Iron segregation in LEC InP crystals

Following the recent results about activation of iron diffused in InP we tried to increase the fraction of electrically active Fe atoms in InP crystals grown by the liquid encapsulated Czochralski method (LEC) by applying a type of "in-situ" annealing. Actually, by varying the pulling rate and the cooling rate, we observed that the Fe active/Fetotal ratio can be modified. Though the ratio normally ranges between 0.60 and 0.70, it is found that the ratio is slighty higher corresponding to low pulling rates and considerably lower for pulling rates>14 mm/h. The purpose of this paper is to show how these growth parameters affect the Feactive/Fetotal ratio.