Proposal of four-valued MRAM based on MTJ/RTD structure
説明
We proposed a novel four-valued magnetic random access memory (MRAM), that uses a double barrier magneto tunnel junction (MTJ) and a resonant tunneling diode (RTD) connected in series. The double barrier MTJ in the form FM1/I/FM2/I/FM1, where FM1 and FM2 represent ferromagnetic materials with different coercive forces and I represents an insulator, respectively, can take four distinct resistance values, depending on the direction of magnetization of each ferromagnetic layer The RTD can increase the tunneling magneto-resistance (TMR) ratio of the MTJ without area penalty due to the nonlinear nature of the NDR characteristics and compactness. The SPICE simulation showed that the RTD with its peak-to-valley current ratio of 12 could increase the effective TMR ratio from 15% to more than 100%. The cell area per bit is 2F/sup 2//bit, which is suitable for an ultra-high density memory.
収録刊行物
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- 33rd International Symposium on Multiple-Valued Logic, 2003. Proceedings.
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33rd International Symposium on Multiple-Valued Logic, 2003. Proceedings. 273-278, 2004-06-22
IEEE