Growth of Wafer Size Graphene on SiC Substrates

Abstract

Graphene, as strict two-dimensional material, exhibits exceptionally good electronic properties. In this paper, graphene was prepared on SiC substrates at different temperature based on two types of pre-treated surface. The surface morphology was characterized by atomic force microscopy (AFM) and scanning electronic microscopy (SEM). The results on SiC surface pre-treatment showed that chemical mechanical polishing (CMP) was an effective surface treatment method for reproducible and controlled growth of graphene. Images of the Si-surface revealed that the thickness of graphitic layers increased with annealing temperature. Meanwhile, a mesh-like network of wrinkles tended to tent-like features with the increase of temperature. The residual stresses, average crystallite size and number of graphene layers were analyzed by Raman spectroscopy. Little shift of 2D-band indicated the presence of certain stresses. Results among four samples showed that graphene layers grown on MP C-surface substrates had the thickest layers，contained the smallest average crystallite size La and exhibited no stresses. While graphene layers grown on Si-surface under 1600°C built upon compressive stresses, exhibited largest La and least number of graphene layers, indicating perfect quality.