Photoluminescence observation of swirl defects and gettering effects in silicon at room temperature

Abstract

Swirl defects are nondestructively observed in silicon using a photoluminescence profile taken at room temperature. A precise geometrical correspondence between the photoluminescence profile and swirl pattern is obtained. High photoluminescence intensity spots correspond to low defect density regions and vice versa. The usefulness of this method for evaluating silicon crystals is also confirmed by observing the gettering effects in oxidized epitaxial wafers where the back surface is ground.