Ion microscope investigations of non-uniform surfaces of thin SiO2 films produced by high-temperature nitridation experiments

Abstract Elemental composition and surface changes of thin high-temperature nitrided SiO 2 films were studied with ion microscopy using 0.92 and 1.4 MeV deuterium ions. Surprisingly, a non-uniform artificial pattern on the surface of samples annealed above 1150°C was observed. Nuclear reaction microprobe analysis and scanning electron microscopy were applied to reveal the origin and composition of the pattern. The surface topology and the maps of the light elements were studied. The backscattered signals in the NRA data provided maps of Si and variations in the elemental compositions at the surface of the specimens. With both techniques, significant differences in the elemental make-up within the pattern were obtained. The light elements were found to be enriched differently in the centre of the non-uniform patterns and the surrounding ring-like structures, suggesting the formation of compounds of C, N, O and Si.