While transition metal dichalcogenides, graphene and related two-dimensional materials have been much researched, not so much has been done toward manufacturing active devices over large areas using these materials. The situation is changing with the posting of a preprint jointly authored by researchers from Berkeley and Cornell in December of last year. After transferring graphene to an SiO2 substrate, gaps (to become the transistor channels) were opened photolithographically. Next, MoS2 was grown into the channels by a CVD process. Finally, top gates were patterned over the channels and contacting electrodes over the graphene to complete the field-effect transistors.
The authors convincingly demonstrate that the MoS2 grows only in the channels and not atop the graphene, postulating that MoS2 growth occurs inward from the graphene edges. If nothing else, this self-aligned growth eliminates a host of error sources affecting channel length. It also results in a manufacturing flow which procedurally differs from standard silicon-based device production only in the initial transfer of the graphene onto the substrate.
Reference: M Zhao, et al., “Chemical assembly of atomically thin transistors and circuits in a large scale”, arXiv:1512.05016.