Presentation Information
[20p-C501-10]Integration of BiSb topological insulator and CoFeB/MgO with perpendicular magnetic anisotropy using an oxide interfacial layer for ultralow power SOT-MRAM cache memory
〇(D)HOANGHUY HO1, R. Zhang1, T. Shirokura1, S. Takahashi2, Y. Hirayama2, Nam Hai Pham1 (1.Tokyo Tech., 2.Samsung Japan Corp.)
Keywords:
BiSb,topological insulator,spin-orbit torque
With a giant charge-to-spin conversion efficiency, BiSb topological insulator has become an attractive candidate for the spin current source in spin-orbit torque (SOT) magnetoresistive random access memory (MRAM). However, the large spin Hall angles have been observed so far only in BiSb grown on top of Co/Pt and Co/Tb multilayers. In realistic SOT-MRAM application, it is essential to the integrate BiSb to CoFeB/MgO-based magnetic tunnel junction (MJT) with perpendicular magnetic anisotropy (PMA). In this work, we studied the PMA and SOT characteristics in bottom BiSb/ CrOx interfacial layer/Ta/CoFeB/MgO/Ta junctions. We observed a large spin Hall angle of 2.8 in Bi85Sb15 (10.0 nm)/CrOx (1.0 nm)/Ta (0.8 nm)/CoFeB (1.0 nm)/MgO (2.0 nm)/Ta (2.0 nm) stack. Afterwards, we realize full SOT magnetization switching by a small current density of 3.1 MA/cm2 at a pulse width of 50 μs, which is an order of magnitude smaller than that in a reference stack with Ta as the SOT layer. Our work demonstrated the capability of integrating BiSb to CoFeB/MgO-based p-MTJ for cache memory using CrOx as the interfacial layer