Key parameters affecting STT-MRAM switching efficiency and improved device performance of 400°C-compatible p-MTJs

Abstract

We report the impact of four key parameters on switching efficiency of STT-MRAM devices with perpendicular magnetic anisotropy: device size, device resistance-area product (RA), blanket film Gilbert damping constant (a), and process temperature. Performance degradation observed in 400°C-processed devices was eliminated by optimizing the perpendicular magnetic tunnel junction (p-MTJ) materials. Furthermore, 400°C-compatible double MTJs were developed for the first time and showed 1.5x improvement in switching efficiency compared to single MTJs with identical free layers.