  We investigate the microscopic processes leading to graphene growth by the
chemical vapor deposition of propane in the argon atmosphere at the SiC
surface. Experimentally, it is known that the presence of argon fastens the
dehydrogenation processes at the surface, in high temperature of about 2000K.
We perform ab-initio calculations, at zero temperature, to check whether
chemical reactions can explain this phenomenon. Density functional theory and
supporting quantum chemistry methods qualitatively describe formation of the
graphene wafers. We find that the 4H-SiC(0001) surface exibits large catalytic
effect in the adsorption process of hydrocarbon molecules, this is also
supported by preliminary molecular dynamics results. Existence of the ArH+
molecule, and an observation from the Raman spectra that the negative charge
transfers into the SiC surface, would suggest that presence of argon atoms
leads to a deprotonization on the surface, which is necessary to obtain pure
carbon add-layer. But the zero-temperature description shows that the cold
environment is insufficient to promote the argon-assisted surface cleaning.
