The dependence of the deep-level transient spectra of n-type crystals, with low dislocation densities, upon the duration of deformation was studied. It was found that, in float-zone material, very short dislocations (with a half-loop size of less than 40) did not exhibit any electrical activity. The total concentration of dislocation-related acceptor centers in such samples, as deduced from C-V measurements, was estimated to be at least 2 orders of magnitude lower than that usually observed for long dislocations. The electrical activity of the dislocations increased during their motion. The transformation of the dislocation energy spectrum into a conventional one was found to occur faster in Czochralski material. That is, the rate of this transformation depended essentially upon the impurity content. The characteristic length for this process agreed well with that which was observed for the initial stress formation.

O.Kononchuk, V.Orlov, O.Feklisova, E.Yakimov, N.Yarykin: Materials Science Forum, 1995, 196-201, 1183-8