Patents by Inventor Choonghoon Oh

Choonghoon Oh 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).

  • Patent number: 6590922
    Abstract: A narrow band F2 laser system having two laser subsystems. The first laser subsystem is configured to provide a very narrow band pulsed beam at a first narrow wavelength range corresponding to a first natural emission line of the F2 laser system. This beam is injected into the gain medium of the second laser subsystem in a first direction where the beam is amplified to produce a narrow band pulsed output beam. The seed laser subsystem also produces a second pulsed beam at a second wavelength range corresponding to a second natural emission line of the F2 laser. This line is injected into the gain medium of the second laser subsystem in a second direction opposite said first direction. The second beam is amplified in the gain medium of the second laser subsystem depleting the gain medium of gain potential at the second wavelength range. (This amplified second beam is preferably wasted.
    Type: Grant
    Filed: June 12, 2001
    Date of Patent: July 8, 2003
    Assignee: Cymer, Inc.
    Inventors: Eckehard D. Onkels, Richard L. Sandstrom, Richard M. Ness, William N. Partlo, Alexander I. Ershov, Choonghoon Oh
  • Patent number: 6556600
    Abstract: The present invention provides a narrow band laser system having two laser subsystems. The first laser subsystem is configured to provide a very narrow band pulsed output beam which is used to injection seed the second laser subsystem where the narrow band pulsed seed beam is amplified to produce a narrow band pulsed output beam. A pulse power supply is provided which is specially configured to precisely time the discharges in the two laser subsystem so that the discharges are properly synchronized. The laser gas comprises F2 at a partial pressure less than about 1% with a buffer gas comprised of helium or neon or a combination of helium and neon. Control of center wavelength of the output beam is provided by adjusting one or more of the following parameters in the first laser: the total laser gas pressure, the relative concentration of helium or neon, F2 partial pressure, laser gas temperature, discharge voltage and pulse energy.
    Type: Grant
    Filed: May 14, 2001
    Date of Patent: April 29, 2003
    Assignee: Cymer, Inc.
    Inventors: Richard L. Sandstrom, Richard M. Ness, William N. Partlo, Alexander I. Ershov, Eckehard D. Onkels, Choonghoon Oh
  • Publication number: 20020186739
    Abstract: The present invention provides a narrow band laser system having two laser subsystems. The first laser subsystem is configured to provide a very narrow band pulsed output beam which is used to injection seed the second laser subsystem where the narrow band pulsed seed beam is amplified to produce a narrow band pulsed output beam. A pulse power supply is provided which is specially configured to precisely time the discharges in the two laser subsystem so that the discharges are properly synchronized. The laser gas comprises F2 at a partial pressure less than about 1% with a buffer gas comprised of helium or neon or a combination of helium and neon. Control of center wavelength of the output beam is provided by adjusting one or more of the following parameters in the first laser: the total laser gas pressure, the relative concentration of helium or neon, F2 partial pressure, laser gas temperature, discharge voltage and pulse energy.
    Type: Application
    Filed: May 14, 2001
    Publication date: December 12, 2002
    Inventors: Richard L. Sandstrom, Richard M. Ness, William N. Partlo, Alexander I. Ershov, Eckehard D. Onkels, Choonghoon Oh
  • Publication number: 20020114370
    Abstract: A narrow band F2 laser system having two laser subsystems. The first laser subsystem is configured to provide a very narrow band pulsed beam at a first narrow wavelength range corresponding to a first natural emission line of the F2 laser system. This beam is injected into the gain medium of the second laser subsystem in a first direction where the beam is amplified to produce a narrow band pulsed output beam. The seed laser subsystem also produces a second pulsed beam at a second wavelength range corresponding to a second natural emission line of the F2 laser. This line is injected into the gain medium of the second laser subsystem in a second direction opposite said first direction. The second beam is amplified in the gain medium of the second laser subsystem depleting the gain medium of gain potential at the second wavelength range. (This amplified second beam is preferably wasted.
    Type: Application
    Filed: June 12, 2001
    Publication date: August 22, 2002
    Inventors: Eckehard D. Onkels, Richard L. Sandstrom, Richard M. Ness, William N. Partlo, Alexander I. Ershov, Choonghoon Oh