Micromagnetic simulations for deterministic switching in SOT-MRAM cell with additional heavy metal capping strip

Abstract

Spin–orbit torque magnetic random-access memory (SOT-MRAM) has received extensive interest in the memory industry. Recent works have focused on a heavy metal (HM)/ferromagnet bilayer with an additional HM capping strip to deterministically switch the magnetization. This paper investigates the switching behaviors of SOT-MRAM utilizing this structure with micromagnetic simulations coupled to the drift-diffusion spin transport model. The mechanism is attributed to the non-negligible negative z-component from spin accumulation on the bottom HM interface, which originates from the associated accumulation at the edges of the HM capping strip. Moreover, device parameters are shown as crucial for deterministic switching and lower power consumption. This study provides fundamental insights into deterministic switching for SOT-MRAM with an additional HM capping strip, which can be readily adopted into practical applications.