The state of the art of 3C-SiC deposited on various silicon pn insulator substrates is reviewed and the result of structural (x-ray and transmission electron microscope) properties as well as micro-Raman, infrared, and electrical examinations is compared with 3C-SiC/Si. It is shown that in order to fully optimize this novel material system one has to call at the same time for a better thermal stability of the current oxides and for an optimized elastic compliance of the buried layer system silicon/silicon dioxide. A proper way seems to lower the standard SiC deposition temperature.