The progresses of MRAM as a memory to save energy consumption and its potential for further reduction

Abstract

Critical switching current, I <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">sw</sub> , of STT (Spin Transfer Torque)-MRAM has been reduced by several orders with perpendicular MTJ and the state-of-the-art write charge, Q <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">w</sub> , becomes the order of 100-150fC. With the small Q <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">w</sub> , MRAM starts to save energy consumption by 70-80% compared with a conventional memory system. Analysis of the write pulse-width dependence of I <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">w</sub> revealed a further potential of perpendicular MTJ to reduce I <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">w</sub> and Q <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">w</sub> . STT-MRAM is thought to achieve a further reduction of energy consumption.