A STUDY OF IRON INCORPORATION IN LEG-GROWN INDIUM-PHOSPHIDE

We have studied iron segregation in Czochralski-grown InP as a functio n of the pulling and cooling rates, We observed that the Fe-active/Fe- total ratio can be modified by varying these growth parameters. The ac tivation ratio, which is normally between 0.60 and 0.70 for pulling ra tes of 8-10 mm/h, is found to be slightly higher corresponding to low pulling rates (2-3 mm/h) and considerably lower for pulling rates > 14 mm/h. Furthermore, we observed that the electrical properties and waf er uniformity are improved in crystals pulled at the lowest rates. The experimental results are discussed considering that low pulling and c ooling rates correspond to an in situ annealing of the InP crystal. Th e principal aim of this work is that of increasing the fraction of ele ctrically active Fe atoms in InP crystals grown by the liquid encapsul ation Czochralski method.