Patents by Inventor Satoshi Niikura

Satoshi Niikura 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: 5384228
    Abstract: A novel alkali-developable photosensitive resin composition, which is suitable for use as a photoresist composition for fine patterning in the manufacture of various electronic devices, is proposed. The photosensitive resin composition comprises, as the essential ingredients, (a) an alkali-soluble novolac resin as the film-forming ingredient and (b) a very specific compound which is a 1,2-quinone diazide sulfonic acid ester of a condensation product having a weight-average molecular weight of 400 to 2000 obtained by the condensation reaction between phenol and a hydroxybenzaldehyde in the presence of an acidic catalyst as the photosensitizing agent. By virtue of the formulation with this specific photosensitizer, the resist layer formed from the inventive composition has a greatly increased focusing latitude in addition to the excellent sensitivity, resolution and heat resistance.
    Type: Grant
    Filed: October 8, 1993
    Date of Patent: January 24, 1995
    Assignee: Tokyo Ohka Kogyo Co., Ltd.
    Inventors: Kousuke Doi, Satoshi Niikura, Nobuo Tokutake, Hidekatsu Kohara, Toshimasa Nakayama
  • Patent number: 5332647
    Abstract: A positive-working photosensitive resin composition useful as a photoresist material in the fine patterning work for the manufacture of semiconductor devices is proposed. The composition is excellent in the storage stability and capable of giving a patterned resist layer having good film thickness retention, cross sectional profile of line patterns, resolution and heat resistance. The composition comprises, in addition to a conventional alkali-soluble novolac resin as a film-forming agent and a quinone diazide group containing compound as a photosensitizing agent, a specific isocyanurate compound substituted at each nitrogen atom with a hydroxy- and ter-butyl-substituted benzyl group.
    Type: Grant
    Filed: August 24, 1993
    Date of Patent: July 26, 1994
    Assignee: Tokyo Ohka Kogyo Co., Ltd.
    Inventors: Hayato Ohno, Nobuo Tokutake, Satoshi Niikura, Hidekatsu Kohara, Toshimasa Nakayama