Cathodoluminescence in the scanning electron microscope was used to study cross-sectional samples of epitaxial films which had been grown on sapphire. Increased cathodoluminescence emissions, attributed to the presence of stacking faults and decorated dislocations, were observed in a region of the buffer layer close to the film/substrate interface. A region of enhanced emission was also observed in the epilayers, which was partially caused by Si doping and in which structural defects were involved. It was concluded that cross-sectional cathodoluminescence appeared to be a useful method for revealing features, of the spatial distribution of luminescence, which were not detectable by using plan-view measurements.

M.H.Zaldivar, P.Fernández, J.Piqueras: Journal of Applied Physics, 1998, 83[5], 2796-9