Process optimization and cryogenic evaluation of spin-orbit torque magnetic random access memory

Magnetoresistive random access memory (MRAM) is proposed to be employed in cryogenic memory for low power consumption due to its excellent outstanding performance at low temperature. In this work, we demonstrate the memory function using optimized spin-orbit torque magnetic tunnel junctions (SOT-MTJ) or MRAM below 10K for the first time. The efficiency of the MTJ is more than doubled by the modified MTJ stack and etching process. In addition, the cryogenic environment significantly increases the tunneling magnetoresistance (TMR) and the coercive field (H <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">C</inf> ) by 40% and 100% respectively, indicating a wider margin and higher reliability. The switching voltage increases by 30% at 8K, which is acceptable compared to the enhancement of H <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">C</inf> . It is believed that SOT-MRAM is a promising technology to meet the needs of cryogenic computing.