Patents by Inventor Gaurav Keswani

Gaurav Keswani 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).

  • Publication number: 20220057017
    Abstract: A valve (10) for selectively opening and closing a flow passageway (12) includes (i) a valve body (14) that defines a body passageway (16); (ii) a first valve surface (18) that defines a first valve opening (18A); (iii) an expandable barrier (22); and (iv) an actuation system (24). The expandable barrier (22) is movable in the body passageway (16) between an open configuration (30) in which the barrier (22) is retracted and does not engage the first valve surface (18); and a closed configuration (28) in which the barrier (22) is expanded, engages the first valve surface (18), and blocks the first valve opening (18A). The actuation system (24) selectively moves the barrier (22) between the configurations (28) (30).
    Type: Application
    Filed: August 18, 2021
    Publication date: February 24, 2022
    Inventors: Alex Ka Tim Poon, Michael Birk Binnard, Gaurav Keswani
  • Patent number: 11092170
    Abstract: A stage assembly (10) includes a stage (14), and a fluid actuator assembly (24) that moves the stage (14). The fluid actuator assembly (24) includes a piston housing (32) that defines a piston chamber (34); (ii) a piston (36) that separates the piston chamber (34) into a first chamber (34A) and a second chamber (34B); (iii) a supply valve (38C) that controls the flow of the working fluid (40) into the first chamber (34A); and (iv) an exhaust valve (38D) that controls the flow of the working fluid (40) out of the first chamber (34A). The supply valve (38C) has a supply orifice (250G) having a supply orifice area, and the exhaust valve (38D) has an exhaust orifice (352G) having an exhaust orifice area. Moreover, the supply orifice area is different from the exhaust orifice area. Further multiple valves of different sizes can be used in combination for the supply and exhaust for each chamber (34A), (34B).
    Type: Grant
    Filed: February 12, 2018
    Date of Patent: August 17, 2021
    Inventors: Alex Ka Tim Poon, Yeong-Jun Choi, Pai-Hsueh Yang, Sandy Lee, Gaurav Keswani, Rocky Mai
  • Publication number: 20190376531
    Abstract: A stage assembly (10) includes a stage (14), and a fluid actuator assembly (24) that moves the stage (14). The fluid actuator assembly (24) includes a piston housing (32) that defines a piston chamber (34); (ii) a piston (36) that separates the piston chamber (34) into a first chamber (34A) and a second chamber (34B); (iii) a supply valve (38C) that controls the flow of the working fluid (40) into the first chamber (34A); and (iv) an exhaust valve (38D) that controls the flow of the working fluid (40) out of the first chamber (34A). The supply valve (38C) has a supply orifice (250G) having a supply orifice area, and the exhaust valve (38D) has an exhaust orifice (352G) having an exhaust orifice area. Moreover, the supply orifice area is different from the exhaust orifice area. Further multiple valves of different sizes can be used in combination for the supply and exhaust for each chamber (34A), (34B).
    Type: Application
    Filed: February 12, 2018
    Publication date: December 12, 2019
    Inventors: Alex Ka Tim Poon, Yeong-Jun Choi, Pai-Hsueh Yang, Sandy Lee, Gaurav Keswani, Rocky Mai
  • Patent number: 9217933
    Abstract: A lithographic projection apparatus includes a stage assembly having a substrate table on which a substrate is supported and exposed with an exposure beam from a final optical element of a projection optical assembly through an immersion liquid. A confinement member encircles a portion of a path of the exposure beam and has an aperture through which the exposure beam is projected. A movable member is movable in a space between the confinement member and the substrate, the substrate table, or both, such that a first portion of the space is located between a first surface of the movable member and the confinement member, and a second portion of the space is located between a second surface of the movable member and the substrate, the substrate table, or both.
    Type: Grant
    Filed: April 25, 2014
    Date of Patent: December 22, 2015
    Assignee: NIKON CORPORATION
    Inventors: Alex Ka Tim Poon, Leonard Wai Fung Kho, Gaurav Keswani, Derek Coon, Daishi Tanaka
  • Patent number: 9176394
    Abstract: An immersion lithography apparatus that includes a substrate holder on which a substrate is held, a projection system having a final optical element and that projects an exposure beam onto the substrate through an immersion liquid, and a liquid confinement member having an aperture through which the exposure beam is projected, a lower surface including a non-fluid removal area surrounding the aperture, and a liquid recovery outlet from which the immersion liquid is recovered, also includes a movable member. The movable member is movable relative to the liquid confinement member in a substantially horizontal direction, and has an opening through which the exposure beam is projected. The movable member has upper and lower surfaces that surround the opening, and is movable while a portion of the upper surface faces the non-fluid removal area in the lower surface of the liquid confinement member.
    Type: Grant
    Filed: November 18, 2013
    Date of Patent: November 3, 2015
    Assignee: NIKON CORPORATION
    Inventors: Alex Ka Tim Poon, Leonard Wai Fung Kho, Derek Coon, Gaurav Keswani, Daishi Tanaka
  • Patent number: 8934080
    Abstract: 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: Grant
    Filed: September 14, 2012
    Date of Patent: January 13, 2015
    Assignee: Nikon Corporation
    Inventors: Alex Ka Tim Poon, Leonard Wai Fung Kho, Derek Coon, Gaurav Keswani
  • Publication number: 20140232999
    Abstract: A lithographic projection apparatus includes a stage assembly having a substrate table on which a substrate is supported and exposed with an exposure beam from a final optical element of a projection optical assembly through an immersion liquid. A confinement member encircles a portion of a path of the exposure beam and has an aperture through which the exposure beam is projected. A movable member is movable in a space between the confinement member and the substrate, the substrate table, or both, such that a first portion of the space is located between a first surface of the movable member and the confinement member, and a second portion of the space is located between a second surface of the movable member and the substrate, the substrate table, or both.
    Type: Application
    Filed: April 25, 2014
    Publication date: August 21, 2014
    Applicant: NIKON CORPORATION
    Inventors: Alex Ka Tim POON, Leonard Wai Fung KHO, Gaurav KESWANI, Derek COON, Daishi TANAKA
  • Patent number: 8780323
    Abstract: 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: Grant
    Filed: March 11, 2011
    Date of Patent: July 15, 2014
    Assignee: Nikon Corporation
    Inventors: Alex Ka Tim Poon, Leonard Wai Fung Kho, Gaurav Keswani
  • Patent number: 8743343
    Abstract: A lithographic projection apparatus includes a projection optical assembly having a final optical element, a stage assembly including a substrate table on which a substrate is supported, the substrate supported by the substrate table being exposed with an exposure beam from the final optical element of the projection optical assembly through an immersion liquid, a confinement member which encircles a portion of a path of the exposure beam, and a movable member which is movable in a space between the confinement member and the substrate, the substrate table, or both, the space being divided by the movable member into a first portion between the confinement member and the movable member and a second portion between the movable member and the substrate, the substrate table, or both. The movable member has a recovery outlet from which the immersion liquid in the second portion is removed.
    Type: Grant
    Filed: January 30, 2013
    Date of Patent: June 3, 2014
    Assignee: Nikon Corporation
    Inventors: Alex Ka Tim Poon, Leonard Wai Fung Kho, Gaurav Keswani, Derek Coon, Daishi Tanaka
  • Publication number: 20140071412
    Abstract: An immersion lithography apparatus that includes a substrate holder on which a substrate is held, a projection system having a final optical element and that projects an exposure beam onto the substrate through an immersion liquid, and a liquid confinement member having an aperture through which the exposure beam is projected, a lower surface including a non-fluid removal area surrounding the aperture, and a liquid recovery outlet from which the immersion liquid is recovered, also includes a movable member. The movable member is movable relative to the liquid confinement member in a substantially horizontal direction, and has an opening through which the exposure beam is projected. The movable member has upper and lower surfaces that surround the opening, and is movable while a portion of the upper surface faces the non-fluid removal area in the lower surface of the liquid confinement member.
    Type: Application
    Filed: November 18, 2013
    Publication date: March 13, 2014
    Applicant: NIKON CORPORATION
    Inventors: Alex Ka Tim POON, Leonard Wai Fung KHO, Derek COON, Gaurav KESWANI, Daishi TANAKA
  • Patent number: 8634055
    Abstract: 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: Grant
    Filed: February 2, 2010
    Date of Patent: January 21, 2014
    Assignee: Nikon Corporation
    Inventors: Alex Ka Tim Poon, Leonard Wai Fung Kho, Derek Coon, Gaurav Keswani
  • Patent number: 8610873
    Abstract: 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: Grant
    Filed: March 9, 2009
    Date of Patent: December 17, 2013
    Assignee: Nikon Corporation
    Inventors: Alex Ka Tim Poon, Leonard Wai Fung Kho, Derek Coon, Gaurav Keswani, Daishi Tanaka
  • Patent number: 8400610
    Abstract: 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: Grant
    Filed: June 25, 2012
    Date of Patent: March 19, 2013
    Assignee: Nikon Corporation
    Inventors: Alex Poon, Leonard Kho, Gaurav Keswani, Derek Coon, Daishi Tanak
  • Publication number: 20130010271
    Abstract: 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: Application
    Filed: September 14, 2012
    Publication date: January 10, 2013
    Applicant: NIKON CORPORATION
    Inventors: Alex Ka Tim POON, Leonard Wai Fung KHO, Derek COON, Gaurav KESWANI
  • Publication number: 20120262687
    Abstract: 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: Application
    Filed: June 25, 2012
    Publication date: October 18, 2012
    Applicant: NIKON CORPORATION
    Inventors: Alex Ka Tim Poon, Leonard Wai Fung Kho, Gaurav Keswani, Derek Coon
  • Patent number: 8289497
    Abstract: 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: Grant
    Filed: February 20, 2009
    Date of Patent: October 16, 2012
    Assignee: Nikon Corporation
    Inventors: Alex Ka Tim Poon, Leonard Wai Fung Kho, Derek Coon, Gaurav Keswani
  • Patent number: 8237911
    Abstract: 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: Grant
    Filed: October 29, 2007
    Date of Patent: August 7, 2012
    Assignee: Nikon Corporation
    Inventors: Alex Poon, Leonard Kho, Gaurav Keswani, Derek Coon
  • Publication number: 20120062866
    Abstract: Electromagnetic actuators are disclosed having at least one actively cooled coil assembly. Exemplary actuators are linear and planar motors of which the cooled coil assembly has a coil having first and second main surfaces. A respective thermally conductive cooling plate is in thermal contact with at least one main surface of the coil. Defined in or on each cooling plate is a coolant passageway that conducts a liquid coolant. A primary pattern of the coolant passageway is coextensive with at least part of the main surface of the coil. The primary pattern can have a secondary pattern through which coolant flows in a manner reducing eddy-current losses. An exemplary secondary pattern is serpentine. An exemplary primary pattern is radial or has a radial aspect, such as an X-shaped pattern. The devices exhibit reduced eddy-current drag.
    Type: Application
    Filed: September 2, 2011
    Publication date: March 15, 2012
    Inventors: Michael B. Binnard, Scott Coakley, Alex Ka Tim Poon, Masahiro Totsu, Derek Coon, Leonard Wai Fung Kho, Gaurav Keswani, Alexander Cooper, Michel Pharand, Matt Bjork
  • Publication number: 20110164239
    Abstract: 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: Application
    Filed: March 11, 2011
    Publication date: July 7, 2011
    Applicant: NIKON CORPORATION
    Inventors: Alex Ka Tim Poon, Leonard Wai Fung Kho, Gaurav Keswani
  • Patent number: 7929109
    Abstract: 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: Grant
    Filed: October 19, 2006
    Date of Patent: April 19, 2011
    Assignee: Nikon Corporation
    Inventors: Alex Ka Tim Poon, Leonard Wai Fung Kho, Gaurav Keswani