising the reflective mask blank of claim 1, wherein the absorption film includes an opening pattern. ### Claim 16 (depends on 1) A method of manufacturing the reflective mask blank of claim 1, comprising: forming the multilayer reflective film and the protection film in this order in a same vacuum chamber. ### Claim 17 (depends on 16) The method of manufacturing a reflective mask blank according to claim 16 further comprising: controlling the vacuum chamber to 0.035 Pa or less during the forming of the protection film. ### Claim 18 (depends on 1) A method of manufacturing a reflective mask comprising: preparing the reflective mask blank of claim 1; and forming an opening pattern in the absorption film.