STUDY OF ION MIXING DURING AUGER DEPTH PROFILING OF GE-SI MULTILAYER SYSTEM .2. LOW ION ENERGY (0.2-2 KEV) RANGE

Auger electron spectroscopy depth profiling was carried out on amorphous Ge-Si multilayer structures of 2 and 3 nm layer thicknesses using a dedicated Auger depth profiling instrument that rotates the specimen during sputtering and applies a grazing angle of incidence. Ion energy was in the range of 0.2-2 keV. The depth profiles of these multilayer systems are oscillating functions. The authors show that the amplitude of the oscillation versus the square root of the ion energy curve is linear in the energy range used. The depth profile cannot be described either by Gaussian broadening or the Liau model. Simulations using the dynamic transport of ions in matter code reproduce the slopes of the amplitude of oscillation versus the square root of ion energy curves, but the simulated and measured intercepts are different. The ratios of the measured and simulated intercepts are constant and do not depend on the layer thickness. This is used to give a recipe for a ''normalization'' of the simulated curves. (C) 1995 American Vacuum Society.