Patents by Inventor Rajesh S. Ramanujam

Rajesh S. Ramanujam 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: 8254767
    Abstract: Embodiments of the invention are directed to methods and apparatus for rapid thermal processing of a substrate over an extended temperature range, including low temperatures. Systems and methods for using an extended temperature pyrometry system employing a transmitted radiation detector system are disclosed. Systems combining transmitted radiation detector systems and emitted radiation detector systems are also described.
    Type: Grant
    Filed: August 26, 2009
    Date of Patent: August 28, 2012
    Assignee: Applied Materials, Inc.
    Inventors: Aaron M. Hunter, Jiping Li, Rajesh S. Ramanujam, Thomas Haw
  • Patent number: 8232503
    Abstract: In a laser annealing system for workpieces such as semiconductor wafers, a pyrometer wavelength response band is established within a narrow window lying between the laser emission band and a fluorescence emission band from the optical components of the laser system, the pyrometer response band lying in a wavelength region at which the optical absorber layer on the workpiece has an optical absorption coefficient as great as or greater than the underlying workpiece. A multi-layer razor-edge interference filter having a 5-8 nm wavelength cut-off edge transition provides the cut-off of the laser emission at the bottom end of the pyrometer response band.
    Type: Grant
    Filed: September 21, 2010
    Date of Patent: July 31, 2012
    Assignee: Applied Materials, Inc.
    Inventors: Jiping Li, Bruce E. Adams, Timothy N. Thomas, Aaron Muir Hunter, Abhilash J. Mayur, Rajesh S. Ramanujam
  • Publication number: 20110089166
    Abstract: The present invention provides apparatus and methods for achieving uniform heating to a substrate during a rapid thermal process. More particularly, the present invention provides apparatus and methods for controlling the temperature of an edge ring supporting a substrate during a rapid thermal process to improve temperature uniformity across the substrate.
    Type: Application
    Filed: December 20, 2010
    Publication date: April 21, 2011
    Inventors: AARON MUIR HUNTER, Bruce E. Adams, Mehran Behdjat, Rajesh S. Ramanujam, Joseph M. Ranish
  • Publication number: 20110006044
    Abstract: In a laser annealing system for workpieces such as semiconductor wafers, a pyrometer wavelength response band is established within a narrow window lying between the laser emission band and a fluorescence emission band from the optical components of the laser system, the pyrometer response band lying in a wavelength region at which the optical absorber layer on the workpiece has an optical absorption coefficient as great as or greater than the underlying workpiece. A multi-layer razor-edge interference filter having a 5-8 nm wavelength cut-off edge transition provides the cut-off of the laser emission at the bottom end of the pyrometer response band.
    Type: Application
    Filed: September 21, 2010
    Publication date: January 13, 2011
    Inventors: Jiping Li, Bruce E. Adams, Timothy N. Thomas, Aaron Muir Hunter, Abhilash J. Mayur, Rajesh S. Ramanujam
  • Patent number: 7860379
    Abstract: The present invention provides apparatus and methods for achieving uniform heating to a substrate during a rapid thermal process. More particularly, the present invention provides apparatus and methods for controlling the temperature of an edge ring supporting a substrate during a rapid thermal process to improve temperature uniformity across the substrate.
    Type: Grant
    Filed: January 15, 2007
    Date of Patent: December 28, 2010
    Assignee: Applied Materials, Inc.
    Inventors: Aaron Muir Hunter, Bruce E. Adams, Mehran Behdjat, Rajesh S. Ramanujam, Joseph M. Ranish
  • Patent number: 7804042
    Abstract: In a laser annealing system for workpieces such as semiconductor wafers, a pyrometer wavelength response band is established within a narrow window lying between the laser emission band and a fluorescence emission band from the optical components of the laser system, the pyrometer response band lying in a wavelength region at which the optical absorber layer on the workpiece has an optical absorption coefficient as great as or greater than the underlying workpiece. A multi-layer razor-edge interference filter having a 5-8 nm wavelength cut-off edge transition provides the cut-off of the laser emission at the bottom end of the pyrometer response band.
    Type: Grant
    Filed: June 18, 2007
    Date of Patent: September 28, 2010
    Assignee: Applied Materials, Inc.
    Inventors: Jiping Li, Bruce E. Adams, Timothy N. Thomas, Aaron Muir Hunter, Abhilash J. Mayur, Rajesh S. Ramanujam
  • Publication number: 20100054720
    Abstract: Embodiments of the invention are directed to methods and apparatus for rapid thermal processing of a substrate over an extended temperature range, including low temperatures. Systems and methods for using an extended temperature pyrometry system employing a transmitted radiation detector system are disclosed. Systems combining transmitted radiation detector systems and emitted radiation detector systems are also described.
    Type: Application
    Filed: August 26, 2009
    Publication date: March 4, 2010
    Applicant: Applied Materials, Inc.
    Inventors: Aaron M. Hunter, Jiping Li, Rajesh S. Ramanujam, Thomas Haw
  • Publication number: 20080308534
    Abstract: In a laser annealing system for workpieces such as semiconductor wafers, a pyrometer wavelength response band is established within a narrow window lying between the laser emission band and a fluorescence emission band from the optical components of the laser system, the pyrometer response band lying in a wavelength region at which the optical absorber layer on the workpiece has an optical absorption coefficient as great as or greater than the underlying workpiece. A multi-layer razor-edge interference filter having a 5-8 nm wavelength cut-off edge transition provides the cut-off of the laser emission at the bottom end of the pyrometer response band.
    Type: Application
    Filed: June 18, 2007
    Publication date: December 18, 2008
    Inventors: Jiping Li, Bruce E. Adams, Timothy N. Thomas, Aaron Muir Hunter, Abhilash J. Mayur, Rajesh S. Ramanujam
  • Publication number: 20080170842
    Abstract: The present invention provides apparatus and methods for achieving uniform heating to a substrate during a rapid thermal process. More particularly, the present invention provides apparatus and methods for controlling the temperature of an edge ring supporting a substrate during a rapid thermal process to improve temperature uniformity across the substrate.
    Type: Application
    Filed: January 15, 2007
    Publication date: July 17, 2008
    Inventors: AARON MUIR HUNTER, Bruce E. Adams, Mehran Behdjat, Rajesh S. Ramanujam, Joseph M. Ranish
  • Publication number: 20080169282
    Abstract: Apparatus and methods for achieving uniform heating or cooling of a substrate during a rapid thermal process are disclosed. More particularly, apparatus and methods for controlling the temperature of an edge ring supporting a substrate and/or a reflector plate during a rapid thermal process to improve temperature uniformity across the substrate are disclosed, which include a thermal mass or plate adjacent the edge ring to heat or cool the edge ring.
    Type: Application
    Filed: March 25, 2008
    Publication date: July 17, 2008
    Inventors: KHURSHED SORABJI, Alexander N. Lerner, Joseph M. Ranish, Aaron M. Hunter, Bruce Adams, Mehran Behdjat, Rajesh S. Ramanujam
  • Patent number: 7112763
    Abstract: A rapid thermal processing (RTP) system including a transmission pyrometer monitoring the temperature dependent absorption of the silicon wafer for radiation from the RTP lamps at a reduced power level. A look-up table is created relating unnormalized values of photodetector photocurrents with wafer and radiant lamp temperatures. A calibrating step measures the photocurrent with known wafer and lamp temperatures and all photocurrents measured thereafter are accordingly normalized. The transmission pyrometer may be used for closed loop control for thermal treatments below 500° C. or used in the pre-heating phase for a higher temperature process including radiation pyrometry in closed loop control. The pre-heating temperature ramp rate may be controlled by measuring the initial ramp rate and readjusting the lamp power accordingly. Radiation and transmission pyrometers may be included in an integrated structure with a beam splitter dividing radiation from the wafer.
    Type: Grant
    Filed: October 26, 2004
    Date of Patent: September 26, 2006
    Assignee: Applied Materials, Inc.
    Inventors: Aaron Hunter, Rajesh S. Ramanujam, Balasubramanian Ramachandran, Corina Elena Tanasa, Tarpan Dixit