A Viscous Flow Model to Explain the Appearance of High Density Thermal Si02 at Low Oxidation Temperatures

Higher density Sio2 results from the thermal oxidation of Si in dry o2 at lower oxidation temperatures. More than 3% higher density is observed for Sio2 grown at 600°C as compared with 1150°C. A consistent model for the formation of this material is deduced based on the following: the temperature dependence of the density, the annealing behavior of the higher density Sio2, and on the literature and new measurements of the intrinsic stress in Sio2 films. The model considers viscous flow of a Maxwell solid and hinges on the attainment of the necessary free volume for oxidation at lower oxidation temperatures. © 1982, The Electrochemical Society, Inc. All rights reserved.