# US 2017/0285488 A1 · Lithographic apparatus and device manufacturing method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2017/0285488 A1 - Document ID: US20170285488A1 - Status: Published application - Kind: A1 - Application number: 15/624,419 - Filed: 2017-06-15 - Published: 2017-10-05 - Earliest claimed: 2004-12-20 - Assignees: ASML Netherlands B.V. - Applicants: Asml Netherlands B.V. - Inventors: Hans Jansen; Johannes Jacobus Matheus Baselmans; Sjoerd Nicolaas Lambertus Donders; Christiaan Alexander Hoogendam; Jeroen Johannes Sophia Maria Mertens; Johannes Catharinus Huberts Mulkens; Marco Koert Stavenga; Bob Streefkerk; Jan Cornelis Van Der Hoeven; Cedric Desire Grouwstra - Web page: https://patentgrep.com/patent/US20170285488A1 ## CPC - G03F 7/70341: {Details of immersion lithography aspects, e.g. exposure media or control of immersion liquid supply (chemical composition of immersion liquids G03F7/2041)} - G03F 7/70925: {Cleaning, i.e. actively freeing apparatus from pollutants, e.g. using plasma cleaning} - 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) ## Abstract A method and apparatus for cleaning the inside of an immersion lithographic apparatus is disclosed. In particular, a liquid supply system of the lithographic apparatus may be used to introduce a cleaning fluid into a space between the projection system and the substrate table of the lithographic apparatus. Additionally or alternatively, a cleaning device may be provided on the substrate table and an ultrasonic emitter may be provided to create an ultrasonic cleaning liquid. ## Claims ### Claim at position 1 -20. (canceled) ### Claim 21 A lithographic apparatus, comprising: a movable table; a projection system configured to project a patterned beam of radiation onto a radiation-sensitive substrate, the projection system comprising a final optical element adjacent the table; a liquid confinement structure configured to at least partly confine liquid in a space between the projection system and the table such that liquid is in direct contact with the final optical element and the liquid confinement structure, the liquid confinement structure having an aperture to allow the patterned beam to pass through to the substrate, an opening configured to supply liquid to above the aperture to flow down through the aperture to the substrate, and an outlet configured to remove liquid from the space, the outlet being in an under surface of the liquid confinement structure; and a liquid supply system configured to provide immersion liquid to the space via the opening for an exposure period and to provide cleaning fluid of different composition than the immersion liquid, to the space via the opening for a cleaning period. ### Claim 22 (depends on 21) The apparatus according to claim 21, further comprising an inlet configured to supply a fluid to a gap between the under surface of the liquid confinement structure and the table. ### Claim 23 (depends on 21) The apparatus according to claim 21, wherein the cleaning fluid comprises heptane, hexane, alcohol or acetone and further comprising a source having the heptane, hexane, alcohol or acetone. ### Claim 24 (depends on 21) The apparatus according to claim 21, further comprising an ultrasonic transmitter configured to turn liquid in the space into an ultrasonic cleaning liquid. ### Claim 25 (depends on 21) The apparatus according to claim 21, further comprising a control system configured to guide a portion of the table to contact with the cleaning fluid that otherwise would not come into an optical path of the patterned beam. ### Claim 26 (depends on 21) The apparatus according to claim 21, further comprising a control system configured to cause supply of radiation from the projection system during a period of time that the cleaning fluid is in the space. ### Claim 27 (depends on 21) The apparatus according to claim 21, further comprising a control system configured to cause supply of immersion liquid to contact cleaning fluid supplied to the space. ### Claim 28 A device manufacturing method, comprising: projecting a patterned beam of radiation, using a projection system, onto a substrate; at least partly confining liquid in a space between the projection system and a movable table using a liquid confinement structure such that liquid is in direct contact with the final optical element and the liquid confinement structure, the liquid confinement structure having an aperture to allow the patterned beam to pass through to the substrate, an opening configured to supply liquid to above the aperture to flow down through the aperture to the substrate, and an outlet configured to remove liquid from the space, the outlet being in an under surface of the liquid confinement structure; and providing immersion liquid to the space via the opening for an exposure period; and providing cleaning fluid of different composition than the immersion liquid, to the space via the opening for a cleaning period. ### Claim 29 (depends on 28) The method according to claim 28, further comprising supplying a fluid to a gap between the under surface of the liquid confinement structure and the table. ### Claim 30 (depends on 28) The method according to claim 28, further comprising causing supply of immersion liquid to contact cleaning fluid supplied to the space. ### Claim 31 (depends on 28) The method according to claim 28, wherein the cleaning fluid comprises heptane, hexane, alcohol or acetone. ### Claim 32 (depends on 28) The method according to claim 28, further comprising using an ultrasonic transmitter to turn liquid in the space into an ultrasonic cleaning liquid. ### Claim 33 (depends on 28) The method according to claim 28, further comprising guiding a portion of the table to contact with the cleaning fluid that otherwise would not come into an optical path of the patterned beam. ### Claim 34 (depends on 28) The method according to claim 28, further comprising supplying radiation from the projection system during a period of time that the cleaning fluid is in the space. ### Claim 35 A lithographic apparatus, comprising: a projection system configured to project a patterned beam of radiation onto a radiation-sensitive substrate, the projection system comprising a final optical element adjacent the substrate; a liquid supply system configured to provide liquid to a space between the projection system and the substrate, the liquid supply system comprising a liquid confinement structure configured to at least partly confine the liquid in the space such that the liquid is in direct contact with the final optical element and the liquid confinement structure, the liquid confinement structure having an outlet configured to remove liquid from the space, the outlet being in a bottom surface of the liquid confinement structure; and a structure movable with respect to the liquid confinement structure, the structure having a flat upper surface of at least same width as a cross-sectional width of the outlet and the structure having a cleaning device configured to clean a surface of the final optical element, of the liquid confinement structure, or of both the final optical element and the liquid confinement structure, the cleaning device located in or under the upper surface so as not to protrude above the upper surface. ### Claim 36 (depends on 35) The apparatus according to claim 35, wherein the cleaning device comprises an ultrasonic transmitter. ### Claim 37 (depends on 35) The apparatus according to claim 35, wherein the cleaning device further comprises an outlet, in the upper surface, to supply cleaning fluid. ### Claim 38 (depends on 35) The apparatus according to claim 35, wherein the cleaning device comprises an optical element to provide radiation toward the liquid confinement structure and/or the final optical element. ### Claim 39 (depends on 35) The apparatus according to claim 35, further comprising a control system configured to cause supply of cleaning fluid to the space and to cause supply of immersion liquid to contact cleaning fluid supplied to the space. ### Claim 40 (depends on 35) The apparatus according to claim 35, further comprising an inlet configured to supply a fluid to a gap between the bottom surface of the liquid confinement structure and the table and the liquid confinement structure further comprises an opening configured to supply the liquid.