An Investigation to Determine the Interface Condition Between Graphene and SiC Substrate

The purpose of this study was to analyze the interface condition between graphene and a Si-faced SiC substrate. We evaluated the interface condition by measuring the interface using time-of-flight secondary ion mass spectroscopy. The detected intensities dependence on depth changed depending on the type of carbon molecular ion, indicating that this evaluation method was highly sensitive to interface conditions. We observed differences in the detection intensity of C6H molecular ions between normal graphene and graphene treated with hydrogen intercalation (H2-IC). Furthermore, we discovered an increase in hydrogen atoms not only at the interface but also between graphene layers when subjected to H2-IC treatment. The application of H2-IC to a graphene transistor resulted in an improved cutoff frequency from 8.2 to 10.3 GHz µm.