EXPLORATION OF HEAVY-ION IRRADIATION EFFECTS ON GATE OXIDE RELIABILITY IN POWER MOSFETS

Heavy ion irradiation effects on gate oxide reliability in power MOSFETs were explored. Devices were exposed to heavy ion fluences and LETs simulating exposure in spacecraft at bias levels not expected to cause catastrophic failure. Time dependent dielectric breakdown measurements and charge separation techniques resulted in no detectable changes. The gate voltage at which oxide breakdown occurs and the gate I-V curves suggest subtle changes in device characteristics that can be detected at high gate biases. However, there is no indication that heavy ion exposure results in a significant reduction in gate oxide reliability.