Graphene, a single atom thick carbon layer, is grown on top of silicon carbide (SiC). When the topmost silicon atoms are sublimated by annealing the SiC substrate, the remaining carbon forms the graphene layer. In order to retrieve the extraordinary electronic properties of the graphene, it must be chemically decoupled from the substrate. This is achieved by inserting hydrogen between graphene and SiC, so-called intercalation, which passivates the substrate. Intercalation of other materials, such as germanium allows to functionalize the graphene, so that a taylor-made doping is possible.