Correlation between the residual stress in 3C-SiC/Si epifilm and the quality of epitaxial graphene formed thereon

The quality of epitaxial graphene on silicon (GOS) is negatively correlated with the residual stress of the 3C-SiC films grown on the Si substrates. This has been systematically demonstrated by use of a series of 3C-SiC films formed on Si(110) substrates with varied residual stress. The residual stress of the 3C-SiC film and the grain size of graphene were estimated with Raman-scattering spectroscopy while the crystallinity of the 3C-SiC film was evaluated by x-ray diffraction. The more it reduces the residual stress the better the GOS quality it becomes. In particular, use of the rotated epitaxial film of 3C-SiC formed on Si(110) substrate, which gives the lowest residual stress, is found to produce a graphene with one of the best quality ever obtained in GOS. The revealed GOS quality improvement opens new opportunities for the production of high-performance GOS-based devices.