Anomalous Natural Linewidth in the 2p Photoelectron Spectrum of SiF4

The silicon 2p photoelectron spectra for SiH 4 , SiF 4 , and SiCl 4 have been analyzed to give the natural linewidths of the Si 2p hole states, which reflect the Auger decay rates of the states. For SiH 4 the measured widthof 38 meV is in approximate agreement with the prediction of the one-center model (32 meV), but that for SiF 4 of 79 meV is more than 5 times the value of 14 meV predicted by this model. Approximate theoretical calculations indicate that valence electrons from the fluorine atoms of SiF 4 play an important role in the Auger decay via interatomic processes.