Patents by Inventor Stacia Keller

Stacia Keller 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: 20160163846
    Abstract: A method of fabricating a III-nitride semiconductor device, including growing an III-nitride semiconductor and an oxide sequentially to form an oxide/III-nitride interface, without exposure to air in between growth of the oxide and growth of the III-nitride semiconductor.
    Type: Application
    Filed: January 28, 2016
    Publication date: June 9, 2016
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Xiang Liu, Umesh K. Mishra, Stacia Keller, Jeonghee Kim, Matthew Laurent, Jing Lu, Ramya Yeluri, Silvia H. Chan
  • Publication number: 20160133737
    Abstract: A method of fabricating a semiconductor device can include forming a III-N semiconductor layer in a reactor and injecting a hydrocarbon precursor into the reactor, thereby carbon doping the III-N semiconductor layer and causing the III-N semiconductor layer to be insulating or semi-insulating. A semiconductor device can include a substrate and a carbon doped insulating or semi-insulating III-N semiconductor layer on the substrate. The carbon doping density in the III-N semiconductor layer is greater than 5×1018 cm?3 and the dislocation density in the III-N semiconductor layer is less than 2×109 cm?2.
    Type: Application
    Filed: December 29, 2015
    Publication date: May 12, 2016
    Inventors: Stacia Keller, Brian L. Swenson, Nicholas Fichtenbaum
  • Publication number: 20160126342
    Abstract: A method of fabricating a semiconductor device can include forming a III-N semiconductor layer in a reactor and injecting a hydrocarbon precursor into the reactor, thereby carbon doping the III-N semiconductor layer and causing the III-N semiconductor layer to be insulating or semi-insulating. A semiconductor device can include a substrate and a carbon doped insulating or semi-insulating III-N semiconductor layer on the substrate. The carbon doping density in the III-N semiconductor layer is greater than 5×1018 cm?3 and the dislocation density in the III-N semiconductor layer is less than 2×109 cm?2.
    Type: Application
    Filed: January 8, 2016
    Publication date: May 5, 2016
    Inventors: Stacia Keller, Brian L. Swenson, Nicholas Fichtenbaum
  • Patent number: 9281183
    Abstract: A method of fabricating a III-nitride semiconductor device, including growing an III-nitride semiconductor and an oxide sequentially to form an oxide/III-nitride interface, without exposure to air in between growth of the oxide and growth of the III-nitride semiconductor.
    Type: Grant
    Filed: January 15, 2015
    Date of Patent: March 8, 2016
    Assignee: The Regents of the University of California
    Inventors: Xiang Liu, Umesh K. Mishra, Stacia Keller, Jeonghee Kim, Matthew Laurent, Jing Lu, Ramya Yeluri, Silvia H. Chan
  • Publication number: 20160042946
    Abstract: Embodiments of the present disclosure include a buffer structure suited for III-N device having a foreign substrate. The buffer structure can include a first buffer layer having a first aluminum composition and a second buffer layer formed on the first buffer layer, the second buffer layer having a second aluminum composition. The buffer structure further includes a third buffer layer formed on the second buffer layer at a second interface, the third buffer layer having a third aluminum composition. The first aluminum composition decreases in the first buffer layer towards the interface and the second aluminum composition throughout the second buffer layer is greater than the first aluminum composition at the interface.
    Type: Application
    Filed: October 16, 2015
    Publication date: February 11, 2016
    Inventors: Stacia Keller, Brian L. Swenson, Nicholas Fichtenbaum
  • Patent number: 9245992
    Abstract: A method of fabricating a semiconductor device can include forming a III-N semiconductor layer in a reactor and injecting a hydrocarbon precursor into the reactor, thereby carbon doping the III-N semiconductor layer and causing the III-N semiconductor layer to be insulating or semi-insulating. A semiconductor device can include a substrate and a carbon doped insulating or semi-insulating III-N semiconductor layer on the substrate. The carbon doping density in the III-N semiconductor layer is greater than 5×1018 cm?3 and the dislocation density in the III-N semiconductor layer is less than 2×109 cm?2.
    Type: Grant
    Filed: March 13, 2014
    Date of Patent: January 26, 2016
    Assignee: Transphorm Inc.
    Inventors: Stacia Keller, Brian L. Swenson, Nicholas Fichtenbaum
  • Patent number: 9245993
    Abstract: A method of fabricating a semiconductor device can include forming a III-N semiconductor layer in a reactor and injecting a hydrocarbon precursor into the reactor, thereby carbon doping the III-N semiconductor layer and causing the III-N semiconductor layer to be insulating or semi-insulating. A semiconductor device can include a substrate and a carbon doped insulating or semi-insulating III-N semiconductor layer on the substrate. The carbon doping density in the III-N semiconductor layer is greater than 5×1018 cm?3 and the dislocation density in the III-N semiconductor layer is less than 2×109 cm?2.
    Type: Grant
    Filed: March 13, 2014
    Date of Patent: January 26, 2016
    Assignee: Transphorm Inc.
    Inventors: Stacia Keller, Brian L. Swenson, Nicholas Fichtenbaum
  • Patent number: 9165766
    Abstract: Embodiments of the present disclosure include a buffer structure suited for III-N device having a foreign substrate. The buffer structure can include a first buffer layer having a first aluminum composition and a second buffer layer formed on the first buffer layer, the second buffer layer having a second aluminum composition. The buffer structure further includes a third buffer layer formed on the second buffer layer at a second interface, the third buffer layer having a third aluminum composition. The first aluminum composition decreases in the first buffer layer towards the interface and the second aluminum composition throughout the second buffer layer is greater than the first aluminum composition at the interface.
    Type: Grant
    Filed: February 3, 2012
    Date of Patent: October 20, 2015
    Assignee: Transphorm Inc.
    Inventors: Stacia Keller, Brian L. Swenson, Nicholas Fichtenbaum
  • Publication number: 20150200286
    Abstract: A method of fabricating a III-nitride semiconductor device, including growing an III-nitride semiconductor and an oxide sequentially to form an oxide/III-nitride interface, without exposure to air in between growth of the oxide and growth of the III-nitride semiconductor.
    Type: Application
    Filed: January 15, 2015
    Publication date: July 16, 2015
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Xiang Liu, Umesh K. Mishra, Stacia Keller, Jeonghee Kim, Matthew Laurent, Jing Lu, Ramya Yeluri, Silvia H. Chan
  • Patent number: 9076927
    Abstract: A method of fabricating a heterostructure device, including (a) obtaining a first layer or substrate; (b) growing a second layer on the first layer or substrate; and (c) forming the second layer that is at least partially relaxed wherein (1) the first layer and the second layer have the same lattice structure but different lattice constants, (2) the first layer and the second layer form a heterojunction, and (3) the heterojunction forms an active area of a device or serves as a pseudo-substrate for the device.
    Type: Grant
    Filed: November 6, 2013
    Date of Patent: July 7, 2015
    Assignee: The Regents of the University of California
    Inventors: Stacia Keller, Carl J. Neufeld, Umesh K. Mishra, Steven P. DenBaars
  • Publication number: 20150021552
    Abstract: A transistor includes a III-N layer structure comprising a III-N channel layer between a III-N barrier layer and a p-type III-N layer. The transistor further includes a source, a drain, and a gate between the source and the drain, the gate being over the III-N layer structure. The p-type III-N layer includes a first portion that is at least partially in a device access region between the gate and the drain, and the first portion of the p-type III-N layer is electrically connected to the source and electrically isolated from the drain. When the transistor is biased in the off state, the p-type layer can cause channel charge in the device access region to deplete as the drain voltage increases, thereby leading to higher breakdown voltages.
    Type: Application
    Filed: July 9, 2014
    Publication date: January 22, 2015
    Inventors: Umesh Mishra, Rakesh K. Lal, Stacia Keller, Srabanti Chowdhury
  • Patent number: 8882935
    Abstract: A method for the fabrication of nonpolar indium gallium nitride (InGaN) films as well as nonpolar InGaN-containing device structures using metalorganic chemical vapor deposition (MOVCD). The method is used to fabricate nonpolar InGaN/GaN violet and near-ultraviolet light emitting diodes and laser diodes.
    Type: Grant
    Filed: June 4, 2013
    Date of Patent: November 11, 2014
    Assignees: The Regents of the University of California, The Japan Science and Technology Agency
    Inventors: Arpan Chakraborty, Benjamin A. Haskell, Stacia Keller, James S. Speck, Steven P. DenBaars, Shuji Nakamura, Umesh K. Mishra
  • Patent number: 8878249
    Abstract: A method for growing high mobility, high charge Nitrogen polar (N-polar) or Nitrogen face (In,Al,Ga)N/GaN High Electron Mobility Transistors (HEMTs). The method can provide a successful approach to increase the breakdown voltage and reduce the gate leakage of the N-polar HEMTs, which has great potential to improve the N-polar or N-face HEMTs' high frequency and high power performance.
    Type: Grant
    Filed: April 12, 2013
    Date of Patent: November 4, 2014
    Assignee: The Regents of the University of California
    Inventors: Jing Lu, Stacia Keller, Umesh K. Mishra
  • Publication number: 20140264455
    Abstract: A method of fabricating a semiconductor device can include forming a III-N semiconductor layer in a reactor and injecting a hydrocarbon precursor into the reactor, thereby carbon doping the III-N semiconductor layer and causing the III-N semiconductor layer to be insulating or semi-insulating. A semiconductor device can include a substrate and a carbon doped insulating or semi-insulating III-N semiconductor layer on the substrate. The carbon doping density in the III-N semiconductor layer is greater than 5×1018 cm?3 and the dislocation density in the III-N semiconductor layer is less than 2×109 cm?2.
    Type: Application
    Filed: March 13, 2014
    Publication date: September 18, 2014
    Applicant: Transphorm Inc.
    Inventors: Stacia Keller, Brian L. Swenson, Nicholas Fichtenbaum
  • Publication number: 20140264370
    Abstract: A method of fabricating a semiconductor device can include forming a III-N semiconductor layer in a reactor and injecting a hydrocarbon precursor into the reactor, thereby carbon doping the III-N semiconductor layer and causing the III-N semiconductor layer to be insulating or semi-insulating. A semiconductor device can include a substrate and a carbon doped insulating or semi-insulating III-N semiconductor layer on the substrate. The carbon doping density in the III-N semiconductor layer is greater than 5×1018 cm?3 and the dislocation density in the III-N semiconductor layer is less than 2×109 cm?2.
    Type: Application
    Filed: March 13, 2014
    Publication date: September 18, 2014
    Applicant: Transphorm Inc.
    Inventors: Stacia Keller, Brian L. Swenson, Nicholas Fichtenbaum
  • Publication number: 20140131730
    Abstract: A method of fabricating a heterostructure device, including (a) obtaining a first layer or substrate; (b) growing a second layer on the first layer or substrate; and (c) forming the second layer that is at least partially relaxed wherein (1) the first layer and the second layer have the same lattice structure but different lattice constants, (2) the first layer and the second layer form a heterojunction, and (3) the heterojunction forms an active area of a device or serves as a pseudo-substrate for the device.
    Type: Application
    Filed: November 6, 2013
    Publication date: May 15, 2014
    Inventors: Stacia Keller, Carl J. Neufeld, Umesh K. Mishra, Steven P. DenBaars
  • Publication number: 20130307027
    Abstract: A method for growing high mobility, high charge Nitrogen polar (N-polar) or Nitrogen face (In, Al, Ga)N/GaN High Electron Mobility Transistors (HEMTs). The method can provide a successful approach to increase the breakdown voltage and reduce the gate leakage of the N-polar HEMTs, which has great potential to improve the N-polar or N-face HEMTs' high frequency and high power performance.
    Type: Application
    Filed: April 12, 2013
    Publication date: November 21, 2013
    Inventors: Jing Lu, Stacia Keller, Umesh K. Mishra
  • Publication number: 20130264540
    Abstract: A method for the fabrication of nonpolar indium gallium nitride (InGaN) films as well as nonpolar InGaN-containing device structures using metalorganic chemical vapor deposition (MOVCD). The method is used to fabricate nonpolar InGaN/GaN violet and near-ultraviolet light emitting diodes and laser diodes.
    Type: Application
    Filed: June 4, 2013
    Publication date: October 10, 2013
    Applicants: JAPAN SCIENCE AND TECHNOLOGY AGENCY, THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Arpan Chakraborty, Benjamin A. Haskell, Stacia Keller, James S. Speck, Steven P. DenBaars, Shuji Nakamura, Umesh K. Mishra
  • Publication number: 20130200495
    Abstract: Embodiments of the present disclosure include a buffer structure suited for III-N device having a foreign substrate. The buffer structure can include a first buffer layer having a first aluminum composition and a second buffer layer formed on the first buffer layer, the second buffer layer having a second aluminum composition. The buffer structure further includes a third buffer layer formed on the second buffer layer at a second interface, the third buffer layer having a third aluminum composition. The first aluminum composition decreases in the first buffer layer towards the interface and the second aluminum composition throughout the second buffer layer is greater than the first aluminum composition at the interface.
    Type: Application
    Filed: February 3, 2012
    Publication date: August 8, 2013
    Applicant: TRANSPHORM INC.
    Inventors: Stacia Keller, Brian L. Swenson, Nicholas Fichtenbaum
  • Patent number: 8502246
    Abstract: A method for the fabrication of nonpolar indium gallium nitride (InGaN) films as well as nonpolar InGaN-containing device structures using metalorganic chemical vapor deposition (MOVCD). The method is used to fabricate nonpolar InGaN/GaN violet and near-ultraviolet light emitting diodes and laser diodes.
    Type: Grant
    Filed: February 12, 2009
    Date of Patent: August 6, 2013
    Assignees: The Regents of the University of California, The Japan Science and Technology Agency
    Inventors: Arpan Chakraborty, Benjamin A. Haskell, Stacia Keller, James S. Speck, Steven P. DenBaars, Shuji Nakamura, Umesh K. Mishra