From STT-MRAM to Voltage-Control Spintronics Memory (VoCSM) in Pursuit of Memory Systems with Lower Energy Consumption

We designed a voltage-control spintronics memory unit-cell, VoCSM, with high write-efficiency to prove a potential to reduce writing energy per bit. By optimizing a self-aligned structure, the cell has the critical switching current (I-csw) smaller than 50 mu A at 20 nsec. for designed MTJ size of about 50 x 150 nm(2). The value is much smaller than that for mature STT-MRAM with the similar dimension. VoCSM also was proved to have unlimited endurance. Finally, with an empirical equation of I-csw further reduction of I-csw is estimated to clarify that VoCSM has a potential to reduce I-csw, down to several mu A.