Incorporation and electrical activity of Fe in LEC InP

InP crystals grown by the liquid encapsulated Czochralski method under different parameters are investigated by Hall effect, IR absorption, atomic absorption spectroscopy and glow discharge mass spectroscopy. The concentrations of total and electrically active Fe atoms (substitutional for In) in ingots pulled under different growth conditions are independently determined. The results prove that the pulling rate can affect the effective Fe distribution coefficient. Quite surprisingly, we found that the electrical activity of the incorporated iron (expressed as ratio Fe-active/Fe-total) changes dramatically between the top and tail of the LEC crystals.