In situboron-doped polycrystallineSi1−xGex(x>0.4)films have been formed on the thermally grown oxides in a rapid thermal chemical vapor deposition processor usingSiH4-GeH4-B2H6-H2gas system. Our results showed thatin situboron-dopedSi1−xGexfilms can be directly deposited on the oxide surface, in contrast to the rapid thermal deposition of undoped silicon-germanium(Si1−xGex)films on oxides which is a partially selective process and requires a thin silicon film pre-deposition to form a continuous film. For thein situboron-dopedSi1−xGexfilms, we observed that with the increase of the germane percentage in the gas source, the Ge content and the deposition rate of the film are increased, while its resistivity is decreased down to 0.66 m&OHgr; cm for a Ge content of 73&percent;. Capacitance-voltage characteristics ofp-type metal-oxide-semiconductor capacitors withp+-Si1−xGexgates showed negligible polydepletion effect for a 75 Å gate oxide, indicating that a high doping level of boron at the poly-Si1−xGex/oxideinterface was achieved. ©1997 American Institute of Physics.