EGaIn-Based Dynamic Metal Alloying Process for Work Function Modulation and Logic Inverter Application

We report a work function modulation strategy based on a liquid-metal-assisted dynamic metal alloying process of Pt and eutectic gallium indium (EGaIn) for molybdenum disulfide (MoS2) metal-insulator-semiconductor field-effect transistors (MISFETs). The work function modulation was precisely tuned from 5.6 eV (ΦM,Pt) to 4.23 eV (ΦM,Pt-EGaIn), enabling direct threshold voltage (Vth) modulation on a single MoS2 channel. The Pt-gate MISFET shows relative-enhancement-mode operation, whereas the Pt-EGaIn liquid metal alloy gate MISFET shows depletion-mode operation with a Vth shift of −1.98 V. By integrating Pt and Pt-EGaIn gates on a single MoS2 active channel, we successfully demonstrated a depletion-load inverter logic circuit exhibiting clear digital signal inversion with a maximum gain of 16.7. These results highlight the Pt-EGaIn dynamic metal alloying process as a simple and low-temperature strategy for gate work function engineering in two-dimensional electronic devices.