Title: Tailoring the SiC surface - a morphology study on the epitaxial growth of graphene and its buffer layer,
Abstract: We investigate the growth of the graphene buffer layer and the involved step
bunching behavior of the silicon carbide substrate surface using atomic force
microscopy. The formation of local buffer layer domains are identified to be
the origin of undesirably high step edges in excellent agreement with the
predictions of a general model of step dynamics. The applied polymer-assisted
sublimation growth method demonstrates that the key principle to suppress this
behavior is the uniform nucleation of the buffer layer. In this way, the
silicon carbide surface is stabilized such that ultra-flat surfaces can be
conserved during graphene growth on a large variety of silicon carbide
substrate surfaces. The analysis of the experimental results describes
different growth modes which extend the current understanding of epitaxial
graphene growth by emphasizing the importance of buffer layer nucleation and
critical mass transport processes.