Parameter set and data sampling strategy for accurate yet efficient statistical MOSFET compact model extraction

摘要

This paper presents an effective statistical compact modelling strategy that can precisely capture a statistical set of MOSFET characteristics into industrial strength statistical compact models. 3D simulation of large statistical sample of microscopically different devices is required for statistical compact model extraction when studying the impact of variability in next CMOS technology generations on circuit and system design. For a particular nominal device design the statistical 3D physical simulations needs two orders of magnitude more CPU time compared to conventional TCAD simulations. A data sampling strategy is presented to reduce the number of bias points in simulated device characteristics used as extraction targets for statistical compact model parameter extraction. We show that for a well balanced set of statistical compact model parameters carefully chosen small number of strategic bias points in the simulated I-V characteristics of each microscopically different transistor is sufficient to capture accurately the statistical device behaviour. The corresponding increase in the RMS error is below 1% compared to results from comprehensive bias point set. The impact of the slight reduction of the compact model accuracy on the accuracy of statistical circuit simulation has also been investigated.