Patents by Inventor Masaaki Todoko

Masaaki Todoko 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: 5223376
    Abstract: A method for producing fine patterns is disclosed, comprising spin-coating a photosensitive resin solution as an upper layer, which comprises a diazonium salt as a photobleachable agent, water and/or an organic solvent, and a polymer, on a photoresist layer as a lower layer and then light-exposing both the upper layer and the lower layer, wherein the polymer in the upper layer has a structural unit shown by formula (I): ##STR1## wherein R.sub.1, R.sub.2, and R.sub.3 each represents a hydrogen atom, an alkyl group having from 1 to 4 carbon atoms, a halogen atom, or a nitrile group; R.sub.4 represents a hydrogen atom, an alkyl group having from 1 to 4 carbon atoms, a halogen atom, a hydroxyl group, or a carboxyl group; and X represents a hydrogen atom, an alkali metal, an alkaline earth metal, or an ammonium group.
    Type: Grant
    Filed: January 6, 1992
    Date of Patent: June 29, 1993
    Assignee: Toyo Soda Manufacturing Co., Ltd.
    Inventors: Masazumi Hasegawa, Masaaki Todoko, Mitsutoshi Fukuda
  • Patent number: 5212043
    Abstract: A photoresist composition comprising:a resin soluble in an aqueous alkaline solution, having units of an aliphatic cyclic hydrocarbon main frame and units derived from maleic anhydride and/or units derived from a maleimide; anda photosensitive agent in a sufficient amount to promote or hinder the solubility of said resin in an aqueous alkaline solution upon exposure to active radiation so as to create a substantial difference in the solubility as between an exposed portion and a non-exposed portion and to form a positive or negative image by subsequent development with an aqueous alkaline solution.
    Type: Grant
    Filed: October 17, 1990
    Date of Patent: May 18, 1993
    Assignee: Tosho Corporation
    Inventors: Takashi Yamamoto, Masaaki Todoko, Toru Seita, Kyoko Nagaoka, Kosaburo Matsumura
  • Patent number: 5202217
    Abstract: A positive resist composition comprising an aromatic group-containing alkali-soluble resin and a compound having an ammonium salt as skeleton, as the main components.
    Type: Grant
    Filed: August 3, 1990
    Date of Patent: April 13, 1993
    Assignee: Tosoh Corporation
    Inventors: Masaaki Todoko, Takashi Taniguchi, Toru Seita, Shinji Sato, Katuya Shibata
  • Patent number: 4508877
    Abstract: A process for producing cyclized isoprene polymers having a dispersion degree not higher than 2, which comprises living-polymerizing isoprene monomers using as initiator an organometal compound which is expressed by a general formula RM (where R is alkyl, aryl or aralkyl group and M is lithium, sodium or potassium atom), to obtain an isoprene polymer having a dispersion degree not larger than 1.1, which is close to a unit dispersion, and bringing the obtained polymer into contact with a catalyst composed of a boron trifluoride-ether complex and a carboxylic acid expressed by a general formula Cl.sub.3-n H.sub.n CCOOH (where n is an integer ranging from 0 to 3) under a mild condition. The cyclized polymer is very useful for negative resists in integrated circuits.
    Type: Grant
    Filed: November 22, 1983
    Date of Patent: April 2, 1985
    Assignee: Toyo Soda Manufacturing Co., Ltd.
    Inventors: Masaaki Todoko, Hiroyuki Watanabe