Early formation of surface states in MOS structures under ionizing irradiation

Abstract

A quantitative model of the early formation of surface states (SS) in MOS structures under ionizing irradiation (II) with a limiting stage --- dispersion transport of holes has been developed. According to the model, the main contribution to the early formation of SS occurs during the microsecond pulse II for a thin gate dielectric and after the end of the pulse for a thick field oxide. The increase in the density of early SS after the end of II is associated with the presence of localized states and the dispersion transport of holes. The late formation of SS is limited by the dispersion transport of hydrogen ions, which delays the formation of late SS from 0.1 to 104 seconds or more. Keywords: MOSFET structure, ionizing irradiation, surface conditions, dispersion transport.