Electrical Characteristics of ML and BL MoS₂ GAA NS FETs With Source/Drain Metal Contacts

This paper reports source/drain (S/D) contact issues in monolayer and bilayer (BL) MoS2 devices through density-functional-theory (DFT) calculation and device simulation. We begin by analyzing material properties and van der Waals gaps at metal contacts of MoS2 using DFT calculation. These results are then used for device simulation, aligning closely with experimental data. For the first time, the model is extended to 3D gate-all-around (GAA) nanosheet (NS) field-effect transistors (FETs) simulation, enabling contact resistance (RC) estimation. This work addresses key challenges by reducing computational demands compared to non-equilibrium Green function method and accurately calibrating devices with various metal contacts and gate lengths. Simulations with C-type S/D contacts achieve an RC of 89.6 Ω-μ m in 7-channel GAA BL MoS2 NS FETs, offering an interesting study for 2D material-based devices.