Patents by Inventor Costas Dimitrios Varmazis

Costas Dimitrios Varmazis 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: 5698875
    Abstract: A metal semiconductor field effect transistor (MESFET) having a reduced control voltage while maintaining appropriate performance characteristics is disclosed. The MESFET is fabricated by a two step implantation technique for fabricating the ohmic contact region in the channel between the source and drain. This implant process results in higher doping levels of the active channel and a increased conductivity. Additionally, this step defines the channel depth, which in turn defines the pinch-off voltage. In the preferred embodiment of the present invention, the channel thickness is on the order of 2000 Angstroms. Parasitic capacitance is reduced to an acceptable level by reduction in the gate length. Finally, after the implantation of donor dopants to effect the active channel, a suitable acceptor dopant, preferably beryllium, is implanted to produce a well defined channel boundary, to reduce the donor dopant tails. This facilitates the control of the pinch-off voltage.
    Type: Grant
    Filed: April 30, 1996
    Date of Patent: December 16, 1997
    Assignee: The Whitaker Corporation
    Inventor: Costas Dimitrios Varmazis