Toward Graphene Field-Effect Transistor Array with Uniform Sensing Characteristics via a Clean Graphene Transfer Process.

The synthesis of uniform, low-defect graphene on copper foil is approaching an industrial scale. However, its practical application remains challenging due to the lack of an appropriate method for its clean transfer to a device substrate. In this study, we demonstrate the use of a lift-off resist (LOR) photoresist as a transfer-supporting layer, resulting in a truly clean transfer of graphene. The surface cleanliness of graphene was assessed through optical microscopy, atomic force microscopy, and Raman spectroscopy. The uniform sensing characteristics of the cleanly transferred graphene were further evidenced by the first-ever implementation of high-throughput graphene field-effect transistors, distinct from those covered with a thin layer of amorphous carbon, such as residual poly(methyl methacrylate). This transfer method provides a novel alternative route for graphene transfer.