SIMS DEPTH PROFILING WITH SAMPLE ROTATION IN A CAMECA IMS3F

The improvements in depth resolution and the suppression of sputter-induced surface topography obtained using sample rotation during SIMS depth profiling in a Cameca IMS 3F are described. The sample rotation was achieved using a stage that maintains the alignment of the ion optical and rotational axes whilst allowing x-y translation to any position on the sample surface. The material systems studied were a Be-spike-doped GaAlAs sample grown by molecular beam epitaxy and a sputter-deposited film of aluminium on silicon. Significant improvement in depth resolution is shown for buried features in both materials; the sputter-induced ripple topography was suppressed in the analysis of the GaAlAs; for the aluminium on silicon sample the surface roughening was much reduced but some topography was still present even with sample rotation. The apparent interface width between the 1 mum thick aluminium film and the silicon substrate was reduced from 310 to 45 nm.