Interactions of dislocations in GaAs grown on Si substrates with InGaAs-GaAsP strained layered superlattices

Abstract
InGaAs-GaAsP strained-layered superlattices have been used as a buffer layer to reduce the dislocation density in GaAs grown on Si substrates. These superlattices have been grown lattice matched to GaAs. Several interactions between the strain field of the strained layered superlattice [GaAs1−yPy-InxGa1−xAs (y=2x)] and the threading dislocations in GaAs/Si are observed. Mixed dislocations are strongly affected by the strain field of the superlattice, however, the interactions with the edge dislocations are less likely to occur. The stress field associated with the strained layered superlattice has a shear component that forces the 60° mixed dislocations to bend at the strained layered superlattice interfaces. Dislocations annihilation or repulsion are observed at the superlattice interfaces.