Lateral Electric Field Engineering in Scaled Transistors Based on 2D Materials via Phase Transition

Effective control of electric field intensity/distribution in field-effect transistors restrains channel self-heating and drives reliable operation over the entire lifetime. However, in two-dimensional material (2DM)-based transistors, it is a great challenge to manipulate the lateral electric field via the dedicated drain/source structure design due to the lack of a CMOS-compatible doping strategy. Here, we developed a widely tunable and high-spatial-resolution doping technology for 2DMs, contributing to effective lateral electric field modulation in 2DM-based transistors. We employed Ar plasma treatment on intrinsic PtSe₂, inducing a phase transition and resulting in controllable doping from the intrinsic semiconductor to metallic layers in a 100 nm length resolution. We designed the Ohmic-contact drain/source structure in PtSe₂ transistors and showed a high current density of 245.5 μA/μm at V_d = 1 V and a low contact resistance of 264 ohm-micrometer. Furthermore, by realizing the graded doping in the drain/source region, the Joule heat generation rate in PtSe₂ transistors was greatly reduced, leading to the weak degradation of the on-state current and a lifetime 33 times longer than that of Ohmic-contact transistors. The lateral electric field modulation also displayed high suppression of the short-channel effect.