Wh. Rippard et al., Ballistic electron microscopy study of ultrathin oxidized aluminum barriers for magnetic tunnel junctions, APPL PHYS L, 78(11), 2001, pp. 1601-1603
Ballistic electron emission microscopy has been used to study thin aluminum
oxide tunnel junction barriers formed both by magnetron sputter deposition
and thermal evaporation. We have found that the barriers made by oxidation
of evaporated Al become fully formed at a significantly thinner mean depos
ited thickness (similar to6 Angstrom) than junctions made by sputter deposi
tion. The effective barrier height of the aluminum oxide has been determine
d to be 1.22 +/-0.05 eV and is independent of the method of deposition, thi
ckness, and oxidation conditions. (C) 2001 American Institute of Physics.