Transition metal dichalcogenide-based field-effect transistors for analog/mixedsignal applications

Abstract

Transition metal dichalcogenides (TMDs), such as MoS2, MoSe2, MoTe2, WS2, WSe2, etc., have been considered as the most promising candidates for energyefficient information processing at ultrascaled devices due to their decent energy gap of around 1–2 eV and singleatomic thickness. Even though there are many efforts to explore their performance for digital applications, their performance considerations for analog/mixed-signal applications are still unexplored. In this regard, we have assessed the analog/RF performance of TMD-based fieldeffect transistors (TMD-FETs) and investigated their benefits over graphene-FET and black phosphorous-FETs. The performance analysis is done by an in-house developed code, which involves the self-consistent solutions of 2-D Poisson’s equation and nonequilibrium Green’s function (NEGF) formalism. The results show that MoS2-FET can offer high intrinsic gain with the intrinsic cutoff frequency and maximum oscillation frequency in terahertz range. However, the significant degradation in high-frequency performance of MoS2-FET is observed in the presence of external resistances and parasitic capacitances. The cutoff frequency has found a few hundreds of gigahertz range in the presence of all parasitic conditions. It has also found that, among TMD-FETs, WSe2-FET could be a promising candidate for analog/RF integrated circuits with a higher drive current, intrinsic gain, cutoff frequency, and maximum oscillation frequency.