Direct microwave annealing of SiC substrate for rapid synthesis of quality epitaxial graphene

Abstract

While the remarkable efficiency of microwave heating is widely exploited in many branches of chemistry, it has been barely considered in relation to the synthesis of epitaxial graphene. In this study, an advanced technique is presented for the rapid synthesis of quality few-layer epitaxial graphene on 4H-SiC(0001). A piece of SiC cut from a single crystal wafer is directly annealed by microwaves at high temperatures in a vacuum using a customized multimode domestic microwave oven. Various temperature/irradiation time combinations are investigated, with extensive surface coverage by the graphene obtained after microwave annealing at 1700 °C for just 1 min. The ramp-up time to the required temperature is extraordinarily fast, occurring within seconds. The annealing is not only selective and volumetric, but also, because the substrate itself acts as a heater, removes the need for heat transport to the sample. This, in turn, reduces the thermal burden placed on the reactor and minimizes contamination levels. Thus, this study presents a novel route for the preparation of quality graphene that has multiple advantages and guarantees the saving of energy through greater heating efficiency.