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:
May. 05, 2015
Filed:
Mar. 12, 2008
Tong Zhao, Fremont, CA (US);
Hui-chuan Wang, Pleasanton, CA (US);
Kunliang Zhang, Fremont, CA (US);
Min LI, Dublin, CA (US);
Tong Zhao, Fremont, CA (US);
Hui-Chuan Wang, Pleasanton, CA (US);
Kunliang Zhang, Fremont, CA (US);
Min Li, Dublin, CA (US);
Headway Technologies, Inc., Milpitas, CA (US);
Abstract
An annealing process for a TMR or GMR sensor having an amorphous free layer is disclosed and employs at least two annealing steps. A first anneal at a temperature Tof 200° C. to 270° C. and for a tof 0.5 to 15 hours is employed to develop the pinning in the AFM and pinned layers. A second anneal at a temperature Tof 260° C. to 400° C. where T>Tand t>tis used to crystallize the amorphous free layer and complete the pinning. An applied magnetic field of about 8000 Oe is used during both anneal steps. The mechanism for forming a sensor with high MR and robust pinning may involve structural change in the tunnel barrier or at an interface between two of the layers in the spin valve stack. A MgO tunnel barrier and a CoFe/CoB free layer are preferred.