# US 12,001,134 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 12,001,134 B2 - Document ID: US12001134B2 - Status: Granted - Kind: B2 - Application number: 18/517,796 - Filed: 2023-11-22 - Published: 2024-03-21 - Granted: 2024-06-04 - Earliest claimed: 2022-07-05 - Assignees: AGC Inc. - Applicants: AGC Inc. - Inventors: Yuya Nagata; Daijiro Akagi; Kenichi Sasaki; Hiroaki Iwaoka - Web page: https://patentgrep.com/patent/US12001134B2 ## CPC - G03F 1/24: Reflection masks; Preparation thereof - C23C 14/04: Coating on selected surface areas, e.g. using masks - C23C 14/06: characterised by the coating material ({C23C14/0021} , C23C14/04 take precedence) - C23C 14/34: Sputtering - G03F 1/26: Phase shift masks [PSM]; PSM blanks; Preparation thereof - 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 1/52: Reflectors - 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) - 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 reflective mask blank includes a substrate; a multilayer reflective film that reflects EUV light; a protection film that protects the multilayer reflective film; and a phase shift film that shifts a phase of the EUV light. The phase shift film contains it as a main component. A ratio of a maximum value of an intensity of a peak of diffracted light from the phase shift film in a 2θrange of 35° to 45° to an average value of an intensity of the diffracted light in a 28 range of 55° to 60° measured using an XRD method with a CuKα ray, upon being irradiated with the EUV light with an incident angle of θ, is 1.0 or more and 30 or less. A refractive index and an extinction coefficient of the phase shift film to the EUV light are 0.925 or less, and 0.030 or more, respectively. ## Claims ### Claim 1 A reflective mask blank comprising: a substrate; a multilayer reflective film that reflects EUV light; a protection film that protects the multilayer reflective film; and a phase shift film that shifts a phase of the EUV light, in this order, wherein the phase shift film contains Ir as a main component, a ratio (Ip/la) of a maximum value Ip of an intensity of a peak in a range of 2θ of 35 degrees to 45 degrees to an average value Ia of an intensity in a range of 2θ of 55 degrees to 60 degrees by an XRD method with a CuKα ray is 1.0 or more and 30 or less, a refractive index n of the phase shift film to the EUV light is 0.925 or less, and an extinction coefficient k of the phase shift film to the EUV light is 0.030 or more, the phase shift film contains 50 at % or more of Ir and a first element X1 selected from the group consisting of O, B, C, and N, and O content being 15 at % or less, and when a grayscale image is obtained by imaging a cross section of the phase shift film with a scanning transmission electron microscope (STEM) and a brightness profile of the grayscale image is created, skewness (Rsk) of the brightness profile is negative. ### Claim 2 (depends on 1) The reflective mask blank according to claim 1, wherein the phase shift film contains a second element X2 selected from the group consisting of Ta, Cr, Mo, W, Re, and Si. ### Claim 3 (depends on 2) The reflective mask blank according to claim 2, wherein a chemical shift of a peak of 4f7/2 of Ir contained in the phase shift film observed by an X-ray photoelectron spectroscopy is less than 0.3 eV, and a chemical shift of a peak of the second element X2 contained in the phase shift film observed by the X-ray photoelectron spectroscopy is larger than the chemical shift of the peak of 4f7/2 of Ir. ### Claim 4 (depends on 2) The reflective mask blank according to claim 2, wherein the phase shift film contains 50 at % to 98 at % of Ir, 1.0 at % to 49 at % in total of the first element X1, and 1.0 at % to 49 at % in total of the second element X2. ### Claim 5 (depends on 4) The reflective mask blank according to claim 4, wherein the phase shift film contains 60 at % to 89 at % of Ir, 1.0 at % to 10 at % in total of the first element X1, and 10 at % to 30 at % in total of the second element X2 or contains 60 at % to 85 at % of Ir, 10 at % to 30 at % in total of the first element X1, and 5.0 at % to 20 at % in total of the second element X2. ### Claim 6 (depends on 4) The reflective mask blank according to claim 4, wherein the phase shift film contains 1.0 at % to 45 at % in total of the first element X1 or 5.0 at % to 49 at % in total of the second element X2. ### Claim 7 (depends on 1) The reflective mask blank according to claim 1, wherein the extinction coefficient k of the phase shift film to the EUV light is 0.034 or more. ### Claim 8 (depends on 1) The reflective mask blank according to claim 1, wherein a full width at half maximum of the phase shift film having a highest intensity in a range of 2θ of 35 degrees to 60 degrees, measured using the XRD method with a CuKα ray, is 1.2 degrees or more. ### Claim 9 (depends on 1) The reflective mask blank according to claim 1, wherein a film thickness of the phase shift film is 20 nm or more and 60 nm or less. ### Claim 10 (depends on 1) The reflective mask blank according to claim 1, wherein the protection film contains at least one element selected from Ru, Rh, and Si. ### Claim 11 (depends on 1) The reflective mask blank according to claim 1, further comprising an etching mask film on a side opposite to the protection film with respect to the phase shift film, wherein the etching mask film contains an element selected from the group consisting of Al, Hf, Y, Cr, Nb, Ti, Mo, Ta, and Si. ### Claim 12 (depends on 11) The reflective mask blank according to claim 11, wherein the etching mask film further contains an element selected from the croup consisting of O, N, and B. ### Claim 13 (depends on 1) The reflective mask blank according to claim 1, wherein the phase shift film contains N in addition to an element selected from the group consisting of O, C, and B, as the first element. ### Claim 14 (depends on 13) The reflective mask blank according to claim 13, wherein the phase shift film contains 1.0 at % to 10 at % of N as the first element. ### Claim 15 (depends on 14) The reflective mask blank according to claim 14, wherein the phase shift film contains 1.0 at % to 15 at % of O as the first element. ### Claim 16 (depends on 1) The reflective mask blank according to claim 1, wherein the refractive index n of the phase shift film to the EUV light is 0.918 or less. ### Claim 17 (depends on 1) A reflective mask comprising the reflective mask blank according to claim 1, wherein the phase shift film includes an opening pattern. ### Claim 18 A method of manufacturing a reflective mask blank comprising a substrate; a multilayer reflective film that reflects EUV light; a protection film that protects the multilayer reflective film; and a phase shift film that shifts a phase of the EUV light in this order, the method comprising: forming the multilayer reflective film, the protection film, and the phase shift film in this order on the substrate, wherein the phase shift film contains Ir as a main component, a ratio (Ip/Ia) of a maximum value Ip of an intensity of a peak in a range of 2θ of 35 degrees to 45 degrees to an average value Ia of an intensity in a range of 2θ of 55 degrees to 60 degrees by an XRD method with a CuKα ray is 1.0 or more and 30 or less, a refractive index n of the phase shift film to the EUV light is 0.925 or less, and an extinction coefficient k of the phase shift film to the EUV light is 0.030 or more, the phase shift film contains 50 at % or more of Ir and a first element X1 selected from the group consisting of O, B, C, and N, an O content being 15 at % or less, and when a grayscale image is obtained by imaging a cross section of the phase shift film with a scanning transmission electron microscope (STEM) and a brightness profile of the grayscale image is created, skewness (Rsk) of the brightness profile is negative. ### Claim 19 (depends on 1) A method of manufacturing a reflective mask, comprising: preparing the reflective mask blank according to claim 1; and forming an opening pattern in the phase shift film.