Amorphous Ta-oxide and Sn-nitride thin films were prepared by reactive sputter deposition on smooth float glass substrates and investigated ex situ using reflection mode XAFS. The absorption coefficient mu and its fine structure were extracted from the measured reflection mode XAFS spectra with a method based on the Kramers-Kronig transform. Bond distances, coordination numbers and Debye-Waller factors were determined by a detailed XAFS data analysis and compared to those of reference compounds. In addition, changes of the atomic short range order of the sputter deposited Ta2O5-films induced by a thermal heat treatment in ambient air were examined as a function of the annealing temperature.