Title :
Effect of nitrogen incorporation to oxidation process on the reliability of magnetic tunnel junctions
Author :
Kim, Kwang-Seok ; Cho, B.K.
Author_Institution :
Dept. of Mater. Sci. & Eng., Gwangju Inst. of Sci. & Technol., South Korea
Abstract :
In this study, nitrogen atoms are added in a post-oxidation process of a thin Al metal layer to enhance the stability of magnetic tunnel junctions (MTJs). Al-N bonds in the tunnel barrier were detected by XPS measurements. The MTJs fabricated by an ultra-high vacuum magnetron sputtering system consisted of Si(100)/SiO2/CoFeB(100 Å)/Cu(250 Å)/CoFe(50 Å)/AIOx or AlOxNy(20 Å)/CoFe(25 Å)/IrMn(200 Å)/Cu(300 Å). The lifetimes of the two barriers were predicted in order to see the nitrogen effect on the reliability. Under the lifetime specification of 1 MTJ failure out of 1012 junctions, the operating voltage of 0.24 V was obtained for the purely oxidized barriers while 0.42 V of operating voltages for the oxy-nitrided barriers.
Keywords :
X-ray photoelectron spectra; aluminium compounds; boron alloys; cobalt alloys; copper; iridium alloys; iron alloys; life testing; manganese alloys; oxidation; reliability; silicon compounds; sputter deposition; surface hardening; tunnelling magnetoresistance; 0.24 V; 0.42 V; 100 angstrom; 20 angstrom; 200 angstrom; 25 angstrom; 250 angstrom; 300 angstrom; 50 angstrom; AlOxNy-CoFe-IrMn-Cu; MTJ failure; Si; Si-SiO2-CoFeB-Cu-CoFe-AlOx; XPS; lifetimes; magnetic tunnel junctions; nitrogen atoms; nitrogen incorporation; oxidation process; oxidized barriers; oxy-nitrided barriers; post-oxidation process; reliability; tunnel barrier; ultrahigh vacuum magnetron sputtering system; Dielectrics and electrical insulation; Electric breakdown; Electron traps; Magnetic tunneling; Materials science and technology; Nitrogen; Oxidation; Plasma density; Plasma measurements; Stress;
Conference_Titel :
Magnetics Conference, 2005. INTERMAG Asia 2005. Digests of the IEEE International
Print_ISBN :
0-7803-9009-1
DOI :
10.1109/INTMAG.2005.1464443
