The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 29, 1996
Filed:
Dec. 07, 1993
Tsunehiro Kawata, Kumagaya, JP;
Katsuhiko Kojo, Fukaya, JP;
Youichiro Kazama, Kumagaya, JP;
Takayuki Fukaya, Kuwana, JP;
Toshihiko Tsujimura, Tsu, JP;
Hitachi Metals, Ltd., Tokyo, JP;
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.