Effect of SiC wafer miscut angle on the morphology and Hall mobility of epitaxially grown graphene

We show that the surface morphology and electrical properties of graphene grown on SiC(0001) wafers depend strongly on miscut angle, even for nominally “on-axis” wafers. Graphene grown on pit-free surfaces with narrow terraces (miscut above 0.28°) shows substantially lower Hall mobility than graphene on surfaces with miscut angles below 0.1° that have wider terraces with some pits. The effect of pits on mobility is not detrimental if flat, pit-free areas with dimensions larger than the carrier mean free path remain between pits. Using these results, we optimized the growth process, achieving room-temperature mobility up to 3015 cm2/V s at N=2.0×1012 cm−2.