Electrical breakdown of multilayer MoS2 field-effect transistors with thickness-dependent mobility†
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 IOn/IOff ∼ 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.