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:
Mar. 13, 2012
Filed:
Oct. 17, 2007
Tom Zhong, Saratoga, CA (US);
Rongfu Xiao, Fremont, CA (US);
Chyu-jiuh Torng, Pleasanton, CA (US);
Adam Zhong, Milpitas, CA (US);
Tom Zhong, Saratoga, CA (US);
Rongfu Xiao, Fremont, CA (US);
Chyu-Jiuh Torng, Pleasanton, CA (US);
Adam Zhong, Milpitas, CA (US);
MagIC Technologies, Inc., Milpitas, CA (US);
Abstract
A method for forming a MTJ in a STT-MRAM is disclosed in which the easy-axis CD is determined independently of the hard-axis CD. One approach involves two photolithography steps and two etch steps to form a post in a hard mask which is transferred through a MTJ stack of layers by a third etch process. Optionally, the third etch may stop on the tunnel barrier or in the free layer. A second embodiment involves forming a first parallel line pattern on a hard mask layer and transferring the line pattern through the MTJ stack with a first etch step. A planar insulation layer is formed adjacent to the sidewalls in the line pattern and then a second parallel line pattern is formed which is transferred by a second etch through the MTJ stack to form a post pattern. Etch end point may be controlled independently for hard-axis and easy-axis dimensions.