Invention Application
- Patent Title: MRAM cell structure and method of fabrication
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Application No.: US11418910Application Date: 2006-05-05
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Publication No.: US20060209591A1Publication Date: 2006-09-21
- Inventor: Liubo Hong , Tom Zhong , Lin Yang
- Applicant: Liubo Hong , Tom Zhong , Lin Yang
- Assignee: Headway Technologies, Inc.,Applied Spintronics, Inc.
- Current Assignee: Headway Technologies, Inc.,Applied Spintronics, Inc.
- Main IPC: G11C11/15
- IPC: G11C11/15

Abstract:
An MRAM structure is disclosed where the distance from a bit line or word line to an underlying free layer in an MTJ is small and well controlled. As a result, the bit line or word line switching current is reduced and tightly distributed for better device performance. A key feature in the method of forming the MRAM cell structure is a two step planarization of an insulation layer deposited on the MTJ array. A CMP step flattens the insulation layer at a distance about 60 to 200 Angstroms above the cap layer in the MTJ. Then an etch back step thins the insulation layer to a level about 50 to 190 Angstroms below the top of the cap layer. Less than 5 Angstroms of the cap layer is removed. The distance variation from the free layer to an overlying bit line or word line is within +/−5 Angstroms.
Public/Granted literature
- US07476919B2 MRAM cell structure and method of fabrication Public/Granted day:2009-01-13
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