PRECIPITATION OF CU, NI, AND FE ON FRANK-TYPE PARTIAL DISLOCATIONS INCZOCHRALSKI-GROWN SILICON

The segregation behavior of metallic impurities, Cu, Ni, and Fe on Fra nk-type partial dislocations in Czochalski-grown silicon depends not o nly on the species of impurities, but also significantly on the coolin g rate of the specimen after contamination. In slowly cooled specimens , Cu develops precipitate colonies in the region away from Frank parti als and does not decorate them even on an atomic scale, while Ni decor ates Frank partials weakly. A high density of Cu or Ni precipitates is observed on Frank partials when specimens are cooled fast. Fe decorat es Frank partials both in fast and slowly cooled specimens. The amount of precipitated Fe on Frank partials is larger in a slowly cooled spe cimen than in a fast cooled one. The difference in segregation behavio r on Frank partials among Cu, Ni, and Fe is reasonably interpreted in terms of three parameters: precipitate nuclei as influenced by the dis location-core structure, crystal structure of precipitates, and diffus ivity of impurities in Si.