Thin films of beta silicon carbide were prepared on alpha silicon carbide substrates by the chemical vapor deposition (CVD) technique involving the hydrogen reduction of silane and propane. The films were prepared under a variety of conditions and subsequently subjected to thermal annealing cycles between 1600 degrees C and 2000 degrees C. It is shown that the single crystallinity of the beta films improved with continued annealing. The beta polytype was found to be stable over the entire range of temperatures studied.