Patents by Inventor Karthik Padmanabhan

Karthik Padmanabhan 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: 20150279989
    Abstract: In some embodiments, a normally on high voltage switch device (“normally on switch device”) incorporates a trench gate terminal and buried doped gate region. In other embodiments, a surface gate controlled normally on high voltage switch device is formed with trench structures and incorporates a surface channel controlled by a surface gate electrode. The surface gate controlled normally on switch device may further incorporate a trench gate electrode and a buried doped gate region to deplete the conducting channel to aid in the turning off of the normally on switch device. The normally on switch devices thus constructed can be readily integrated with MOSFET devices and formed using existing high voltage MOSFET fabrication technologies.
    Type: Application
    Filed: June 10, 2015
    Publication date: October 1, 2015
    Inventors: Madhur Bobde, Hamza Yilmaz, Daniel Calafut, Karthik Padmanabhan
  • Patent number: 9082790
    Abstract: In some embodiments, a normally on high voltage switch device (“normally on switch device”) incorporates a trench gate terminal and buried doped gate region. In other embodiments, a surface gate controlled normally on high voltage switch device is formed with trench structures and incorporates a surface channel controlled by a surface gate electrode. The surface gate controlled normally on switch device may further incorporate a trench gate electrode and a buried doped gate region to deplete the conducting channel to aid in the turning off of the normally on switch device. The normally on switch devices thus constructed can be readily integrated with MOSFET devices and formed using existing high voltage MOSFET fabrication technologies.
    Type: Grant
    Filed: July 18, 2013
    Date of Patent: July 14, 2015
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventors: Madhur Bobde, Hamza Yilmaz, Daniel Calafut, Karthik Padmanabhan
  • Publication number: 20150162410
    Abstract: This invention discloses a semiconductor power device formed in a semiconductor substrate of a first conductivity type comprises an active cell area and a termination area surrounding the active cell area and disposed near edges of the semiconductor substrate. The termination area includes a plurality of trenches filled with a conductivity material forming a shield electrode and insulated by a dielectric layer along trench sidewalls and trench bottom surface wherein the trenches extending vertically through a body region of a second conductivity type near a top surface of the semiconductor substrate and further extending through a surface shield region of the first conductivity type. A dopant region of the second conductivity type disposed below the surface shield region extending across and surrounding a trench bottom portion of the trenches.
    Type: Application
    Filed: December 6, 2013
    Publication date: June 11, 2015
    Inventors: Karthik Padmanabhan, Madhur Bobde
  • Publication number: 20150021682
    Abstract: In some embodiments, a normally on high voltage switch device (“normally on switch device”) incorporates a trench gate terminal and buried doped gate region. In other embodiments, a surface gate controlled normally on high voltage switch device is formed with trench structures and incorporates a surface channel controlled by a surface gate electrode. The surface gate controlled normally on switch device may further incorporate a trench gate electrode and a buried doped gate region to deplete the conducting channel to aid in the turning off of the normally on switch device. The normally on switch devices thus constructed can be readily integrated with MOSFET devices and formed using existing high voltage MOSFET fabrication technologies.
    Type: Application
    Filed: July 18, 2013
    Publication date: January 22, 2015
    Applicant: Alpha and Omega Semiconductor Incorporated
    Inventors: Madhur Bobde, Hamza Yilmaz, Daniel Calafut, Karthik Padmanabhan
  • Patent number: 8907414
    Abstract: Aspects of the present disclosure describe high voltage fast recovery trench diodes and methods for make the same. The device may have trenches that extend at least through a top P-layer and an N-barrier layer. A conductive material may be disposed in the trenches with a dielectric material lining the trenches between the conductive material and sidewalls of the trenches. A highly doped P-pocket may be formed in an upper portion of the top P-layer between the trenches. A floating N-pocket may be formed directly underneath the P-pocket. The floating N-pocket may be as wide as or wider than the P-pocket. It is emphasized that this abstract is provided to comply with rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.
    Type: Grant
    Filed: March 26, 2014
    Date of Patent: December 9, 2014
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventors: Jun Hu, Karthik Padmanabhan, Madhur Bobde, Hamza Yilmaz
  • Publication number: 20140332919
    Abstract: A termination structure for a semiconductor power device includes a plurality of termination groups formed in a lightly doped epitaxial layer of a first conductivity type over a heavily doped semiconductor substrate of a second conductivity type. Each termination group includes a trench formed in the lightly doped epitaxial layer of the first conductivity type. All sidewalls of the trench are covered by a plurality of epitaxial layers of alternating conductivity types disposed on two opposite sides and substantially symmetrical with respect to a central gap-filler layer disposed between two innermost epitaxial layers of an innermost conductivity type as the first conductivity type.
    Type: Application
    Filed: July 28, 2014
    Publication date: November 13, 2014
    Inventors: Lingpeng Guan, Madhur Bobde, Hamza Yilmaz, Karthik Padmanabhan
  • Publication number: 20140239436
    Abstract: Aspects of the present disclosure describe high voltage fast recovery trench diodes and methods for make the same. The device may have trenches that extend at least through a top P-layer and an N-barrier layer. A conductive material may be disposed in the trenches with a dielectric material lining the trenches between the conductive material and sidewalls of the trenches. A highly doped P-pocket may be formed in an upper portion of the top P-layer between the trenches. A floating N-pocket may be formed directly underneath the P-pocket. The floating N-pocket may be as wide as or wider than the P-pocket. It is emphasized that this abstract is provided to comply with rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.
    Type: Application
    Filed: March 26, 2014
    Publication date: August 28, 2014
    Applicant: Alpha & Omega Semiconductor Incorporated
    Inventors: Jun Hu, Karthik Padmanabhan, Madhur Bobde, Hamza Yilmaz
  • Patent number: 8710585
    Abstract: Aspects of the present disclosure describe high voltage fast recovery trench diodes and methods for make the same. The device may have trenches that extend at least through a top P-layer and an N-barrier layer. A conductive material may be disposed in the trenches with a dielectric material lining the trenches between the conductive material and sidewalls of the trenches. A highly doped P-pocket may be formed in an upper portion of the top P-layer between the trenches. A floating N-pocket may be formed directly underneath the P-pocket. The floating N-pocket may be as wide as or wider than the P-pocket. It is emphasized that this abstract is provided to comply with rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.
    Type: Grant
    Filed: February 25, 2013
    Date of Patent: April 29, 2014
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventors: Jun Hu, Karthik Padmanabhan, Madhur Bobde, Hamza Yilmaz