# US 12,001,135 B2 · Method of manufacturing a membrane assembly > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,001,135 B2 - Document ID: US12001135B2 - Status: Granted - Kind: B2 - Application number: 17/413,845 - Filed: 2019-12-16 - Published: 2022-02-24 - Granted: 2024-06-04 - Earliest claimed: 2018-12-20 - Assignees: ASML Netherlands B.V. - Applicants: Asml Netherlands B.V. - Inventors: Paul Janssen; Jan Hendrik Willem Kuntzel - Web page: https://patentgrep.com/patent/US12001135B2 ## CPC - G03F 1/64: characterised by the frames, e.g. structure or material, including bonding means therefor - G03F 1/24: Reflection masks; Preparation thereof - G03F 1/62: Pellicles, e.g. pellicle assemblies, e.g. having membrane on support frame; Preparation thereof - G03F 7/70983: {Optical system protection, e.g. pellicles or removable covers for protection of mask} - 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 method of manufacturing a membrane assembly for EUV lithography, wherein a layer which forms at least part of a pellicle membrane is provided after one or more etching steps which define a pellicle border holding the pellicle membrane. Also provided is a pellicle substrate, the substrate including: a stack having a front face and back face, wherein one or more layers on the back face of the stack have been selectively removed to define a pellicle border region for holding the pellicle membrane before the layer which forms at least part of a pellicle membrane has been provided. ## Claims ### Claim 1 A method of manufacturing a membrane assembly for EUV lithography, wherein a layer which forms at least part of a pellicle membrane is provided at a first side of the assembly prior to etching, if any, at the first side and after one or more etching steps which define a pellicle border holding the pellicle membrane at a second side of the assembly opposite the first side. ### Claim 2 (depends on 1) The method according to claim 1, further comprising providing a stack having a front face and a back face. ### Claim 3 (depends on 2) The method according to claim 2, further comprising providing at least one emissive layer on the front face of the stack such that the pellicle assembly comprises a membrane comprising at least one membrane layer and the at least one emissive layer. ### Claim 4 (depends on 2) The method according to claim 2, further comprising providing at least one capping layer on the front face of the stack. ### Claim 5 (depends on 2) The method according to claim 2, further comprising providing a resist on the stack and patterning the resist prior to selectively removing one or more portions from the back face of the stack. ### Claim 6 (depends on 5) The method according to claim 5, further comprising etching at least a portion of the stack during selectively removing one or more portions from the back face of the stack and/or further comprising selectively removing one or more portions of the stack to form a pellicle assembly. ### Claim 7 (depends on 2) The method according to claim 2, wherein the stack comprises a planar substrate. ### Claim 8 (depends on 7) The method according to claim 7, wherein the substrate comprises at least one sacrificial layer that comprises silicon nitride, silicon oxide, tetraethyl orthosilicate (TEOS), a chemical silicon oxide or a thermal silicon oxide. ### Claim 9 (depends on 1) The method according to claim 1, wherein at least one membrane layer comprises at least one silicon layer, or a MoSiNx layer, and/or where at least one protective layer is provided and comprises a cross-linked polymer or a resist. ### Claim 10 (depends on 3) The method according to claim 3, wherein the at least one membrane layer is provided so as to be disposed between the at least one emissive layer and a face of the stack. ### Claim 11 (depends on 3) The method according to claim 3, wherein the at least one emissive layer comprises boron, Zr, Mo and/or Ru. ### Claim 12 (depends on 3) The method according to claim 3, wherein the at least one emissive layer comprises a plurality of emissive sub-layers. ### Claim 13 (depends on 6) The method according to claim 6, wherein after etching, the resulting pellicle membrane comprises a MoSiNx core layer with no further functional cap layers, or a MoSiNx core layer having at least one surface covered with a native oxide layer. ### Claim 14 (depends on 6) The method according to claim 6, wherein after etching and metal deposition, the stack comprises SiN/Ox at the front face, a pSi pellicle core layer, a low stress nitride (LSN) layer and a cap layer of Ru on Mo deposited at the back face. ### Claim 15 (depends on 1) A lithography apparatus comprising a pellicle assembly manufactured according to the method of claim 1. ### Claim 16 A pellicle substrate, the substrate comprising: a stack having a front face and back face, wherein at least part of one or more layers on the back face of the stack have been selectively removed to define a pellicle border region for holding the pellicle membrane before a layer which forms at least part of a pellicle membrane has been provided to the front face, wherein the layer which forms at least part of the pellicle membrane is provided at the front face prior to etching, if any, at the front face. ### Claim 17 (depends on 16) The pellicle substrate according to claim 16, further comprising at least one protective layer on the front face of the stack. ### Claim 18 (depends on 16) The pellicle substrate according to claim 16, wherein the stack comprises a planar substrate. ### Claim 19 (depends on 16) The pellicle substrate according to claim 16, comprising a pellicle core layer selected from a silicon-based material or a carbon-based material. ### Claim 20 (depends on 16) The pellicle substrate according to claim 16, wherein the stack comprises two or more layers of SiO/MoSiNx/MoSi2, or comprises layers of two of more layers of SiON/MoSiNx/SiON.