High-resolution Auger depth profiling by sub-keV ion sputtering

Auger electron spectroscopy depth profiling of a GaAs/AlAs superlattice sample was performed with Ar+ ions of 100–500 eV using a compact floating‐type low‐energy ion gun. The practical etching rate of >1.5 nm min−1 was ensured in the energy region beyond 150 eV. High depth resolutions of 1.3, 1.6, 1.8 and 2.0 nm (84 − 16%) were obtained with Ar+ ions of 100, 150, 200 and 300 eV at the leading edge of Al LVV depth profiles, respectively. At the sputtering energy of 100 eV, remarkable improvement of the depth resolution at the leading edge (Δzl = 1.3 nm) has been observed but this is followed by considerable deterioration at the trailing edge (Δzt = 2.7 nm). Dynamic Monte‐Carlo simulation for sputtering energies of 150–300 eV was performed for comparison. Although the Monte‐Carlo simulation overestimates the depth resolutions by ∼0.6 nm larger than the relevant experimental values, it describes the energy dependence of the depth resolution with considerable success. Copyright © 2005 John Wiley & Sons, Ltd.