Test structures for evaluating Al2O3 dielectrics for graphene field effect transistors on flexible substrates

We have developed a test structure for evaluating the quality of Al
₂
O
₃
gate dielectrics grown on graphene for graphene field effect transistors on flexible substrates. The test structure consists of a metal/dielectric/ graphene stack on a PET substrate and requires only one lithography step for the patterning of the topside metal electrodes. Results from measurements of leakage current, capacitance and loss tangent are presented.