Role of extended defected SiC interface layer on the growth of epitaxial graphene on SiC

This study identifies a previously unnoticed defected SiC layer induced by heat treatment prior to growth of graphene on SiC. This layer strongly affects the thickness, surface morphology, and Raman G and 2D band peak positions of the graphene grown on it during further decomposition of the SiC. [Display omitted] ► SiC-like interface layer is induced by thermal treatment at relative lower temperature. ► It strongly affects the properties of graphene such as surface morphology and phonon interaction, and the decomposition rate of SiC. ► More defected layer induce compressive strain, which results in wrinkle formation, and unintentional doping confirmed by the shift of D and 2D band. An extended layer of defected SiC has been observed in SiC subjected to heat treatments at 850 and 1050 °C prior to growth of graphene by thermal decomposition. This layer is found to strongly affect the graphene thickness, surface morphology, and Raman spectrum of graphene grown on it. By comparing the strength of the XPS signal associated with this layer it was found that the samples with stronger defected layer signal had the least number of surface pits but also showed the increase in Raman D to G band ratio. The shifts in 2D and G peaks are associated with varying amounts of strain and unintentional doping induced by the SiC defected interface layer, respectively.