The mechanism of cyclic stress enhanced oxidation in monocrystalline silicon microstructures

Abstract

Researchers have conducted extensive research on the fatigue mechanism of silicon microstructures. But the key step in some mechanisms that localized oxide can thicken at high stress concentration sites after fatigue failure lacks support. Based on the Deal-Grove model of the thermal oxidation of silicon, we have proposed a chemical kinetics principle of cyclic stress enhanced oxidation: Tension can promote the diffusion of oxygen and the reaction of silicon and oxygen. Compression can damage the silica. Oxygen atoms are delivered to interior layers gradually and react with silicon to generate silica under cyclic stress. So the oxide layer grows thicker.