Patents by Inventor Robert W. Ryan

Robert W. Ryan 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: 5106766
    Abstract: A novel method of making a semiconductor device that comprises p-type III-V semiconductor material is disclosed. The method comprises heating of a graphite body such that the body serves as a sublimation source of carbon atoms that are incorporated into the III-V semiconductor material. Exemplarily, the carbon doped material is the base of a GaAs-based HBT.
    Type: Grant
    Filed: October 30, 1990
    Date of Patent: April 21, 1992
    Assignee: AT&T Bell Laboratories
    Inventors: Leda M. Lunardi, Roger J. Malik, Robert W. Ryan
  • Patent number: 5001534
    Abstract: A scalable and relatively easily manufacturable heterojunction bipolar transistor (HBT) comprises a thin (exemplarily 5-25 nm) emitter layer that serves as an etch stop layer and that furthermore passivates the extrinsic base region. The portion of the emitter layer that overlies the extrinsic base region is essentially fully depleted at all bias voltages in the normal operating range of the transistor. Base contact is established through the emitter layer, exemplarily by means of a metallized region on the emitter layer. A novel technique for carbon doping is also disclosed. Use of the novel technique makes possible a further embodiment of the inventive HBT, wherein base contact is made by means of Be implantation into the emitter layer.
    Type: Grant
    Filed: July 11, 1989
    Date of Patent: March 19, 1991
    Assignee: AT&T Bell Laboratories
    Inventors: Leda M. Lunardi, Roger J. Malik, Robert W. Ryan