Figure 1.

Confocal laser scanning microscopy (CLSM) images of epitaxial graphene samples fabricated by the LPD technique on different miscut angle 6H wafers and two different rinsing times. (a) and (b) Show the growth results of epitaxial graphene on the low-miscut wafer (−0.03°). (c) and (d) show epitaxial graphene grown on the high (−0.1°) miscut wafer. The dark contrast denotes the buffer layer, gray contrast shows monolayer graphene, and white patches indicate bilayer graphene. The polymer amount on the SiC surface was varied by different isopropanol rinsing times as denoted in the columns. (a) and (c) Show results for the longer rinsing time of 10–12 s. Longer rinsing leads to lower polymer content, leading to higher percentages of buffer and bilayer. On the high-miscut substrate (c), step bunching has taken place which favors the growth of elongated bilayer stripes along the terrace steps. (b) and (d) Show results obtained by optimum rinsing times of 6–8 s. A homogenous graphene monolayer (gray) is observed in both (b) and (d). Buffer layer and bilayer spots as observed in (b) but disappear on the higher-miscut substrate due to an enhanced carbon supply from step edge decomposition.