Self-aligned, direct-write graphene channel FETs

A simple yet versatile, lithography-free process has been demonstrated to make direct-write, self-aligned graphene Field Effect Transistors (FETs). The critical step to define the source, drain and the top-gate electrodes is achieved by the near-field electrospinning process and the electrospun polymer fiber is utilized as the gate dielectric material. Fabricated FETs show a carrier mobility at 5056 cm²/Vs which corresponds to a typical graphene carrier density of n =10¹² cm^-2. Three distinctive advancements have been achieved as compared with the state-of-art technologies: (1) top-gate graphene FETs utilizing a lithography-free process; (2) polymer fiber as the top-gate oxide material; and (3) dual functions/operations as top-gate or back-gate FETs. As such, the proposed self-aligned, direct-write graphene fabrication process could open up a new class of manufacturing path for graphene-based microelectronics.