Patents by Inventor Quesnell Hartmann

Quesnell Hartmann 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: 20030042503
    Abstract: A transistor having a substrate formed of indium phosphide (InP), and having emitter, base and collector layers formed over the substrate such that the base layer is disposed between the emitter and collector layers. The collector layer formed from InGaAs, and the collector layer being doped n-type. The emitter layer formed from InP, and the emitter layer being doped n-type. The base layer formed of indium gallium arsenide (InGaAs), the base layer being tensile mismatched, and doped p-type. A lattice mismatch between the substrate and the base material is greater than 0.2%. In an x-ray rocking curve of the heterojunction bipolar transistor, a peak corresponding to the base layer is separated from a peak corresponding to the substrate layer by at least 250 arcseconds. In one embodiment this results from the percentage of indium in the base layer is less than 51.5%, that is the lattice constant of the base layer is substantially smaller than a lattice constant of the substrate throughout an entire base region.
    Type: Application
    Filed: June 18, 2001
    Publication date: March 6, 2003
    Inventor: Quesnell Hartmann
  • Patent number: 6525349
    Abstract: A heterojunction bipolar transistor (HBT), having a substrate formed of indium phosphide (InP), and having emitter, base and collector layers formed over the substrate such that the base layer is disposed between the emitter and collector layers. The collector layer formed from InGaAs, and the collector layer being doped n-type. The emitter layer formed from InP, and the emitter layer being doped n-type. The base layer formed of indium gallium arsenide (InGaAs) and grown by MOCVD, the base layer being tensile strained and graded, and the base layer being doped p-type with carbon. A lattice mismatch, for at least a portion of the base layer, between the substrate and the base material is greater than 0.2%.
    Type: Grant
    Filed: June 18, 2001
    Date of Patent: February 25, 2003
    Assignee: Epiworks, Inc.
    Inventor: Quesnell Hartmann
  • Publication number: 20020190271
    Abstract: A heterojunction bipolar transistor (HBT) having a substrate formed of indium phosphide (InP) and having emitter, base and collector layers formed over the substrate such that the base layer is disposed between the emitter and collector layers. The collector layer formed from InGaAs, and the collector layer being doped n-type. The emitter layer formed from InP, and the emitter layer being doped n-type. The base layer formed of indium gallium arsenide (InGaAs), the base layer being compressively mismatched, and doped p-type. A lattice mismatch between the substrate and the base material is greater than 0.2%. In an x-ray rocking curve of the heterojunction bipolar transistor, a peak corresponding to the base layer being separated from a peak corresponding to the substrate layer by at least −250 arcseconds. In one embodiment this results from a percentage of indium in the base layer being greater than 54.
    Type: Application
    Filed: June 18, 2001
    Publication date: December 19, 2002
    Inventor: Quesnell Hartmann
  • Publication number: 20020190272
    Abstract: A heterojunction bipolar transistor (HBT), having a substrate formed of indium phosphide (InP), and having emitter, base and collector layers formed over the substrate such that the base layer is disposed between the emitter and collector layers. The collector layer formed from InGAs, and the collector layer being doped n-type. The emitter layer formed from InP, and the emitter layer being doped n-type. The base layer formed of indium gallium arsenide (InGaAs) and grown by MOCVD, the base layer being tensile strained and graded, and the base layer being doped p-type with carbon. A lattice mismatch, for at least a portion of the base layer, between the substrate and the base material is greater than 0.2%.
    Type: Application
    Filed: June 18, 2001
    Publication date: December 19, 2002
    Inventor: Quesnell Hartmann