LPE Growth of Misfit Dislocation‐Free Thick In1 − xGaxAs Layers on InP

Abstract

The conditions for equilibrium LPE growth of exactly and nearly lattice‐matched epitaxial layers on (100) substrates were determined at 650°C by lattice constant measurements. It was found that the half‐width of the diffraction peak of the ternary layer was much smaller than that of an layer, and that the composition of the ternary layer scarcely varied along the thickness. The threshold region for the formation of misfit dislocations into the ternary layers were experimentally determined by using an x‐ray topograph. This region can be displayed by both the lattice misfit and the thickness. It was found that the layers thicker than 10 μm without misfit dislocations could be grown starting from 650°C only when the lattice misfit at room temperature was between and . It is most important for the growth of misfit dislocation‐free thick layers that the layers should be lattice‐matched to the substrates at the growth temperature and that tensile stress should not be incurred at the growth temperature. The relationships between the photoluminescence peak wavelength or solid composition and the lattice misfit were determined experimentally.