Si(LVV) Auger and resonance Auger spectra of SiF4 molecules with the use of synchrotron radiation.

Abstract

Si(LVV) Auger spectra have been obtained for gas-phase ${\mathrm{SiF}}_{4}$ molecules with use of tunable photon energies from monochromatized synchrotron radiation. In addition to the normal Auger spectrum excited by photon energies well above the Si 2p photoionization threshold, resonance Auger spectra were measured by exciting the Si 2p electrons to different empty molecular and Rydberg orbitals. Our normal Auger spectrum shows more detailed structure than those previously reported using electron-beam excitation, and verifies the double structure corresponding to the case where the two final-state holes are either in the same or different Si---F bonding orbitals. In the resonance Auger spectra, the peaks shift by 7.5\ifmmode\pm\else\textpm\fi{}0.5, 4.6\ifmmode\pm\else\textpm\fi{}1.0, or 2.7\ifmmode\pm\else\textpm\fi{}1.0 eV to higher energies when the Si 2p electron is excited to the ${\ensuremath{\sigma}}^{\mathrm{*}}$[3s(${a}_{1}$)], 4s, and 3d orbitals, respectively.