Enhanced indium phosphide substrate protection for liquid phase epitaxy growth of indium-gallium-arsenide-phosphide double heterostructure lasers

Thermal degradation of indium phosphide (InP) single crystal substrates prior to liquid phase epitaxy growth has been virtually eliminated by using an improved protection technique. The phosphorus partial pressure provided by a Sn-In-P solution localized inside an external chamber surrounding the InP substrate prior to growth prevents thermal damage to the surface. Nomarski contrast photomicrographs, as well as photoluminescence and x-ray diffractometric measurements indicate that InP substrates protected by this method suffer a negligible deterioration, in contrast to the results of the more commonly used cover-wafer method.