Differences in the SiO₂/InP interfaces obtained by thermal and UV-induced chemical vapour deposition

The interface between InP covered by its native oxide and SiO₂ is built up the thermal or UV-assisted chemical vapour deposition from silane precursor gas. It is analyzed in situ by X-ray photoemission spectroscopy in an ultra-high-vacuum environment and by infrared absorption spectroscopy in a low-pressure deposition reactor. Both techniques indicate that the two processes lead to a grossly similar interface InPSiOSi⋯ involving the reduction of native oxides. However, significant differences are observed concerning the state of oxidation of silicon, the presence of hydrogen, and the morphology of the interfacial layer. Results are discussed in an interface engineering perspective.