Patents by Inventor Rong-Tai Kao

Rong-Tai Kao 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).

  • Guard ring structure with deep N well on ESD devices
    Patent number: 6274909
    Abstract: In this invention a deep N-type wall is created surrounding an area that contains an ESD device, or circuit. The ESD device, or circuit, is connected to a chip pad and is first surrounded by a P+ guard ring. The P+ guard ring is then surrounded by the deep N-type wall to block excess current from an ESD event or voltage overshoot from reaching the internal circuitry. The deep N-type wall comprises an N+ diffusion within an N-well which is on top of a deep N-well. The height of the deep N-type wall is approximately 4 to 6 micrometers which provides a capability to absorb much of the current from an ESD event or voltage overshoot.
    Type: Grant
    Filed: November 12, 1999
    Date of Patent: August 14, 2001
    Assignee: Etron Technology, Inc.
    Inventors: Kun-Zen Chang, Deng-Shun Chang, Rong-Tai Kao