Time-dependent statistical NBTI model for aging assessment in circuit level implemented with open model interface

Abstract

As technology nodes continue to shrink, the impact of aging problems on devices has become increasingly important. One significant aging problem that affects device characteristics and circuit performance is Negative Bias Temperature Instability (NBTI). Under small-size conditions, fluctuations in device parameters such as threshold voltage due to aging are not negligible. To capture these fluctuations, an improved statistical model has been proposed. The time-dependent statistical model accounts for the average change in the number of charged defects due to NBTI and enables the evaluation of degradation fluctuations over time. The model prediction of the threshold voltage degradation of devices in advanced technology is verified with different measured data. Furthermore, the model is implemented with the Open Model Interface (OMI) for the circuit-level degradation simulation, taking advantage of OMI's convenience and compatibility with different circuit simulators. The integration of the proposed model into the OMI benefits in predicting the degradations difference among the transistors in the circuits, reducing the overestimation of aging degradation compared to the methods that assume every transistor experiences the same and worst degradation.