  (See the complete abstract within the thesis in both English and German
versions)
  In this thesis, the process conditions of the epitaxial graphene growth
through a socalled polymer-assisted sublimation growth method are minutely
investigated. Atomic force microscopy (AFM) is used to show that the previously
neglected flow-rate of the argon process gas has a significant influence on the
morphology of the SiC substrate and atop carbon layers. The results can be well
explained using a simple model for the thermodynamic conditions at the layer
adjacent to the surface. The resulting control option of step-bunching on the
sub-nanometer scales is used to produce the ultra-flat, monolayer graphene
layers without the bilayer inclusions that exhibit the vanishing of the
resistance anisotropy. The comparison of four-point and scanning tunneling
potentiometry measurements shows that the remaining small anisotropy represents
the ultimate limit, which is given solely by the remaining resistances at the
SiC terrace steps. ... The precise control of step-bunching using the Ar flow
also enables the preparation of periodic non-identical SiC surfaces under the
graphene layer. Based on the work function measurements by Kelvin-Probe force
microscopy and X-ray photoemission electron microscopy, it is shown for the
first time that there is a doping variation in graphene, induced by a proximity
effect of the different near-surface SiC stacks. The comparison of the AFM and
low-energy electron microscopy measurements have enabled the exact assignment
of the SiC stacks, and the examinations have led to an improved understanding
of the surface restructuring in the framework of a step-flow mode. ...
