Patents by Inventor Ben G. Streetman

Ben G. Streetman 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: 5436474
    Abstract: A MODFET device has highly doped source and drain regions separated by an undoped semiconductor alloy in which the mole fraction is graded between the source and the drain and with a conduction (and/or valence) band discontinuity at the heterojunction between the source and semiconductor alloy channel region of the device. Due to the graded mole fraction, the bandgap of the undoped semiconductor alloy decreases along the channel from the source to the drain and creates a built-in electric field. The higher bandgap in the source compared to that in the channel permits high energy carrier injection into the channel, with the built-in longitudinal electric field increasing carrier drift velocity and reducing transit time between the source and drain. In a preferred embodiment, the MODFET device has a vertical structure with the source and semiconductor alloy layers stacked on a drain substrate.
    Type: Grant
    Filed: December 7, 1994
    Date of Patent: July 25, 1995
    Assignee: Board of Regents of the University of Texas System
    Inventors: Sanjay K. Banerjee, Aloysious F. Tasch, Jr., Ben G. Streetman
  • Patent number: 5156815
    Abstract: A sublimating and cracking device which may be used to produce a collimated beam of molecules from a solid source. The device includes an elongated sublimating tube and an elongated cracking tube adapted to be axially oriented off axis to each other. The sublimating and cracking tubes are interconnected and heated in use.
    Type: Grant
    Filed: September 8, 1988
    Date of Patent: October 20, 1992
    Assignee: Board of Regents, The University of Texas System
    Inventors: Ben G. Streetman, Terry J. Mattord, Craig W. Farley
  • Patent number: 5080870
    Abstract: A furnace having a sublimating section, a cracking section oriented off axis to the sublimating section, and a valve for controlling flux between the sections. The valve includes an annular plug having at least one longitudinal slot. The plug is retractable from a fully closed position where the slot is completely covered, to a fully open position where the slot is completely exposed. The slot becomes increasingly exposed as the plug is moved from the fully closed position to the fully opened position, thereby increasing flux from the sublimating section to the cracking section.
    Type: Grant
    Filed: August 28, 1989
    Date of Patent: January 14, 1992
    Assignee: Board of Regents, The University of Texas System
    Inventors: Ben G. Streetman, Terry J. Mattord, Dean P. Neikirk
  • Patent number: 5034604
    Abstract: A device and method for producing an ultra pure molecular beam of elemental molecules utilizing a reduced thermal gradient filament construction in an effusion cell is provided. The effusion cell comprises a crucible having an open and a closed end and at least one heating filament distributed immediate the crucible. The at least one heating filament or filaments are provided having a first portion having a first pitch in proximal relationship to the open end of the crucible and having a second portion having a second pitch wherein the first pitch is of a higher spatial frequency than the second pitch. The heating filament is non-inductively wound about the crucible and positioned in conformity to the outside structure of the crucible. The heat shield is positioned proximate and about the crucible and heating filament or filaments. The heating filaments are connected to a controllable electric power supply producing a near constant temperature along the long axis of the crucible.
    Type: Grant
    Filed: August 29, 1989
    Date of Patent: July 23, 1991
    Assignee: Board of Regents, The University of Texas System
    Inventors: Ben G. Streetman, Terry J. Mattord, Vijay P. Kesan, Ben G. Treetman, Terry Mattord
  • Patent number: 4257055
    Abstract: Described is a heterostructure semiconductor device of sandwich type construction. The central layer exhibits high charge carrier mobility and a relatively narrow band gap characteristic. The outer sandwich layers exhibit low charge carrier mobilities and a larger band gap characteristic. Under quiescent conditions, the charge carriers from the outer sandwich layers reside in the central layer due to the "potential well" created by the band gap difference between the layers. The application of an appropriate electrical field to the central layer, aligned with the interface between the layers, causes a very rapid transfer of the electrons residing therein to the outer sandwich layers. This transfer results in the device exhibiting a negative resistance characteristic. Two and three terminal switching applications of the device are described as well as its application as a radiant energy detector.
    Type: Grant
    Filed: July 26, 1979
    Date of Patent: March 17, 1981
    Assignee: University of Illinois Foundation
    Inventors: Karl Hess, Ben G. Streetman, Hadis Morkoc