Impact of LER and Random Dopant Fluctuations on FinFET Matching Performance

Abstract

Parameter variations pose an increasingly challenging threat to the CMOS technology scaling. Among the sources of variability, line-edge-roughness (LER) and random dopant (RD) fluctuations are significant in current technology nodes. In this paper, the impact of the LER and RD on the matching performance of FinFETs is investigated for the LSTP-32 nm node, where these devices represent an attractive alternative to the planar CMOS transistors. Line-edge-roughness contributions from the fin, top-, and side wall-gates of n- and p-channel FinFETs are compared by means of 2-D and 3-D technology computer-aided design (TCAD) simulations, performed with a quantum-corrected hydrodynamic model on large statistical ensembles. Correlations between geometrical roughness and resulting electrical parameters are analyzed to provide further insight into the impact of the LER. A noise analysis approach is adopted to evaluate the impact of RD fluctuations throughout the impurity concentration ranges of interest, providing a direct comparison with the line-edge-roughness contributions. The impact of the extension doping profile specifications on the LER- and RD-induced mismatch is investigated, highlighting the potential drawbacks of junction engineering.