Molybdenum oxide/silicon oxide and tungsten oxide/silicon oxide: multilayer with 24 periods and a period thickness of 9.2 nm were fabricated with plasma-enhanced MOCVD. The layer thickness was controlled by an in situ soft X-ray reflectivity measurement. For the deposition of the SiO2 layers, a new silicon organic precursor, pentamethylcyclopentadienyldisilane (Me5C5Si2H5) was used in an O-2 remote: plasma process. The high quality of multilayer interfaces was observed by cross-section transmission electron microscopy (TEM), the interface toughness was measured by hard X-ray reflectivity and diffuse scattering at grazing incidence experiments to be about 0.1 nm. Auger electron spectroscopy (AES) gives the information, that the silicon oxide is practically carbon free, and the carbon content of the metal oxides is low (<5%).