The increase of the scattering at high electric fields in multilayer ReS2 FETs: Output characteristics and 1/f noise

Abstract

Field-effect transistors (FETs) employing two-dimensional (2D) materials have attracted significant attention as a potential alternative to silicon FETs. Among these materials, multilayer rhenium disulfide (ReS₂) has emerged as a focal point of interest owing to its distinctive direct bandgap properties. While there is extensive research on the electrical characteristics and doping, studies on the changes in electrical properties during scale-down for practical applications are insufficient. In this study, we investigated the mobility reduction of ReS₂ FETs at high drain bias of ReS₂ FETs by comparing the different channel lengths of 0.24 μm and 1.5 μm. A reduction in mobility was observed for the shorter channel length, attributed to the enhanced scattering factor at high electric field. To assess the impact of scattering degradation, we conducted a low-frequency noise analysis at drain-source voltage (V_DS) = 0.4 V and V_DS = 3.0 V for the 0.24 μm length FET. The decrease of the Hooge parameter (α_H) at high V_DS was observed, which was attributed to an augmentation in Coulomb scattering. This study observed mobility degradation under high electrical fields during scale-down and identified the cause of mobility degradation through low-frequency noise analysis. This contributes to scaling down for practical applications of 2D FETs.