Compensation defects in annealed undoped liquid encapsulated Czochralski InP

As-grown undoped n-type semiconducting and annealed undoped semi-insulating (SI) liquid encapsulated Czochralski (LEC) InP has been studied by tempera ture dependent Hall measurement, photoluminescence spectroscopy, infrared a bsorption, and photocurrent spectroscopy. P-type conduction SI InP can freq uently be obtained by annealing undoped LEC InP. This is caused by a high c oncentration of thermally induced native acceptor defects. In some cases, i t can be shown that the thermally induced n-type SI property of undoped LEC InP is caused by a midgap donor compensating for the net shallow acceptors . The midgap donor is proposed to be a phosphorus antisite related defect. Traps in annealed SI InP have been detected by photocurrent spectroscopy an d have been compared with reported results. The mechanisms of defect format ion are discussed. (C) 1999 American Institute of Physics. [S0021-8979(99)0 3014-5].