Heterostructures were grown by means of gas-source molecular beam epitaxy, using tertiarybutylphosphine, and their bulk and interface deep levels were studied by using deep level transient spectroscopy, photoluminescence and cathodoluminescence techniques. Five bulk deep levels, which were related to P vacancies and their complexes, were detected by means of deep level transient spectroscopy. They could be almost completely removed by using a tertiarybutylphosphine flow rate that was higher than 4 to 5sccm. This was accompanied by a marked increase in the bulk band-edge photoluminescence intensity. On the other hand, heterostructures which were grown under high tertiarybutylphosphine flow rates exhibited anomalous photoluminescence and cathodoluminescence peaks near to 1.7eV. Cathodoluminescence studies which were performed by changing the acceleration voltage showed that these peaks were hetero-interface-related, and were probably due to P vacancies near to interfaces. Quantum wells without such peaks, and with intense emissions, were successfully prepared by avoiding P vacancy formation via the elimination of growth interruptions.

Bulk and Interface Deep Levels in InGaP/GaAs Heterostructures Grown by Tertiarybutylphosphine-Based Gas Source Molecular Beam Epitaxy. F.Ishikawa, A.Hirama, H.Hasegawa: Japanese Journal of Applied Physics - 1, 2001, 40[4B], 2769-74