Grown thin films ofSiO2play an important role in the performance and stability of silicon insulated gate field effect transistors, bipolar transistors, and diodes used in modern integrated circuits. The principal properties of theSi–SiO2system which can influence device characteristics are fixed charge, interface states and drift. Fixed charge and interface states can adversely affect device characteristics like gain, noise, junction reverse currents, and junction breakdown voltage, while drift undermines the stability of these device characteristics. Our present understanding of some of the chemistry and physics of theSi–SiO2system pertaining to device performance and stability will be reviewed. The metal-oxide–silicon capacitor has been the principal measurement tool used in this work. Its operation and how it was used to determine the oxide growth conditions, annealing treatments, and other processing required to get low fixed charge and interface state densities and minimum drift will be emphasized.