Correlation between preirradiation channel mobility and radiation-induced interface-trap charge in metal-oxide-semiconductor transistors

We find a strong correlation between preirradiation channel resistance and radiation-induced interface-trap charge in n-channel metal-oxide-semiconductor (MOS) transistors. While it has long been known that the postirradiation mobility of MOS transistors degrades with exposure to ionizing radiation, we believe this is the first time that differences in the postirradiation interface-trap charge have been linked to differences in preirradiation device parameters. A simple model is presented that relates the observed variations in preirradiation channel resistance to scattering from defects at the Si/SiO2 interface which may be precursors to the radiation-induced interface-trap charge.