Abstract
The effect that ionizing radiation has on Si‐SiO2 MOS devices is to create trapped holes and interface states at the Si‐SiO2 interface. Several recent publications claim that it is possible to distinguish donor or acceptor interface states by analyzing CV curves. It is shown here that in the presence of interface states it is not possible, in general, to determine either interface‐state type or the quantity of fixed oxide charge from CV measurements. Furthermore, observed differences between flatband voltage shifts on p‐ and n‐type MOS devices are shown to be independent of whether interface states are donors or acceptors.