Photoluminescence and high-resolution X-ray diffraction were used to monitor the diffusion of a lattice matched InGaAs/InP heterostructure at various annealing temperatures. At 900C, no strain was observed by high-resolution X-ray diffraction and this indicated that the two sub-lattices in the sample diffused at an equal rate and only compositions on the tie line between the two initial compositions were formed. At lower annealing temperatures strain was observed in the wells and barriers, the signs of which changed during the annealing process. This was indicative of the diffusion rates of the two sub-lattices changing during the annealing process. It was suggested that these effects may be due to the presence of the miscibility gap in the InGaAsP system.

Photoluminescence and X-ray Diffraction Studies of the Diffusion Behavior of Lattice Matched InGaAs/InP Heterostructures. F.Bollet, W.P.Gillin: Journal of Applied Physics, 2003, 94[2], 988-92