INVESTIGATION OF SPUTTER-INDUCED SURFACE-COMPOSITION MODIFICATION DURING IN-DEPTH PROFILING OF IMPLANTED MATERIALS BY SIMS, XPS AND AES

Depth profile analyses by SIMS (secondary ion mass spectrometry), XPS (x-ray photoelectron spectroscopy) and AES (Auger electron spectroscop y) have been performed on copper-implanted monocrystalline silicon and zinc-implanted polycrystalline copper under various ion sputtering co nditions. A comparison of the different composition profiles shows an important influence of the ion sputtering parameters and of the analys is method on the apparent distribution of the implanted impurities. Th e results can be interpreted in terms of variations of the surface or subsurface composition during sputtering, taking into account preferen tial sputtering and/or sputter-induced segregation phenomena. An unexp ected improvement of ionization yields owing to contaminating oxygen m ay also induce artefactal modifications during the transitory sputteri ng period. The analysis of sputtered matter (SIMS) under O2 sputtering appears to be the most reliable analysis method, although the results , even in that case, can be altered by segregation phenomena. A compar ison of the sputtered matter and the surface analysis method leads to the experimental determination of differential sputtering ratios for b oth systems.