Clean wurtzite InN surfaces prepared with atomic hydrogen

Abstract

Conventional methods of surface preparation for III–V semiconductors, such as thermal annealing and sputtering, are severely limited for InN, resulting in In-enrichment and the introduction of donorlike defects. This is explained in terms of the unusually low Γ-point conduction band minimum of InN with respect to its Fermi stabilization energy. Here, low energy atomic hydrogen irradiation is used to produce clean wurtzite InN surfaces without such detrimental effects. A combination of x-ray photoelectron spectroscopy (XPS) and high-resolution electron-energy-loss spectroscopy was used to confirm the removal of atmospheric contaminants. Low energy electron diffraction revealed a (1×1) surface reconstruction after cleaning. Finally, XPS revealed In∕N intensity ratios consistent with a predominantly In polarity InN film terminated by In-adlayers in analogy with c-plane GaN{0001}-(1×1) surfaces.