Achieving Low Contact Resistance by Engineering a Metal–Graphene Interface Simply with Optical Lithography

High-performance graphene-based transistors crucially depend on the creation of the high-quality graphene–metal contacts. Here we report an approach for achieving ultralow contact resistance simply with optical lithography by engineering a metal–graphene interface. Note that a significant improvement with optical lithography for the contact-treated graphene device leads to a contact resistance as low as 150 Ω·μm. The residue-free sacrificial film impedes the photoresist from further doping graphene, and all of the source and drain contact regions defined by optical lithography remain intact. This approach, being compatible with complementary metal–oxide–semiconductor (CMOS) fabrication processes regardless of the source of graphene, would hold promise for the large-scale production of graphene-based transistors with optical lithography.