Lattice strain and misfit dislocations in GaAs-GaAlAsP heterojunctions

The lattice strain and misfit dislocations in a GaAs-GaAlAsP heterojunction were examined. The change in lattice strain with the composition ratio or the position of the crystal was measured, and it was found that some of the misfit dislocations introduced in the heterojunction were edge-type dislocations. The critical thickness of the epitaxial layer for the generation of misfit dislocations was also measured. The critical differential strain between the atomic layers was on the order of several angstroms. The distribution of lattice strain was analyzed by a two-dimensional simple cubic lattice model, and the distribution of differential strain was examined.