Formation of Si1+ in the early stages of the oxidation of the Si[001] 2x1 surface

The early stages of the oxidation of the Si[001] 2 x 1 surface were studied with synchrotron radiation photoelectron spectroscopy. The analysis was based on the block approach, which is a refinement of spectra-subtraction that accounts for changes on the background signal and for band-bending shifts. By this method, it was possible to robustly show that the formation of Si1+ is due to oxygen bonding to the upper dimer atoms. Our results contrast with ab initio calculation, which indicates that the most favorable bonding site is the back-bond of the down-dimer. (C) 2015 American Vacuum Society.