Fall 2010 IAB
September 15 to 17
Epitaxial Graphene Layers on alpha-SiC
Epitaxial graphene grown on silicon carbide surfaces retains many of the exciting electronic and mechanical properties of the 2D graphene, while showing promise in terms of scalability and applications in large-scale device fabrication. Here we present a detailed investigation of the early stages of epitaxial graphene layer growth on the Si-terminated 6H-SiC surface by depolarized Raman spectroscopy and electron channeling contrast imaging. We find that whereas film thickness is determined by growth temperature, increasing growth times at constant temperature affects both internal stress and film morphology. Annealing times in excess of 8-10 min lead to an increase in the mean square roughness of SiC step edges to which graphene films are pinned, and compressively stressed films at room temperature. Shorter annealing times produce minimal changes in the morphology of the terrace edges and result in nearly stress-free films upon cooling to room temperature.