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.

Date of Patent:
May. 20, 2014

Filed:

Nov. 04, 2011
Applicants:

Cheng T. Horng, San Jose, CA (US);

Ru-ying Tong, Los Gatos, CA (US);

Inventors:

Cheng T. Horng, San Jose, CA (US);

Ru-Ying Tong, Los Gatos, CA (US);

Assignee:

Headway Technologies, Inc., Milpitas, CA (US);

Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
G11B 5/127 (2006.01); H04R 31/00 (2006.01);
U.S. Cl.
CPC ...
Abstract

A dual spin filter that minimizes spin-transfer magnetization switching current (Jc) while achieving a high dR/R in STT-RAM devices is disclosed. The bottom spin valve has a MgO tunnel barrier layer formed with a natural oxidation process to achieve low RA, a CoFe/Ru/CoFeB—CoFe pinned layer, and a CoFeB/FeSiO/CoFeB composite free layer with a middle nanocurrent channel (NCC) layer to minimize Jc. The NCC layer may have be a composite wherein conductive M(Si) grains are magnetically coupled with adjacent ferromagnetic layers and are formed in an oxide, nitride, or oxynitride insulator matrix. The upper spin valve has a Cu spacer to lower the free layer damping constant. A high annealing temperature of 360° C. is used to increase the MR ratio above 100%. A Jcof less than 1×10A/cmis expected based on quasistatic measurements of a MTJ with a similar MgO tunnel barrier and composite free layer.


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