Multi-strained short-period superlattice ($) and GaP buffer layers were added to InP/Si hetero-epitaxial structures in order to suppress the generation of threading dislocations. It was found that the density of threading dislocations in an InP/$/GaAs/$/GaP/Si structure, including (InAs)m(GaAs)n and (GaAs)i(GaP)j strained short-period superlattices, was markedly reduced when compared to that in an InP/GaP/Si structure. Misfit dislocations which lay along <011> directions were observed at hetero-interfaces in the InP/$/GaAs/$/GaP/Si structure. It was concluded that the lattice mismatch strain was step-wise accommodated by the generation of misfit dislocations at the hetero-interfaces. It was confirmed that multi-strained short-period superlattices were effective in reducing the density of threading dislocations in hetero-epitaxial systems with a large lattice mismatch.

K.Samonji, H.Yonezu, Y.Takagi, K.Iwaki, N.Ohshima, J.K.Shin, K.Pak: Applied Physics Letters, 1996, 69[1], 100-2