Atomic force microscopy investigations of rapid thermal carbonized silicon

Thin cubic silicon carbide layers grown by carbonization in a rapid thermal processing equipment were investigated by atomic force microscopy. Different roughness descriptions were applied and compared for the characterisation. A special attention was drawn on the morphology evolution during the initial stages of the growth. The surface roughness increases during the first, i.e. the linear growth period, run through a maximum at the point where the growth rate is decreasing, i.e. the saturation set in, and decreases slightly with further growth. Regarding to the common growth model, at the maximum point, the laterally grown crystallites are touching and sealing off the surface. Decreasing the propane concentration in hydrogen results in a slight decreasing of the density of the crystallites and increase of its size. Additionally pits in the surface and well shaped objects were also observed. In increasing the temperature the surface features were shaped more clearly. This indicates predominant three-dimensional growth.