MODULATED BEAM EPITAXIAL-GROWTH OF HIGH-QUALITY GAAS SINGLE QUANTUM-WELLS AT LOW-TEMPERATURE

High quality AlGaAs/GaAs quantum wells and low-threshold current density lasers (< 1 kA/cm2) have been successfully grown at low temperatures (500-degrees-C) by a modulated beam epitaxy process in which the group III flux is held constant while the As flux is periodically shut off to produce a metal-rich surface. The improved quality of these low-temperature-grown quantum structures is attributed to both a smoothing of the growth front and a reduction of excess As during the modulated beam epitaxy process. The high growth rates and less frequent shutter operation of this technique make it more practical than migration-enhanced epitaxy or atomic layer epitaxy for low-temperature growth.