The dynamic process of the reactions during deposition of M(Hf or Zr)O-2 thin films on SiO2-covered silicon substrate in oxygen deficient conditions has been investigated. A series of reactions across the interface were identified with thermodynamic arguments and with X-ray Photoelectron Spectroscopy (XPS) and transmission electron microscopy (TEM) analyses. The oxygen deficient MOx<2 absorbs the oxygen in the SiO2 layer to form fully oxidized metal oxide. The SiO2 can be an oxygen source for the growth of metal oxide in the initial several monolayers. An epitaxial YSZ on silicon without amorphous low-kappa interfacial layer has been obtained in the experiments. The finding here implies that an oxide/semiconductor interface with excellent physical properties and chemical stability can be built up by applying this dynamic mechanism. (C) 2004 Elsevier B.V. All rights reserved.