Radiation effects of e-beam fabricated submicron NMOS transistors

This paper reports radiation effects of submicron NMOS devices fabricated by e-beam lithography. This study was initiated because e-beam lithography creates neutral traps in the gate oxides of MOS devices, which may make these devices more sensitive to radiation. Indeed, we have found that for radiation doses above 10 Krad, the threshold shift for an e-beam fabricated device is twice that for the corresponding device made by optical lithography. However, with the submicron process used here the threshold shift for both types of device is quite low (<100mV below 10 Krad), Moreover, there was no correlation observed between radiation sensitivity and device gate length.