Control of Epitaxial Graphene Thickness on 4H-SiC(0001) and Buffer Layer Removal through Hydrogen Intercalation

Abstract

We report graphene thickness, uniformity and surface morphology dependence on the growth temperature and local variations in the off-cut of Si-face 4H-SiC on-axis substrates. The transformation of the buffer layer through hydrogen intercalation and the subsequent influence on the charge carrier mobility are also studied. A hot-wall CVD reactor was used for in-situ etching, graphene growth in vacuum and the hydrogen intercalation process. The number of graphene layers is found to be dependent on the growth temperature while the surface morphology also depends on the local off-cut in the substrate and results in a non-homogeneous surface. Additionally, the influence of dislocations on surface morphology and graphene thickness uniformity is also presented.