AES depth profiles of thin SiC-layers – simulation of ion beam induced mixing

Thin carbonized SiC layers were investigated by Auger depth profiling. If the layers are smooth, ion induced mixing and Auger electron escape depth are the dominant factors that degrade the depth profiles. With the help of the Monte Carlo simulation code T-DYN by Biersack and an escape depth correction program, simulations can describe the measured Auger depth profiles. For quantitative comparison of simulations and measurements the Auger data must be quantified. The sputter time scale must be converted into depth using a known or best fitting sputter rate. The Auger peak-to-peak height must be converted into concentration using sensivity factors which do not include the sputter correction for selective sputtering. Since these sensitivity factors are normaly estimated at a sputtered single crystal, selective sputter correction must be excluded later. A good quantitative agreement was found for a simulated adsorbate/SiC/Si layer system with a measured Auger depth profile of a carbonized SiC layer on Si. This allows a description of the layer structure and of the composition of the layers.