Patents by Inventor Takamasa Kosai

Takamasa Kosai 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).

  • Semiconductor device formed within asymetrically-shaped seed crystal region
    Patent number: 5821562
    Abstract: Into an amorphous silicon film, catalyst elements for accelerating the crystallization are introduced. After patterning the amorphous silicon films in which the catalyst elements have been introduced into an island pattern, a heat treatment for the crystallization is conducted. Thus, the introduced catalyst elements efficiently diffuse only inside the island-patterned amorphous silicon films. As a result, a high-quality crystalline silicon film, having the crystal growth direction aligned in one direction and having no grain boundaries, is obtained. Using the thus formed crystalline silicon film, semiconductor devices having a high performance and stable characteristics are fabricated efficiently over the entire substrate, irrespective of the size of the devices.
    Type: Grant
    Filed: May 30, 1995
    Date of Patent: October 13, 1998
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Naoki Makita, Takashi Funai, Yoshitaka Yamamoto, Yasuhiro Mitani, Katsumi Nomura, Tadayoshi Miyamoto, Takamasa Kosai
  • Method for fabricating a semiconductor device using a catalyst introduction region
    Patent number: 5696003
    Abstract: Into an amorphous silicon film, catalyst elements for accelerating the crystallization are introduced. After patterning the amorphous silicon films in which the catalyst elements have been introduced into an island pattern, a heat treatment for the crystallization is conducted. Thus, the introduced catalyst elements efficiently diffuse only inside the island-patterned amorphous silicon films. As a result, a high-quality crystalline silicon film, having the crystal growth direction aligned in one direction and having no grain boundaries, is obtained. Using the thus formed crystalline silicon film, semiconductor devices having a high performance and stable characteristics are fabricated efficiently over the entire substrate, irrespective of the size of the devices.
    Type: Grant
    Filed: December 16, 1994
    Date of Patent: December 9, 1997
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Naoki Makita, Takashi Funai, Yoshitaka Yamamoto, Yasuhiro Mitani, Katsumi Nomura, Tadayoshi Miyamoto, Takamasa Kosai