Spinodal-like decomposition of InGaAsP/InP grown by gas source molecular beam epitaxy

Transmission electron microscopy (TEM), photoluminescence (PL), and X-ray diffraction (XRD) have been used to characterize GSMBE grown In/sub I-x/Ga/sub x/As/sub y/P/sub 1-y//InP layers in terms of a spinodal-like decomposition. Because tensile layers lie deeper within the spinodal isotherm, they were observed to have far more decomposition than lattice-matched or compressively strained layers. Reducing growth temperature, increasing group V overpressure, and the use of (311)B oriented substrates were found to reduce the decomposition in lattice-matched layers indicating the role of surface kinetics in limiting the decomposition. These same efforts are expected to improve the quality of tensile strained layers to facilitate their incorporation in various strained layer structures.