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, 2014
Filed:
Sep. 22, 2008
Hui-chuan Wang, Pleasanton, CA (US);
Tong Zhao, Fremont, CA (US);
Min LI, Dublin, CA (US);
Kunliang Zhang, Fremont, CA (US);
Hui-Chuan Wang, Pleasanton, CA (US);
Tong Zhao, Fremont, CA (US);
Min Li, Dublin, CA (US);
Kunliang Zhang, Fremont, CA (US);
Headway Technologies, Inc., Milpitas, CA (US);
Abstract
A TMR sensor with a free layer having a FL1/FL2/FL3 configuration is disclosed in which FL1 is FeCo or a FeCo alloy with a thickness between 2 and 15 Angstroms. The FL2 layer is made of CoFeB or a CoFeB alloy having a thickness from 2 to 10 Angstroms. The FL3 layer is from 10 to 100 Angstroms thick and has a negative λ to offset the positive λ from FL1 and FL2 layers and is comprised of CoB or a CoBQ alloy where Q is one of Ni, Mn, Tb, W, Hf, Zr, Nb, and Si. Alternatively, the FL3 layer may be a composite such as CoB/CoFe, (CoB/CoFe)where n is ≧2 or (CoB/CoFe)/CoB where m is ≧1. The free layer described herein affords a high TMR ratio above 60% while achieving low values for λ (<5×10), RA (1.5 ohm/μm), and Hc (<6 Oe).