Observation of Ring-Distributed Microdefects in Czochralski-Grown Silicon Wafers with a Scanning Photon Microscope and Its Diagnostic Application to Device Processing

A scanning photon microscope (SPM) based on ac surface photovoltage imaging is applied to observe oxygen-related microdefects which are distributed in a ring in oxidized Czochralski-grown silicon wafers, and morphological and microstructural characteristics of the microdefects are then analyzed. The overall distribution of the ring-shaped region revealed by the SPM correspond well to that observed with X-ray topography. The SPM is able to differentiate deteriorated regions as different image contrasts, where stacking faults or oxide precipitates accompanying punched-out dislocation loops exist.