Co2Fe6B2/MgO-based perpendicular spin-transfer-torque magnetic-tunnel-junction spin-valve without [Co/Pt](n) lower synthetic-antiferromagnetic layer

Abstract

We design a Co2Fe6B2/MgO-based p-MTJ spin-valve without a [Co/Pt](n) lower synthetic-antiferromagnetic (SyAF) layer to greatly reduce the 12-inch wafer fabrication cost of the p-MTJ spin-valve. This spin-valve achieve a tunneling magnetoresistance (TMR) of 158% and an exchange field (H-ex) of 1.4 kOe at an ex situ annealing temperature of >350 degrees C, which ensures writing error immunity. In particular, the TMR ratio strongly depends on the body-center-cubic capping-layer nanoscale thickness (t(bcc)), i.e., the TMR ratio peaks at t(bcc) = 0.6 nm.