Patents by Inventor Janna B. Casady

Janna B. Casady 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: 20130062628
    Abstract: A method for the epitaxial growth of SiC is described which includes contacting a surface of a substrate with hydrogen and HCl, subsequently increasing the temperature of the substrate to at least 1550° C. and epitaxially growing SiC on the surface of the substrate. A method for the epitaxial growth of SiC is also described which includes heating a substrate to a temperature of at least 1550° C., contacting a surface of the substrate with a C containing gas and a Si containing gas at a C/Si ratio of 0.5-0.8 to form a SiC buffer layer and subsequently contacting the surface with a C containing gas and a Si containing gas at a C/Si ratio >0.8 to form a SiC epitaxial layer on the SiC buffer layer. The method results in silicon carbide epitaxial layers with improved surface morphology.
    Type: Application
    Filed: August 21, 2012
    Publication date: March 14, 2013
    Applicant: SEMISOUTH LABORATORIES, INC.
    Inventors: Hrishikesh DAS, Swapna SUNKARI, Timothy OLDHAM, Janna B. CASADY
  • Patent number: 7510921
    Abstract: A self-aligned silicon carbide power MESFET with improved current stability and a method of making the device are described. The device, which includes raised source and drain regions separated by a gate recess, has improved current stability as a result of reduced surface trapping effects even at low gate biases. The device can be made using a self-aligned process in which a substrate comprising an n+-doped SiC layer on an n-doped SiC channel layer is etched to define raised source and drain regions (e.g., raised fingers) using a metal etch mask. The metal etch mask is then annealed to form source and drain ohmic contacts. A single- or multilayer dielectric film is then grown or deposited and anisotropically etched. A Schottky contact layer and a final metal layer are subsequently deposited using evaporation or another anisotropic deposition technique followed by an optional isotropic etch of dielectric layer or layers.
    Type: Grant
    Filed: January 30, 2007
    Date of Patent: March 31, 2009
    Assignee: SemiSouth Laboratories, Inc.
    Inventors: Igor Sankin, Janna B. Casady, Joseph N. Merrett
  • Patent number: 7470967
    Abstract: A self-aligned silicon carbide power MESFET with improved current stability and a method of making the device are described. The device, which includes raised source and drain regions separated by a gate recess, has improved current stability as a result of reduced surface trapping effects even at low gate biases. The device can be made using a self-aligned process in which a substrate comprising an n+-doped SiC layer on an n-doped SiC channel layer is etched to define raised source and drain regions (e.g., raised fingers) using a metal etch mask. The metal etch mask is then annealed to form source and drain ohmic contacts. A single- or multilayer dielectric film is then grown or deposited and anisotropically etched. A Schottky contact layer and a final metal layer are subsequently deposited using evaporation or another anisotropic deposition technique followed by an optional isotropic etch of dielectric layer or layers.
    Type: Grant
    Filed: March 11, 2005
    Date of Patent: December 30, 2008
    Assignee: SemiSouth Laboratories, Inc.
    Inventors: Igor Sankin, Janna B. Casady, Joseph N. Merrett