Title :
Interdiffusion in the pinned electrode of the exchanged-biased magnetic tunnel junctions
Author :
Lee, J.H. ; Rho, I.C. ; Jeong, H.D. ; Kim, Katherine K. ; Yoon, Chang Soo ; Kim, Choong Ki
Author_Institution :
Dept. of Mater. Sci. & Eng., Hanyang Univ., Seoul, South Korea
Abstract :
Summary form only given. The pinned electrode of the exchange biased magnetic tunneling junction (MTJ), consisting of Ta/NiFe/IrMn/CoFe/AlO/sub x//Ta layer was annealed at 300/spl deg/C under vacuum to study the extent of interdiffusion within the pinned electrode. In addition, the tunnel barrier layer, AlO/sub x/ was deliberately under- and over-oxidized in the oxygen plasma in order to elucidate the effects of plasma oxidation on the interdiffusion within the thin film stack. A significant amount of Mn diffusion into the AlO/sub x/ layer was observed in the over-oxidized electrode from the compositional depth profiling using Auger Electron Spectroscopy (AES) while the under-oxidized electrode exhibited a minimal amount of Mn diffusion after annealing at 300/spl deg/C. Further interfacial analysis using X-ray Photoelectron Spectroscopy (XPS) proved that the Mn found at the CoFe/AlO/sub x/ interface in the over-oxidized electrode was in the form of MnO/sub 2/ while the Co in the CoFe layer remained unoxidized.
Keywords :
Auger electron spectra; X-ray photoelectron spectra; alumina; annealing; antiferromagnetic materials; chemical interdiffusion; cobalt alloys; exchange interactions (electron); ferromagnetic materials; iridium alloys; iron alloys; magnetic multilayers; manganese alloys; nickel alloys; oxidation; plasma materials processing; tantalum; tunnelling magnetoresistance; 300 degC; AES; Auger electron spectroscopy; Mn diffusion; MnO/sub 2/; Ta-NiFe-IrMn-CoFe-AlO/sub x/-Ta; Ta/NiFe/IrMn/CoFe/AlO/sub x//Ta; X-ray photoelectron spectroscopy; XPS; compositional depth profiling; exchanged-biased magnetic tunnel junctions; interdiffusion; interfacial analysis; over-oxidized electrode; oxygen plasma; pinned electrode; plasma oxidation; thin film stack; tunnel barrier layer; Acceleration; Annealing; Electrodes; Electrons; Magnetic tunneling; Materials science and technology; Oxidation; Plasma temperature; Spectroscopy; Transistors;
Conference_Titel :
Magnetics Conference, 2002. INTERMAG Europe 2002. Digest of Technical Papers. 2002 IEEE International
Conference_Location :
Amsterdam, The Netherlands
Print_ISBN :
0-7803-7365-0
DOI :
10.1109/INTMAG.2002.1001031
