Spin Transfer on Low Resistance-Area MgO-Based Magnetic Tunnel Junctions Prepared by Ion Beam Deposition

This work reports spin transfer switching results on nano-sized MgO-based magnetic tunnel junctions (MTJs) prepared by Ion Beam deposition (IBD). Nano-devices with areas down to 60 nm $\times$ 180 nm have been successfully nanofabricated. The MgO deposition conditions were optimized aiming at reducing the resistance-area (RA) product, and RA value as low as 0.8 $\Omega\mu{\hbox {m}}^{2}$ could be successfully obtained for 0.75 nm thick MgO barriers. The average switching current density of 5.45 $\times 10^{6}\ {\hbox {A/cm}}^{2}$ can be obtained for a MTJ nanopillar with the dimension of 225 nm $\times$ 730.3 nm with low RA of 1.47 $\Omega\mu{\hbox {m}}^{2}$ .