Patents by Inventor Debra S. Woolsey

Debra S. Woolsey 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: 8936985
    Abstract: A method can include forming a drift region, forming a well region above the drift region, and forming an active trench extending through the well region and into the drift region. The method can include forming a first source region in contact with a first sidewall of the active trench and a second source region in contact with a second sidewall of the active trench. The method also includes forming a charge control trench where the charge control trench is aligned parallel to the active trench and laterally separated from the active trench by a mesa region, and where the portion of the well region is in contact with the charge control trench and excludes any source region. The method also includes forming an oxide along a bottom of the active trench having a thickness greater than a thickness of an oxide along the first sidewall of the active trench.
    Type: Grant
    Filed: March 12, 2012
    Date of Patent: January 20, 2015
    Assignee: Fairchild Semiconductor Corporation
    Inventors: Ashok Challa, Alan Elbanhawy, Dean E. Probst, Steven P. Sapp, Peter H. Wilson, Babak S. Sani, Becky Losee, Robert Herrick, James J. Murphy, Gordon K. Madson, Bruce D. Marchant, Christopher B. Kocon, Debra S. Woolsey
  • Publication number: 20120220091
    Abstract: A method for forming thick oxide at the bottom of a trench formed in a semiconductor substrate includes forming a conformal oxide film by a sub-atmospheric chemical vapor deposition process that fills the trench and covers a top surface of the substrate. The method also includes etching the oxide film off the top surface of the substrate and inside the trench to leave a substantially flat layer of oxide having a target thickness at the bottom of the trench.
    Type: Application
    Filed: March 12, 2012
    Publication date: August 30, 2012
    Inventors: Ashok Challa, Alan Elbanhawy, Thomas E. Grebs, Nathan L. Kraft, Dean E. Probst, Rodney S. Ridley, Steven P. Sapp, Qi Wang, Chongman Yun, J.G. Lee, Peter H. Wilson, Joseph A. Yedinak, J.Y. Jung, H.C. Jang, Babak S. Sani, Richard Stokes, Gary M. Dolny, John Mytych, Becky Losee, Adam Selsley, Robert Herrick, James J. Murphy, Gordon K. Madson, Bruce D. Marchant, Christopher L. Rexer, Christopher B. Kocon, Debra S. Woolsey
  • Patent number: 8143124
    Abstract: A method of manufacturing a semiconductor device having a charge control trench and an active control trench with a thick oxide bottom includes forming a drift region, a well region extending above the drift region, an active trench extending through the well region and into the drift region, a charge control trench extending deeper into the drift region than the active trench, an oxide film that fills the active trench, the charge control trench and covers a top surface of the substrate, an electrode in the active trench, and source regions. The method also includes etching the oxide film off the top surface of the substrate and inside the active trench to leave a substantially flat layer of thick oxide having a target thickness at the bottom of the active trench.
    Type: Grant
    Filed: February 15, 2008
    Date of Patent: March 27, 2012
    Assignee: Fairchild Semiconductor Corporation
    Inventors: Ashok Challa, Alan Elbanhawy, Dean E. Probst, Steven P. Sapp, Peter H. Wilson, Babak S. Sani, Becky Losee, Robert Herrick, James J. Murphy, Gordon K. Madson, Bruce D. Marchant, Christopher B. Kocon, Debra S. Woolsey
  • Publication number: 20100187602
    Abstract: Semiconductor devices and methods for making such devices using nitride consumption LOCOS oxidation are described. The semiconductor devices contain a planar field oxide structure that has been grown using a nitride layer as an oxidation mask. Once the field oxide structure has been grown, the nitride mask is not etched away, but rather converted to an oxide layer by an oxidation process using radicals of hydrogen and oxygen. The semiconductor devices also contain a shielded gate trench MOSFET that can be created using an oxide layer with an overlying nitride layer as the channel (sidewall) gate dielectric. An inter-poly-dielectric (IPD) layer can be formed from a thermally grown oxide which uses the nitride layer as a oxidation mask. The thickness of the IPD layer can be adjusted to any thickness needed with minimal effect of the channel gate dielectric layer.
    Type: Application
    Filed: January 29, 2009
    Publication date: July 29, 2010
    Inventors: Debra S. Woolsey, Tony L. Olsen, Gordon K. Madson
  • Publication number: 20080150020
    Abstract: A semiconductor power device includes a drift region of a first conductivity type, a well region extending above the drift region and having a second conductivity type opposite the first conductivity type, an active trench extending through the well region and into the drift region. The active trench, which includes sidewalls and bottom lined with dielectric material, is substantially filled with a first conductive layer and a second conductive layer. The second conductive layer forms a gate electrode and is disposed above the first conductive layer and is separated from the first conductive layer by an inter-electrode dielectric material. The device also includes source regions having the first conductivity type formed inside the well region and adjacent the active trench and a charge control trench that extends deeper into the drift region than the active trench and is substantially filled with material to allow for vertical charge control in the drift region.
    Type: Application
    Filed: January 22, 2008
    Publication date: June 26, 2008
    Inventors: Ashok Challa, Alan Elbanhawy, Thomas E. Grebs, Nathan L. Kraft, Dean E. Probst, Rodney S. Ridley, Steven P. Sapp, Qi Wang, Chongman Yun, J. G. Lee, Peter H. Wilson, Joseph A. Yedinak, J. Y. Jung, H. C. Jang, Babak S. Sani, Richard Stokes, Gary M. Dolny, John Mytych, Becky Losee, Adam Selsley, Robert Herrick, James J. Murphy, Gordon K. Madson, Bruce D. Marchant, Christopher L. Rexer, Christopher B. Kocon, Debra S. Woolsey
  • Publication number: 20080138953
    Abstract: A method for forming thick oxide at the bottom of a trench formed in a semiconductor substrate includes forming a conformal oxide film that fills the trench and covers a top surface of the substrate. and etching the oxide film off the top surface of the substrate and inside the trench to leave a substantially flat layer of oxide having a target thickness at the bottom of the trench. The oxide film can be deposited by sub-atmospheric chemical vapor deposition processes, directional Tetraethoxysilate (TEOS) processes, or high density plasma deposition processes that form a thicker oxide at the bottom of the trench than on the sidewalls of the trench.
    Type: Application
    Filed: February 15, 2008
    Publication date: June 12, 2008
    Inventors: Ashok Challa, Alan Elbanhawy, Dean E. Probst, Steven P. Sapp, Peter H. Wilson, Babak S. Sani, Becky Losee, Robert Herrick, James J. Murphy, Gordon K. Madson, Bruce D. Marchant, Christopher B. Kocon, Debra S. Woolsey
  • Publication number: 20080135931
    Abstract: A semiconductor power device includes a drift region of a first conductivity type, a well region extending above the drift region and having a second conductivity type opposite the first conductivity type, an active trench extending through the well region and into the drift region, source regions having the first conductivity type formed in the well region adjacent the active trench, and a first termination trench extending below the well region and disposed at an outer edge of an active region of the device. The sidewalls and bottom of the active trench are lined with dielectric material, and substantially filled with a first conductive layer forming an upper electrode and a second conductive layer forming a lower electrode, the upper electrode being disposed above the lower electrode and separated therefrom by inter-electrode dielectric material.
    Type: Application
    Filed: February 15, 2008
    Publication date: June 12, 2008
    Inventors: Ashok Challa, Alan Elbanhawy, Thomas E. Grebs, Nathan L. Kraft, Dean E. Probst, Rodney S. Ridlay, Steven P. Sapp, Qi Wang, Chongman Yun, J.G. Lee, Peter H. Wilson, Joseph A. Yedinak, J.Y. Jung, H.C. Jang, Babak S. Sanl, Richard Stokes, Gary M. Dolny, John Mytych, Becky Losee, Adam Selsley, Robert Herrick, James J. Murphy, Gordon K. Madson, Bruce D. Marchant, Christopher L. Rexer, Christopher B. Kocon, Debra S. Woolsey