Large-Scale-Compatible Stabilization of a 2D Semiconductor Platform toward Discrete Components

Abstract

Atomically thin 2D materials have drawn considerable attention in the past years with potential ranging from transistors to optoelectronics. As such, they are now foreseen as strong candidates for epitaxy-free technologies and the tetrad of size-weight-power-and-cost (SWAP-C) reduction. Targeting radiofrequency (RF) applications, the 2D semiconducting transition metal dichalcogenides (TMDC) family can offer the opportunity of wide tunability of their electronic properties, providing a large variety of band gaps. However, evaluation and integration of those materials into discrete components requires a stabilization of their properties. This work focuses on the evaluation of a large-scale compatible fabrication/passivation process on large area (>1000 µm2) monolayers of the prototypical 2D semiconductor MoS2. The process is developed including pre- and post-patterning protection/passivation layers. It is shown to reduce the initial natural p-doping of the sample, leading to lower transistor threshold voltages, a 106 ION/IOFF ratio, and an effective averaged field-effect mobility under ambient conditions of 20 cm2 V−1 s−1 (up to 35 cm2 V−1 s−1 for some devices), which represents an increase by a 40-fold factor compared to a conventional process carried on the large scale platform. This work represents an important step toward the integration of 2D TMDCs in discrete RF circuits and components.