Epitaxial graphene transistors: Enhancing performance via hydrogen intercalation

We directly demonstrate the importance of buffer elimination at the graphene/SiC(0001) interface for high frequency applications. Upon successful buffer elimination, carrier mobility increases from an average of 800 cm ²/(V s) to >2000 cm²/(V s). Additionally, graphene transistor current saturation increases from 750 to >1300 mA/mm, and transconductance improves from 175 mS/mm to >400 mS. Finally, we report a 10× improvement in the extrinsic current gain response of graphene transistors with optimal extrinsic current-gain cutoff frequencies of 24 GHz.