STRESS-ANALYSIS IN SILICON SUBSTRATES DURING THERMAL-OXIDATION

The stress development mechanism during local thermal oxidation of a s ilicon substrate is discussed based on the predicted results using a t wo-dimensional thermal oxidation process simulation program OXSIM2D de veloped by the authors. Predicted stress change during the oxidation a grees well with the measured data obtained by means of micro-Raman spe ctroscopy. There are three main factors which play important roles in stress delelopment in the newly grown oxide film and the substrate. Th ey are the volume expansion of the oxide film, the viscosity of the ox ide film, and the bending of the silicon nitride film which is used as the oxidation barrier. These factors give rise to the complicated str ess distribution and the stress change near the edge of the nitride fi lm during thermal oxidation.