Stress Analysis in Silicon Substrates during Thermal Oxidation

The stress development mechanism during local thermal oxidation of silicon substrates is discussed based on the predicted results using a two-dimensional thermal oxidation simulation program, OXSIM 2 D, which the authors developed. Predicted stress changes during the oxidation agree well with the measured data obtained by means of microscopic Raman spectroscopy. There are three main factors which have important roles in stress development in the newly grown oxide film and the substrate. They are the volume expansion of the oxide film, the viscosity of the oxide film, and the bending of the silicon nitride film which is used for the oxidation barrier. These factors give rise to the complicated stress distribution and the stress change near the edge of the nitride film during thermal oxidation.