Patents by Inventor Leonard Wai Fung Kho
Leonard Wai Fung Kho has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 8054448Abstract: An apparatus and method are disclosed for providing fluid for immersion lithography. Immersion fluid is injected into an inner cavity in a direction that is different than a direction in which the nozzle moves. The immersion fluid can also be injected at different rates into the inner cavity at different sides. A wafer substrate is then exposed by light through the immersion fluid.Type: GrantFiled: April 27, 2005Date of Patent: November 8, 2011Assignee: Nikon CorporationInventors: Alex Ka Tim Poon, Leonard Wai Fung Kho
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Publication number: 20110164239Abstract: Immersion fluid remaining on a portion of a substrate after that portion has passed an immersion nozzle is removed by moving the substrate relative to an immersion nozzle so that the portion of the substrate on which the immersion fluid remains is passed by the immersion nozzle again. A path is determined along which the substrate is to be moved to remove the remaining immersion fluid. The path can be determined based upon previous movements of the substrate, including factors such as the speed and/or length of the previous movements. Alternatively, portions of the substrate on which immersion fluid remains can be detected, and then the substrate can be moved so that the portion of the substrate on which the immersion fluid remains is passed by the immersion nozzle based on the results of the detection. Immersion fluid also can be removed from the stage surface located beyond the substrate.Type: ApplicationFiled: March 11, 2011Publication date: July 7, 2011Applicant: NIKON CORPORATIONInventors: Alex Ka Tim Poon, Leonard Wai Fung Kho, Gaurav Keswani
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Patent number: 7929109Abstract: Immersion fluid remaining on a portion of a substrate after that portion has passed an immersion nozzle is removed by moving the substrate relative to an immersion nozzle so that the portion of the substrate on which the immersion fluid remains is passed by the immersion nozzle again. A path is determined along which the substrate is to be moved to remove the remaining immersion fluid. The path can be determined based upon previous movements of the substrate, including factors such as the speed and/or length of the previous movements. Alternatively, portions of the substrate on which immersion fluid remains can be detected, and then the substrate can be moved so that the portion of the substrate on which the immersion fluid remains is passed by the immersion nozzle based on the results of the detection. Immersion fluid also can be removed from the stage surface located beyond the substrate.Type: GrantFiled: October 19, 2006Date of Patent: April 19, 2011Assignee: Nikon CorporationInventors: Alex Ka Tim Poon, Leonard Wai Fung Kho, Gaurav Keswani
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Publication number: 20100271159Abstract: Methods and apparatus for improving the thermal performance of electromagnetic coils are disclosed. According to one aspect of the present invention, an electromagnetic actuator includes a core and a coil. The coil is formed form a conductor wire that includes a plurality of windings. The windings are arranged around the core, and include at least a first set of windings and a second set of windings. The first set of windings has a different geometry from the second set of windings.Type: ApplicationFiled: March 5, 2010Publication date: October 28, 2010Inventors: Alex Ka Tim Poon, Masahiro Totsu, Leonard Wai Fung Kho, Derek Coon, Gaurav Keswani
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Publication number: 20100231876Abstract: Apparatus and methods recover a fluid from an immersion area formed in a gap between a projection system and an object of exposure in an immersion lithography system. Liquid is supplied through a supply inlet. A porous member is disposed adjacent to a space. The porous member includes a first portion and a second portion. A recovery capability to remove the supplied liquid from the space through the first portion is different from a recovery capability to remove the supplied liquid from the space through the second portion.Type: ApplicationFiled: May 20, 2010Publication date: September 16, 2010Applicant: NIKON CORPORATIONInventors: Alex Ka Tim Poon, Leonard Wai Fung Kho, Gaurav Keswani
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Publication number: 20100220301Abstract: An immersion liquid confinement apparatus confines an immersion liquid in an immersion area that includes a gap between a projection system and an object of exposure in an immersion lithography system. The apparatus also recovers the immersion liquid from the immersion area. The apparatus includes a confinement member and a liquid-permeable member. The confinement member includes an outlet and an aperture through which a patterned image is projected onto the object. The liquid-permeable member covers the outlet and has a first surface that faces the object and a second surface opposite the first surface, the second surface contacting a chamber. The confinement member includes at least one liquid inlet within the chamber through which a liquid is introduced into the chamber to reduce liquid from becoming stagnated within the chamber.Type: ApplicationFiled: January 21, 2010Publication date: September 2, 2010Applicant: NIKON CORPORATIONInventors: Alex Ka Tim POON, Leonard Wai Fung KHO, Derek COON, Gaurav KESWANI
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Publication number: 20100186942Abstract: Methods and apparatus for cooling a reticle are disclosed. According to one aspect of the present invention, an apparatus for providing top side cooling to a reticle includes a heat exchanger arrangement and an actuator. The heat exchanger arrangement includes a first surface arranged to facilitate heat transfer between the reticle and the heat exchanger arrangement. The heat transfer provides cooling to at least some portions of the reticle. The actuator positions the first surface of the heat exchanger arrangement at a distance over the reticle.Type: ApplicationFiled: December 21, 2009Publication date: July 29, 2010Inventors: Alton H. Phillips, Douglas C. Watson, Hiromitsu Yoshimoto, Noriya Kato, Yusaku Uehara, Leonard Wai Fung Kho
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Patent number: 7751026Abstract: A apparatus and methods recover a fluid from an immersion area formed in a gap between a projection system and an object of exposure in an immersion lithography system. A porous member is disposed adjacent to the immersion area. A pressure control system provides a first low pressure to a first portion of the porous member to remove immersion fluid that escapes from the immersion area, and provides a second low pressure to a second portion of the porous member to remove immersion fluid that escapes from the immersion area. The second low pressure is different from the first low pressure.Type: GrantFiled: May 31, 2006Date of Patent: July 6, 2010Assignee: Nikon CorporationInventors: Alex Ka Tim Poon, Leonard Wai Fung Kho, Gaurav Keswani
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Publication number: 20100134773Abstract: An immersion liquid confinement apparatus recovers an immersion liquid from an immersion area that includes a gap between a projection system and an object of exposure in an immersion lithography system. The apparatus includes a confinement member that includes an outlet and an aperture through which a patterned image is projected onto the object. A first liquid-permeable member covers the outlet and has a first surface that faces the object and a second surface opposite the first surface, the second surface contacting a first chamber. A second liquid-permeable member has first and second oppositely-facing surfaces, the first surface of the second liquid-permeable member contacts the first chamber, the second surface of the second liquid-permeable member contacts a second chamber that is different from the first chamber. A hydrophobic porous member is provided between the first chamber and a vacuum system that supplies a low pressure to the first chamber.Type: ApplicationFiled: February 2, 2010Publication date: June 3, 2010Applicant: NIKON CORPORATIONInventors: Alex Ka Tim POON, Leonard Wai Fung KHO, Derek COON, Gaurav KESWANI
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Publication number: 20100097585Abstract: An immersion liquid confinement apparatus confines an immersion liquid in an immersion area that includes a gap between a projection system and an object of exposure in an immersion lithography system. The apparatus also recovers the immersion liquid from the immersion area. The apparatus includes a confinement member and first and second liquid-permeable members. The confinement member includes an outlet and an aperture through which a patterned image is projected onto the object. The first liquid-permeable member covers the outlet and has a first surface that faces the object and a second surface opposite the first surface, the second surface contacting a first chamber. The second liquid-permeable member has first and second oppositely-facing surfaces, the first surface of the second liquid-permeable member contacts the first chamber, the second surface of the second liquid-permeable member contacts a second chamber that is different from the first chamber.Type: ApplicationFiled: October 5, 2009Publication date: April 22, 2010Applicant: NIKON CORPORATIONInventors: Alex Ka Tim POON, Leonard Wai Fung KHO, Derek COON
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Publication number: 20090296053Abstract: A lithographic projection apparatus projects a pattern from a patterning device onto a substrate using a projection system. The apparatus has a liquid supply system to supply a liquid to a space between the projection system and the substrate. The apparatus also has a fluid removal system including a chamber to hold liquid and having an open end adjacent to a volume in which fluid will be present. The open end removes, through a pressure differential across-the open end when liquid is present in the chamber, substantially only liquid from the volume when liquid in the volume is adjacent to the open end but not gas from the volume when gas in the volume is adjacent to the open end.Type: ApplicationFiled: August 5, 2009Publication date: December 3, 2009Applicant: NIKON CORPORATIONInventors: Alex Ka Tim Poon, Leonard Wai Fung Kho
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Publication number: 20090237631Abstract: An immersion lithography apparatus includes a projection system having a final optical element, a movable stage that is movable below the projection system such that a gap exists between the final optical element and a surface of the stage, an immersion liquid being filled in the gap, a liquid confinement member and a liquid diverter. The liquid confinement member maintains the immersion liquid in the gap, and includes a liquid recovery portion that faces the stage surface and recovers liquid from the gap. The liquid recovery portion includes a first porous portion through which a first suction force is applied and a second porous portion through which a second suction force less than the first suction force is applied, the second portion being located outward of the first portion. The liquid diverter is positioned between the stage and at least the first porous portion.Type: ApplicationFiled: February 20, 2009Publication date: September 24, 2009Applicant: NIKON CORPORATIONInventors: Alex Ka Tim Poon, Leonard Wai Fung Kho, Derek Coon, Gaurav Keswani
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Publication number: 20090231560Abstract: An immersion lithography apparatus includes a projection system having a final optical element and a stage that is movable to a position below the projection system such that a gap exists between the final optical element and a surface of the stage. An immersion liquid fills the gap between the surface and the final optical element. A liquid confinement member maintains the immersion liquid in the gap. The immersion liquid has a meniscus where the liquid contacts ambient gas, the meniscus defining a footprint of an immersion area. A movable liquid diverter is positioned between the liquid confinement member and the stage. The movable liquid diverter moves relative to the liquid confinement member in a direction parallel to the surface of the stage, and includes an opening that surrounds the immersion area, the opening contacting or being slightly spaced from the immersion area when the stage is stationary.Type: ApplicationFiled: March 9, 2009Publication date: September 17, 2009Applicant: NIKON CORPORATIONInventors: Alex Ka Tim Poon, Leonard Wai Fung Kho, Derek Coon, Gaurav Keswani, Daishi Tanaka
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Patent number: 7576833Abstract: A gas curtain type immersion lithography apparatus has a fluid removing porous region adjacent the gas inlet to prevent evaporative cooling. The apparatus includes a substrate holder which holds a substrate having an imaging surface and a projection optical system having a last optical element. The projection optical system projects an image onto a target imaging area on the substrate through an immersion fluid filled in a gap between the imaging surface of the substrate and the last optical element. An immersion element maintains the immersion fluid in the gap. Gas is provided through an inlet into the gap. A porous region is provided adjacent the gas inlet. Immersion fluid that collects near the gas inlet is removed by the porous region.Type: GrantFiled: December 4, 2007Date of Patent: August 18, 2009Assignee: Nikon CorporationInventors: Alex Ka Tim Poon, Leonard Wai Fung Kho, Gaurav Keswani, Derek Coon
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Patent number: 7532309Abstract: A lithography apparatus includes a fluid confinement plate which can completely submerge the imaging surface of a substrate. A gap, filled with immersion fluid, is provided between the imaging surface of the substrate and the last optical element of a projection optical system. The fluid confinement plate, which is positioned within the gap between the last optical element and the substrate, is sufficiently sized so that the imaging surface is completely submerged in the immersion fluid. The fluid confinement plate includes a first surface facing the gap and opposing the imaging surface of the substrate. The first surface includes a droplet control element to control the formation of droplets forming on the first surface.Type: GrantFiled: September 20, 2006Date of Patent: May 12, 2009Assignee: Nikon CorporationInventors: Alex Ka Tim Poon, Leonard Wai Fung Kho, Gaurav Keswani, Derek Coon
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Publication number: 20090002648Abstract: A gas curtain type immersion lithography apparatus has a fluid removing porous region adjacent the gas inlet to prevent evaporative cooling. The apparatus includes a substrate holder which holds a substrate having an imaging surface and a projection optical system having a last optical element. The projection optical system projects an image onto a target imaging area on the substrate through an immersion fluid filled in a gap between the imaging surface of the substrate and the last optical element. An immersion element maintains the immersion fluid in the gap. Gas is provided through an inlet into the gap. A porous region is provided adjacent the gas inlet. Immersion fluid that collects near the gas inlet is removed by the porous region.Type: ApplicationFiled: December 4, 2007Publication date: January 1, 2009Applicant: NIKON CORPORATIONInventors: Alex Ka Tim Poon, Leonard Wai Fung Kho, Gaurav Keswani, Derek Coon
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Publication number: 20080231822Abstract: An immersion lithography tool with a diverter element, positioned between the immersion element and the substrate, for altering the “footprint” or shape of the meniscus of the body of immersion liquid between the last optical element and an immersion element on one side, and the substrate on the other side when the substrate is moved. The apparatus includes a substrate holder to hold the substrate having an imaging surface and a projection optical system having a last optical element. The projection optical system projects an image onto a target imaging area on the substrate through the immersion liquid filled in a gap between the imaging surface of the substrate and the last optical element. An immersion element maintains the immersion fluid in the gap. The diverter element is positioned between the immersion element and the substrate.Type: ApplicationFiled: March 10, 2008Publication date: September 25, 2008Applicant: NIKON CORPORATIONInventors: Alex Ka Tim Poon, Leonard Wai Fung Kho, Gaurav Keswani, Derek Coon
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Publication number: 20080231823Abstract: A stage assembly includes a workpiece table that supports the workpiece adjacent to an optical assembly. An environmental system supplies and removes immersion liquid to and from a space between the workpiece and the optical assembly to form an immersion area. The environmental system has a lower surface disposed opposite from an upper surface of the workpiece and/or the workpiece table. The lower surface is spaced a first distance from the workpiece and/or the workpiece table to form a meniscus at a periphery of the immersion area. An edge member is provided on the environmental system and extends past the lower surface of the environmental system so that a lower portion of the edge member is spaced a second distance, smaller than the first distance, from the upper surface of the workpiece and/or the workpiece table at a position beyond the periphery of the immersion area.Type: ApplicationFiled: March 19, 2008Publication date: September 25, 2008Applicant: NIKON CORPORATIONInventors: Alex Ka Tim Poon, Leonard Wai Fung Kho, Gaurav Keswani, Derek Coon, Yasufumi Nishii
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Publication number: 20080225246Abstract: Apparatus and methods keep immersion liquid in a space adjacent to an optical assembly. An optical assembly projects an image onto a substrate supported adjacent to the optical assembly by a substrate table. An insertion member insertable into the space between the optical assembly and the substrate, the substrate table, or both, divides the immersion liquid into a first portion and a second portion, the first portion disposed between the optical assembly and the insertion member, and the second portion disposed between the insertion member and the substrate, the substrate table, or both. The insertion member keeps the optical assembly in contact with the first portion when the substrate is moved away from being disposed adjacent to the optical assembly.Type: ApplicationFiled: October 29, 2007Publication date: September 18, 2008Applicant: NIKON CORPORATIONInventors: Alex Ka Tim Poon, Leonard Wai Fung Kho, Gaurav Keswani, Derek Coon
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Publication number: 20080225248Abstract: Apparatus, systems and methods remove liquid from a workpiece. A first station subjects a workpiece to processing that leaves a liquid on a surface of the workpiece. A second station is disposed at a location spaced apart from the first station. A porous member is disposed between the first and second stations. The porous member has a liquid-phyllic surface that faces the workpiece and is spaced from a surface of the workpiece by a gap. The porous member has a length in a direction perpendicular to a movement direction in which the workpiece moves from the first station to the second station, the length being at least as large as a dimension of the workpiece in the direction perpendicular to the movement direction.Type: ApplicationFiled: March 11, 2008Publication date: September 18, 2008Applicant: NIKON CORPORATIONInventors: Alex Ka Tim Poon, Leonard Wai Fung Kho, Gaurav Keswani, Derek Coon