Characterization of nano-oxide layers fabricated by ion beam oxidation

In this paper, a remote O/sub 2/ 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 O/sub 2/ content in the Ar-O/sub 2/ plasma. These results were applied in optimizing the fabrication of Al/sub 2/O/sub 3/ barrier for tunnel junctions. This method was also used to fabricate junctions with Fe-oxide layers inserted at the Al/sub 2/O/sub 3/-CoFe interface. TEM and magnetization data indicate that after anneal at 385/spl deg/C, a homogeneous ferromagnetic Fe-oxide layer (Fe/sub 3/O/sub 4/?) is formed.