Impact of LER and Random Dopant Fluctuations on FinFET matching performance

FinFETs may start to replace planar MOSFETs for specific applications at the 32nm node and beyond due to their intrinsically better scalability. Mainstream applications of such a technology require a reliable and reproducible process. However, stochastic process fluctuations represent a major concern for matching performance of nanoscale devices. In particular, Line-Edge Roughness (LER) in printed device features and Random Dopant fluctuations (RD) are reported as becoming a serious concern. In this work, impact of both LER and RD on matching performance of FinFET structures conforming to LSTP-32nm specifications is investigated through statistically performed 2D and 3D device simulations. Contributions to LER from the fin, top- and sidewall-gates are decoupled and compared. Simulations have been performed on both n- and p-channel FinFETs, taking their extension doping profile specifications into account. Impact of fin-, extension- and S/D-doping concentrations on RD-induced variations is also evaluated. This analysis allows estimating relative importance of individual contributions in determining the impact of stochastic fluctuations on FinFET performance.