A medium energy ion scattering analysis of the Si-SiO2 interface formed by ion beam oxidation of silicon

Abstract

The Si-SiO2 interface formed by 3 keV O-2(+) ion bombardment on silicon at room temperature and 600 degrees C was studied by in situ medium energy ion scattering spectroscopy (MEIS). The amorphization process at the initial stage of the oxygen ion bombardment and the subsequent formation of the suboxide layer and the disordered silicon layer at the Si-SiO2 interface were studied as a function of the ion dose from 2.5 X 10(15) atoms/cm(2) to 5 X 10(17) atoms/cm(2) at room temperature and 600 degrees C. After reaching the steady state, below a similar to 6 nm SiO2 layer, a similar to 2 nm suboxide layer and a similar to 3 nm disordered Si layer were observed at the Si-SiO2 interface. The annealing effect at 600 degrees C decreased the number of disordered silicon atoms and the suboxide silicon atoms, which make the Si-SiO2 interface more abrupt, was more clearly observed at the initial stage of the bombardment.