Stress Analysis in Silicon Substrates during Thermal Oxidation

The stress development mechanism during local thermal oxidation of a silicon substrate is discussed based on the predicted results using a two-dimensional thermal oxidation process simulation program OXSIM2D developed by the authors. Predicted stress change during the oxidation agrees well with the measured data obtained by means of micro-Raman spectroscopy. There are three main factors which play important roles in stress delelopment 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 as 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.