Patents by Inventor Shoichiro Ohga

Shoichiro Ohga 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).

  • Selector device for the determination of the type of electroconductivity in semiconductor wafers
    Patent number: 4213086
    Abstract: A novel selector device for the determination of the conductivity-type in a semiconductor wafer utilizes the determination of the polarity of the electromotive force produced in the wafer by the Hall effect. The device comprises two pairs of probes in diagonal arrangement for supplying an electric current through the wafer and for detecting the electromotive force, respectively, by contacting the wafer surface, and a pair of permanent magnets positioned oppositely with the wafer in between to produce a magnetic field perpendicular to the wafer. One of the permanent magnets is located within the circumference determined by the probes.
    Type: Grant
    Filed: July 6, 1978
    Date of Patent: July 15, 1980
    Assignee: Shin-Etsu Handotal Co., Ltd.
    Inventors: Yoshiya Iida, Shoichiro Ohga