Realization of Large Area Co20Fe60B20-Based Perpendicular Magnetic Tunnel Junction for CMOS Compatible Device Application

Abstract

This study reports the current-induced switching of a Co20Fe60B20/MgO/Co20Fe60B20-based perpendicular magnetic tunnel junction (p-MTJ) with a [Co/Pt]4 stack as a synthetic anti-ferromagnetic (SAF) layer. Electrical and spectroscopic evidence of p-MTJs reveals that the pinning of the Co20Fe60B20 layer by the SAF through a Ta spacer layer enhances the switching resistance after annealing at 650 K (375 °C). A drastic improvement of 6 times in the tunneling magnetoresistance (TMR) was observed after annealing in an external magnetic field (14% for as-deposited and 83% for annealed both for zero bias). The TMR also shows a gradual increased behavior with bias at room temperature, which may be attributed to the multi-domain switching with increase in current. The analogous SAF-based MTJ devices were modeled using the non-equilibrium Green’s function (NEGF) to validate the experimental results. The existence of a stable TMR and the low switching current density of the fabricated p-MTJ structures provides higher reliability and low-power operation. This makes it attractive for next-generation MTJ applications, especially for embedded memory, system-on-chip, IoT, and neuromorphic computing applications.