Title :
Characterization of nano-oxide layers fabricated by ion beam oxidation
Author :
Cardoso, Susana ; Zhang, Zongzhi ; Li, Haohua ; Ferreira, Ricardo ; Freitas, Paulo P. ; Wei, Peng ; Soares, José C. ; Snoeck, Etienne ; Batlle, Xavier
Author_Institution :
Instituto Superior Tecnico, Lisbon, Portugal
fDate :
9/1/2002 12:00:00 AM
Abstract :
In this paper, a remote O2 ion source is used for the formation of nano-oxide layers. The oxidation efficiency was measured in CoFe-oxide films, and a decrease of the oxide layer with the pan angle and the oxidation pressure is observed. For the same oxidation pressure, the oxidation efficiency depends on the O2 content in the Ar-O2 plasma. These results were applied in optimizing the fabrication of Al2O3 barrier for tunnel junctions. This method was also used to fabricate junctions with Fe-oxide layers inserted at the Al2O3-CoFe interface. TEM and magnetization data indicate that after anneal at 385°C, a homogeneous ferromagnetic Fe-oxide layer (Fe3O4?) is formed.
Keywords :
alumina; annealing; cobalt alloys; interface magnetism; ion beam effects; iron alloys; magnetisation; oxidation; plasma materials processing; transmission electron microscopy; tunnelling; 385 degC; Al2O3 barrier; Al2O3-CoFe; Al2O3-CoFe interface; Ar-O2 plasma; CoFe-oxide film; Fe-oxide layer; Fe3O4; TEM; annealing; fabrication process; ion beam oxidation; magnetic tunnel junction; magnetization; nano-oxide layer; oxidation efficiency; oxidation pressure; pan angle; remote O2 ion source; Annealing; Argon; Fabrication; Ion beams; Oxidation; Plasma accelerators; Plasma applications; Plasma sources; Spin valves; Tunneling magnetoresistance;
Journal_Title :
Magnetics, IEEE Transactions on
DOI :
10.1109/TMAG.2002.802863
