METALORGANIC CHEMICAL-VAPOR-DEPOSITION GROWTH OF HIGH-QUALITY ALGAAS USING DIMETHYLETHYLAMINE ALANE AND TRIETHYLGALLIUM-DIMETHYLETHYLAMINE ADDUCT

High-purity Al0.25Ga0.75As layer has been successfully obtained by met alorganic chemical vapor deposition (MOCVD) using new precursors of di methylethylamine alane (DMEAA) and triethylgallium-dimethylethylamine adduct (TEG-DMEA). It is shown that the concentrations of residual car bon and oxygen in the AlGaAs layer grown at a relatively low V/III rat io were under detection limits of secondary-ion mass spectrometry (3.0 x 10(15) and 5.0 x 10(15) cm(-3), respectively). In the photoluminesc ence spectra at 4.2 K, the peak intensity of carbon-related emission w as much weaker than that of bound-exciton (BE) emission. The full-widt h at half-maximum for the BE peak was as narrow as 5.6 meV. Any predep osition between these precursors due to a gas-phase prereaction was no t observed. These results indicate that the combination of DMEAA and T EG-DMEA are promising precursors for MOCVD growth of AlGaAs with low r esidual impurity concentration. (C) 1998 Elsevier Science B.V. All rig hts reserved.