DIFFERENCES IN THE SIO2/INP INTERFACES OBTAINED BY THERMAL AND UV-INDUCED CHEMICAL VAPOR-DEPOSITION

The interface between InP covered by its native oxide and SiO2 is built up by 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 InP-Si-O-Si- ... 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.