Reduction of Random Dopant Fluctuation-induced Variation in Junctionless FinFETs via Negative Capacitance Effect

In this study, we investigated the impact of random dopant fluctuation (RDF) on junctionless (JL) fin field-effect transistors (FinFETs) with ferroelectric (FE) negative capacitance (NC) effect. The RDF-induced variations were captured by using built-in Sano methodology in three-dimensional technology computer-aided design (TCAD) simulation. Compared to the regular JL-FinFETs, the variations in JL-FinFETs with NC effect (NCJL-FinFETs) was observed to be less via statistical Monte Carlo analysis, which further enhanced its performance as well. The evaluation and estimation of threshold voltage (V-T), ON-state current (I-on), OFF-state current (I-off), and subthreshold swing (SS) by different FE layer thicknesses indicated reduction in the standard deviations of VT (dV T) and Ion (delta I-on) by 34.7% and 7.08%, respectively; the OFF-state current and its standard deviation shrank by approximately three orders of magnitude than the JL-FinFET counterpart. Although delta SS was not monotonous, the SS was significantly improved to sub-60 mV/decade. To sum up, the regular JL-FinFETs containing the FE layer as NC effect not only improved the electrical performance, but also led to the resilience of the RDF-induced statistical variability.