Patents by Inventor James A. Cooper, Jr.

James A. Cooper, Jr. 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: 6362495
    Abstract: A dual-metal-trench silicon carbide Schottky pinch rectifier having a plurality of trenches formed in an n-type SiC substrate, with a Schottky contact having a relatively low barrier height on a mesa defined between adjacent ones of the trenches, and a Schottky contact having a relatively high barrier height at the bottom of each trench. The same metal used for the Schottky contact in each trench is deposited over the Schottky contact on the mesa. A simplified fabrication process is disclosed in which the high barrier height metal is deposited over the low barrier height metal and then used as an etch mask for reactive ion etching of the trenches to produce a self-aligned low barrier contact.
    Type: Grant
    Filed: March 5, 1999
    Date of Patent: March 26, 2002
    Assignee: Purdue Research Foundation
    Inventors: Kipp J. Schoen, Jason P. Henning, Jerry M. Woodall, James A. Cooper, Jr., Michael R. Melloch
  • Patent number: 5465249
    Abstract: A random access memory (RAM) cell in 6H-SiC having storage times when all bias is removed long enough to be considered nonvolatile. The nonvolatile random access memory (NVRAM) cell comprises a bit line, a charge storage device in silicon carbide, and a transistor in silicon carbide connecting the charge storage device to the bit line. The bipolar NVRAM cell has a bipolar transistor with a base region, an emitter region, and a floating collector region, wherein the charge storage device in the bipolar NVRAM is a p-n junction adjacent the floating collector region of the cell. The metal-oxide-semiconductor (MOS) NVRAM has a MOS field effect transistor (MOSFET) with a channel region, a source region, and a drain region, wherein the charge storage device in the MOS NVRAM is a MOS capacitor adjacent the drain region of the MOSFET.
    Type: Grant
    Filed: November 26, 1991
    Date of Patent: November 7, 1995
    Assignees: Cree Research, Inc., Purdue Research Foundation
    Inventors: James A. Cooper, Jr., John W. Palmour, Calvin H. Carter, Jr.
  • Patent number: 5365477
    Abstract: A vertically integrated DRAM cell having a storage time of at least 4.5 hours at room temperature, formed from a wide-bandgap semiconductor such as GaAs or AlGaAs, in which an n-p-n bipolar access transistor is merged with a p-n-p storage capacitor, with the middle p-n layers being common to both. Similarly, a p-n-p transistor can be merged with an n-p-n storage capacitor.
    Type: Grant
    Filed: June 16, 1992
    Date of Patent: November 15, 1994
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: James A. Cooper, Jr., Michael R. Melloch, Theresa B. Stellwag
  • Patent number: 4894689
    Abstract: A transferred electron device is described in which the charge of the drifting packets is imaged perpendicular to the charge-packet direction so that essentially all of the packet-averaged, space-charge field is normal to the drift direction. This permits continuous formation of contiguous charge packets.
    Type: Grant
    Filed: December 28, 1984
    Date of Patent: January 16, 1990
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventors: James A. Cooper, Jr., Karvel K. Thornber
  • Patent number: 4719496
    Abstract: Semiconductor structures suitable for repeated velocity overshoot are described. The structure comprises at least two velocity overshoot sections with each section comprising a first semiconductor region having a rapid change in potential and a dimension such that the carrier transit time is comparable to or shorter than the mean scattering time and a second semiconductor region having a more gradual change in potential and a dimension such that the carrier transit time is sufficient to allow the energy relaxation time to be exceeded.
    Type: Grant
    Filed: February 12, 1986
    Date of Patent: January 12, 1988
    Inventors: Federico Capasso, James A. Cooper, Jr., Karvel K. Thornber
  • Patent number: 4635083
    Abstract: A memory device includes a relative lower bandgap energy first semiconductor layer, a relatively higher bandgap energy second semiconductor layer on the first, an alloy source rectifying to the first layer, a well for storing charge and a gate for controlling charge flow between the source and the well. The gate is formed on the second layer, as is a field plate for controlling the storage charge in the well. In one embodiment, a buried channel field effect transistor is combined with the basic memory device, with the charge content of the well controlling current flow between the source and drain of the buried channel FET.
    Type: Grant
    Filed: April 10, 1986
    Date of Patent: January 6, 1987
    Assignee: Purdue Research Foundation
    Inventor: James A. Cooper, Jr.
  • Patent number: 4324038
    Abstract: A method for making a MOSFET device (20) in a semiconductor body (10) includes the step of forming source and drain contact electrodes (12.1, 12.2) prior to growth of the gate oxide (10.3) and after formation of a high conductivity surface region (10.5). The exposed mutually opposing sidewall edges of each of the contact electrodes (12.1, 12.2) are coated with a sidewall silicon dioxide layer (15.1, 15.2), and the then exposed surface of the semiconductor body (10) between these sidewalls is etched to depth beneath the high conductivity surface region (10.5) in order to separate it into the source and drain regions (10.1, 10.2).Formation of the high conductivity region may be omitted by using Schottky barrier or impurity doped material for the contact electrodes (12.1, 12.2).
    Type: Grant
    Filed: November 24, 1980
    Date of Patent: April 13, 1982
    Assignee: Bell Telephone Laboratories, Incorporated
    Inventors: Chuan C. Chang, James A. Cooper, Jr., Dawon Kahng, Shyam P. Murarka
  • Patent number: 4291247
    Abstract: Logic circuits, particularly of the integrated semiconductor type, are accessed at improved speeds by preventing pull-ups from occurring during the access time and by the inclusion of on-chip delay circuitry to avoid switching later stages in a manner to lose information while output nodes of earlier stages are high. All stages are activated in response to a single clock pulse edge.
    Type: Grant
    Filed: September 21, 1979
    Date of Patent: September 22, 1981
    Assignee: Bell Telephone Laboratories, Incorporated
    Inventors: James A. Cooper, Jr., Robert H. Krambeck
  • Patent number: 4208728
    Abstract: The decoder portion of a programable logic array (PLA) includes logic devices at crosspoints defined between the word (x) lines and the address (y) lines characteristic of a decoder portion. The devices are operative to combine two or more word lines to activate a single word line in the associated read only memory (ROM) in response to one of two or more possible inputs. The technique is effective even in cases where "don't care" conditions relating the two or more possible inputs cannot be found. A substantial reduction in chip area is achieved.
    Type: Grant
    Filed: December 21, 1978
    Date of Patent: June 17, 1980
    Assignee: Bell Telephone Laboratories, Incorporated
    Inventors: Donald E. Blahut, James A. Cooper, Jr.
  • Patent number: 4139907
    Abstract: The word conductors of a semiconductor integrated ROM are foreshortened where permitted by the organization of data in the memory. The space made available by the eliminated portions of the word conductors is used for electrical connection to the bit conductors from the sides of the array rather than at the ends. A space reduction of about thirty percent is achieved.
    Type: Grant
    Filed: August 31, 1977
    Date of Patent: February 13, 1979
    Assignee: Bell Telephone Laboratories, Incorporated
    Inventors: Donald E. Blahut, James A. Cooper, Jr.