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).

  • Publication number: 20080212050
    Abstract: Apparatus and methods assist in the removal of immersion liquid from a surface of a substrate. In particular, the apparatus/method removes immersion liquid from a surface of a substrate that has been subjected to immersion lithographic exposure. A temperature control unit controls a temperature of the substrate to create a temperature gradient across at least a portion of the surface of the substrate such that a first portion of the surface of the substrate has a first temperature that is higher than a second temperature of a second portion of the surface of the substrate. The temperature gradient induces the immersion liquid remaining on the substrate to move from the higher temperature portion(s) toward the lower temperature portion(s).
    Type: Application
    Filed: February 1, 2008
    Publication date: September 4, 2008
    Applicant: NIKON CORPORATION
    Inventors: Alex Ka Tim Poon, Leonard Wai Fung Kho, Gaurav Keswani, Derek Coon, Soichi Owa
  • Publication number: 20080198348
    Abstract: A lithographic projection apparatus includes an optical assembly that projects an image onto a workpiece, and a containment member disposed adjacent to a lower end of the optical assembly. The containment member has an aperture through which an exposure beam passes from the optical assembly to the workpiece. The lithographic projection apparatus also includes a stage assembly including a workpiece table that supports the workpiece adjacent to the containment member. A space between the containment member and the workpiece is filled with an immersion liquid. The lithographic projection apparatus further includes a liquid collection system that has a recess in the workpiece table that receives immersion liquid that overflows the space between the containment member and the workpiece. At least part of the recess is disposed radially outward of the workpiece. The recess is partially filled with a porous material.
    Type: Application
    Filed: February 11, 2008
    Publication date: August 21, 2008
    Applicant: NIKON CORPORATION
    Inventors: Alex Ka Tim Poon, Leonard Wai Fung Kho, Gaurav Keswani, Derek Coon
  • Patent number: 7375800
    Abstract: Methods and apparatus for enabling a fine stage to be moved using pneumatics such that disturbances associated with a pneumatic transfer system are not transmitted to the fine stage are disclosed. According to one aspect of the present invention, a stage apparatus includes a first stage, a second stage, and a pneumatic transfer system. The pneumatic transfer system includes at least one transfer mechanism and a transfer block. The transfer mechanism is substantially directly coupled be coupled between the first stage and the transfer block, and the first stage provides a flow through the transfer mechanism to the transfer block. The transfer block is arranged to be positioned over a surface of the second stage to provide the flow to the second stage substantially without contacting the second stage.
    Type: Grant
    Filed: September 9, 2004
    Date of Patent: May 20, 2008
    Assignee: Nikon Corporation
    Inventors: Alex Ka Tim Poon, Leonard Wai-Fung Kho
  • Publication number: 20080100812
    Abstract: An immersion lithography apparatus having a substrate chuck made of a porous material. The porous substrate chuck is provided to contact and support the back surface of the substrate and hold the substrate in place. The porous substrate chuck facilitates in the removal of any immersion liquid under the substrate.
    Type: Application
    Filed: October 10, 2007
    Publication date: May 1, 2008
    Applicant: NIKON CORPORATION
    Inventors: Alex Ka Tim Poon, Leonard Wai Fung Kho, Gaurav Keswani, Derek Coon
  • Publication number: 20080073563
    Abstract: A mover combination (226) for moving and positioning a device (34) includes a mover (328) that defines a fluid passageway (370) and a circulation system (330) having a passageway inlet (374) and a passageway outlet (376). The circulation system (330) directs a circulation fluid (378) into the fluid passageway (370). The circulation system (330) can include a liquid/gas separator (384) that is in fluid communication with the fluid passageway (370). With this design, the plumbing for the liquid (378A) and the gas (378B) can each be optimized. Additionally, the circulation system (330) can include a pressure control device (388) that controls the pressure of the circulation fluid (378) in at least a portion of the fluid passageway (370).
    Type: Application
    Filed: July 1, 2006
    Publication date: March 27, 2008
    Inventors: W. Thomas Novak, Michael Binnard, Alex Ka Tim Poon, Masahiro Totsu, Leonard Wai Fung Kho, Gaurav Keswani
  • Publication number: 20070279608
    Abstract: A lithography apparatus having a fluid confinement plate, which completely submerges the imaging surface of a substrate, is disclosed. The apparatus includes an imaging element defining an image and a stage configured to support the substrate. A projection optical system is provided to project the image defined by the imaging element onto the imaging surface of the substrate. A gap, filled with immersion fluid, is provided between the imaging surface of the substrate and the last optical element of the 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: Application
    Filed: September 20, 2006
    Publication date: December 6, 2007
    Applicant: NIKON CORPORATION
    Inventors: Alex Ka Tim Poon, Leonard Wai Fung Kho, Gaurav Keswani, Derek Coon
  • Patent number: 7292313
    Abstract: Systems and methods control the fluid flow and pressure to provide stable conditions for immersion lithography. A fluid is provided in a space between a lens and a substrate during the immersion lithography process. Fluid is supplied to the space and is recovered from the space through a porous member in fluidic communication with the space. Maintaining the pressure in the porous member under the bubble point of the porous member can eliminate noise created by mixing air with the fluid during fluid recovery. The method can include drawing the fluid from the space via a recovery flow line through a porous member, and maintaining a pressure of the fluid in the porous member below a bubble point of the porous member during drawing of the fluid from the space.
    Type: Grant
    Filed: February 28, 2006
    Date of Patent: November 6, 2007
    Assignee: Nikon Corporation
    Inventors: Alex Ka Tim Poon, Leonard Wai Fung Kho
  • Patent number: 7283200
    Abstract: A measurement system (222) for measuring the position of a stage (248) along a first axis includes a first system (260) having a first beam source (260A) that directs a first beam (260H) on a first path that is parallel with a second axis and a first redirector (260D) that redirects the first beam so that the redirected first beam (260H) is on a first redirected path that is parallel with the first axis irrespective to the orientation of the first redirector (260D) about a third axis. The measurement system (222) can include a shield (380) that protects the first beam (260H) from environmental conditions.
    Type: Grant
    Filed: July 17, 2003
    Date of Patent: October 16, 2007
    Assignee: Nikon Corporation
    Inventors: Alex Ka Tim Poon, Leonard Wai Fung Kho, Toru Kawaguchi, Hisashi Tazawa, Saburo Kamiya, Yasuhiro Hidaka
  • Publication number: 20050162802
    Abstract: A stage apparatus includes a first assembly including a target member, a second assembly including a first attracting member and a second attracting member located on opposite sides of the target member, and an actuator associated with the second assembly. The actuator of the stage apparatus moves the second assembly to adjust the relative distance between the target member and the first attracting member.
    Type: Application
    Filed: January 22, 2004
    Publication date: July 28, 2005
    Inventors: Leonard Wai Fung Kho, Alex Ka Tim Poon
  • Patent number: 6917412
    Abstract: Methods and apparatus for providing a stage apparatus which is modular and allows for reaction force cancellation are described. According to one aspect of the present invention, a stage apparatus includes a table assembly and a first stage. The table assembly supports an object, e.g., a wafer or a reticle, which is to be moved. The first stage includes a counter mass arrangement, a plurality of carriages, and a plurality of linkages. The plurality of carriages is coupled to the table assembly through the plurality of linkages such that a first carriage and a second carriage are arranged to move in substantially opposite directions along a first axis to cause the table assembly to move along a second axis while reaction forces generated when the first carriage and the second carriage are substantially cancelled by the counter mass arrangement.
    Type: Grant
    Filed: February 26, 2003
    Date of Patent: July 12, 2005
    Assignee: Nikon Corporation
    Inventors: Alex Ka Tim Poon, Leonard Wai Fung Kho, Pai-Hsueh Yang, Ping-Wei Chang
  • Publication number: 20040165172
    Abstract: Methods and apparatus for providing a stage apparatus which is modular and allows for reaction force cancellation are described. According to one aspect of the present invention, a stage apparatus includes a table assembly and a first stage. The table assembly supports an object, e.g., a wafer or a reticle, which is to be moved. The first stage includes a counter mass arrangement, a plurality of carriages, and a plurality of linkages. The plurality of carriages is coupled to the table assembly through the plurality of linkages such that a first carriage and a second carriage are arranged to move in substantially opposite directions along a first axis to cause the table assembly to move along a second axis while reaction forces generated when the first carriage and the second carriage are substantially cancelled by the counter mass arrangement.
    Type: Application
    Filed: February 26, 2003
    Publication date: August 26, 2004
    Inventors: Alex Ka Tim Poon, Leonard Wai Fung Kho, Pai-Hsueh Yang, Ping-Wei Chang
  • Publication number: 20040119964
    Abstract: A vibration isolation system is provided. A frame is provided. A stage supported by the frame is provided. The stage comprises a stage body supported by the frame, a first isolation stage supported by the stage body, a first stage vibration isolation device that reduces vibrations transferred from the stage body to the first isolation stage, a second isolation stage supported by the first isolation stage, and a second stage vibration isolation device that reduces vibrations transferred from the first isolation stage to the second isolation stage.
    Type: Application
    Filed: December 18, 2002
    Publication date: June 24, 2004
    Applicant: Nikon Corporation
    Inventors: Alex Ka Tim Poon, Leonard Wai Fung Kho, Pai-Hsueh Yang, Ping-Wei Chang