The Combined Impact of Total Ionizing Dose Effect and Negative Bias Temperature Stress on Deep Sub-Micron pMOSFETs

Abstract

In this paper, we investigate the combined effects of total ionizing dose (TID) and negative bias temperature instability (NBTI) on deep sub-micron pMOSFETs. It is found that the high temperature of the NBT stress induces an annealing effect by removing part of the radiation-induced positive charges. If we choose a relatively low temperature to avoid the annealing effect, a remarkable radiation acceleration effect on device degradation is observed and the lifetime of pMOSFETs significantly reduces due to more radiation-induced new hole traps in the oxide. However, the acceleration effect seems independent of the oxide electric field during NBT stress. The work in this paper indicates that it is important to choose proper NBT stress conditions if we use NBTI to predict the lifetime of the pMOSFETs which operate in the radiation environments.