Scalability of FinFETs and Unstrained-Si/Strained-Si FDSOI-MOSFETs

Abstract

Full—band Monte Carlo simulations are performed for n—type FinFETs as well as for unstrained—Si and strained—Si fully—depleted (FD) SOI-MOSFETs. Gate lengths of 50 nm down to 10 nm are considered, and a fixed off—current of 100 nA/μzm is in each case ensured by adjusting the silicon film thickness. The FinFET shows the best scaling trend, but the strained-Si FDSOI-MOSFET always involves the largest absolute value for the on—current. However, the on—current decreases upon scaling to 10 nm which might stem from a larger influence of surface roughness scattering in thin Si films affecting most strongly quasi—ballistic transport in strained Si. The feature of a decreasing current is found to be absent in drift—diffusion simulation because this approach does not include quasi—ballistic transport.