Four point probe measurements of the Surface electrical resistance at an oxide film-metal interface and at an oxide-film semiconductor interface have shown with A sensitivity that the direction of the buried interface motion during oxide film growth is opposite in the two cases in accordance with the Mott-Cabrera theory. During the formation of amorphous Al2O3 layers on Al(I 11) at 300 K, outward film growth occurs due to Al3+ ion transport from the metal into the growing oxide film. For the fort-nation of amorphous SiO2 layers on Si(100) at 300 K, oxygen transport occurs inwardly into the Si lattice as the oxide film forms. (c) 2005 Elsevier B.V. All rights reserved.