Patents by Inventor Toshihiko Tsujimura

Toshihiko Tsujimura 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: 5569334
    Abstract: Stainless steel member for semiconductor fabrication equipment having a passive state coating on the surface of the stainless steel comprising, in weight percent, 0.1% or less of C, 2.0% or less of Si, 3.0% or less of Mn, 10% or more of Ni, 15 to 25% of Cr, 1.5 to 4.5% of Mo, 0.5% or less of one or more rare earth element and Fe for substantially the whole remainder. Said passive state coating has a pitting potential of at least 900 mV (when the current density of the anode polarization curve determined with a potentiostat in 3.5% aqueous sodium chloride solution is 10 .mu.A/cm.sup.2) and has a thickness of 0.5 to 20 nm. The invention also includes a surface treatment method for the stainless steel.
    Type: Grant
    Filed: December 7, 1993
    Date of Patent: October 29, 1996
    Assignee: Hitachi Metals, Ltd.
    Inventors: Tsunehiro Kawata, Katsuhiko Kojo, Youichiro Kazama, Takayuki Fukaya, Toshihiko Tsujimura