-However, mismatches in the thermal expansion coefficient and the lattice parameter cause a considerably high concentration of various defects, which is responsible for structural and electrical qualities that are not not yet statisfactory.
+However, mismatches in the thermal expansion coefficient and the lattice parameter cause a considerably high concentration of various defects, which is responsible for structural and electrical qualities that are not yet statisfactory.
+
+The alternative attempt to grow SiC on SiC substrates has shown to drastically reduce the concentration of defects in deposited layers.
+By CVD, both, the 3C \cite{kong88,powell90,powell91} as well as the 6H \cite{kong88_2,powell90_2} polytype could be successfully grown.
+In order to obtain the homoepitactically grown 6H polytype, off-axis 6H-SiC wafers are required as a substrate \cite{kimoto93}.
+%In the so called step-controlled epitaxy, lateral growth proceeds from atomic steps without the necessity of preceding nucleation events.
+Investigations indicate that in so-called step-controlled epitaxy, crystal growth proceeds through the adsorbtion of Si species at atomic steps and their carbonization by hydrocarbon molecules.
+A model is suggested ...
+
+... diffusion of reactants in a stagnant layer.