Enhanced tunneling magnetoresistance and thermal stability of magnetic tunnel junction by rapid thermal anneal

Abstract

The effect of rapid thermal anneal (RTA) has been investigated on the properties of an FeMn exchange-biased magnetic tunnel junction (MTJ) using magneto resistance and I-V measurements and transmission electron microscopy (TEM). The tunneling magnetoresistance (TMR) in an as-grown MTJ is found to be similar to27%, while the TMR in MTJs annealed by RTA increases with annealing temperature up to 300degreesC, reaching similar to46%. TEM images reveal that the interface of Al2O3 layer for the annealed MTJ has changed into a relatively clear morphology, as compared to that for the as-grown MTJ. The oxide barrier parameters are found to vary abruptly with annealing time within a few ten seconds. Our results demonstrate that the present RTA enhances the thermal stability of MTJs. (C) 2002 Published by Elsevier Science B.V.