Amplicification of Voltage Controlled Magnetic Anisotropy Effect with Negative Capacitance

Abstract

The high current density required by Magnetic Tunneling Junction (MTJ) switching driven by Spin Transfer Torque (STT) effect leads to large power consumption and severe reliability issues therefore hinder the timetable for STT Magnetic Random Access Memory (STT-MRAM) to mass market. By utilizing Voltage Controlled Magnetic Anisotropy (VCMA) effect, the MTJ can be switched by voltage effect and is postulated to achieve ultra-low power (fJ). However, the VCMA coefficient measured in experiments is far too small for MTJ dimension below 100 nm. Here in this work, a novel approach for the amplification of VCMA effect which borrow ideas from negative capacitance is proposed. The feasibility of the proposal is proved by physical simulation and in-depth analysis.