Observation and analysis of the spectrum of electrons emitted following the Auger decay of hot holes in the valence band of Si*

The Auger decay of a hot hole in the valence band of Si can result in the emission of an electron from the surface due to its wide valence band (~ 12 eV). The energy spectra and the intensity of electrons resulting from such Auger transitions (termed VVV) may provide a way to investigate the Auger recombination processes in Si valence band. Traditional photon-based or electron-based Auger electron spectroscopies have limited ability to measure the spectra of the low energy VVV Auger electrons due to the obscuring presence of large probe-induced secondary electron background. Here, we present the spectrum of VVV Auger electrons emitted from Si without any probe induced secondary background. This is made possible by the application of positron annihilation induced Auger electron spectroscopy (PAES) where the Auger initiating valence hole is created via annihilation. PAES, therefore, allows the characterization of sample surfaces with positron energies (~1.25eV) much lower than the minimum energy required for secondary electron emission. We will discuss the theoretical analysis of the shape of the Si VVV Auger electron spectrum and estimate the efficiency of Auger recombination of the hot holes in Si.