Deterministic and Field-Free Voltage-Controlled MRAM for High Performance and Low Power Applications

We propose a deterministic VCMA writing concept that allows exclusion of the pre-read which is required in conventional VCMA write scheme. We apply it on 400°C compatible pMTJ devices with high TMR 246% and retention = 54 and demonstrate a genuine ns-scale write speed. Furthermore, we realize reliable 1.1 GHz external field-free VCMA switching with 20fJ write energy by integrating a magnetic hard mask as the in-plane magnetic field generator. An endurance of more than 10
¹⁰
cycles is achieved. Our results address the fundamental write operation challenges of the voltage-controlled MRAM technologies.