Patents by Inventor Colombo R. Bolognesi

Colombo R. Bolognesi 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).

  • Thin gallium-arsenide-antimonide base heterojunction bipolar transistor (HBT) having improved gain
    Patent number: 6762480
    Abstract: An HBT having an InP collector, a GaAsSb base and an InP emitter in which the base is constructed using a thin layer of GaAsSb. The thin base layer can be constructed of a GaAsSb material with a composition having a bulk lattice constant that matches the bulk lattice constant of the material of the collector. The thickness of the GaAsSb base layer is less than 49 nm, and preferably less that about 20 nm. Alternatively, the thin base layer is of a GaAsSb composition that includes a higher As content, resulting in a low conduction band energy discontinuity at the emitter-base junction. Such a GaAsSb base layer has a lattice constant that conforms to the lattice constant of the collector because it is thinly grown so as to be pseudomorphically “strained” over the collector. A high base doping level is used to reduce the sheet resistivity and lower the base series resistance that results from the thinly grown base layer.
    Type: Grant
    Filed: February 27, 2001
    Date of Patent: July 13, 2004
    Assignee: Agilent Technologies, Inc.
    Inventors: Nicolas J. Moll, Colombo R. Bolognesi
  • Thin gallium-arsenide-antimonide base heterojunction bipolar transistor (HBT) having improved gain
    Publication number: 20040104403
    Abstract: An HBT having an InP collector, a GaAsSb base and an InP emitter in which the base is constructed using a thin layer of GaAsSb. The thin base layer can be constructed of a GaAsSb material with a composition having a bulk lattice constant that matches the bulk lattice constant of the material of the collector. The thickness of the GaAsSb base layer is less than 49 nm, and preferably less that about 20 nm. Alternatively, the thin base layer is of a GaAsSb composition that includes a higher As content, resulting in a low conduction band energy discontinuity at the emitter-base junction. Such a GaAsSb base layer has a lattice constant that conforms to the lattice constant of the collector because it is thinly grown so as to be pseudomorphically “strained” over the collector. A high base doping level is used to reduce the sheet resistivity and lower the base series resistance that results from the thinly grown base layer.
    Type: Application
    Filed: November 12, 2003
    Publication date: June 3, 2004
    Inventors: Nicolas J. Moll, Colombo R. Bolognesi
  • Thin gallium-arsenide-antimonide base heterojunction bipolar transistor (HBT) having improve gain
    Publication number: 20020145137
    Abstract: An HBT having an InP collector, a GaAsSb base and an InP emitter in which the base is constructed using a thin layer of GaAsSb. The thin base layer can be constructed of a GaAsSb material with a composition having a bulk lattice constant that matches the bulk lattice constant of the material of the collector. The thickness of the GaAsSb base layer is less than 49 nm, and preferably less that about 20 nm. Alternatively, the thin base layer is of a GaAsSb composition that includes a higher As content, resulting in a low conduction band energy discontinuity at the emitter-base junction. Such a GaAsSb base layer has a lattice constant that conforms to the lattice constant of the collector because it is thinly grown so as to be pseudomorphically “strained” over the collector. A high base doping level is used to reduce the sheet resistivity and lower the base series resistance that results from the thinly grown base layer.
    Type: Application
    Filed: February 27, 2001
    Publication date: October 10, 2002
    Inventors: Nicolas J. Moll, Colombo R. Bolognesi