Patents by Inventor Kaysuya Takemura

Kaysuya Takemura 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).

  • Sulfonium salts and chemically amplified positive resist compositions
    Patent number: 5824824
    Abstract: The invention provides a novel sulfonium salt having at least one acid labile group attached to a phenyl group in a molecule and a C.sub.2 -C.sub.20 alkylsulfonate or arylsulfonate anion whose alkyl or aryl has as a substituent an electron withdrawing group such as fluorine and nitro group. The novel sulfonium salt is effective for increasing the dissolution contrast between exposed and unexposed areas. Upon exposure, it generates a substituted alkyl or arylsulfonic acid which is a weak acid, minimizing the influence of side reaction and deactivation during PEB step. The sulfonium salt is useful in a chemically amplified positive resist composition which lends itself to fine patterning and features high resolution.
    Type: Grant
    Filed: November 1, 1996
    Date of Patent: October 20, 1998
    Assignees: Shin-Etsu Chemical Co., Ltd., Nippon Telegraph and Telephone Corp.
    Inventors: Yoichi Osawa, Satoshi Watanabe, Kaysuya Takemura, Shigehiro Nagura, Akinobu Tanaka, Yoshio Kawai