High carrier mobility in suspended-channel graphene field effect transistors

摘要

A channel suspension method to fabricate high performance graphene field effect transistors (GFET) is presented in this paper. The balance is reached between gate efficiency and carrier mobility. A GFET with 15 μm × 15 μm gate dimension achieves a high normalized transconductance. Peak intrinsic carrier mobility is extracted to be 44 600 cm~2v~(-1)s~(-1). Suspension of the graphene channel is confirmed by AFM, SEM, and gate capacitance measurements. Unlike traditional substrate supported GFET, the proposed suspended-channel structure suppresses the influence of extrinsic scatterings and, meanwhile, maintains a certain gate controllability.