Oxide thickness dependence of electron-induced surface states in MOS structures

Abstract

To gain insight into the origin of the surface state induced by electron radiation, MOS structures with different oxide thicknesses were irradiated with a 25‐keV electron beam. For a dose of 0.95×10− 5 C/cm2, the surface states increased montonically as the oxide thickness increased from 90 to 2100 Å. Since all the oxides were grown under the same oxidation conditions and their initial surface states were of the same density, the results could not be due to the difference in their interface properties. The experimental results can be explained by a postulation based on a broken‐bond model.