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:
May. 01, 2007
Filed:
Apr. 06, 2004
Yimin Guo, San Jose, CA (US);
Po-kang Wang, San Jose, CA (US);
Xizeng Shi, Fremont, CA (US);
Tai Min, San Jose, CA (US);
Yimin Guo, San Jose, CA (US);
Po-Kang Wang, San Jose, CA (US);
Xizeng Shi, Fremont, CA (US);
Tai Min, San Jose, CA (US);
Headway Technologies, Inc., Milpitas, CA (US);
Applied Spintronics, Inc., Milpitas, CA (US);
Abstract
An MTJ MRAM cell element, whose free layer has a shape induced magnetic anisotropy, is formed between orthogonal word and bit lines. The bit line is a composite line which includes a high conductivity current carrying layer and a soft adjacent magnetic layer (SAL). During operation, the soft magnetic layer concentrates the magnetic field of the current and, due to its proximity to the free layer, it magnetically couples with the free layer to produce two magnetization states of greater and lesser stability. During switching, the layer is first placed in the less stable state by a word line current, so that a small bit line current can switch its magnetization direction. After switching, the state reverts to its more stable form as a result of magnetostatic interaction with the SAL, which prevents it from being accidentally rewritten when it is not actually selected and also provides stability against thermal agitation.