A reassessment of ac hot-carrier degradation in deep-submicrometer LDD N-MOSFET

Abstract

In deep submicrometer N-MOSFET, a "backdrop" of substantial defect generation by the quasi-static V/sub g/=V/sub d/ stress phase is shown to significantly influence the accuracy of interpretation of ac stress data. If neglected, a severe overestimation of ac stress induced degradation would result. Through an approach that eliminates this damage component from the overall ac stress damage, increased parametric shifts, associated with the gate pulse transition phase, are found to occur in different time windows, delineated by the relative importance of hot-hole and hot-electron induced damage at different stages of the stress, the interaction between the two damages at specific stages of the stress, as well as the sensitivities of the device parameters to the spatial evolution of the two damages.