Structure and Performance Co-optimization for the Development of Highly Reliable Spin-Orbit Torque Magnetic Random Access Memory

In this study, we optimized the SOT-MRAM structure and extensively investigated the corresponding SOT switching properties. A wafer-level statistical study of the SOT switching properties, such as the ratio of tunnel magnetoresistance (TMR), SOT switching voltage, and parallel/antiparallel state resistances
$(R_{\mathrm{P}}/R_{\text{AP}})$
, was investigated in detail. The pulse width, temperature, and program/erase cycle-dependent SOT switching reliability were investigated. Finally, the optimized SOT-MRAM cell shows a high TMR of > 165%, a fast write speed of 5 ns, a long endurance of > 10
⁸
cycles, and a high thermal stability factor of
$\Delta\approx 59$
, which meets the retention criteria of > 10 years.