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:
Jan. 05, 1999
Filed:
Jun. 13, 1997
Keiichiro Tanabe, Hyogo, JP;
Akihoko Ikegaya, Hyogo, JP;
Yuichiro Seki, Hyogo, JP;
Naoji Fujimori, Hyogo, JP;
Sumitomo Electric Industries, Ltd., Osaka, JP;
Abstract
A hard material-coated wafer that having a distortable substrate and a hard material film deposited thereon by a CVD method is provided. The substrate is substantially flat while in a free-standing state. However, deposition of the hard material film having a Vickers hardness of more than Hv3000 on the substrate causes the substrate to distort into a generally convex-shape. Specifically, the wafer is distorted to the film side with a distortion height H of -150 .mu.m to -2 .mu.m. The resulting wafer can have a total thickness that ranges from 0.1 mm to 2.1 mm; and a diameter that is bigger than 25 mm. Moreover, more than 50% of the film can be polished to a roughness less than Rmax 50 nm and Ra 20 nm.