Effects of Device Scaling on the Performance of Junctionless FinFETs Due to Gate-Metal Work Function Variability and Random Dopant Fluctuations

This letter reports an investigation of the impact of device scaling on the performance of a junctionless FinFET due to gate-metal work function variability (WFV) and random dopant fluctuations (RDFs). Such investigation is made by using a 3-D numerical device simulator. Impacts of both WFV and RDF are found to increase with technology scaling when channel doping is also increased to meet the targeted V
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for the scaled technology nodes. Our investigations, however, suggest that the impact of RDF can be reduced significantly for scaled technology nodes if such target is met by keeping the channel doping unaltered and adjusting the gate-metal work function. This results in improved RDF-induced variability and deteriorated WFV-induced variability that in turn increases the relative impact of WFV for scaled technology nodes.