# US 7,411,203 B2 · EUV light source > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,411,203 B2 - Document ID: US7411203B2 - Status: Granted - Kind: B2 - Application number: 11/647,016 - Filed: 2006-12-27 - Published: 2007-07-12 - Granted: 2008-08-12 - Earliest claimed: 2004-03-10 - Assignees: Cymer, Inc. - Inventors: Igor V. Fomenkov; Alexander I. Ershov - Web page: https://patentgrep.com/patent/US7411203B2 ## CPC - G03F 7/70033: {by plasma extreme ultraviolet [EUV] sources} - B82Y 10/00: Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic - G03F 7/70175: {Lamphouse reflector arrangements or collector mirrors, i.e. collecting light from solid angle upstream of the light source} - G03F 7/70916: {Pollution mitigation, i.e. mitigating effect of contamination or debris, e.g. foil traps} - G21K 1/062: {Devices having a multilayer structure} - H05G 2/0023: {Constructional details of the ejection system} - H05G 2/0027: {Arrangements for controlling the supply; Arrangements for measurements} - H05G 2/0084: {Control of the laser beam} - H05G 2/0086: {Optical arrangements for conveying the laser beam to the plasma generation location} - G21K 2201/061: characterised by a multilayer structure - G21K 2201/065: provided with cooling means - G21K 2201/067: Construction details - 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 - 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) ## Abstract An apparatus and method for EUV light production is disclosed which may comprise a laser produced plasma (“LPP”) extreme ultraviolet (“EUV”) light source control system comprising a target delivery system adapted to deliver moving plasma initiation targets and an EUV light collection optic having a ibeus defining a desired plasma initiation site, comprising; a target tracking and feedback system comprising: at least one imaging device providing as an output an image of a target stream track, wherein the target stream track results from the imaging speed of the camera being too slow to image individual plasma formation targets forming the target stream imaged as the target stream track; a stream track error detector detecting an error in the position of the target stream track in at least one axis genemily perpendicular to the target stream track from a desired stream truck intersecting the desired plasma initiation site. ## Claims ### Claim 1 A laser produced plasma (“LPP”) extreme ultraviolet (“EUV”) light source having a drive laser producing a drive laser output pulse beam and a drive laser output pulse beam directing system and an EUV light collector having a collector focus, comprising: a beam focusing system intermediate the beam directing system and the collector focus, operative to focus the output laser pulse beam to a selected position in the vicinity of the collector focus defining a selected plasma initiation site comprising a focusing lens and a reflective focusing element intermediate the focusing lens and the collector focus and having a focusing lens focal point intermediate the focusing lens and the reflective focusing element; and the reflective focusing element focusing the beam at the selected position. ### Claim 2 (depends on 1) The apparatus of claim 1 further comprising: the beam focusing system being moveable and movement of the beam focusing system being operative to locate the focus of the beam focusing system at the selected position. ### Claim 3 (depends on 2) The apparatus of claim 2 further comprising: a aperture in the vicinity of the focus of the focusing lens, intermediate the focusing lens and the reflective element operative to block plasma initiation debris from reaching the focusing lens. ### Claim 4 (depends on 1) The apparatus of claim 1 further comprising: the beam focusing system being moveable and movement of the beam focusing system being operative to locate the focus of the beam focusing system at the selected position. ### Claim 5 (depends on 4) The apparatus of claim 4 further comprising: at least one of the focusing lens and the reflective focusing element being moveable and the relative movement between the focusing lens and the reflective focusing element being operative at least in part to locate the focus of the beam at the selected position. ### Claim 6 (depends on 5) The apparatus of claim 5 further comprising: the reflective focusing element comprises a grazing angle of incidence reflecting element. ### Claim 7 (depends on 5) The apparatus of claim 5 further comprising: the reflective focusing element comprises a normal angle of incidence reflective element. ### Claim 8 (depends on 4) The apparatus of claim 4 further comprising: the reflective focusing element comprises a grazing angle of incidence reflecting element. ### Claim 9 (depends on 4) The apparatus of claim 4 further comprising: the reflective focusing element comprises a normal angle of incidence reflective element. ### Claim 10 (depends on 4) The apparatus of claim 4 further comprising: the reflective focusing element comprises a normal angle of incidence reflective element. ### Claim 11 (depends on 1) The apparatus of claim 1 further comprising: at least one of the focusing lens and the reflective focusing element being moveable and the relative movement between the focusing lens and the reflective focusing element being operative at least in part to locate the focus of the beam at the selected position. ### Claim 12 (depends on 11) The apparatus of claim 11 further comprising: the reflective focusing element comprises a grazing angle of incidence reflecting element. ### Claim 13 (depends on 1) The apparatus of claim 1 further comprising: the reflective focusing element comprises a grazing angle of incidence reflecting element. ### Claim 14 (depends on 1) The apparatus of claim 1 further comprising: the reflective focusing element comprises a normal angle of incidence reflective element. ### Claim 15 A method for producing laser produced plasma (“LPP”) extreme ultraviolet (“EUV”) light comprising utilizing a drive laser producing a drive laser output pulse beam and a drive laser output pulse beam directing system and an EUV light collector having a focus, comprising: focusing the beam intermediate the beam directing system and the collector focus, utilizing a focusing optic to focus the output laser pulse beam to a selected position in the vicinity of the focus. ### Claim 16 A laser produced plasma (“LPP”) extreme ultraviolet (“EUV”) light source having a drive laser producing a drive laser output pulse beam and an EUV light collector having a collector focus, comprising: a beam focusing system intermediate the drive laser and the collector focus, operative to focus the output laser pulse beam to a selected position in the vicinity of the collector focus defining a selected plasma initiation site, comprising a focusing lens and a reflective focusing element intermediate the focusing lens and the collector focus and having a focusing lens focal point intermediate the focusing lens and the reflective focusing element; and the reflective focusing element focusing the beam at the selected position. ### Claim 17 (depends on 16) The apparatus of claim 16 further comprising: the beam focusing system being moveable and movement of the beam focusing system being operative to locate the focus of the beam focusing system at the selected position. ### Claim 18 (depends on 17) The apparatus of claim 17 further comprising: at least one of the focusing lens and the reflective focusing element being moveable and the relative movement between the focusing lens and the reflective focusing element being operative at least in part to locate the focus of the beam at the selected position. ### Claim 19 (depends on 18) The apparatus of claim 18 further comprising: the reflective focusing element comprises a normal angle of incidence reflective element. ### Claim 20 (depends on 18) The apparatus of claim 18 further comprising: a aperture in the vicinity of the focus of the focusing lens, intermediate the focusing lens and the reflective element operative to block plasma initiation debris from reaching the focusing lens. ### Claim 21 (depends on 20) The apparatus of claim 20 further comprising: the reflective focusing element comprises a grazing angle of incidence reflecting element. ### Claim 22 (depends on 17) The apparatus of claim 17 further comprising: a aperture in the vicinity of the focus of the focusing lens, intermediate the focusing lens and the reflective element operative to block plasma initiation debris from reaching the focusing lens. ### Claim 23 (depends on 22) The apparatus of claim 22 further comprising: the reflective focusing element comprises a grazing angle of incidence reflecting element. ### Claim 24 (depends on 17) The apparatus of claim 17 further comprising: the reflective focusing element comprises a normal angle of incidence reflective element. ### Claim 25 (depends on 16) The apparatus of claim 16 further comprising: at least one of the focusing lens and the reflective focusing element being moveable and the relative movement between the focusing lens and the reflective focusing element being operative at least in part to locate the focus of the beam at the selected position. ### Claim 26 (depends on 25) The apparatus of claim 25 further comprising: the reflective focusing element comprises a grazing angle of incidence reflecting element. ### Claim 27 (depends on 25) The apparatus of claim 25 further comprising: the reflective focusing element comprises a normal angle of incidence reflective element. ### Claim 28 (depends on 25) The apparatus of claim 25 further comprising: a aperture in the vicinity of the focus of the focusing lens, intermediate the focusing lens and the reflective element operative to block plasma initiation debris from reaching the focusing lens. ### Claim 29 (depends on 16) The apparatus of claim 16 further comprising: the reflective focusing element comprises a grazing angle of incidence reflecting element. ### Claim 30 (depends on 16) The apparatus of claim 16 further comprising: the reflective focusing element comprises a normal angle of incidence reflective element. ### Claim 31 (depends on 16) The apparatus of claim 16 further comprising: a aperture in the vicinity of the focus of the focusing lens, intermediate the focusing lens and the reflective element operative to block plasma initiation debris from reaching the focusing lens. ### Claim 32 A method for producing laser produced plasma (“LPP”) extreme ultraviolet (“EUV”) light comprising utilizing a drive laser producing a drive laser output pulse beam and an EUV light collector having a focus, comprising: focusing the beam to a focal plane intermediate the laser and the collector focus, and utilizing a focusing element intermediate the focal plane of the beam and the collector focus to focus the output laser pulse beam to a selected position in the vicinity of the collector focus.