Patents by Inventor Ping K. Ko

Ping K. Ko 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: 5559368
    Abstract: A dynamic threshold voltage IGFET such as a MOSFET is operable at voltages of 0.6 volt or less. The threshold voltage of the transistor is reduced to zero volt or less by interconnecting the gate contact and the device body in which the voltage controlled channel is located. Several efficient connections using through hole plating or polycrystalline silicon gate extension are disclosed. A higher power supply voltage can be used by interconnecting the gate and device body through a smaller MOSFET.
    Type: Grant
    Filed: August 30, 1994
    Date of Patent: September 24, 1996
    Assignee: The Regents of the University of California
    Inventors: Chenming Hu, Ping K. Ko, Fariborz Assaderaghi, Stephen Parke
  • Patent number: 5489792
    Abstract: An SOI MOSFET having improved electrical characteristics includes a low barrier body contact under the source region, and alternatively under the drain region, to facilitate collection and removal of current carriers generated by impact ionization. Fully-depleted and non-fully-depleted SOI MOSFETs can be integrated on the same chip by providing some transistors with thicker source and drain regions with a recessed channel therebetween and by selective channel dopant implant. Accordingly, digital circuitry and analog circuitry can be combined on one substrate. Improved electrostatic discharge protection is provided by fabricating transistors for the protection circuit directly in the supporting substrate by first removing the silicon thin film and underlying insulation barrier.
    Type: Grant
    Filed: April 7, 1994
    Date of Patent: February 6, 1996
    Assignee: Regents of the University of California
    Inventors: Chenming Hu, Mansun J. Chan, Hsing-Jen Wann, Ping K. Ko
  • Patent number: 4794565
    Abstract: An electrically programmable and eraseable memory element using source-side hot-electron injection. A semi-conductor substrate of a first conductivity type is provided with a source region and a drain region of opposite conductivity type and a channel region of the first conductivity type extending between the source and drain regions. A control gate overlies the channel region, and a floating gate insulated from the control gate, the source and drain regions and the channel region is located either directly underneath the control gate over the channel region, partially underneath the control gate over the channel region or spaced to the source side of the control gate. A weak gate control region is provided in the device near the source so that a relatively high channel electric field for promoting hot-electron injection is created under the weak gate control region when the device is biased for programming.
    Type: Grant
    Filed: September 15, 1986
    Date of Patent: December 27, 1988
    Assignee: The Regents of the University of California
    Inventors: Albert T. Wu, Ping K. Ko, Tung-Yi Chan, Chenming Hu
  • Patent number: 4532697
    Abstract: In a metal-oxide-semiconductor device process, parasitic capacitance is significantly reduced by differentially oxidizing a substrate and a gate mesa thereon prior to ion implantation and "drive-in" of the drain and source regions. This results in a channel region being formed in the substrate beneath and substantially coextensive with the gate mesa. The conductivity of the channel region is different from the conductivity of the adjacent source and drain regions. In one embodiment, the source and drain regions each extend to a greater depth into the substrate with increasing distance from the channel region.
    Type: Grant
    Filed: December 2, 1983
    Date of Patent: August 6, 1985
    Assignee: AT&T Bell Laboratories
    Inventor: Ping K. Ko