Efficient Spin-Orbit Torque Switching of Perpendicular Magnetization using Topological Insulators with High Thermal Tolerance

Recent advances in using topological insulators (TIs) with ferromagnets (FMs) at room temperature have opened an innovative avenue in spin-orbit torque (SOT) nonvolatile magnetic memory and low dissipation electronics. However, direct integration of TIs with perpendicularly magnetized FM, while retaining an extraordinary charge-to-spin conversion efficiency (>100%), remains a major challenge. In addition, the indispensable thermal compatibility with modern CMOS technologies has not yet been demonstrated in TI-based structures. Here, high-quality integration of a perpendicularly magnetized CoFeB/MgO system with TI through a Mo insertion layer is achieved and efficient current-induced magnetization switching at ambient temperature is demonstrated. The calibrated energy efficiency of TIs is at least 1 order magnitude larger than those found in heavy metals. Moreover, it is demonstrated that the perpendicular anisotropy of the integrated CoFeB/MgO system and the current-induced magnetization switching behavior are well-preserved after annealing at >350 °C, offering a wide temperature window for thermal treatments. This thermal compatibility with the modern CMOS back-end-of-line process achieved in these TI-based structures paves the way toward TI-based low-dissipation spintronic applications.