Epitaxial Graphene Growth on the Step-Structured Surface of Off-Axis C-Face 3C-SiC(1 over bar 1 over bar 1 over bar )

Graphene layers grown on the C-face SiC exhibit quite different structural and electronic properties compared with those grown on the Si-face SiC. Herein, the growth and structural properties of graphene on the off-axis C-face 3C-SiC(1 over bar 1 over bar 1 over bar ) are studied. The as-grown 4 degrees off-axis 3C-SiC(1 over bar 1 over bar 1 over bar ) exhibits highly periodic steps with step height of approximate to 0.75 nm and terrace width of approximate to 50 nm. After annealing at 1800 degrees C under 850 mbar argon atmosphere, relatively uniform large graphene domains can be grown. The low-energy electron microscopy (LEEM) results demonstrate that one monolayer (ML) to four-ML graphene domains are grown over several micrometers square, which enables us to measure micro low-energy electron diffraction (mu-LEED) on the single graphene domain. The mu-LEED pattern collected on the monolayer domain mainly exhibits four sets of graphene (1 x 1) spots, indicating the presence of graphene grains with different azimuthal orientations in the same graphene sheet. Raman spectra collected on the graphene domains show rather small D peaks, indicating the presence of less defects and higher crystalline quality of the graphene layers grown on the C-face off-axis 3C-SiC(1 over bar 1 over bar 1 over bar )