The tunneling magnetoresistance (TMR) ratios of magnetic tunnel junctions (MTJs), in general, decrease abruptly above 250℃ due to Mn interdiffusion from an antiferromagnet IrMn layer to a ferromagnetic CoFe and/or a tunnel barrier. To improve therma...
The tunneling magnetoresistance (TMR) ratios of magnetic tunnel junctions (MTJs), in general, decrease abruptly above 250℃ due to Mn interdiffusion from an antiferromagnet IrMn layer to a ferromagnetic CoFe and/or a tunnel barrier. To improve thermal stability, we prepared MTJs with nano-oxide layers. Using a MTJ structure consisting of underlayer CoNbZr 4/bufferlayer CoFe 10/ antiferromaget IrMn 7.5/pinned layer CoFe 3/tunnel barrier AlO/freelayer CoFe 3/capping CoNbZr 2 (㎚), we placed a nano-oxide layer (NOL) into the underlayer or bufferlayer. Then, the thermal, structural and magneto-electric properties were measured. The TMR ratio, surface flatness, and thermal stability of the MTJs with NOLs were promoted.