Patents by Inventor James W. Kretchmer

James W. Kretchmer 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: 7655514
    Abstract: A silicon carbide metal semiconductor field-effect transistor includes a bi-layer silicon carbide buffer for improving electron confinement in the channel region and/or a layer disposed over at least the channel region of the transistor for suppressing surface effects caused by dangling bonds and interface states. Also, a sloped MESA fabrication method which utilizes a dielectric etch mask that protects the MESA top surface during MESA processing and enables formation of sloped MESA sidewalls.
    Type: Grant
    Filed: December 13, 2007
    Date of Patent: February 2, 2010
    Assignee: Lockheed Martin Corporation
    Inventors: An-Ping Zhang, Larry B. Rowland, James W. Kretchmer, Jesse Tucker, Edmund B. Kaminsky
  • Patent number: 7345309
    Abstract: A silicon carbide metal semiconductor field-effect transistor includes a bi-layer silicon carbide buffer for improving electron confinement in the channel region and/or a layer disposed over at least the channel region of the transistor for suppressing surface effects caused by dangling bonds and interface states. Also, a sloped MESA fabrication method which utilizes a dielectric etch mask that protects the MESA top surface during MESA processing and enables formation of sloped MESA sidewalls.
    Type: Grant
    Filed: August 31, 2004
    Date of Patent: March 18, 2008
    Assignee: Lockheed Martin Corporation
    Inventors: An-Ping Zhang, Larry B. Rowland, James W. Kretchmer, Jesse Tucker, Edmund B. Kaminsky
  • Patent number: 7002156
    Abstract: A detection system for detecting gamma rays including a scintillator crystal for receiving at least one gamma ray and generating at least one ultraviolet ray and an avalanche photodiode for detecting the ultraviolet ray. The avalanche photodiode includes: a substrate having a first dopant; a first layer having a second dopant, positioned on top of the substrate; a passivation layer for providing electrical passivation on a surface of the avalanche photodiode; a phosphorous silicate glass layer for limiting mobile ion transport, positioned above of the first layer; and a pair of metal electrodes for providing an ohmic contact wherein a first electrode is positioned below the substrate and a second electrode is positioned above the first layer. The avalanche photodiode comprises a first sidewall and a second sidewall forming a sloped mesa shape.
    Type: Grant
    Filed: November 19, 2004
    Date of Patent: February 21, 2006
    Assignee: General Electric Company
    Inventors: Peter M. Sandvik, Dale M. Brown, Stephen D. Arthur, Kevin S. Matocha, James W. Kretchmer
  • Patent number: 6838741
    Abstract: An aspect of the present invention is directed to an avalanche photodiode (APD) device for use in oil well drilling applications in harsh, down-hole environments where shock levels are near 250 gravitational acceleration (G) and/or temperatures approach or exceed 150° C. Another aspect of the present invention is directed to an APD device fabricated using SiC materials. Another aspect of the present invention is directed to an APD device fabricated using GaN materials.
    Type: Grant
    Filed: December 10, 2002
    Date of Patent: January 4, 2005
    Assignee: General Electtric Company
    Inventors: Peter M. Sandvik, Dale M. Brown, Stephen D. Arthur, Kevin S. Matocha, James W. Kretchmer
  • Patent number: 6784430
    Abstract: A flame sensor for combustion flame temperature determination comprises elongated extensions that are positioned with parallel interdigitated longitudinal axis with respect to one another. An optical spectrometer comprises the sensor and a system comprises the sensor. A method for combustion flame temperature determination comprises obtaining a first photodiode signal and a second photodiode signal by using photodiode devices comprising photodiodes with elongated extending interdigitated digits. A method of fabricating a flame sensor for combustion flame temperature determination, comprises forming first and second photodiodes with elongated extending interdigitated digits.
    Type: Grant
    Filed: October 23, 2002
    Date of Patent: August 31, 2004
    Assignee: General Electric Company
    Inventors: Kevin S. Matocha, Jeffrey B. Fedison, James W. Kretchmer, Dale M. Brown, Peter M. Sandvik
  • Publication number: 20040108530
    Abstract: An aspect of the present invention is directed to an avalanche photodiode (APD) device for use in oil well drilling applications in harsh, down-hole environments where shock levels are near 250 gravitational acceleration (G) and/or temperatures approach or exceed 150° C. Another aspect of the present invention is directed to an APD device fabricated using SiC materials. Another aspect of the present invention is directed to an APD device fabricated using GaN materials.
    Type: Application
    Filed: December 10, 2002
    Publication date: June 10, 2004
    Applicant: General Electric Company
    Inventors: Peter M. Sandvik, Dale M. Brown, Stephen D. Arthur, Kevin S. Matocha, James W. Kretchmer
  • Publication number: 20030080294
    Abstract: A flame sensor for combustion flame temperature determination, comprising a first photodiode formed with elongated extending digits, and having a range of optical responsivity within an OH band for producing a first output signal; and a second photodiode formed with for receiving light from a combustion flame and having a range of optical responsivity in a different and overlapping portion of the OH band than the first photodiode device OH band for producing a second output signal; wherein the elongated extensions are positioned with parallel interdigitated longitudinal axis with respect to one another. An optical spectrometer comprises the sensor and a system comprises the sensor.
    Type: Application
    Filed: October 23, 2002
    Publication date: May 1, 2003
    Inventors: Kevin S. Matocha, Jeffrey B. Fedison, James W. Kretchmer, Dale M. Brown, Peter M. Sandvik
  • Patent number: 5510281
    Abstract: A method for fabricating a semiconductor device includes patterning a refractory dielectric layer over a semiconductor layer of a first conductivity type; conformally depositing a first spacer layer over the patterned refractory dielectric layer and the semiconductor layer; patterning the first spacer layer to leave a first spacer adjacent to an edge of the patterned refractory dielectric layer; implanting ions of a second conductivity type to form a base region in the semiconductor layer; conformally depositing a second spacer layer over the patterned refractory dielectric layer and the semiconductor layer; patterning the second spacer layer to leave a second spacer adjacent to an edge of the first spacer; implanting ions of the first conductivity type to form a source region in the base region; removing the first and second spacers; applying a gate insulator layer over at least a portion of the semiconductor layer; conformally depositing a gate electrode layer over the gate insulator layer and the semicondu
    Type: Grant
    Filed: March 20, 1995
    Date of Patent: April 23, 1996
    Assignee: General Electric Company
    Inventors: Mario Ghezzo, Tat-Sing P. Chow, James W. Kretchmer, Richard J. Saia, William A. Hennessy
  • Patent number: 5385855
    Abstract: A depletion mode MOSFET and resistor are fabricated as a silicon carbide (SiC) integrated circuit (IC). The SiC IC includes a first SiC layer doped to a first conductivity type and a second SiC layer overlaid on the first SiC layer and doped to a second conductivity type. The second SiC layer includes at least four more heavily doped regions of the second conductivity type, with two of such regions comprising MOSFET source and drain electrodes and two other of such regions comprising resistor electrodes. The second SiC layer includes an isolation trench between the MOSFET electrodes and the resistor electrodes. At least two electrically conductive contacts are provided as MOSFET electrode contacts, each being positioned over at least a portion of a respective MOSFET electrode and two other electrically conductive contacts are provided as resistor electrode contacts, each being positioned over at least a portion of a respective resistor electrode.
    Type: Grant
    Filed: February 24, 1994
    Date of Patent: January 31, 1995
    Assignee: General Electric Company
    Inventors: Dale M. Brown, Gerald J. Michon, Vikram B. Krishnamurthy, James W. Kretchmer