The Ge concentration in a MBE grown SiGe and the depth of the quantum well has been quantitatively analysed by means of low energy Rutherford backscattering (RBS) and secondary ion mass spectrometry (SIMS). The concentrations of Si and Ge were supposed to be constant, except for the quantum well, where the nominal germanium concentration, was at 5%. Quantitative information was deduced out of raw data by comparison to SIMNRA simulated spectra. With the knowledge of the response function of the SIMS instrument (germanium delta (delta) layer) and using the model of forward convolution (point to point convolution) it is possible to determine the germanium concentration and the thickness of the analysed quantum well out of raw SIMS data. (c) 2005 Published by Elsevier B.V.