A statistical study of magnetic tunnel junctions for high-density spin torque transfer-MRAM (STT-MRAM)

We have demonstrated a robust magnetic tunnel junction (MTJ) with a resistance-area product RA=8 Omega-mum 2 that simultaneously satisfies the statistical requirements of high tunneling magnetoresistance TMR > 15sigma(R p ), write threshold spread sigma(Vw)/ -9 , and sufficient write endurance, and is free of unwanted write-induced magnetic reversal. The statistics suggest that a 64 Mb chip at the 90-nm node is feasible.