Patents by Inventor Joseph J. Sumakeris

Joseph J. Sumakeris 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: 7880171
    Abstract: A bipolar device has at least one p? type layer of single crystal silicon carbide and at least one n? type layer of single crystal silicon carbide, wherein those portions of those stacking faults that grow under forward operation are segregated from at least one of the interfaces between the active region and the remainder of the device.
    Type: Grant
    Filed: December 22, 2004
    Date of Patent: February 1, 2011
    Assignee: Cree, Inc.
    Inventors: Joseph J. Sumakeris, Ranbir Singh, Michael James Paisley, Stephan Georg Mueller, Hudson M. Hobgood, Calvin H. Carter, Jr., Albert Augustus Burk, Jr.
  • Patent number: 7427326
    Abstract: A method of forming a bipolar device includes forming at least one p-type layer of single crystal silicon carbide and at least one n-type layer of single crystal silicon carbide on a substrate. Stacking faults that grow under forward operation of the device are segregated from at least one of the interfaces between the active region and the remainder of the device. The method of forming bipolar devices includes growing at least one of the epitaxial layers to a thickness greater than the minority carrier diffusion length in that layer. The method also increases the doping concentration of epitaxial layers surrounding the drift region to decrease minority carrier lifetimes therein.
    Type: Grant
    Filed: November 16, 2006
    Date of Patent: September 23, 2008
    Assignee: Cree, Inc.
    Inventors: Joseph J. Sumakeris, Ranbir Singh, Michael James Paisley, Stephan Georg Mueller, Hudson M. Hobgood, Calvin H. Carter, Jr., Albert Augustus Burk, Jr.
  • Patent number: 6849874
    Abstract: A bipolar device has at least one p-type layer of single crystal silicon carbide and at least one n-type layer of single crystal silicon carbide, wherein those portions of those stacking faults that grow under forward operation are segregated from at least one of the interfaces between the active region and the remainder of the device.
    Type: Grant
    Filed: October 26, 2001
    Date of Patent: February 1, 2005
    Assignee: Cree, Inc.
    Inventors: Joseph J. Sumakeris, Ranbir Singh, Michael James Paisley, Stephan Georg Mueller, Hudson M. Hobgood, Calvin H. Carter, Jr., Albert Augustus Burk, Jr.
  • Patent number: 6653659
    Abstract: Silicon carbide devices and methods of fabricating silicon carbide devices are provided by forming a first p-type silicon carbide epitaxial layer on an n-type silicon carbide substrate. At least one first region of n-type silicon carbide is formed extending through the first p-type silicon carbide epitaxial layer and to the n-type silicon carbide substrate so as to provide at least one channel region in the first p-type silicon carbide epitaxial layer. At least one second region of n-type silicon carbide is also formed adjacent and spaced apart from the first region of n-type silicon carbide. A gate dielectric is formed-over the first region of n-type silicon carbide and at least a portion of the second region of n-type silicon carbide. A gate contact is formed on the gate dielectric. A first contact is also formed so as to contact a portion of the p-type epitaxial layer and the second region of n-type silicon carbide. A second contact is also formed on the substrate.
    Type: Grant
    Filed: June 7, 2002
    Date of Patent: November 25, 2003
    Assignee: Cree, Inc.
    Inventors: Sei-Hyung Ryu, Joseph J. Sumakeris, Anant K. Agarwal, Ranbir Singh
  • Publication number: 20030080842
    Abstract: A bipolar device has at least one p-type layer of single crystal silicon carbide and at least one n-type layer of single crystal silicon carbide, wherein those portions of those stacking faults that grow under forward operation are segregated from at least one of the interfaces between the active region and the remainder of the device.
    Type: Application
    Filed: October 26, 2001
    Publication date: May 1, 2003
    Inventors: Joseph J. Sumakeris, Ranbir Singh, Michael James Paisley, Stephan Georg Mueller, Hudson M. Hobgood, Calvin H. Carter, Albert Augustus Burk
  • Publication number: 20020149022
    Abstract: Silicon carbide devices and methods of fabricating silicon carbide devices are provided by forming a first p-type silicon carbide epitaxial layer on an n-type silicon carbide substrate. At least one first region of n-type silicon carbide is formed extending through the first p-type silicon carbide epitaxial layer and to the n-type silicon carbide substrate so as to provide at least one channel region in the first p-type silicon carbide epitaxial layer. At least one second region of n-type silicon carbide is also formed adjacent and spaced apart from the first region of n-type silicon carbide. A gate dielectric is formed-over the first region of n-type silicon carbide and at least a portion of the second region of n-type silicon carbide. A gate contact is formed on the gate dielectric. A first contact is also formed so as to contact a portion of the p-type epitaxial layer and the second region of n-type silicon carbide. A second contact is also formed on the substrate.
    Type: Application
    Filed: June 7, 2002
    Publication date: October 17, 2002
    Inventors: Sei-Hyung Ryu, Joseph J. Sumakeris, Anant K. Agarwal, Ranbir Singh
  • Patent number: 6429041
    Abstract: Silicon carbide devices and methods of fabricating silicon carbide devices are provided by forming a first p-type silicon carbide epitaxial layer on an n-type silicon carbide substrate. At least one first region of n-type silicon carbide is formed extending through the first p-type silicon carbide epitaxial layer and to the n-type silicon carbide substrate so as to provide at least one channel region in the first p-type silicon carbide epitaxial layer. At least one second region of n-type silicon carbide is also formed adjacent and spaced apart from the first region of n-type silicon carbide. A gate dielectric is formed over the first region of n-type silicon carbide and at least a portion of the second region of n-type silicon carbide. A gate contact is formed on the gate dielectric. A first contact is also formed so as to contact a portion of the p-type epitaxial layer and the second region of n-type silicon carbide. A second contact is also formed on the substrate.
    Type: Grant
    Filed: July 13, 2000
    Date of Patent: August 6, 2002
    Assignee: Cree, Inc.
    Inventors: Sei-Hyung Ryu, Joseph J. Sumakeris, Anant K. Agarwal, Ranbir Singh