Patents by Inventor Hitoshi Mashio

Hitoshi Mashio 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).

  • Process for preparing polymer compound for resist
    Patent number: 6653418
    Abstract: There is provided a process for preparing a polymer compound for a resist, which can improve the performance, such as the heat resistance, sensitivity and resolution of the resist, without causing film loss of the resist, line width reduction of the resist or deterioration of the dry etching resistance of the polymer. This process comprises dissolving a styrene-based monomer containing at least a 4-acetoxystyrene monomer, and a dimethyl-2,2′-azobiscarboxylate ester in a solvent, thereby to polymerize the styrene-based monomer; adding an alkali catalyst to the resulting polymer solution, thereby to hydrolyze the polymer solution; and washing the resulting polymer compound with water.
    Type: Grant
    Filed: August 16, 2002
    Date of Patent: November 25, 2003
    Assignee: Gun EI Chemical Industry Co., Ltd.
    Inventors: Katsuhiro Maruyama, Satoru Yoshida, Satoru Kitano, Hitoshi Mashio