Reproducible Performance Improvements to Monolayer MoS2 Transistors through Exposed Material Forming Gas Annealing
Nicholas B. Guros, Son T. Le, Siyuan Zhang, Brent A. Sperling, Jeffery B. Klauda, Curt A. Richter, Arvind K. Balijepalli
We have developed an optimized process to realize high-performance field-effect transistor (FET) arrays from large-area 2D MoS2 films with an average yield of 85 %. A central element of the technique is a new exposed film forming gas anneal (EF- FGA) that results in a narrow distribution of electrical performance metrics (i.e., flatband voltage, gate leakage current, and Ohmic contact performance) for devices fabricated on atomically thin semi-conducting films with an area of ~5000 um2, obtained using metal-mediated exfoliation. The devices were found to be free of both organic and metal contamination following the EF-FGA process. Complimentary analytical measurements show that the EF-FGA process drastically decreases organic contamination that is characteristic of metal-mediated exfoliation, thereby reducing deleterious channel doping effects. The large film area, uniform performance characteristics, and high device yield will allow the fabrication of complex device architectures with 2D materials and advance the realization of new classes of quantum metamaterials that are being investigated by combining heterogeneous films.