X-ray photoelectron spectroscopic study of room-temperature evolution of oxide-covered hydrogenated amorphous silicon/aluminium interface

Interfacial reactions between aluminium and native-oxide-covered hydrogenated amorphous silicon have been investigated by depositing aluminium layer-by-layer and monitoring the growth interface at each stage by X-ray photoelectron spectroscopy. Core-level spectra of silicon and aluminium obtained indicate the reduction of the native silicon oxide by the deposited aluminium and presence of a graded interface consisting of suboxides of silicon and aluminium. The results also suggest that this interface acts as diffusion barrier for further reaction.