Direct transformation of a resist pattern into a graphene field effect transistor through interfacial graphitization of liquid gallium

The authors found that an extremely thin resist pattern on a silicon dioxide can be directly transformed into a graphene channel through interfacial graphitization of liquid gallium. These patterned graphene field effect transistors show p-type field effect conductance characteristics and a maximum conductance modulation of 100% against an applied gate voltage range from -50 to +50 V at room temperature, which is almost identical to the on/off ratio of 2. These conductance modulation ratios improved with decreasing the initial resist thickness below 2 nm; however, the absolute value of the channel conductance also deteriorated with decreasing the resist thickness, suggesting that electron scattering at the domain boundary dominates the channel conductance. (c) 2010 American Vacuum Society. [DOI: 10.1116/1.3511511]