Controversial issues in negative bias temperature instability

In spite of 50 years of history, there is still no consensus on the basic physics of Negative Bias Temperature Instability. Two competing models, Reaction-Diffusion and Defect-Centric, currently vie for dominance. The differences appear fundamental: one model holds that NBTI is a diffusion-limited process and the other holds that it is reaction-limited. Basic issues of disagreement are summarized and the main controversial aspects of each model are reviewed and contrasted

Modeling of NBTI Kinetics in RMG Si and SiGe FinFETs, Part-I: DC Stress and Recovery

An ultrafast (10-mu s delay) measurement technique is used to characterize the negative bias temperature instability-induced threshold voltage shift (Delta V-T) in replacementmetal gate-based high-Kmetal gate Si andSiGe p-FinFETs. The dc stress-recovery Delta V-T time kinetics, voltage acceleration factor (VAF), and temperature activation energy (E-A) are compared for different germanium percentages (Ge%) in the channel and nitrogen percentages (N%) in the gate-stack. A comprehensive physicalmodel framework based on uncorrelated contributions from the generation of interface (Delta V-IT) and bulk oxide (Delta V-OT) traps and hole trapping in preexisting defects (Delta V-HT) is used to explain the measured data. The impact of Ge% and N% on Delta V-T, VAF, E-A, temperature (T) dependenceof VAF, and stress bias (V-GSTR) dependence of EA are quantified. The interface trap generation component is independently verified by directcurrent I-V (DCIV) measurements

Ultrafast Measurements and Physical Modeling of NBTI Stress and Recovery in RMG FinFETs Under Diverse DC-AC Experimental Conditions

Threshold voltage shift (Delta V-T) due to negative-bias temperature instability (NBTI) in p-FinFETs with replacement metal gate-based high-k metal gate process is measured using an ultrafast method. A comprehensive modeling framework involving uncorrelated contributions from the generation of interface traps (Delta V-IT), hole trapping in preexisting (Delta V-HT), and generation of new (Delta V-OT) bulk insulator traps is used to quantify measured data. The model can explain dc stress and recovery data over an extended temperature range (-40 degrees C to 150 degrees C), for different stress and recovery biases. It can explain ac stress and recovery data for different bias, temperature, frequency, and duty cycle. The differences in time kinetics and temperature activation of Delta V-IT, Delta V-HT, and Delta V-OT, and their relative dominance at various experimental conditions are shown. End-of-life NBTI for dc and ac stress is estimated by using the model and compared to prediction from conventional analytical methods