Patents by Inventor Toshihiro Imamura

Toshihiro Imamura 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).

  • Method of fabricating a semiconductor device having a decreased concentration of phosphorus impurities in polysilicon
    Patent number: 7186632
    Abstract: In a method for manufacturing a semiconductor device having a laminated gate electrode, a phosphorus-doped polysilicon is formed on a gate oxide film. A high-melting metal or a compound of a high-melting metal and silicon is formed on the polysilicon. Phosphorus is doped into the polysilicon so that a concentration of the phosphorus in the polysilicon at an interface between the polysilicon and the gate oxide film is 2×1020(1/cm3) or less. Then, thermal oxidation is carried out in a wet-hydrogen atmosphere containing water vapor.
    Type: Grant
    Filed: March 24, 2003
    Date of Patent: March 6, 2007
    Assignee: Elpida Memory, Inc.
    Inventors: Kazuo Ogawa, Kiyonori Ohyu, Kensuke Okonogi, Toshihiro Imamura, Keiichi Watanabe, Hiroyuki Ohta
  • Method for manufacturing semiconductor device
    Publication number: 20040018708
    Abstract: In a method for manufacturing a semiconductor device having a laminated gate electrode, a phosphorus-doped polysilicon is formed on a gate oxide film. A high-melting metal or a compound of a high-melting metal and silicon is formed on the polysilicon. Phosphorus is doped into the polysilicon so that a concentration of the phosphorus in the polysilicon at an interface between the polysilicon and the gate oxide film is 2×1020 (1/cm3) or less. Then, thermal oxidation is carried out in a wet-hydrogen atmosphere containing water vapor.
    Type: Application
    Filed: March 24, 2003
    Publication date: January 29, 2004
    Inventors: Kazuo Ogawa, Kiyonori Ohyu, Kensuke Okonogi, Toshihiro Imamura, Keiichi Watanabe, Hiroyuki Ohta