Raman analysis of epitaxial graphene on 6H-SiC (0001̄) substrates under low pressure environment

This article investigates the formation mechanism of epitaxial graphene on 6H-SiC (000) substrates under low pressure of 2 mbar environment. It is shown that the growth temperature dramatically affects the formation and quality of epitaxial graphene. The higher growing temperature is of great benefit to the quality of epitaxial graphene and also can reduce the impact of the substrate for graphene. By analyzing Raman data, we conclude that epitaxial graphene grown at 1600 °C has a turbostratic graphite structure. The test from scanning electron microscopy (SEM) indicates that the epitaxial graphene has a size of 10 μm. This research will provide a feasible route for fabricating larger size of epitaxial graphene on SiC substrate.