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:
Dec. 14, 2021
Filed:
Dec. 30, 2019
Western Digital Technologies, Inc., San Jose, CA (US);
Ronghui Zhou, Fremont, CA (US);
Ming Mao, Dublin, CA (US);
Ming Jiang, San Jose, CA (US);
Yuankai Zheng, Fremont, CA (US);
Chen-jung Chien, Mountain View, CA (US);
Yung-Hung Wang, San Jose, CA (US);
Chih-Ching Hu, Pleasanton, CA (US);
WESTERN DIGITAL TECHNOLOGIES, INC., San Jose, CA (US);
Abstract
A Wheatstone bridge array comprising a tunneling magnetoresistive (TMR) sensor and a method for manufacturing is disclosed. The bottom lead for the TMR sensor has a very small surface roughness due to not only chemical mechanical planarization (CMP) but also due to forming the bottom lead from multiple layers. The multiple layers include at least a bottom first metal layer and a top second metal layer disposed on the first metal layer. The second metal layer generally has a lower surface roughness than the first metal layer. Additionally, the second metal layer has a slower polishing rate. Therefore, not only does the second metal layer reduce the surface roughness simply be being present, but the slower polishing rate enables the top second metal film to be polished to a very fine surface roughness of less than or equal to ˜2 Angstroms.