# US 10,481,510 B2 · Graphene spectral purity filter > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,481,510 B2 - Document ID: US10481510B2 - Status: Granted - Kind: B2 - Application number: 15/974,661 - Filed: 2018-05-08 - Published: 2018-09-13 - Granted: 2019-11-19 - Earliest claimed: 2010-06-25 - Assignees: ASML Netherlands B.V. - Applicants: Asml Netherlands B.V. - Inventors: Andrei Mikhailovich Yakunin; Vadim Yevgenyevich Banine; Erik Roelof Loopstra; Harmen Klaas Van Der Schoot; Lucas Henricus Johannes Stevens; Maarten Van Kampen - Web page: https://patentgrep.com/patent/US10481510B2 ## CPC - G03F 7/70958: {Optical materials or coatings, e.g. with particular transmittance, reflectance or anti-reflection properties} - B82Y 10/00: Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic - B82Y 40/00: Manufacture or treatment of nanostructures - G02B 5/0816: {Multilayer mirrors, i.e. having two or more reflecting layers (G02B5/0883, G02B5/0891 take precedence)} - G02B 5/0891: {Ultraviolet [UV] mirrors (apparatus for microlithography exposure G03F7/70; X-ray multilayer structures G21K1/06)} - G02B 5/204: {in which spectral selection is performed by means of a conductive grid or array, e.g. frequency selective surfaces (for use with wavelengths longer than the infrared light H01Q15/0006)} - G02B 5/208: {for use with infrared or ultraviolet radiation, e.g. for separating visible light from infrared and/or ultraviolet radiation} - G02B 27/0006: {with means to keep optical surfaces clean, e.g. by preventing or removing dirt, stains, contamination, condensation (G02B1/18 takes precedence; cleaning in general B08B)} - G03B 27/54: Lamp housings; Illuminating means - 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 1/64: characterised by the frames, e.g. structure or material, including bonding means therefor - G03F 7/70058: {Mask illumination systems} - G03F 7/702: {Reflective illumination, i.e. reflective optical elements other than folding mirrors, e.g. extreme ultraviolet [EUV] illumination systems} - G03F 7/70916: {Pollution mitigation, i.e. mitigating effect of contamination or debris, e.g. foil traps} - G03F 7/70983: {Optical system protection, e.g. pellicles or removable covers for protection of mask} - G21K 1/062: {Devices having a multilayer structure} - H01B 1/04: mainly consisting of carbon-silicon compounds, carbon or silicon - H01B 1/24: the conductive material comprising carbon-silicon compounds, carbon or silicon - G21K 2201/061: characterised by a multilayer structure - 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) - B82Y: SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - G03B: APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR (optical parts of such apparatus G02B; photosensitive materials or processes for photographic purposes G03C; apparatus for processing exposed photographic materials G03D) - G21K: HANDLING OF PARTICLES OR IONISING RADIATION NOT OTHERWISE PROVIDED FOR; IRRADIATION DEVICES; GAMMA RAY OR X-RAY MICROSCOPES - H01B: CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES (selection for magnetic properties H01F1/00; waveguides H01P {; printed circuits H05K}) ## Abstract A pellicle that includes graphene is constructed and arranged for an EUV reticle. A multilayer mirror includes graphene as an outermost layer. ## Claims ### Claim 1 A spectral purity filter comprising a graphene structure having uniform thickness and homogeneous composition wherein the graphene has an EUV transmittance of greater than 85%. ### Claim 2 (depends on 1) The spectral purity filter according to claim 1, comprising a graphene layer. ### Claim 3 (depends on 1) The spectral purity filter according to claim 1, comprising a graphene sheet. ### Claim 4 (depends on 3) The spectral purity filter according to claim 3, wherein the graphene sheet is disposed on a spectral purity filter frame. ### Claim 5 (depends on 4) The spectral purity filter according to claim 4, wherein the graphene sheet is supported by the spectral purity frame without a supporting grid. ### Claim 6 (depends on 3) The spectral purity filter according to claim 3, wherein the graphene sheet supports an out-of-band radiation suppression structure. ### Claim 7 (depends on 6) The spectral purity filter according to claim 6, wherein the graphene sheet is configured to prevent oxidation of the out-of-band radiation suppression structure. ### Claim 8 (depends on 6, 7) The spectral purity filter according to claim 6 or 7, wherein both sides of the out-of-band radiation suppression structure are covered with graphene. ### Claim 9 (depends on 6) The spectral purity filter according to claim 6, wherein the suppression structure comprises a suppression layer comprising a material selected from the group consisting of: Mo, W, Si, and Zr. ### Claim 10 (depends on 1) The spectral purity filter according to claim 1, comprising graphene flakes. ### Claim 11 (depends on 10) The spectral purity filter according to claim 10, wherein the graphene flakes support an out-of-band radiation suppression structure. ### Claim 12 (depends on 11) The spectral purity filter according to claim 11, wherein the graphene flakes are configured to prevent oxidation of the out-of-band radiation suppression structure. ### Claim 13 (depends on 11) The spectral purity filter according to claim 11, wherein the suppression structure comprises a suppression layer comprising a material selected from the group consisting of: Mo, W, Si, and Zr. ### Claim 14 (depends on 1) The spectral purity filter according claim 1, further comprising a material which blocks out-of-band radiation and wherein the graphene is configured to protect the material from oxidation and/or outgassing. ### Claim 15 (depends on 14) The spectral purity filter according to claim 14, comprising a grid of the material to block the out-of-band radiation. ### Claim 16 (depends on 15) The spectral purity filter according to claim 15, wherein the grid is a tungsten grid. ### Claim 17 (depends on 16) The spectral purity filter according to claim 16, wherein the graphene is applied such that none of the tungsten grid is exposed. ### Claim 18 (depends on 16) The spectral purity filter according to claim 16, wherein the graphene is applied as graphene layers on either side of the tungsten grid. ### Claim 19 (depends on 14, 15, 16, 17, 18) The spectral purity filter according to any of the claims 14 to 18, wherein the graphene is provided as a layer, a sheet or as flakes. ### Claim 20 (depends on 15) The spectral purity filter according to claim 15, wherein the grid comprises a support structure and a reflective coating, reflective to the out-of-band radiation. ### Claim 21 (depends on 20) The spectral purity filter according to claim 20, wherein the reflective coating comprises molybdenum to reflect the out-of-band radiation. ### Claim 22 (depends on 1) The spectral purity filter according to claim 1, further comprising a grid, the graphene being disposed on the grid. ### Claim 23 (depends on 22) The spectral purity filter according to claim 22, wherein the grid is configured to block out-of-band radiation, a pitch of the grid being smaller than wavelengths of the to be blocked out-of-band radiation. ### Claim 24 (depends on 1) The spectral purity filter according to claim 1, further comprising a filter constructed and arranged to pass a selected band of radiation and to suppress out of band radiation. ### Claim 25 (depends on 24) The spectral purity filter according to claim 24, wherein the out of band radiation is selected from the group consisting of: DUV radiation and infrared radiation. ### Claim 26 (depends on 1) The spectral purity filter according to claim 1, wherein the graphene comprises between 1 and 100 layers of graphene. ### Claim 27 (depends on 26) The spectral purity filter according to claim 26, wherein the graphene comprises between 10 and 100 layers of graphene.