Meltback and pullover as causes of disturbances in liquid-phase epitaxial growth of InGaAsP/InP 1.3-μm laser material

Abstract
InGaAsP/InP 1.3-μm laser material grown by liquid-phase epitaxy occasionally exhibits an anomalous x-ray diffraction pattern and may also have a high threshold current density. The origin of this effect is shown to be the contamination of the normal p-type InP cladding layer with Ga and As. A typical composition of this quaternary cladding layer is determined, and secondary-ion mass-spectrometry analyses are used to show the contamination is most likely caused by pullover from the previous melt.