Compact Modeling of High Spin Transfer Torque Efficiency Double-Barrier Magnetic Tunnel Junction

The considerable power consumption on logic and memory circuit system will be an unavoidable bottleneck with the shrinking of complementary metal oxide semiconductor (CMOS) technology size. One promising solution is to build non-volatile spintronic device, e.g. spin transfer torque magnetic random access memory (STT-MRAM). The basic storage unit of STT-MRAM, i.e. magnetic tunnel junction (MTJ), has thus been extensively studied. Double-barrier MTJ (DMTJ), as an optimized structure, enhances the STT effect with a second MgO barrier layer and reduces its critical switching current. In this paper, we present a physics-based compact model of CoFeB/MgO DMTJ with perpendicular magnetic anisotropy (PMA). The modeling results show a great agreement with experimental results. More efficient STT switching and similar magnetoresistance features compared with single-barrier MTJ (SMTJ) can be realized. Mixed circuits simulations have also been carried out to validate its functionality. This SPICE-compatible compact model will be useful for high-performance hybrid DMTJ/CMOS circuit and system designs.