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

It is shown that investigations on substitutional TM-defects grown-in by th e 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 d iffusion and recombination of intrinsic point defects and for the capture p rocess connected with the formation of substitutional TM-defects. The analy sis is demonstrated on dislocation-free FZ-crystals doped with Pt and Rh, r espectively. The capture of the interstitial TM-defects by the vacancies ta kes place in different temperature ranges depending on the metal type. Firs t results about the capture coefficients for Si- and TM-interstitials are d erived. (C) 1999 Elsevier Science B.V. All rights reserved.