Synchrotron radiation photoemission study of the thermal annealing and atomic hydrogen cleaning of native oxide covered InAs(1 0 0) surfaces

Changes induced in the surface chemical composition of native oxide covered InAs(1 0 0) by both thermal annealing and atomic hydrogen cleaning have been investigated by soft X-ray photoemission spectroscopy. Annealing up to 450 °C shows a reduction in the intensity of the In and As oxides, however this anneal is not sufficient to produce an oxide and carbon free surface. Exposure to a beam of atomic hydrogen at 360 °C results in the removal of both native oxides and surface carbon contamination resulting in a clean In rich surface. The chemical stability of the cleaned InAs surface to prolonged atomic hydrogen exposure times at temperatures up to 420 °C has also been investigated and shown to have no effect on the surface stoichiometry.