Patents by Inventor Takateru Asano

Takateru Asano 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: 5948592
    Abstract: A water-soluble photoresist composition is provided which comprises a water-soluble photosensitive composition containing a casein component and a water-soluble photosensitive agent and at least one calcium salt of an organic acid. The photoresist composition has excellent sensitivity, resolution, and etching resistance and can be used for the production of highly refined electronic components such as shadow masks, lead frame, etc.
    Type: Grant
    Filed: July 7, 1998
    Date of Patent: September 7, 1999
    Assignee: Fuji Chemicals Industrial Co., Ltd.
    Inventors: Hiroshi Umehara, Takateru Asano
  • Patent number: 5128231
    Abstract: A photoresist composition is disclosed. The photoresist composition comprises a base resin, a photosensitizer, and a solvent. The base resin comprises polyhydroxystyrene represented by the following structural formula (I): ##STR1## (wherein k is a positive integer). The photosensitizer comprises a polyhalogen compound(s). The photoresist composition of the present invention has dry etching resistance characteristics comparable to those of conventional positive novolak photoresist compositions and can form a resist pattern with a high resolution and vertical sidewall profiles. This makes microprocessing possible.
    Type: Grant
    Filed: November 29, 1991
    Date of Patent: July 7, 1992
    Assignees: Oki Electric Industry Co., Ltd., Fuji Chemicals Industrial Co., Ltd.
    Inventors: Toshio Itoh, Miwa Sakata, Yoshio Yamashita, Takateru Asano, Yuuzi Kosuga, Hiroshi Umehara
  • Patent number: 4889795
    Abstract: A process for forming a photoresist pattern comprises the steps of forming a photoresist layer on an underlying layer, forming a contrast enhancement layer for enhancing the contrast of light entering the photoresist layer on the photoresist layer, selectively exposing the photoresist layer through the contrast enhancement layer to light, and developing the photoresist layer to form a photoresist pattern. The contrast enhancement layer is formed as a layer containing a photobleachable agent and a material soluble in both of a nonpolar organic solvent and an aqueous alkali solution. The material is selected from the group of abietic acid, a derivative thereof, a rosin containing abietic acid as the main component, and a derivative thereof. The contrast enhancement layer is treated and removed simultaneously with development for the photoresist. The stability of a coating solution for the contrast enhancement layer is remarkably high.
    Type: Grant
    Filed: February 23, 1988
    Date of Patent: December 26, 1989
    Assignees: Oki Electric Industry Co., Ltd., Fuji Chemicals Industrial Co., Ltd.
    Inventors: Katsuaki Kaifu, Maki Kosuge, Yoshio Yamashita, takateru Asano, Kenji Kobayashi
  • Patent number: 4845143
    Abstract: A pattern-forming material is made by halogenoacetylation of the hydroxyl group of the copolymer of hydroxystyrene, and methyl methacrylate or ethyl methacrylate copolymer. The pattern-forming material in this invention is based on a resin copolymer of hydroxystyrene which has excellent dry etching resistance properties and methyl methacrylate or hydroxy ethyl methacrylate which is transparent to deep UV radiation over a relatively wide spectral range, combined with halogenoacetyl groups as photoreactive groups. Further, as the pattern-forming materials of this invention are soluble in the various liquids described below, a resist solution can easily be prepared, and a film of the material can easily be formed by the spin coating process.
    Type: Grant
    Filed: August 19, 1988
    Date of Patent: July 4, 1989
    Assignees: Oki Electric Industry Co., Ltd., Fuji Chemicals Industrial Co., Ltd.
    Inventors: Toshio Ito, Miwa Sakata, Yoshio Yamashita, Takateru Asano, Kenji Kobayashi
  • Patent number: 4801518
    Abstract: A method of forming a photoresist pattern wherein a photoresist coating film of naphthoquinone diazide sulfonate of novolak is formed on a substrate layer, the photoresist coating film is exposed by selectively irradiating with near ultraviolet radiation of 350 to 450 nm through a photomask, and the exposed photoresist coating film is developed with an either a negative type or positive type developing solution. The resultant photoresist pattern is usable for manufacturing a highly integrated circuit such as LSI which requires fine processing techniques.
    Type: Grant
    Filed: December 3, 1987
    Date of Patent: January 31, 1989
    Assignee: Oki Electric Industry, Co., Ltd.
    Inventors: Yoshio Yamashita, Ryuji Kawazu, Toshio Itoh, Takateru Asano, Kenji Kobayashi
  • Patent number: 4588669
    Abstract: A photosensitive lithographic plate comprising a hydrophilic substrate, a photosensitive diazo resin layer superposed on the substrate, and a layer of a photosensitive polyvinyl acetal resin containing an aromatic azide group in a side chain thereof and having an acid number of 10 to 100 and superposed on the diazo resin layer, and a method for the manufacture of this photosensitive lithographic plate.
    Type: Grant
    Filed: May 9, 1984
    Date of Patent: May 13, 1986
    Assignee: Fuji Chemicals Industrial Co., Ltd.
    Inventor: Takateru Asano
  • Patent number: 4560640
    Abstract: A photosensitive high polymer which is a random copolymer comprising a structural unit represented by the formula ##STR1## wherein A is ##STR2## wherein R is hydrogen, methyl or methoxy and a structural unit represented by the formula ##STR3## the polymer containing about 5 to about 80 mole % of structural units of the formula (I) and having a polymerization degree of about 300 to about 3000, a process for preparing the photosensitive high polymer and a composition comprising the photosensitive high polymer and solvent.
    Type: Grant
    Filed: June 11, 1984
    Date of Patent: December 24, 1985
    Assignees: Director-General of Agency of Industrial Science & Technology, Sanbo Chemical Industries Co., Ltd.
    Inventors: Taichi Ichihashi, Wasaburo Kawai, Tadashi Naraoka, Takateru Asano
  • Patent number: 4097283
    Abstract: A water-soluble, photosensitive resin composition containing a water-soluble polymer having an ethylenic unsaturated bond in its side-chains, a water-soluble anthraquinone sulfonic acid or anthraquinone carboxylic acid sensitizer, or salts thereof, and if desired, a water-soluble azide compound.
    Type: Grant
    Filed: December 15, 1975
    Date of Patent: June 27, 1978
    Assignee: Fuji Chemicals Industrial Company Limited
    Inventors: Takateru Asano, Keiko Ito