Characterization of haze-forming precipitates in silicon

Abstract

The defects leading to haze formation after diffusion of the transition metals cobalt, nickel, copper, and palladium have been studied by means of transmission electron microscopy and preferential etching. In all cases crystalline metal silicide particles have been observed. Both cobalt and nickel form disilicide particles of different morphologies in the surface regions of silicon wafers, whereas copper and palladium form metal-rich silicide particles causing a supersaturation of Si self-interstitials or undersaturation of vacancies and leading to the formation of extrinsic dislocation loops.