Silicon Oxidation and Oxynitridation in the Ultrathin Regime: Ion Scattering Studies

The paper reviews our recent studies of the mechanistic and structural aspects of ultrathin (<5 nm) dielectric lms (oxides, SiO2, and oxynitrides, SiOxNy) thermally grown on silicon surfaces. High resolution medium energy ion scattering (MEIS) has been used as the primary tool in these studies. We discuss: (i) the growth mechanism of ultrathin lms using isotopic (O2/O2) labeling methods, (ii) the initial stages of the interaction of oxygen with silicon surfaces under di erent temperature and pressure conditions, including a new roughening regime, (iii) the transition region near the oxide/substrate interface, and (iv) silicon oxynitridation in N2O and NO.