Effect of diffusion barrier in the thermally annealed exchange-biased IrMn-CoFe electrode in magnetic tunnel junctions

Exchange-biased electrodes IrMn/Ta(2 /spl Aring/)/CoFe/AlO/sub x/ and IrMn/CoFe/Ta(2 /spl Aring/)-AlO/sub x/ used in a magnetic tunnel junction were annealed at 300/spl deg/C to study the Mn diffusion characteristics. Auger electron spectroscopy and X-ray photoelectron spectroscopy analysis of the annealed electrodes show that the Ta diffusion barrier effectively blocked the Mn migration, regardless of the barrier location. Also concluded from the study was that the Mn migration is largely enhanced by the preferential oxidation of Mn.