Improved Contacts to Synthetic Monolayer MoS2 – A Statistical Study

Two-dimensional (2D) semiconductors are promising candidates for scaled transistors because they are immune to mobility degradation at the monolayer limit. However, sub-10 nm scaling of 2D semiconductors, such as MoS
2
, is limited by the contact resistance. In this work, we show for the first time a statistical study of Au contacts to chemical vapor deposited monolayer MoS
2
using transmission line model (TLM) structures, before and after dielectric encapsulation. We report contact resistance values as low as 330 ohm-um, which is the lowest value reported to date. We further study the effect of Al
2
O
3
encapsulation on variability in contact resistance and other device metrics. Finally, we note some deviations in the TLM model for short-channel devices in the back-gated configuration and discuss possible modifications to improve the model accuracy.