Precise in situ thickness analysis of epitaxial graphene layers on SiC(0001) using low-energy electron diffraction and angle resolved ultraviolet photoelectron spectroscopy

We demonstrate an easy and practical method for the thickness analysis of epitaxial graphene on SiC(0001) that can be applied continuously during the preparation procedure. Fingerprints in the spot intensity spectra in low energy electron diffraction (LEED) allow for the exact determination of the number of layers for the first three graphene layers. The LEED data have been correlated with the electronic bandstructure around the (K) over bar -point of the graphene Brillouin zone as investigated by laboratory based angle resolved ultraviolet photoelectron spectroscopy using He II excitation. The morphology and homogeneity of the graphene layers can be analyzed by low energy electron microscopy. (C) 2008 American Institute of Physics.