Interfacial property tuning of heavy metal/CoFeB for large density STT-MRAM

Abstract

Perpendicular magnetic tunnel junctions (MTJs) based on MgO/CoFeB structures are of particular interest for spin-transfer torque magnetic random access memories (STT-MRAMs). However, their major challenges of combining both a large tunnel magneto-resistance ratio (TMR) and a low junction resistance, a strong interfacial perpendicular magnetic anisotropy (PMA) for the high thermal stability and a low STT switching critical current density are still to be met. In this paper, we show our recent progress in studying the pertinence of capping layers to several principal spintronic effects such as PMA, TMR and Gilbert damping. And we predict and experimentally prove the performance optimization the by the interfacial property tuning of heavy metal/CoFeB.