# US 9,753,383 B2 · Radiation source and lithographic apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,753,383 B2 - Document ID: US9753383B2 - Status: Granted - Kind: B2 - Application number: 14/409,048 - Filed: 2013-06-13 - Published: 2015-11-26 - Granted: 2017-09-05 - Earliest claimed: 2012-06-22 - Assignees: ASML Netherlands B.V. - Applicants: ASML Netherlands B.V. - Inventors: Michel Riepen; Dzmitry Labetski; Wilbert Jan Mestrom; Wim Ronald Kampinga; Jan Okke Nieuwenkamp; Jacob Brinkert; Henricus Jozef Castelijns; Nicolaas Ten Kate; Hendrikus Gijsbertus Schimmel; Hans Jansen; Dennis Jozef Maria Paulussen; Brian Vernon Virgo; Reinier Theodorus Martinus Jilisen; Ramin Badie; Albert Pieter Rijpma; Johannes Christiaan Leonardus Franken; Peter Van Putten; Gerrit Van Der Straaten - Web page: https://patentgrep.com/patent/US9753383B2 ## CPC - G03F 7/70983: {Optical system protection, e.g. pellicles or removable covers for protection of mask} - G03F 7/70008: {Production of exposure light, i.e. light sources} - G03F 7/70033: {by plasma extreme ultraviolet [EUV] sources} - G03F 7/70916: {Pollution mitigation, i.e. mitigating effect of contamination or debris, e.g. foil traps} - G21K 1/06: using diffraction, refraction or reflection, e.g. monochromators (G21K1/10, G21K7/00 take precedence) - G21K 5/08: Holders for targets or for other objects to be irradiated - H05G 2/008: {involving an energy-carrying beam in the process of plasma generation} - H05G 2/0094: {Reduction, prevention or protection from contamination; Cleaning} - F15D 1/0065: {using active means, e.g. supplying external energy or injecting fluid} - Y10T 137/206: Flow affected by fluid contact, energy field or coanda effect [e.g., pure fluid device or system] - 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) - G21K: HANDLING OF PARTICLES OR IONISING RADIATION NOT OTHERWISE PROVIDED FOR; IRRADIATION DEVICES; GAMMA RAY OR X-RAY MICROSCOPES - H05G: X-RAY TECHNIQUE (investigating or analysing materials by the use of X-rays G01N23/00; apparatus for X-ray photography G03B42/02; X-ray tubes H01J35/00; TV systems having X-ray input H04N5/321) - F15D: FLUID DYNAMICS, i.e. METHODS OR MEANS FOR INFLUENCING THE FLOW OF GASES OR LIQUIDS - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A radiation source comprising a fuel source configured to deliver fuel to a location from which the fuel emits EUV radiation. The radiation source further comprises an immobile fuel debris receiving surface provided with a plurality of grooves. The grooves have orientations which are arranged to direct the flow of liquid fuel under the influence of gravity in one or more desired directions. ## Claims ### Claim 1 A radiation source comprising: a fuel source configured to deliver fuel to a location from which the fuel emits EUV radiation; and an immobile fuel debris receiving surface provided with a plurality of vanes and a plurality of grooves, the grooves being arranged to direct a flow of liquid fuel under the influence of gravity along a same plane towards a drain or gutter, wherein the plurality of grooves are provided in the vanes, and wherein the vanes are reflective structures located in the vicinity of an intermediate focus of the radiation source. ### Claim 2 (depends on 1) The radiation source of claim 1, wherein the immobile fuel debris receiving surface is provided with a plurality of vanes, and wherein the plurality of grooves are provided in the vanes. ### Claim 3 (depends on 1) The radiation source of claim 1, wherein at least some of the grooves have a cross-sectional size and/or shape that gives rise to capillary action. ### Claim 4 (depends on 1) The radiation source of claim 1, wherein at least some of the grooves have a cross-sectional size and/or shape that gives rise to wicking action which draws liquid fuel into the grooves. ### Claim 5 (depends on 1) The radiation source of claim 1, wherein the grooves comprise a set of grooves that extend substantially parallel to one another. ### Claim 6 (depends on 1) The radiation source of claim 1, wherein adjacent vanes are separated by a distance that is equal to or less than six millimeters. ### Claim 7 (depends on 1) The radiation source of claim 1, wherein the vanes are heated by a heating apparatus to a temperature that is above the melting temperature of the fuel and below the evaporation temperature of the fuel. ### Claim 8 An apparatus comprising a radiation source having a fuel source configured to deliver fuel to a location from which the fuel emits EUV radiation, wherein the radiation source further comprises an immobile fuel debris receiving surface provided with a plurality of vanes and a plurality of grooves, the grooves being arranged to direct a flow of liquid fuel under the influence of gravity along a same plane towards a drain or gutter, wherein the plurality of grooves are provided in the vanes, and wherein the vanes are reflective structures located in the vicinity of an intermediate focus of the radiation source. ### Claim 9 A method of generating EUV radiation using a radiation source, the method comprising: delivering fuel to a location at which a plasma that emits EUV radiation is generated using the fuel; and receiving liquid fuel on an immobile surface of the radiation source, wherein grooves provided in a plurality of vanes on the immobile surface direct the flow of liquid fuel under the influence of gravity along a same plane towards a drain or gutter, wherein the vanes are reflective structures located in the vicinity of an intermediate focus of the radiation source. ### Claim 10 A radiation source comprising: a fuel source configured to deliver fuel to a location from which the fuel emits EUV radiation; a fuel debris receiving surface; and a conduit connected to a source of liquid fuel and configured to deliver the liquid fuel from the source via openings through a wall of the conduit directly onto the fuel debris receiving surface disposed outside of the conduit, such that a coating of liquid fuel is maintained and continuously flows across the fuel debris receiving surface. ### Claim 11 (depends on 10) The radiation source of claim 10, wherein the fuel debris receiving surface comprises a plurality of vanes. ### Claim 12 A method of controlling contamination in a radiation source that uses fuel to generate EUV radiation, the method comprising: delivering liquid fuel from a source connected to a conduit directly onto a fuel debris receiving surface via openings through a wall of the conduit, such that a coating of liquid fuel is maintained and continuously flows across the fuel debris receiving surface, wherein the fuel debris receiving surface is disposed outside of the conduit. ### Claim 13 A method of generating EUV radiation using a radiation source, the method comprising: delivering fuel to a location at which a plasma that emits EUV radiation is generated using the fuel; receiving liquid fuel on an immobile surface of the radiation source, and using grooves provided in a plurality of vanes on the immobile surface to direct a flow of the liquid fuel under the influence of gravity along a same plane towards a drain or gutter, wherein the vanes are reflective structures located in the vicinity of an intermediate focus of the radiation source. ### Claim 14 A radiation source comprising: a fuel source configured to deliver fuel to a location from which the fuel emits EUV radiation; a fuel debris receiving surface; and a conduit connected to a source of liquid alloy or metal and configured to deliver the liquid alloy or metal from the source via openings through a wall of the conduit directly onto the fuel debris receiving surface disposed outside of the conduit, such that a coating of the liquid alloy or metal is maintained and continuously flows across the fuel debris receiving surface at room temperature.