Magnetic Random Access Memories (MRAM) beyond Information Storage

Magnetic random access memory (MRAM) is now available as embedded memory from major CMOS foundries. In this study, we demonstrated that slightly modified magnetic tunnel junctions than those used in conventional STT -MRAM can be used for multifunctional purposes, namely magnetic field sensing and RF oscillators. For that, the F eCoB storage layer thickness in the perpendicular anisotropy magnetic stack was adjusted to 1.3-1.4 nm, closer to the transition region from perpendicular to in-plane anisotropy. Two possible configurations of magnetic field sensing using the same stack can be used, achieving high sensitivity in small field range or lower sensitivity in large field range. Additionally, RF oscillator GHz detection and generation were also demonstrated. Further applications of this multifunctional stack can be envisioned including non-volatile and reprogrammable logic, special functions such as random number generator and memristors.