In this work, we present results and analysis which demonstrate the influence of rapid thermal annealing (RTA) on the properties of the Si(100)-SiO2 interface. Polysilicon/oxide/silicon capacitor structures were subjected to RTA treatments, in a nitrogen ambient, over the temperature range 600-1050°C. The structures were examined using high frequency and quasi-static capacitance-voltage (CV) analysis to determine the interface state density profile across the energy gap immediately following the RTA step. The effect of hydrogen annealing subsequent to the RTA process is also presented. Based on the analysis of the interface state density profiles, it is suggested in this work, that RTA (T > 600°C) exposes silicon dangling bond (Pb) centres at the Si(100)-SiO2 interface. The implications of this work to the study of the Si-SiO2 interface, and the technological implications for silicon based MOS processes, are discussed.