Patents by Inventor Jian H. Zhao

Jian H. Zhao 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: 20100148224
    Abstract: A semiconductor vertical junction field effect power transistor formed by a semiconductor structure having top and bottom surfaces and including a plurality of semiconductor layers with predetermined doping concentrations and thicknesses and comprising at least a bottom layer as drain layer, a middle layer as blocking and channel layer, a top layer as source layer. A plurality of laterally spaced U-shaped trenches with highly vertical side walls defines a plurality of laterally spaced mesas. The mesas are surrounded on the four sides by U-shaped semiconductor regions having conductivity type opposite to that of the mesas forming U-shaped pn junctions and defining a plurality of laterally spaced long and vertical channels with a highly uniform channel opening dimension. A source contact is formed on the top source layer and a drain contact is formed on the bottom drain layer.
    Type: Application
    Filed: January 19, 2009
    Publication date: June 17, 2010
    Applicant: Rutgers, The State University of New Jersey
    Inventor: Jian H. Zhao
  • Patent number: 7479672
    Abstract: A semiconductor vertical junction field effect power transistor formed by a semiconductor structure having top and bottom surfaces and including a plurality of semiconductor layers with predetermined doping concentrations and thicknesses and comprising at least a bottom layer as drain layer, a middle layer as blocking and channel layer, a top layer as source layer. A plurality of laterally spaced U-shaped trenches with highly vertical side walls defines a plurality of laterally spaced mesas. The mesas are surrounded on the four sides by U-shaped semiconductor regions having conductivity type opposite to that of the mesas forming U-shaped pn junctions and defining a plurality of laterally spaced long and vertical channels with a highly uniform channel opening dimension. A source contact is formed on the top source layer and a drain contact is formed on the bottom drain layer.
    Type: Grant
    Filed: April 9, 2007
    Date of Patent: January 20, 2009
    Assignee: Rutgers, The State University
    Inventor: Jian H. Zhao
  • Patent number: 6107649
    Abstract: Power semiconductor devices have a plurality of semiconductor layers of alternating p-type and n-type conductivity and top and bottom device surfaces. A layer of the top surface forms a control layer. A semiconductor layer junction, remote from top and bottom device surfaces, forms a blocking p-n junction capable of sustaining the applied device voltage. A top ohmic contact overlays a top conductive region extending from the top surface into the control layer. A conductive tub region, spaced apart from the top conductive region, extends from the top surface at least through the control layer. A field effect region is disposed in the control layer between the top conductive region and tub region. A gate contact is formed over the field effect region causing the creation and interruption of a conductive channel between the top conductive region and the conductive tub region so as to turn the device on and off.
    Type: Grant
    Filed: June 10, 1998
    Date of Patent: August 22, 2000
    Assignee: Rutgers, The State University
    Inventor: Jian H. Zhao
  • Patent number: 5569943
    Abstract: A heterostructure semiconductor device having source and drain electrodes sistively coupled to opposite ends of a channel, a barrier layer on one side of the channel, a delta doped layer in the channel or within a given distance of it, a gate electrode on the barrier so as to form a Schottky diode and at least one collector electrode mounted on said barrier layer. The collector electrode or electrodes can be resistively coupled to the barrier layer, but preferably the coupling is such as to form a Schottky diode. Changes to the gate bias affect the source current through the field effect mechanism. The collector current depends on the transfer of heated, energized carriers out of the channel over the front heterobarrier. At low gate bias, electrons entering the source travel to the drain while none travel to the collector. Energized carriers are localized to the depletion region due its high electric field drop.
    Type: Grant
    Filed: September 1, 1995
    Date of Patent: October 29, 1996
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventors: Thomas E. Koscica, Jian H. Zhao
  • Patent number: 5323030
    Abstract: The present Field Effect Real Space Transistor, or FERST, is a four terminal device with S, G, C, and D representing the source, gate, collector, and drain, respectively. The S, G, and D terminals can be likened to those of the MODFET. The collector name is borrowed from other real space transfer devices. Surrounding the entire device is an oxygen implant isolation. The source and drain ohmic contacts penetrate to the 150 .ANG. GaAs channel while the collector ohmic contact does not penetrate due to its position upon an elevated submesa. AlGaAs layers are used as etch stops during processing of the device and a Schottky barrier gate is placed on an undoped layer. Channel carriers are provided by modulation doping the lower barrier of the channel. An Al.sub.0.35 Ga.sub.0.65 As layer on the upper channel side is used as a real space transfer barrier. In operation and under appropriate bias conditions, real space transfer occurs across this upper barrier and into the collector.
    Type: Grant
    Filed: September 24, 1993
    Date of Patent: June 21, 1994
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventors: Thomas E. Koscica, Jian H. Zhao
  • Patent number: 5291041
    Abstract: The present invention comprises a semi-insulating layer of GaAs with p+ and layers of aluminum gallium arsenide AlGaAs grown on one side of the semi-insulating GaAs and with p and n+ layers of AlGaAs grown on the other side of the semi-insulating GaAs. Ohmic contacts are grown on both sides of the thyristor as well as low temperature GaAs to provide for surface passivity.
    Type: Grant
    Filed: March 1, 1993
    Date of Patent: March 1, 1994
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventors: Terence Burke, Maurice Weiner, Jian H. Zhao