Total ionizing dose effects and annealing behavior for domestic VDMOS devices

Abstract

Total dose effects and annealing behavior of domestic n-channel VDMOS devices under different bias conditions were investigated. The dependences of typical electrical parameters such as threshold voltage, breakdown voltage, leakage current, and on-state resistance upon total dose were discussed. We also observed the relationships between these parameters and annealing time. The experiment results show that: the threshold voltage negatively shifts with the increasing of total dose and continues to decrease at the beginning of 100 °C annealing; the breakdown voltage under the drain bias voltage has passed through the pre-irradiation threshold voltage during annealing behaving with a “rebound" effect; there is a latent interface-trap buildup (LITB) phenomenon in the VDMOS devices; the leakage current is suppressed; and on-state resistance is almost kept constant during irradiation and annealing. Our experiment results are meaningful and important for further improvements in the design and processing.