# US 12,117,737 B2 · Apparatus and method for cleaning a support structure in a lithographic system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,117,737 B2 - Document ID: US12117737B2 - Status: Granted - Kind: B2 - Application number: 17/418,487 - Filed: 2019-12-18 - Published: 2022-03-03 - Granted: 2024-10-15 - Earliest claimed: 2018-12-28 - Assignees: ASML Holding N.V. - Applicants: ASML Holding N.V. - Inventors: Keane Michael Levy - Web page: https://patentgrep.com/patent/US12117737B2 ## CPC - G03F 7/70733: {Handling masks and workpieces, e.g. exchange of workpiece or mask, transport of workpiece or mask} - G03F 7/70691: {Handling of masks or workpieces} - G03F 7/707: {Chucks, e.g. chucking or un-chucking operations or structural details} - G03F 7/70708: {being electrostatic; Electrostatically deformable vacuum chucks} - G03F 7/70716: {Stages} - G03F 7/70783: {Handling stress or warp of chucks, masks or workpieces, e.g. to compensate for imaging errors or considerations related to warpage of masks or workpieces due to their own weight} - G03F 7/70925: {Cleaning, i.e. actively freeing apparatus from pollutants, e.g. using plasma cleaning} - H10P 72/0406: {for cleaning followed by drying, rinsing, stripping, blasting or the like} - H10P 72/7614: {characterised by a plurality of individual support members, e.g. support posts or protrusions} - 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) - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 ## Abstract Apparatus for and method of removing a contaminant from a working surface of a lithography support such as a reticle or wafer stage in an EUV or a DUV photolithography system in which abase supporting the substrate is provided with a surface profile so as to be thicker towards a middle portion of the base so that when a substrate supported by the base is pressed between the working surface and the base the contaminant is transferred from the working surface to the substrate. ## Claims ### Claim 1 An apparatus for use in a system for generating radiation for photolithography, the apparatus comprising: a base arranged to support a substrate on a first surface of the base, the first surface being configured to have a surface profile that is higher at a middle portion of the first surface than at a laterally peripheral portion of the first surface; and a clamping structure configured to make contact with the substrate, wherein the clamping structure is configured to tilt with respect to the base, such that the clamping structure exerts a force on the substrate, and wherein an insert is disposed between the substrate and the base, at least one lateral surface of the insert having convex curvature. ### Claim 2 (depends on 1) The apparatus of claim 1, wherein the base is a part of a substrate transport module. ### Claim 3 (depends on 1) The apparatus of claim 1, wherein the surface profile comprises a first protrusion at a first position at the middle portion of the first surface and a second protrusion at a second position between the first protrusion and the laterally peripheral portion of the first surface, the base having a first thickness at the first protrusion and a second thickness at the second protrusion, the first thickness being greater than the second thickness. ### Claim 4 (depends on 3) The apparatus of claim 3, wherein the first protrusion is configured to provide a spherical contact with the substrate. ### Claim 5 (depends on 3) The apparatus of claim 3, wherein the first protrusion and the second protrusion have a substantially hemispherical cross section. ### Claim 6 (depends on 1) The apparatus of claim 1, wherein the surface profile comprises a first protrusion at a first position at the middle portion of the first surface, a second protrusion at a second position between the first protrusion and the laterally peripheral portion of the first surface, and a third protrusion at a third position between the second protrusion and the laterally peripheral portion of the first surface, the base having a first thickness at the first protrusion, a second thickness at the second protrusion, and a third thickness at the third protrusion, the first thickness being greater than the second thickness and the second thickness being greater than the third thickness. ### Claim 7 (depends on 3) The apparatus of claim 3, wherein the first protrusion is integral with the base. ### Claim 8 (depends on 3) The apparatus of claim 3, wherein the first protrusion is formed on the base. ### Claim 9 (depends on 1) The apparatus of claim 1, wherein the substrate comprises a cleaning reticle. ### Claim 10 An apparatus for use in a system for generating radiation for photolithography, the apparatus comprising: a substrate; a base arranged to support the substrate on a first surface of the base, the substrate being supported in a manner such that a middle portion of a top surface of the substrate extends vertically farther from the base than a peripheral portion of the substrate; and a clamping structure configured to make contact with the substrate, wherein the clamping structure is configured to tilt with respect to the base such that the clamping structure exerts a force on the substrate, and wherein an insert is disposed between the substrate and the base, at least one lateral surface of the insert having convex curvature. ### Claim 11 (depends on 10) The apparatus of claim 10, wherein the base has convex curvature. ### Claim 12 (depends on 10) The apparatus of claim 10, wherein at least one surface of the substrate has convex curvature.