Recent progresses in spin transfer torque-based magnetoresistive random access memory (STT-MRAM)

Abstract

Spin transfer torque-based magnetoresistive random access memory (STT-MRAM) promises to be the next-generation low-power universal memory thanks to the non-volatility, infinite endurance and fast switching speed. In particular, recently the research and application of the STT-MRAM have been greatly advanced by the launch of the commercial chip. In this paper, we firstly present the basic principle and development history of the STT-MRAM, highlighting the improvement in the write technology and magnetic anisotropy. Then the recent progresses are reviewed including the following three aspects: first, much research effort has been made to explore the influence of the fabrication process and device structure on the interfacial perpendicular magnetic anisotropy; second, CoFeB-MgO double-interface structure has been proposed to enhance the thermal stability of the magnetic tunnel junction (MTJ) without the increase in the write current; third, emerging spin-orbit torque (SOT) has attracted massive research interest since it promises to overcome the speed bottleneck and high-risk barrier breakdown suffered by the conventional STT. Finally, the recent development of the STT-MRAM chips is summarized.