Growth kinetics of epitaxial graphene on SiC substrates

Optical absorption and Raman scattering studies of epitaxial graphene structures obtained by annealing of carbon terminated face of $4H\text{-SiC}(000\text{\ensuremath{-}}1)$ on-axis substrates using standard chemical-vapor deposition reactor are presented. Two series of samples grown at different argon pressures in the reactor and different annealing times were studied. Optical absorption and Raman scattering were used to determine the number of graphene layers formed on the substrate surface. The observed dependence of the number of graphene layers formed on annealing time and argon pressure strongly indicates that the growth kinetics of graphene is limited by Si evaporation and two-dimensional Si diffusion.