Monte Carlo Simulation of Electrical Transport with Joule Heating and Strain in Monolayer MoS₂ Devices.

Abstract

Two-dimensional (2D) semiconductors are candidates for future nanoscale (e.g., nanosheet) transistors, wherein high current densities and high-density integration cause self-heating, limiting performance and reliability. Here, we study the effects of self-heating and strain on electrical transport in monolayer MoS₂ using electro-thermal Monte Carlo simulations. Incorporating Joule self-heating with a generalizable thermal resistance model reveals that at high lateral field (∼5 V/μm) and high charge carrier density (∼10¹³ cm^-2), transistor temperatures can increase by more than 200 K in steady state. The electron saturation velocity decreases to 2.1 × 10⁶ cm/s with self-heating but can reach 5.3 × 10⁶ cm/s at room temperature if self-heating is mitigated and tensile strain is applied to reduce intervalley scattering. Simulations also reveal that electron mean free paths are just 2-3 nm in this high-field regime. These results provide fundamental insights showing that both self-heating and strain must be considered in emerging 2D transistors.