Study of statistical variability in nanoscale transistors introduced by LER, RDF and MGG

A 3D drift-diffusion device simulator with implemented density-gradient quantum corrections is developed to run hundreds of simulations to gather variability characteristics in non-planar transistors. We have included the line edge roughness (LER), random dopants (RD), and metal gate granularity (MGG) induced variabilities, which are considered to be the most important sources of variability in device characteristics. The simulator is then applied to study a threshold voltage variability in a $25$~nm gate length Si SOI FinFET due to LER and MGG. We found that the LER induced threshold variability has a mean value of $344.5\ \mathsf{mV}$ and $\sigma$ of $4.7\ \mathsf{mV}$ while the MGG induced has a mean value of $349.9\ \mathsf{mV}$ and $\sigma$ of $13.3\ \mathsf{mV}$, an order of magnitude greater than the LER variability.