An Accurate Lifetime Analysis Methodology Incorporating Governing NBTI Mechanisms in High-k/SiO2 Gate Stacks

Abstract

Extraction of the intrinsic NBTI degradation rate in the high-k pMOSFETs was found to require correction of the measured threshold voltage shift (DeltaVTH) for the fast transient charging contribution caused by the charge trapping in pre-existing defects in high-k films. The proposed analysis methodology leads to a significantly lower estimated lifetime than that obtained by the generally used approach. It was determined that the interface state generation process contains a fast component most likely associated with the defects in the SiO2 interfacial layer induced by the overlaying high-k film. An intrinsic interface state generation rate obtained by subtracting the fast trapping component is found to be similar to that of the conventional SiO2 dielectric