Voltage-Controlled Magnetic Tunnel Junctions Demonstrate Resilience to Displacement Damage

Magnetic tunnel junctions (MTJs) with voltage-controlled magnetic anisotropy (VCMA) properties were electrically profiled and subjected to microbeam irradiation. The microbeam allows for precise analysis of ion fluence effects on the switching ratio [tunneling magnetoresistance (TMR)] and magnetic field response (switching field, or coercivity) of the devices. The devices are resilient to 20 MeV Au ion fluences up to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1 \times 10^{12}$ </tex-math></inline-formula> ions/cm2. Beyond this, they show electrical differences: a significant reduction in both coercivity and TMR was observed across the range of bias voltages used to exercise the VCMA effect. Notably, the lowest biases where VCMA induces the largest energy barrier modification survived the most. We also find that the devices are not notably more temperature sensitive post-irradiation and are not any more sensitive to displacement damage than previously analyzed perpendicular anisotropy MTJs (pMTJs). Our work confirms that these MTJ devices are a promising candidate for resilient, next-generation computing.