Dislocation Generation due to Stress Induced by Oxidation in Si Grooves

Stress induced by thermally grown SiO2 in grooves formed on a Si surfaceis experimentally and theoretically discussed. It is shown that dislocations are generated from the fine groove when the Si crystal is annealed at 1000°C in an O2 gas. However, dislocations are hardly generated when the Si crystal is annealed at 1100°C. Growing SiO2 film on the bottom of a groove exerts compressive stress, because Si volume expands about 2.3 times when it changes into SiO2 and because the grown SiO2 cannot horizontally expand. The stress is calculated by using Maxwell viscoelastic theory to explain the experimental results.