Thermal stability and memristive spin-orbit torque switching at elevated temperature

Recently, many spin-orbit torque (SOT) related works commit to enhancing the SOT efficiency but neglect the thermal stabilities. The thermal stability factor (Δ) is crucial for robust storage, especially when SOT-based devices integrated with CMOS. The thermal dissipation from transistor can cause the increase of ambient temperature and therefore may affect the performance of SOT efficiency and thermal stability. Additionally, the thermal effect may have influence on the multi-states in memristive switching which can be controlled by changing the applied currents widths.
In this work, through comprehensive temperature-dependent study on standard W/CoFeB/MgO and field-free CoFeB/W/CoFeB/MgO devices, the SOT efficacies of both are found to be invariant from 298 K to 353 K.¹ Δ is shown to degrade with increasing the temperature. The memristive SOT switching behaviors in both systems with various pulse-widths and temperatures are also examined. Our results suggest that although the SOT efficacy is robust against thermal effects, the reduction of Δ at elevated temperatures could be detrimental to standard memory as well as neuromorphic device applications.

References
¹W.-B. Liao, et al. Appl. Phys. Lett. 117, 182402 (2020).