Investigations on InP:Ti grown by metalorganic vapor phase epitaxy

Abstract
Ti doped InP layers were grown by atmospheric pressure metalorganic vapor phase epitaxy. Using the commercially available tetrakis(diethylamino)‐titanium, we obtained total Ti doping levels up to 1020 cm−3. Photocurrent measurements and deep level transient spectroscopy enabled us to investigate the internal 3d‐transitions of Ti3+ (2E2T2: 546.5 and 550 meV) and the Ti3+/Ti4+ transition (0.62 eV) confirming substitutional incorporation of Ti in InP. The concentration of electrically active Ti is limited to a value of 2.5×1017 cm−3, as determined by InP:Ti:Zn co‐doping experiments. Secondary ion mass spectroscopy demonstrated, that oxygen incorporation is one reason for incomplete electrical activity, especially in the lower Ti doping region.