Interplay and Effects of Atomicity, Polarization Fields, and Quantization on Variability in GaN FinFETs: A Multiscale Numerical Analysis

We numerically investigate the role of atomistic inhomogeneity and quantization in low-dimensionality lateral tri-gated AlGaN/GaN FinFET devices. It is shown that atomicity leads to pronounced dependence of the threshold voltage on the barrier layer thickness. This demands the use of non-symmetry preserving models in the calculation of polarization fields and induced interfacial charges in device simulation. The overall simulation framework is primarily based on two modules: i) a fully-atomistic framework to calculate strain and polarization fields, and ii) a full 3-D quantum-corrected Monte Carlo electron transport module to obtain the device's terminal current-voltage characteristics.