REDUCTION OF DISLOCATIONS IN MULTILAYER STRUCTURES OF ZINC-BLENDE MATERIALS

摘要

Abstract of the DisclosureDescribed is a procedure for virtually eliminatingdislocations in multilayer structures of materials having acrystallographic zinc-blende structure, in particularquaternary layers of AlyGal-yASl-zPz grown on AlxGal-xASsubstrates (Y x ?O). By carefully controlling thequaternary layer thickness and the lattice parametermismatch at the growth temperature, it is possible to changethe direction of substrate dislocations as they enter thesubstrate/layer interface. The length of the dislocation inthe interracial plane can be extended so that it is"infinitely" long, i.e., it reaches the edge of the water.As a result, the epitaxial quaternary layer and all layerssubsequently grown thereon will be virtually dislocationfree, provided that the thickness, stress and uniformity ofthe layers are such that no surface dislocation sources areactivated. Also described are double heterostructurejunction lasers with reduced values of both stress anddislocations.