Depth profiles and resolution limits in accelerator-based solid state analysis

A ubiquitous problem in solid state analysis is the determination of the elemental composition of a sample as a function of the depth. The determination of the depth profiles from ion-beam experiments is an ill-posed inversion problem due to ion-beam and detector-induced energy spreads as well as energy-loss straggling and small-angle scattering effects. The inversion problem is solved in the framework of Bayesian probability theory, which provides a method for quantifying and combining uncertain data and uncertain additional information. By deconvolving the apparatus transfer function and modeling the scattering events in the sample we reconstructed depth profiles of C-13 in tetrahedral amorphous carbon (ta-C) and depth profiles in C-12/C-13 marker probes. An enhancement of the energy resolution by a factor of 6 was obtained