SiO2/Si interface oxidation and defects in O2 plasma processing

Abstract

The SiO2/Si interface oxidation and defects are studied in a low-pressure capacitively-coupled oxygen (O2) plasma. The interface oxidation is clearly observed for a thinner SiO2 layer under a high-energy ion’s irradiation condition for a long period of processing. The oxidation thickness is changed from several angstroms to a few nanometers, depending on the processing period and ion’s energy. Associated with the oxidation, a large number of the interface defects are generated; the density is estimated to be an order of 1012 cm−2 or more. The defects are recovered mostly by hydrogen annealing, however some of them remain as residual.