Patents by Inventor Youhei Ichikawa

Youhei Ichikawa 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: 5510639
    Abstract: A non-volatile semiconductor memory cell having a novel structure is provided. The memory cell has a ring-shaped channel region formed on a semiconductor substrate, a drain region formed in a zone surrounded by the channel region, and a source region formed outside the channel region. The cell further includes a first gate insulation layer formed on the substrate in such a manner as to cover the boundary between the channel region and the drain region, a ring-shaped floating gate electrode formed on the first gate insulation layer, a second gate insulation layer formed on the floating gate electrode; and a control gate electrode which is capacitive-coupled with the floating gate via the second gate insulation layer.
    Type: Grant
    Filed: February 9, 1995
    Date of Patent: April 23, 1996
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Yasushi Okuda, Yoshinori Odake, Ichiro Nakao, Youhei Ichikawa