# US 2014/0151580 A1 · Methods of using polished silicon wafer strips for euv homogenizer > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0151580 A1 - Document ID: US20140151580A1 - Status: Published application - Kind: A1 - Application number: 14/082,676 - Filed: 2013-11-18 - Published: 2014-06-05 - Earliest claimed: 2012-11-30 - Assignees: KLA-Tencor Corporation - Applicants: KLA-Tencor Corporation - Inventors: Daimian Wang; Frank Chilese - Web page: https://patentgrep.com/patent/US20140151580A1 ## CPC - G02B 19/0095: {for use with ultraviolet radiation} - G02B 27/0994: {Fibers, light pipes (optical fibers per se G02B6/02)} - G03F 1/84: Inspecting - G03F 1/22: Masks or mask blanks for imaging by radiation of 100nm or shorter wavelength, e.g. X-ray masks, extreme ultraviolet [EUV] masks; Preparation thereof - Y10T 29/49002: Electrical device making - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - 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) - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract The present invention is a light homogenizer or light tunnel with highly reflective sides that enable the focusing of EUV illumination. The sides of the homogenizer are cut from a highly polished silicon wafer. The wafer is coated with a reflective coating before the strips are cut from the wafer. The invention also includes a method for flattening the strips and applying a backing to the strips enabling easier manipulation of the strips during assembly and use. ## Claims ### Claim 1 A EUV light homogenizer for a EUV reticle inspection system comprising: a hollow four sided tunnel, wherein said four sided tunnel include four flat strips, each of said four flat strips having an inner surface and an outer surface; wherein each of said inner surfaces is coated with a high reflectivity coating; and, wherein said four strips are joined to form said four-sided tunnel. ### Claim 2 (depends on 1) The EUV light homogenizer as recited in claim 1 further comprising a mounting substrate applied to said outer surface. ### Claim 3 (depends on 2) The EUV light homogenizer as recited in claim 2 wherein said mounting substrate is a ceramic material. ### Claim 4 (depends on 2) The EUV light homogenizer as recited in claim 2 wherein said mounting substrate is metal. ### Claim 5 (depends on 1) The EUV light homogenizer as recited in claim 1 wherein said high reflectivity coating is ruthenium. ### Claim 6 (depends on 1) The EUV light homogenizer as recited in claim 1 wherein said four strips are joined to form said four-sided tunnel using an epoxy, said epoxy having a low outgassing rate. ### Claim 7 (depends on 1) The EUV light homogenizer as recited in claim 1 wherein said four-sided tunnel ranges in length from about 100 mm to about 800 mm. ### Claim 8 (depends on 7) The EUV light homogenizer as recited in claim 7 wherein said EUV light homogenizer comprises two attached EUV light homogenizers, wherein said two attached EUV light homogenizers are attached lengthwise end-to-end. ### Claim 9 (depends on 1) The EUV light homogenizer as recited in claim 1 wherein each of said four strips ranges in width from about 0.2 mm to about 4 mm. ### Claim 10 (depends on 1) The EUV light homogenizer as recited in claim 1 wherein said four-sided tunnel is substantially rectangular in shape. ### Claim 11 (depends on 1) The EUV light homogenizer as recited in claim 1 wherein purge gas is passed through said EUV light homogenizer. ### Claim 12 (depends on 11) The EUV light homogenizer as recited in claim 11 wherein said purge gas is hydrogen. ### Claim 13 (depends on 11) The EUV light homogenizer as recited in claim 11 wherein said purge gas is helium. ### Claim 14 A method of assembling a light tunnel for a EUV illumination reticle inspection system comprising: polishing a silicon wafer; coating said silicon wafer with a high reflectivity coating; cutting said silicon wafer into at least four strips, each of said at least four strips having a first side and a second side, wherein said high reflectivity coating is on said first side; applying mounting substrate to said second side of each of said at least four strips; flattening each of said at least four strips against a flat surface; and, assembling said at least four strips to form said light tunnel; wherein each first side of said at least four strips forms a single interior surface of said light tunnel. ### Claim 15 (depends on 14) The method of assembling a light tunnel for a EUV illumination reticle inspection as recited in claim 14 wherein said substrate mounting is ceramic. ### Claim 16 (depends on 14) The method of assembling a light tunnel for a EUV illumination reticle inspection as recited in claim 14 wherein said substrate mounting is metal. ### Claim 17 (depends on 14) The method of assembling a light tunnel for a EUV illumination reticle inspection as recited in claim 14 wherein flat surface defines a plurality of holes extending from a top of said flat surface through a bottom of said flat surface and wherein each of said at least four strips is flattened against said flat surface by a vacuum. ### Claim 18 (depends on 14) The method of assembling a light tunnel for a EUV illumination reticle inspection as recited in claim 14 further comprising pressing each of said at least four strips against said flat surface. ### Claim 19 (depends on 14) The method of assembling a light tunnel for a EUV illumination reticle inspection as recited in claim 14 further comprising the step of directing a purge gas through said tunnel. ### Claim 20 (depends on 19) The method of assembling a light tunnel for a EUV illumination reticle inspection as recited in claim 19 wherein said purge gas is hydrogen. ### Claim 21 (depends on 19) The method of assembling a light tunnel for a EUV illumination reticle inspection as recited in claim 19 wherein said purge gas is helium. ### Claim 22 (depends on 14) The method of assembling a light tunnel for a EUV illumination reticle inspection as recited in claim 14 wherein said assembly of said at least four strips is performed using epoxy. ### Claim 23 (depends on 14) The method of assembling a light tunnel for a EUV illumination reticle inspection as recited in claim 14 wherein said assembly of said at least four strips is performed using nut and bolt assemblies. ### Claim 24 (depends on 14) The method of assembling a light tunnel for a EUV illumination reticle inspection as recited in claim 14 wherein said high reflectivity coating is ruthenium. ### Claim 25 (depends on 14) The method of assembling a light tunnel for a EUV illumination reticle inspection as recited in claim 14 further comprising the step of attaching two assembled light tunnels lengthwise end-to-end.