High-Performance MoS2 Field-Effect Transistors Enabled by Chloride Doping: Record Low Contact Resistance (0.5 kohm*um) and Record High Drain Current (460 uA/um)

TL;DR

This paper introduces a chloride doping method using DCE to significantly reduce contact resistance in MoS2 FETs, achieving record low resistance and high drain current, advancing high-performance TMD electronic devices.

Contribution

The study presents a novel chemical doping technique with DCE that drastically lowers contact resistance and enhances MoS2 FET performance beyond previous records.

Findings

Record low contact resistance of 0.5 kohm*um achieved.

Drain current of 460 uA/um at 1.6 V Vds demonstrated.

Doping density > 2*10^19 cm^-3 in MoS2.

Abstract

In this paper, we report a novel chemical doping technique to reduce the contact resistance (Rc) of transition metal dichalcogenides (TMDs) - eliminating two major roadblocks (namely, doping and high Rc) towards demonstration of high-performance TMDs field-effect transistors (FETs). By using 1,2 dichloroethane (DCE) as the doping reagent, we demonstrate an active n-type doping density > 2*1019 cm-3 in a few-layer MoS2 film. This enabled us to reduce the Rc value to a record low number of 0.5 kohm*um, which is ~10x lower than the control sample without doping. The corresponding specific contact resistivity (pc) is found to decrease by two orders of magnitude. With such low Rc, we demonstrate 100 nm channel length (Lch) MoS2 FET with a drain current (Ids) of 460 uA/um at Vds = 1.6 V, which is twice the best value reported so far on MoS2 FETs.