Stacking Graphene Channels in Parallel for Enhanced Performance With the Same Footprint

Using the unique ability of graphene to be transferred to virtually any surface, field-effect transistors are demonstrated with vertically stacked graphene channels that are electrically connected in parallel. The graphene in each layer is double gated, with all gates in the stack connected to a common gate electrode. We show that the performance of these devices scales linearly with the number of stacked graphene channels at rates of approximately 500 $\mu\hbox {A}/\mu\hbox {m}$ and 200 $\mu\hbox {S}/\mu\hbox {m}$ per layer for the on-current and peak transconductance, respectively. This demonstration reveals the ability to employ graphene in a novel fashion for tuning and amplifying the performance of a transistor without changing the device footprint.