Platinum-silicon dioxide-silicon carbide, MOSiC, sensors are possible to operate at high temperatures and show a gas sensitivity pattern which is of interest for many applications including exhaust gases from car engines. The introduction of a buffer layer of tantalum silicide between the metal and the silicon dioxide resulted, after an annealing step, in a very good adhesion of the gate contact and fast responding sensors with improved signal stability. Depth profiling using X-ray photoemission and Auger electron spectroscopy showed that the annealing step converts the tantalum silicide to a mixed phase predominantly containing tantalum pentoxide. Tantalum silicide as well as platinum silicide are also present in the metal-oxide interface region.