Discussions on switching mechanism for ultimate reduction in energy consumption for STT-MRAM

摘要

Critical switching current, ICsw, of STT (Spin Transfer Torque)-MRAM has been reduced by several orders with PMA (Perpendicular Magnetic Anisotropy)-MTJs and the state-of-the-art writing-charge, Q_w, becomes the order of 100fC. With the small Q_w, MRAM starts to save energy consumption even for mobile applications. The key to the Q_w reduction is a development of MTJs having higher writing-efficiency. Especially coherent switching of storage-layer magnetization was found to be the root key to the high efficiency.