Low temperature solid-source molecular-beam epitaxy growth of Al-free quantum well laser diodes using a GaP-decomposition source

Abstract

Low threshold aluminum-free, InGaP/GaAs/InGaAs quantum well laser diodes have been grown at low temperature on GaAs using a GaP sublimation source for phosphorous and an atomic hydrogen cracker source for substrate surface preparation. The growth cycle was conducted entirely below 470°C so that it is compatible with growth on GaAs very large scale integrated circuits, as in the epitaxy-on-electronics monolithic optoelectronic integration processes. The room temperature pulsed threshold current density of broad-area stripe contact laser diodes was consistently on the order of 0.38 kA/cm2. InGaP grown with the GaP cell is found by secondary ion mass spectroscopy to contain significant amounts of oxygen, particularly in Be- and Si-doped layers.