Patents by Inventor Yasuo Uo-ochi

Yasuo Uo-ochi 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: 4804560
    Abstract: A method of selectively depositing tungsten upon a silicon semiconductor substrate. A silicon substrate is coated with a masking film of PSG or SiO.sub.2 that is patterned to provide an opening for forming an electrode or wiring. On a portion of the substrate in the opening, a layer of tungsten having a thickness of approximately 2000 .ANG. is deposited by a CVD method from an atomosphere containing a gaseous mixture of WF.sub.6 and H.sub.2 . During this processing, tungsten nucleuses deposit on the surface of the masking film as well. Before such nucleuses form a film, the deposition processing is discontinued and H.sub.2 gas is fed into the CVD apparatus to produce HF, which etches the surface of the masking film, and thus tungsten nucleuses are removed. The deposition and removal steps are repeated several times until the height of the deposited tungsten and the thickness of the masking film are essentially equal to present a flat surface.
    Type: Grant
    Filed: March 17, 1987
    Date of Patent: February 14, 1989
    Assignee: Fujitsu Limited
    Inventors: Yoshimi Shioya, Yasushi Oyama, Norihisa Tsuzuki, Mamoru Maeda, Masaaki Ichikawa, Fumitake Mieno, Shin-ichi Inoue, Yasuo Uo-ochi, Akira Tabuchi, Atsuhiro Tsukune, Takuya Watanabe, Takayuki Ohba