PHOTOINDUCED CURRENT TRANSIENT SPECTROSCOPY OF AL0.48IN0.52AS SEMIINSULATING LAYERS GROWN ON INP BY MOLECULAR-BEAM EPITAXY

Deep levels in undoped semi-insulating In0.52Al0.48As layers grown by molecular beam epitaxy on iron-doped InP have been studied by photolum inescence and photo-induced current transient spectroscopy. The effect of the growth temperature T-g in the range from 300 degrees C to 530 degrees C has been investigated. The results show that low T-g causes the material quality to deteriorate and leads to formation of a higher concentration of deep traps. It is shown that optimized material qual ity can be obtained for InAlAs layers on InP substrates with T-g aroun d 530 degrees C with sufficiently high resistivity, reduced trap densi ty and good structural properties which is appropriate for fabrication of high electron mobility transistors.