CMOS-Compatible Au Doping Boosts Hole Carrier Transport in CVD-Grown 2-inch Monolayer WSe2 Films for p-Type Transistors

Abstract

Although the wafer-scale growth of n-type MoS2 and its NMOS devices already show great potential application in future electronics with ultra-short channel, the development of p-type two-dimensional semiconductor is still in early stage. The CMOS-compatible fabrication and stable p-type transistor is a significantly challenge, which hinder the development of CMOS-based integrated circuits with ultra-low-power. In this study, we realized the 2-inch wafer-scale growth of monolayer WSe2 film and propose a strategy to achieve uniform doping effect by depositing 0.5 nm Au on the surface of WSe2 via electron beam evaporation followed by annealing. The results show that after annealing at 400°C, the deposited thin Au layer aggregated to form Au nanoparticles, which uniformly distributed on the surface of WSe2 films with good interface proofed by atomic-resolution cross section analysis. Moreover, investigation of the top-gate transistor arrays verified that the WSe2-Au sample annealed at 400°C exhibited excellent doping stability and uniformity, with mobility increased by 46 times, the ON/OFF ratio improved by two orders of magnitude, and a significant reduction in subthreshold swing from 2.35 V dec -1 to 0.77 V dec -1 . This uniform doping method brings great prospects for the development of wafer-scale 2D materials in the field of integrated circuits.