A well-controlled technique for high-temperature epitaxial growth on 6H-SiC(0001) substrates is shown to allow development of monolayer graphene that exhibits promise for precise metrological applications. Face-to-face (FTF) and face-to-graphite (FTG) annealing in a furnace at 1200 °C to 2000 °C with one atmosphere Ar background gas lowers the rates of SiC decomposition and Si sublimation/diffusion and thus provides a means of control over the rate of graphene layer development. We employ a wide range of growth temperatures and times, and describe the resulting sample surface morphology changes and graphene layer structures. Our resulting samples are analyzed using several techniques to determine the layer thickness and quality and the results are compared to a kinetic model based on two diffusion processes: Si vapor diffusion in the Ar-filled gap and atomic diffusion through graphitic surface layers.
Citation: IEEE Transactions on Instrumentation and Measurement
Pub Type: Journals
Epitaxial growth, graphene, surface morphology, diffusivity, quantum Hall effec, quantized Hall resistance standard