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

Abstract

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.

Selective graphene growth from DLC thin film patterned by focused-ion-beam chemical vapor deposition

“…Previous research has suggested that graphitization occurs at the interface between carbon and liquid Ga, 14,15,19 but we found that during Ga evaporation graphene was formed not only on the SiO 2 layer but also above any dimples on the SiO 2 layer, which is inconsistent with previous reports. Previous research has suggested that graphitization occurs at the interface between carbon and liquid Ga, 14,15,19 but we found that during Ga evaporation graphene was formed not only on the SiO 2 layer but also above any dimples on the SiO 2 layer, which is inconsistent with previous reports.…”

“…First, carbon has negligible solubility in liquid Ga. 19 In this paper, we report selective graphene growth from diamondlike carbon (DLC) film. 14 This means that Ga can dissolve at least negligible amounts of carbon, which is promising, because copper, the outstanding catalyst of monolayer graphene fabrication, also has a low solubility of carbon.…”

Low-temperature growth of graphene using interfacial catalysis of molten gallium and diluted methane chemical vapor deposition

“…19,20) We have demonstrated that liquid gallium can catalyze the amorphous carbon at the interfacial region. [21][22][23][24][25][26] Graphene nanoribbons were transformed from amorphous carbon templates of amyloid fibrils by solid-phase graphitization within the gallium vapor ambient. 21) Moreover, a large area of graphene can be formed using methane CVD combined with gallium vapor.…”