Photo- and Cathodo- luminescence of hydrogenated Silicon Rich Oxide

Photoluminescence and Cathodoluminescence of hydrogenated Silicon Rich Oxide (SRO:H) films were studied. The samples were prepared by Low Pressure Chemical Vapor Deposition (LPCVD) on Si substrates, some samples were thermally annealed at high temperature and hydrogenation was made by low temperature annealing in forming gas. Strong red PL (Photoluminescence) and CL (Cathodoluminescence) in almost all the visible range were obtained. It was found that it is necessary to apply thermal treatment at high temperatures in order to obtain strong Photo and Cathodo-luminescence. Samples with lower silicon excess show maximum luminescence (CL and PL) while samples with higher silicon excess show poor luminescence. The hydrogen promotes the PL emission, but electron beam irradiation (after CL measurements) quenches the red band observed by PL. The results are analyzed to find the dependency of the PL and CL with respect to hydrogenation, silicon excess and thermal treatment. An explanation is presented in order to interpret these experimental results.