Patents by Inventor Toshitaka Shiobara

Toshitaka Shiobara 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).

  • Method for detecting an end point of etching in a plasma-enhanced etching process
    Patent number: 6537460
    Abstract: In a plasma-enhanced etching process, the end point of the etching is detected based on the light intensity of the plasma and the second derivative of the light intensity. First, magnitude of the light intensity is judged based on a threshold to determine whether the etching area ratio is large or small with respect to the total area. Then, the second derivative of the light intensity is calculated after selecting sampling time interval based on the judgement of the etching area ration. The end point is detected when the second derivative assumes zero after exceeding a threshold in the absolute value thereof.
    Type: Grant
    Filed: June 20, 2000
    Date of Patent: March 25, 2003
    Assignee: NEC Corporation
    Inventor: Toshitaka Shiobara