Scanning nuclear microprobes using Rutherford backscattering (RBS) with light ions have been applied to semiconductor process steps, in which minimum feature sizes of several microns down to submicron and multi-layered structures were used. Two or three dimensional RBS mapping of processed semiconductor layers such as multi-layered wiring, semiconductor-on-insulator (SOI), focused ion implanted layers, and laser processed layers, has clearly revealed process failures and inhomogeneity in buried layers without layer removal processes. Radiation damage due to the probe beams was found to be induced by high probe doses at and above 1017/cm2, in which the degradation of crystallinity by probe beams differs between Si and GaAs