Growth of GaAs/AlGaAs quantum well structures using a large-scale MOCVD reactor

GaAs/AlGaAs quantum well structures were grown on 2 inch GaAs(100) substrates by a large-scale metalorganic chemical vapor deposition (MOCVD) reactor. The cross-sectional TEM images clearly showed quantum well structures which contained 20, 40, 70, 100, and 200 Å thick GaAs wells. High resolution lattice images showed that the grading region at the heterointerface was no more than one half of a lattice constant. The photoluminescence (PL) peak energies for various well widths at room temperature agreed well with the calculated values based on the rectangular potential model. On the other hand, at 4.2 K the peak energy was lower than the theoretical value by 20 meV. The distribution of well widths was less than one half of a lattice constant for the whole wafers.