We investigated the growth of a simple oxide, Hf02, and a complex oxide, SrTi03, on Si(100) and SiO2/Si(l00) substrates. For the case of SrTi03, the growth kinetics of the amorphous SiOX interlayer was investigated in detail by high-resolution transmission electron microscopy. The interlayer thickness showed a fast initial increase, which is much faster than the corresponding growth of amorphous Si02 in the absence of the precursors, and seemingly approached saturation after a short time. The thickness of the interfacial layer increases with the oxygen partial pressure during deposition and a reduction to a value acceptable for gate-oxide applications has been achieved for the minimum pressure given by the oxygen content of the present precursors. However, this comes at the expense of a dramatic increase of the carbon content of the film. For the case of Hf02 we additionally discuss the influence of different precursors containing oxygen (Hafnium butoxide-mmp and -dmae) or not (Hafnium diethyl amide). With the amide precursor the highest low temperature, 300-500°C, deposition rate was achieved. The electrical properties of the MOS capacitors were determined for films of different thickness. The results are discussed in terms of the film microstructure, amorphous vs. crystalline, and of the post-annealing in different atmospheres.