Spin-orbit torque magnetic random access memory (SOT-MRAM), which is theoretically predicted with “unlimited” endurance, has been regarded as a promising alternative to conventional static random access memory (SRAM)-based L1 to L3 caches in advanced complementary metal-oxide-semiconductor (CMOS) technology nodes. However, contrary to the predicted “unlimited” endurance, the experimental test reveals that practical SOT-MRAM fails upon reaching an endurance limit, and the underlying mechanism remains unclear. We also lack information on how these limits depend on the materials or structures used, particularly at the array level. In this work, we conducted a thorough investigation of the endurance performance of SOT-MRAM arrays through cycling tests under various voltages and thermal stress conditions. Experimental results show that SOT-MRAM failures mainly happen due to thermal interdiffusion in the magnetic tunnel junctions (MTJs). This process is largely caused by Joule heating over 180 K in the SOT channel during write operations. This heat generation creates a fundamental limitation on achieving “unlimited” endurance in practical implementations. To enhance the endurance of SOT-MRAM, we proposed several optimization strategies from the perspectives of material and structure engineering, including optimizing the SOT channel material and reducing the SOT channel length. Through these optimization measures, we successfully improved the endurance of SOT-MRAM to over 10¹⁸ cycles at 125 °C, meeting the requirements for “unlimited” operation (≥ 10¹⁷ cycles) in edge computing applications. This provides design guidelines for realizing SOT-MRAM’s potential as a candidate to SRAM in high-performance cache hierarchies.

The novel non-volatile MRAM (magnetic random access memory) has the advantages of fast read and write speed, long data retention time and low power consumption, which attracts wide attention from researchers. Its excellent anti-irradiation capabilities are explored in depth, and further applications in aerospace and other fields are expected. The industrial development, technological changes and applications of MRAM were reviewed, the mature MRAM products of recent years were listed, and the advantages and disadvantages of different generations of MRAM were analyzed. The radiation effects of MTJ(magnetic tunnel junction) and read/write circuit based CMOS (complementary metal oxide semiconductor) were discussed. The recent achievements in anti-radiative hardening design for MRAM were summarized. The development prospect of anti-irradiation MRAM in aerospace field and even nuclear energy field was prospected.