A MEDIUM-ENERGY ION-SCATTERING ANALYSIS OF THE SI-SIO2 INTERFACE FORMED BY ION-BEAM OXIDATION OF SILICON

The Si-SiO2 interface formed by 3 keV O-2(+) ion bombardment on silico n at room temperature and 600 degrees C was studied by in situ medium energy ion scattering spectroscopy (MEIS). The amorphization process a t the initial stage of the oxygen ion bombardment and the subsequent f ormation 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 an d 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 annea ling effect at 600 degrees C decreased the number of disordered silico n atoms and the suboxide silicon atoms, which make the Si-SiO2 interfa ce more abrupt, was more clearly observed at the initial stage of the bombardment.