Matrix effects in particle induced x-ray emission channeling measurements of ZnSe/GaAs heterostuctures

The significance of the matrix effects, i.e., of self-absorption and second ary fluorescence, in particle induced x-ray emission (PIXE) channeling meas urements was studied in epitaxial ZnSe layers on a GaAs substrate. The effe ct of self-absorption on Zn and Se channeling minimum yields was found to b e significant only with thick ZnSe layers. The importance of secondary fluo rescence was estimated by applying an introduced correction formula to the measured Zn minimum yields for ZnSe/GaAs heterostructures. The corrections in Zn minimum yields were significant at high proton energies (> 2 MeV). Th us, errors for instance in impurity atom lattice location determinations by PIXE channeling occur unless these effects are correctly taken into accoun t. (C) 1999 American Institute of Physics. [S0003-6951(99)00132-1].