Thin heteroepitaxial films of Si1-x-yGexCy have been investigated for potential use in low-power electronic applications, Films were grown on (100)Si substrates using atmospheric pressure chemical vapor deposition at 625 and 700 degrees C. The crystallinity, composition and microstructure of the SiGeC films were characterized using Rutherford backscattering spectrometry and secondary ion mass spectrometry. The crystallinity of the films was very sensitive to the flow rate of C2H4 that served as the C source. Si1-x-yGexCy films with up to 2.0 at.% C and 20 at.% Ge were epitaxial with good crystallinity. Current-voltage measurements were obtained from the electrical characterization of Si1-x-yGexCy/Si heterojunction diodes. Stable layers and low diode turn-on voltage make the Si1-x-yGexCy/Si structure an appropriate candidate for future low-power research.