Limited Stochastic Current for Energy-Optimized Switching of Spin-Transfer-Torque Magnetic Random-Access Memory

Abstract

Reducing the write-error rate (WER) is one of the main concerns for commercialization of spin-transfer-torque magnetic random-access memory (STT-MRAM). While most studies have been focused on finding proper material, this work discusses the use of limited stochastic (LS) current, for which WER is controlled. By solving the Fokker-Planck equation, an analytical expression for the LS current for a given WER is obtained. Most importantly, by using the LS current and optimizing it together with the related pulse duration, the authors find the optimum combination of current amplitude and pulse duration, which can reduce the energy consumption of STT-MRAM by up to 75%.