Semi-insulating InP materials were prepared via Fe-doping in liquid encapsulated Czochralski growth and high temperature annealing undoped InP, respectively. The semi-insulating materials exhibited different electrical properties and thermal stability. Deep level defects in the material were studied in order to understand the mechanism. It was found that the quality of semi-insulating InP depended upon the concentration of deep level defects with energy levels in the range of 0.1 to 0.4eV within the band-gap. Semi-insulating InP with a negligibly low concentration of the defects exhibited a high mobility and good thermal stability. The Fe-diffused semi-insulating InP, which was obtained by annealing in an iron phosphide ambient contained very low concentrations of the defects. The origin of the defects was studied by comparing the influence of the Fe incorporation method and stoichiometry upon defect formation in the semi-insulating materials.

Approach for Defect Suppression and Preparation of High Quality Semi-Insulating InP. Y.W.Zhao, Z.Y.Dong, C.J.Li: Journal of Crystal Growth, 2005, 275[1-2], e381-5