# US 11,307,489 B2 · EUV photomask and manufacturing method of the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,307,489 B2 - Document ID: US11307489B2 - Status: Granted - Kind: B2 - Application number: 16/542,179 - Filed: 2019-08-15 - Published: 2020-03-05 - Granted: 2022-04-19 - Earliest claimed: 2018-08-30 - Assignees: Taiwan Semiconductor Manufacturing Company, Ltd. - Applicants: Taiwan Semiconductor Manufacturing Company Ltd. - Inventors: Feng Yuan Hsu; Tran-Hui Shen; Ching-Hsiang Hsu - Web page: https://patentgrep.com/patent/US11307489B2 ## CPC - G03F 1/24: Reflection masks; Preparation thereof - G03F 1/38: Masks having auxiliary features, e.g. special coatings or marks for alignment or testing; Preparation thereof - Y02P 70/50: Manufacturing or production processes characterised by the final manufactured product - 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) - Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS ## Abstract A photomask and a method of manufacturing a photomask are provided. According to an embodiment, a method includes: providing a substrate; depositing a reflective layer over the substrate; depositing a capping layer over the reflective layer; depositing an absorption layer over the capping layer; and treating the reflective layer by a laser beam to form a border region. The laser beam includes a pulse duration of less than about ten picoseconds. ## Claims ### Claim 1 A method, comprising: providing a substrate; depositing a reflective layer over the substrate; depositing a capping layer over the reflective layer; depositing an absorption layer over the capping layer; and treating the reflective layer by a laser beam to form a border region, the laser beam comprising a pulse duration of less than about ten picoseconds. ### Claim 2 (depends on 1) The method according to claim 1, wherein treating the reflective layer causes a thickness of the border region to be less than a thickness of a remaining portion in the reflective layer. ### Claim 3 (depends on 1) The method according to claim 1, wherein treating the reflective layer causes the capping layer and the absorption layer to have substantially same thicknesses during the treating of the reflective layer. ### Claim 4 (depends on 1) The method according to claim 1, wherein depositing a reflective layer comprises alternatingly depositing molybdenum layers and silicon layers. ### Claim 5 (depends on 1) The method according to claim 1, wherein treating the reflective layer to form a border region comprises forming molybdenum silicide in the border region. ### Claim 6 (depends on 1) The method according to claim 1, wherein the laser beam comprises a beam profile having a top-hat shape. ### Claim 7 (depends on 1) The method according to claim 1, wherein treating the reflective layer comprises forming a transition zone adjacent to the border region, the transition zone comprising a reflectivity value between about 0.05% and about 60%. ### Claim 8 (depends on 7) The method according to claim 7, wherein a width ratio between the transition zone and the border region is between about 0.01 and about 0.05. ### Claim 9 (depends on 1) The method according to claim 1, further comprising patterning the absorption layer by etching through a portion of the absorption layer and exposing the capping layer. ### Claim 10 (depends on 1) The method according to claim 1, wherein the border region comprises a rectangular ring shape from a top-view perspective. ### Claim 11 A method of manufacturing a photomask, comprising: providing a substrate; depositing a multilayer stack comprising Mo/Si layers over the substrate, the multilayer stack comprising a first portion and a second portion circumscribing the first portion; depositing a capping layer over the multilayer stack; forming an absorption layer over the capping layer; and performing a treatment on the second portion using a laser beam to form molybdenum silicide in the second portion, the laser beam comprising a beam intensity of less than an ablation energy of the multilayer stack and a pulse duration of less than a nanosecond. ### Claim 12 (depends on 11) The method according to claim 11, wherein performing a treatment on the second portion using a laser beam further comprises controlling the beam intensity to be higher than an ionization energy of the Mo/Si layers. ### Claim 13 (depends on 11) The method according to claim 11, wherein performing a treatment on the second portion using a laser beam comprises forming a recess on a surface of the absorption layer, the recess following a pattern of the second portion. ### Claim 14 (depends on 11) The method according to claim 11, wherein the pulse duration is between about 50 femtoseconds and about 10 picoseconds. ### Claim 15 (depends on 11) The method according to claim 11, wherein forming an absorption layer over the capping layer comprises patterning the absorption layer, further comprising forming an antireflective layer over the absorption layer, the antireflective layer following a pattern of the absorption layer. ### Claim 16 A photomask, comprising: a substrate; a multilayer stack over the substrate, the multilayer stack comprising alternating molybdenum layers and silicon layers and including a first area and a second area laterally surrounding the first area, the second area comprising a thickness less than a thickness of the first area; a cap layer over the multilayer stack; and an absorption layer over the cap layer. ### Claim 17 (depends on 16) The photomask according to claim 16, wherein the second area comprises molybdenum silicide. ### Claim 18 (depends on 16) The photomask according to claim 16, wherein the second area comprises a reflectivity value less than a reflectivity value of the first area with respect to extreme ultraviolet. ### Claim 19 (depends on 18) The photomask according to claim 18, wherein the multilayer stack further comprises a third area between the first area and the second area, and the third area comprises a reflectivity value between about 0.05% and about 60% with respect to extreme ultraviolet. ### Claim 20 (depends on 16) The photomask according to claim 16, wherein the absorption layer comprises a circuit pattern and a portion of the cap layer is exposed through the circuit pattern.