Critical Modeling Issues in Negative Bias Temperature Instability

Both the physical mechanisms as well as the modeling of negative bias temperature instability (NBTI) have attracted growing attention during the last years. While the reaction-diffusion theory had been the dominant explanation for a relatively long period, a growing number of authors have recently voiced their doubts regarding its validity. We give a brief review of suggested models and highlight their strengths and, more importantly, their weaknesses. We take care not to get lost in the intricacies of the various models by only qualitatively discussing their features. As will be shown, this is more than sufficient to demonstrate considerable shortcomings. Finally, we summarize our latest modeling attempts which try to overcome the observed modeling contradictions and show comparisons to experimental data.