Patents by Inventor Krishnan Shrinivasan

Krishnan Shrinivasan 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: 6563092
    Abstract: Methods and an apparatus for providing a non-contact probe for accurately measuring the temperature of a substrate in a process chamber are disclosed. One exemplary apparatus is a processing chamber, which includes a heating source, where the heating source heats the substrate. Also included is a window maintained at a substantially constant temperature. The window allows only a first wavelength spectrum of energy emitted from the heating source to pass. In addition, the window isolates the heating source from an internal region of the processing chamber. A probe configured to detect a second wavelength spectrum of energy emitted directly from the substrate is included. The energy emitted directly from the substrate corresponds to a temperature of the substrate, and the temperature of the substrate is provided to the controller, which adjusts an intensity of the heating source based on a set point temperature for the substrate.
    Type: Grant
    Filed: November 28, 2001
    Date of Patent: May 13, 2003
    Assignee: Novellus Systems, Inc.
    Inventors: Krishnan Shrinivasan, Arkadiy Shimanovich, Prasad N. Gadgil
  • Patent number: 6550484
    Abstract: The present invention pertains to apparatus and methods for maintaining wafer back side, bevel, and front side edge exclusion during supercritical fluid processing. Apparatus of the invention include a pedestal and an exclusion ring. When the exclusion ring is engaged with the pedestal a channel is formed. A reactant-free supercritical fluid is passed through the channel and over a circumferential front edge of a wafer. The flow of reactant-free supercritical fluid protects the bevel and circumferential front edge of the wafer from exposure to reactants in a supercritical processing medium. The back side of the wafer is protected by contact with the pedestal and the flow of reactant-free supercritical fluid. Exclusion rings of the invention, when engaged with their corresponding pedestals make no or very little physical contact with the wafer front side.
    Type: Grant
    Filed: December 7, 2001
    Date of Patent: April 22, 2003
    Assignee: Novellus Systems, Inc.
    Inventors: Sanjay Gopinath, Patrick A. Van Cleemput, Francisco Juarez, Krishnan Shrinivasan
  • Patent number: 6333268
    Abstract: Adherent matrix layers such as post-etch and other post-process residues are removed from a substrate by exposing them to a vapor phase solvent to allow penetration of the vapor phase solvent into the adherent matrix layers and condensing the vapor phase solvent into the adherent matrix layers and revaporized to promote fragmentation of the matrix and facilitate removal. Megasonic energy may be transmitted via a transmission member to the adherent matrix through the solvent condensed thereon to loosen fragments and particles. The substrate is typically rotated to improve contact between the megasonic energy transmission member and the condensed solvent and achieve more uniform cleaning. A co-solvent which is soluble in the vapor phase solvent may be added to enhance removal of specific adherent matrix materials.
    Type: Grant
    Filed: August 1, 2000
    Date of Patent: December 25, 2001
    Assignee: Novellus Systems, Inc.
    Inventors: Vladimir Starov, Shmuel Erez, Syed S. Basha, Arkadiy I. Shimanovich, Ravi Vellanki, Krishnan Shrinivasan, Karen A. Reinhardt, Aleksandr Kabansky
  • Patent number: 6228563
    Abstract: Adherent matrix layers such as post-etch and other post-process residues are removed from a substrate by exposing them to a vapor phase solvent to allow penetration of the vapor phase solvent into the adherent matrix layers and condensing the vapor phase solvent into the adherent matrix layers and revaporized to promote fragmentation of the matrix and facilitate removal. Megasonic energy may be transmitted via a transmission member to the adherent matrix through the solvent condensed thereon to loosen fragments and particles. The substrate is typically rotated to improve contact between the megasonic energy transmission member and the condensed solvent and achieve more uniform cleaning. A co-solvent which is soluble in the vapor phase solvent may be added to enhance removal of specific adherent matrix materials.
    Type: Grant
    Filed: September 17, 1999
    Date of Patent: May 8, 2001
    Assignee: Gasonics International Corporation
    Inventors: Vladimir Starov, Syed S. Basha, Krishnan Shrinivasan, Karen A. Reinhardt, Aleksandr Kabansky