Modifying the Ni-MoS2 Contact Interface Using a Broad-Beam Ion Source

Charge transport at the contacts is a dominant factor in determining the performance of devices using 2D MoS2. Using a low-energy beam of Ar ions, the interface between Ni and MoS2 was modified to improve the performance in 2D field-effect transistors (FETs). This broad-beam ion source is integrated into an ultrahigh vacuum, physical vapor deposition system that allowed for in situ modification of the MoS2 immediately prior to Ni contact deposition. The contact resistance decreased leading to a corresponding and highly reproducible boost in the on-current by up to four times. Spectroscopic analysis of the ion beam-modified MoS2 suggests that there are generated defects, which supply dangling bonds that improve carrier injection between the Ni metal contact and MoS2. This approach for modifying the Ni-MoS2 interface opens a promising new path for reducing the impact of contacts on MoS2 FET performance.

Duke Scholars

Author Aaron D. Franklin Electrical and Computer Engineering