The thickness of copper films (100-450 nm) on silicon substrates was d
etermined by electron probe microanalysis (EPMA) applying phi(rho z) p
rocedures of Pouchou and Pichoir. Film thickness was calculated from e
xperimental k-ratios analyzed with electron energies between 6 and 30
keV using commercial software (LAYERF distributed by CAMECA). The infl
uence of the incident electron energy and X-ray line chosen for analys
is on the results was investigated. Accuracy of film thickness determi
nation was evaluated by comparison with Rutherford backscattering spec
troscopy (RBS) and secondary ion mass spectrometry (SIMS). The differe
nce between layer thicknesses determined with EPMA and RBS is in gener
al less than 2%, if EPMA measurements are performed with various elect
ron energies. Layer thicknesses determined with Cu-L alpha are mostly
closer to values obtained by RBS than those derived from Cu-K alpha ra
diation. Preliminary SIMS measurements yielded inconsistent results an
d, thus, cannot be used in this case to determine the layer thickness
of Cu films on Si accurately.