Patents by Inventor Saburou Oikawa

Saburou Oikawa 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).

  • Semiconductor device and power converter using the same
    Patent number: 6566726
    Abstract: To reduce the field intensity on the termination surface, almost not affecting the on-characteristic, a drift layer is made of two layers, an n-layer and n− layer, and a termination region is formed on the surface of the above n− layer. An impurity concentration ratio between the n− layer and the n-layer is less than 1:2, and the thickness of the n− layer is less than that of a source n+ layer. Reliability can be secured even in a high temperature operation.
    Type: Grant
    Filed: March 1, 2000
    Date of Patent: May 20, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Hidekatsu Onose, Tsutomu Yatsuo, Toshiyuki Ohno, Saburou Oikawa