Thin Si1-yCy films with a range of carbon contents have been prepared by both solid-phase epitaxy (SPE) and rapid thermal chemical vapour deposition (RTCVD) techniques. For SPE growth, layers with carbon levels of up to 1.6 at. % exhibit strong substitutional incorporation. For RTCVD growth, substitutional carbon incorporation is difficult to achieve at a growth temperature of 800 degrees C, but has been achieved in layers estimated to contain 2 at.% carbon at a growth temperature of 700 degrees C. These results indicate that strain-compensated growth of Si1-x-yGexCy with a wide range of composition should be possible in the present RTCVD system at temperatures of approximately 700 degrees C.