THERMAL-OXIDATION OF GALLIUM ANTIMONIDE - SURFACE STUDIES OF THE SUBSTRATE AND THE OXIDE FILM

Native oxide was thermally grown on GaSb by a wet oxidation method. XPS analysis confirmed the formation of both Ga2O3 and Sb2O3. The surface morphology was studied by scanning electron microscopy. n- and p-type polycrystalline and single-crystal GaSb were used as substrates. n-type substrates showed a more defective oxide surface than the p-type ones. Also substrates with higher carrier concentration showed pit formation during the oxidation process. Prolonged oxidation appreciably deteriorated the GaSb surface. The results were confirmed through C-V measurements of the MOS diodes. SIMS depth profile analysis showed Sb pile up at the oxide/substrate interface.