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:
Nov. 11, 2008
Filed:
Jun. 15, 2004
Cheng T. Horng, San Jose, CA (US);
Ru-ying Tong, San Jose, CA (US);
Liubo Hong, San Jose, CA (US);
Min LI, Dublin, CA (US);
Cheng T. Horng, San Jose, CA (US);
Ru-Ying Tong, San Jose, CA (US);
Liubo Hong, San Jose, CA (US);
Min Li, Dublin, CA (US);
Headway Technologies, Inc., Milpitas, CA (US);
Applied Spintronics, Inc., Milpitas, CA (US);
Abstract
An MTJ in an MRAM array or in a TMR read head is comprised of a capping layer with a lower inter-diffusion barrier layer, an intermediate oxygen gettering layer, and an upper metal layer that contacts a top conductor. The composite capping layer is especially useful with a moderate spin polarization free layer such as a NiFe layer with a Fe content of about 17.5 to 20 atomic %. The capping layer preferably has a Ru/Ta/Ru configuration in which the lower Ru layer is about 10 to 30 Angstroms thick and the Ta layer is about 30 Angstroms thick. As a result, a high dR/R of about 40% is achieved with low magnetostriction less than about 1.0 E−6 in an MTJ in an MRAM array. Best results are obtained with an AlOx tunnel barrier layer formed by an in-situ ROX process on an 8 to 10 Angstrom thick Al layer.