Thermal and Electrical Stability Behavior of a Magnetic Tunnel Junction With a New Zr-Alloyed Al-Oxide Barrier

Abstract

The thermal and electrical stability of a magnetic tunnel junction (MTJ) with a Zr-alloyed Al-oxide (ZrAl-oxide) tunnel barrier were investigated. A significant tunneling magnetic resistance (TMR) value of 10% was maintained in the MTJ with a ZrAl-oxide barrier (9.89 at.% Zr) annealed at 450 C. The breakdown voltage of 1.75 V was highest for the MTJ with a 9.89 at.% Zr-alloyed Al-oxide barrier. The quality of the barrier material microstructure in the pre-oxidation state had a dominant effect on the thermal and electrical stability of the MTJ. In addition, plasma oxidation of an ultra-thin 0.6-nm-thick ZrAl barrier led to an MTJ with 8% TMR and a junction resistance area ( ) of 0.72 M m 2 .Index Terms-Amorphous Zr-alloyed Al-oxide barrier, magnetic tunnel junction, thermal and electrical stability.