Instability of In-Ga-As-P Liquid Solution during Low Temperature LPE of In1-xGaxAs1-yPy on InP

Liquid phase epitaxial (LPE) growth of In1-x Ga x As1-y P y crystals lattice matched to InP was studied systematically with a controlled amount of supersaturation for whole range of composition at relatively low temperature (590°C). A region of extremely slow growth rate was found for the quaternary crystal with 1.35 µm band-gap and surfaces of quaternary layers became rough around 1.44 µm. The growth rate of the crystals around 1.35 µm was found to be relatively slow even when the growth temperature is 640°C. Comparison of these phenomena with those observed in AlGaAsSb system suggests the existence of immiscible region in this system below 600°C.