Electrical breakdown of multilayer MoS2 field-effect transistors with thickness-dependent mobility

Abstract

We report on the experimental investigation and modeling of electrical breakdown in multilayer (a few to tens of nanometers thick) molybdenum disulfide (MoS₂) field-effect transistors (FETs). By measuring MoS₂ devices ranging from 5.7 nm to 77 nm in thicknesses, we achieve a breakdown current of 1.2 mA, mobility of 42 cm² V⁻¹ s⁻¹, and on/off current ratio I_On/I_Off ∼ 10⁷. Through measurements and simulations, we find the dependence of the breakdown current limit on MoS₂ thicknesses, channel lengths and conductivities. We also explore, both experimentally and analytically, the effects of different device parameters upon carrier mobility, which is directly related to the current carrying capacity. The results suggest that, compared to single-layer devices, multilayer MoS₂ FETs could be advantageous for circuit applications requiring higher carrier mobility and power handling capacities.