Stress effects in the oxidation of planar SiO2 thin films

We summarize here the results of recent experimental and analytical investigations into stress effects in planar SiO2 thin films. Experimentally, we examine the effects of a constant superposed in-plane stress upon the growth of thin oxide Films in the 100 Angstrom range. In contradiction to a widely accepted model of stress effects upon SiO2 film growth, we find that both compressive and tensile in-plane stresses tend to retard oxide growth by a roughly equal amount. Analytically, we investigate the effects of the small component of strain induced parallel to the oxidation interface by the large volume expansion inherent in the oxidation of silicon. Depending upon the circumstances, this strain component, dubbed the "intrinsic strain", can have a non-negligible effect upon the growth of planar oxide layers.