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:
Oct. 21, 2014
Filed:
Oct. 25, 2012
Headway Technologies, Inc., Milpitas, CA (US);
Ruhang Ding, Pleasanton, CA (US);
Hui-Chuan Wang, Pleasanton, CA (US);
Minghui Yu, Fremont, CA (US);
Jianing Zhou, Fremont, CA (US);
Min Li, Fremont, CA (US);
Cherng Chyi Han, San Jose, CA (US);
Headway Technologies, Inc., Milpitas, CA (US);
Abstract
A two part ion beam etch sequence involving low energy (<300 eV) is disclosed for fabricating a free layer width (FLW) as small as 20-25 nm in a MTJ element. A first etch process has one or more low incident angles and accounts for removal of 70% to 100% of the MTJ stack that is not covered by an overlying photoresist layer. The second etch process employs one or more high incident angles and a sweeping motion that is repeated during a plurality of cycles. Sidewall slope may be adjusted by varying the incident angle during either of the etch processes. FLW is about 30 nm less than an initial critical dimension in the photoresist layer while maintaining a MR ratio over 60% and low RA (resistance×area) value of 1.0 ohm-μm.