Gradual variation of the content y of Group-V components by Δ y of up to 0.08 across the thickness (600–850 nm) of an epitaxial layer has been observed for Ga_1 – x In_ x As_ y P_1 – y solid solutions ( x = 0.86, y = 0.07–0.42) produced on InP by metal-organic vapor-phase epitaxy under lowered pressure, although the composition of the gas mixture, temperature, and pressure were maintained invariable in the course of the growth process. For different gas mixture compositions, the value of Δ y and the manner of its variation were different. An analysis of the data obtained demonstrated that Δ y is due to the deformations that appear in a growing layer because of the lattice mismatch with the substrate.

GaInPAs/InP heterostructures grown by low pressure (0.1 bar, 600 oC) metal-organic chemical vapor phase deposition were investigated. The thicknesses of grown GaInAsP layers were about 1 µm. For the epitaxial layers Ga_1-xIn_xP_1-yAs_y) with average compositions of x = 0.77 – 0.87 and y = 0.07 – 0.42 the variation of V group elements content y with the epilayer depth were revealed, weher the compositions of V-group elements were changed up to Δy = 0.1 atomic fractions in V group elements sublattice. In most cases, y change occurs in a GaInAsP region up to 200 nm thick adjacent to the InP. In some cases, y changes throughout the whole GaInPAs layer thickness. Fo the epitaxial layers with a satisfactory crystal perfection the less was the mismatch between the substrate and the GaInPAs epitaxial layer, the smaller was the value of Δy. For GaInPAs layers characterized by a low degree of crystal perfection and a high lattice mismatch between GaInAsP and InP layers, the value of Δy was about zero. These data let us suggest that the incorporation of atoms of the V group in the epitaxial layer strongly depends on elastic deformation of the growing monolayer, that is mismatched with the underlying crystal surface.