Electron diffraction study of the transformation 6√3 reconstruction on 4H–SiC(0001) into quasi-free-standing epitaxial graphene

A structural study of the transformation of 6√3 reconstruction on the surface of a 4H–SiC substrate into quasi-free epitaxial graphene was carried out by the reflection high-energy electron diffraction (RHEED) method. The conversion was carried out via hydrogen intercalation between the reconstructed layer and the adjacent top layer of SiC. The initial 6√3 reconstruction was obtained during short sublimation annealing of the 4H–SiC substrate in an argon medium. A slight violation of the 6√3 reconstruction layer formation uniformity was found. The results of the study of the crystal structure of quasi-free-standing graphene and single-layer graphene comprising a buffer layer formed on 4H–SiC in the traditional way in an Ar atmosphere without intercalation were compared.