Impact of High-Energy Heavy Ion Irradiation on Spin-Orbit Torque Magnetic Random Access Memory Arrays

Spin-orbit torque magnetic random access memory (SOT-MRAM) demonstrates significant potential for space applications due to its intrinsic radiation tolerance properties. However, evaluating the reliability of SOT-MRAM arrays integrated with metal-oxide-semiconductor (MOS) under high-energy heavy-ion irradiation remains the critical technical challenge. In this study, we assess the radiation tolerance of the SOT-MRAM arrays using high-energy heavy-ion irradiation sources, including Bi ions (1820 MeV), Ta ions (1332 MeV), and Kr ions (500 MeV). Experimental results indicate that the core electrical parameters of the devices, including the critical switching current (<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Ic</i>), the tunneling magnetoresistance ratio (TMR), and the bit error rate (BER), remain excellent in stability under irradiation. Notably, post-irradiation testing revealed several short-circuit failures in the SOT-MRAM array after Bi and Ta ions irradiation. These failures are due to radiation-induced defect formation in MgO tunnel barriers, which creates localized conductive pathways. We propose an approach to improve the radiation tolerance of SOT-MRAM arrays. This research supports the practical application of SOT-MRAM devices in space radiation environments.