Contact Resistance Optimization in MoS_2 Field-Effect Transistors Through Reverse Sputtering-Induced Structural Modifications

Two-dimensional material (2DM)-based field-effect transistors (FETs), such as molybdenum disulfide (MoS2)-FETs, have gained significant attention for their potential for ultrashort channels, thereby extending Moore's law. However, MoS2-FETs are prone to the formation of Schottky barriers at the metal-MoS2 interface, resulting in high contact resistance (Rc) and, consequently, reduced transistor currents in the ON-state. Our study explores the modification of MoS2 to induce the formation of conductive 1T-MoS2 at the metal-MoS2 interface via reverse sputtering. MoS2-FETs exposed to optimized reverse sputtering conditions in the contact area show Rc values reduced to less than 50% of their untreated counterparts. This reduction translates into improvements in other electrical characteristics, such as higher ON-state currents. Since reverse sputtering is a standard semiconductor process that enhances the electrical performance of MoS2-FETs, it has great potential for broader application scenarios in 2DM-based microelectronic devices and circuits.