APPLICATION OF COPPER-DECORATION METHOD TO CHARACTERIZE AS-GROWN CZOCHRALSKI-SILICON

Czochralski-silicon wafers having ring-likely distributed stacking faults (ring-SFs) were investigated by means of copper decoration. The size and density of copper precipitates were measured by X-ray transmission topography and preferential etching. In the outer region of the ring-SFs, electrical properties (recombination lifetime of minority carriers, the dielectric breakdown strength) were found to be excellent. On the other hand, in the inner region of the ring-SFs electrical properties were degraded. These phenomena may be explained by the large defects which remain in the center region of the ingot.