The In xGa 1− xAs yP 1− y (0.53< x

Abstract

A systematic study in the growth of In x Ga 1- x As y P 1- y (0.53< x<1,0< y<1) compound semiconductor and its application to laser diode structure had been carried out by the low-pressure organometallic vapor phase epitaxy (LP-OMVPE) technique. The indium, gallium, arsenic and phosphorus incorporation efficiencies were studied. At the optimized growth conditions, the In incorporation efficiency has been found to be about 0.7 as compared with that of Ga in both In 0.53Ga 0.47As and InGaAsP epilayers. However, the P incorporation efficiency was found to be much lower than that of the As. Furthermore, we found that the As composition in In x Ga 1- x As y P 1- y quaternary epilayers (Q layers) is determined by the arsine (AsH 3) flow-rate and not by the AsH 3/PH 3 flow-rate ratio in the gas phase. The hydride flow-rates have been explained by the proposed As/P competition model and then formulated. According to this model, the AsH 3 flow-rate was found to be proportional to y 2.24259(1- y) -0.4889, while the PH 3 flow-rate was controlled by a varying incorporation efficiency, C p that is varying as [ y(1- y] -0.27138. For the dummy laser structures, the photoluminescence (PL) measurements show higher emission intensity of a GRIN/strained QW/GRIN heterostructure than that of a non-strained GRIN/QW/GRIN structure. Moreover, we demostrate a sawtooth MQW structure having strong PL intensity, but widened peak shpae toward the high energy side that can be used as an active layer of a tunable wavelength LD structure.