Impact of vacancies and self-interstitials on the formation of substitutional transition metal defects in float-zone silicon crystals

Abstract

It is shown that investigations on substitutional TM-defects grown-in by the FZ-technique can be used as a suitable detection method for vacancies and self-interstitials in silicon. For the interpretation of the experimental results, approximate analytical solutions are presented for the temperature field in the growing crystal, for the transport equations describing the diffusion and recombination of intrinsic point defects and for the capture process connected with the formation of substitutional TM-defects. The analysis is demonstrated on dislocation-free FZ-crystals doped with Pt and Rh, respectively. The capture of the interstitial TM-defects by the vacancies takes place in different temperature ranges depending on the metal type. First results about the capture coefficients for Si- and TM-interstitials are derived.