Model of the behavior of MOS structures under ionizing irradiation

A quantitative model describing the behavior of MOS structures under ionizing irradiation is developed. The model is based on the capture of holes by hydrogen-containing traps. Some traps are charged and thus form a positive space charge in the insulator. The other traps decay to release positive hydrogen ions. These ions migrate in the insulator electric field to the insulator-semiconductor interface, where they depassivate surface states. The charging of surface states both under irradiation and during measurement of the threshold voltage is taken into account.