Conduction band energies and hot-electron transport characteristics of epitaxial $Sc2O3∕Si$ (111) studied by ballistic electron emission microscopy and internal photoemission

Ballistic electron emission microscopy (BEEM) and internal photoemission measurements on a $20-nm$-thick epitaxial $Sc2O3$ film on Si (111) show the existence of a lower “tail state” conduction band (CB) extending $∼0.9eV$ below the upper CB (similar to that reported for amorphous $Sc2O3$ films), indicating that these states are not simply due to disorder in amorphous films. This lower CB is also found to support elastic hot-electron transport even against an applied electric field, indicating transport via extended rather than localized states.