Hybrid methodology to model random dopant fluctuations in low doped FinFETs

A hybrid approach to model the effect of random dopant fluctuations in low doped FinFETs is proposed. Existing Monte Carlo and atomistic approaches are found to be inadequate to capture device variability correctly when applied independently. Instead a hybrid methodology which uses an atomistic approach in low doped regions and Monte Carlo everywhere else is developed. The hybrid approach is shown to capture the threshold voltage variability adequately. Comparison with analytical results for planar MOSFETs shows an excellent agreement and establishes the validity of the approach. The results suggest that accurate modeling of low doped regions is essential to be able to estimate variability correctly.