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:
Jun. 10, 2003
Filed:
Aug. 30, 2001
Hong Deng, San Jose, CA (US);
George William Tyndall, III, San Jose, CA (US);
Richard Longstreth White, Los Altos, CA (US);
Hitachi Global Storage Technologies Netherlands B.V., Amsterdam, NL;
Abstract
A thin film structure comprising a protective layer structure having at least two different compositions of carbon and nitrogen with the surface of the protective layer having the lowest nitrogen content is disclosed. The protective layer structure of the invention is preferably used over the magnetic material in a thin film magnetic disk. In the protective layer structure of the invention, the durability of a relatively high nitrogen content CNx material is improved by the addition of a surface sublayer of CNx with a relatively low nitrogen concentration. The resulting protective layer structure provides superior durability to either of the thin film compositions used alone achieving a synergistic result. The protective layer structure of the invention has the additional benefit of decreasing the polar surface energy and therefore, improving the corrosion resistance of the film structure. In one embodiment the protective layer of the invention is implemented as two discrete sublayers with the surface sublayer having the lowest nitrogen concentration. In this embodiment the surface sublayer has from 0 to 8 at. % nitrogen and the higher nitrogen content is between 10 and 25 at. % nitrogen at the magnetic layer interface. The protective layer structure of the invention can also be implemented as a film in which the nitrogen content gradually decreases between the magnetic layer and the surface of the protective layer structure.