The results of a preliminary study on the growth of epitaxial Si, hetero-epitaxial Ge and Si/SixGe1-x multilayer structures on (100) Si substrates using r.f. plasma-assisted chemical vapour deposition are described, Silane and germane were used as the precursor gases. The lowest temperature for homo-epitaxial Si growth was 600 degrees C and epitaxy was critically dependent on an in-situ hydrogen plasma clean of the substrate. Ge and SiGe growth was carried out following the growth of an initial Si epitaxial layer, also at the lowest temperature of 600 degrees C. Successful Ge epitaxy required a continuously graded SixGe1-x "buffer layer" (with x decreasing from 1 to 0), on top of the initial Si epilayer. Si/SixGe1-x superlattice structures having in excess of 100 alternating layers of Si and SixGe1-x with x approximate to 0.6 and good layer uniformity, periodicity and abruptness have been demonstrated.