Transition Metal Dichalcogenide-Based Field-Effect Transistors for Analog/Mixed-Signal Applications

Transition metal dichalcogenides (TMDs), such as MoS2, MoSe2, MoTe2, WS2, WSe2, etc., have been considered as the most promising candidates for energy-efficient information processing at ultrascaled devices due to their decent energy gap of around 1-2 eV and single-atomic 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 field-effect 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.