Stopping power measurements of H-1, He-4 and N-14 in Si in the energy range of 0.02-1 MeV/amu

In order to obtain precise stopping power data for ion beam analysis of surface layers we have used high-quality target films produced by advanced molecular beam epitaxy. Thus, multi-delta-layers of Sb or Ge in an amorphous Si matrix have been tailored to define a set of targets for energy-loss measurements in backscattering geometry. The stopping powers of ions of H-1, He-4 and N-14 in the energy range of 0.02-1 MeV/amu have been obtained with a precision as high as about 1% with an additional systematic error of similar magnitude. Discrepancies of up to 10% with recent experimental literature data will be discussed, Scaling laws for electronic stopping have been checked by comparing theoretical predictions with our measurements. Very close agreement with the experimental data is obtained, if the projectile charge is described within the formalism given by Betz et al.