EFFECTS OF LOW-TEMPERATURE-GROWN GAAS LAYER ON COMPOSITIONAL DISORDERING OF ALGAAS/GAAS SUPERLATTICES

Effects of thickness and position of the low-temperature-grown GaAs (LT-GaAs) layer on the compositional disordering of AlGaAs/GaAs superlattice have been studied. Samples with a top LT-GaAs layer or a bottom LT-GaAs layer have been studied with various annealing conditions. It was found that the LT-GaAs layer grown on top of the superlattice is more effective in causing disordering than the LT-GaAs layer grown at the bottom. The amount of disordering increases with the thickness of the LT-GaAs layer. A selective disordering process has been developed using a patterned LT-GaAs cap layer. This disordering technique is very simple and can be easily applied to device fabrication.