Title :
Improved thermal stability of ferromagnetic tunnel junctions with a CoFe/CoFeOx/CoFe pinned layer
Author :
Ochiai, T. ; Tezuka, N. ; Inomata, K. ; Sugimoto, S. ; Saito, Y.
Author_Institution :
Dept. of Mater. Sci., Tohoku Univ., Sendai, Japan
Abstract :
Annealing temperature dependence of the tunnel magnetoresistance (TMR) ratio for magnetic tunnel junctions with CoFeOx inserted in the pinned layer was investigated. A junction with a CoFe/CoFeOx/CoFe pinned layer exhibited TMR ratios of 46.5% and 42.5% after annealing at 350°C and 375°C, respectively. The reason for the improvement of the thermal stability is related to oxygen diffusion from the CoFeOx layer, and there is a possibility that CoFeOx plays the role of a Mn (in MnIr exchange layer) diffusion barrier.
Keywords :
annealing; cobalt alloys; cobalt compounds; diffusion barriers; ferromagnetic materials; iron alloys; magnetic multilayers; magnetic tunnelling; thermal stability; tunnelling magnetoresistance; 350 degC; 375 degC; CoFe-CoFeO-CoFe; CoFe/CoFeOx/CoFe pinned layer; TMR; annealing temperature dependence; diffusion barrier; ferromagnetic tunnel junctions; oxygen diffusion; thermal stability; tunnel magnetoresistance ratio; Annealing; Argon; CMOS technology; Electrodes; Magnetic tunneling; Materials science and technology; Sputtering; Temperature dependence; Thermal stability; Tunneling magnetoresistance;
Journal_Title :
Magnetics, IEEE Transactions on
DOI :
10.1109/TMAG.2003.815715
