In this paper, we present a technological process that can be used to prepare strain-relaxed InAsP/InGaAs bilayer membranes, 0.8% lattice mismatched to InP substrates, with diameters up to 300 µm. It is shown that high-quality thick In 0.65 Ga 0.35 As layers can be grown fully relaxed on these membranes, without any structural defect, as demonstrated by atomic force microscopy (AFM), transmission electron microscopy (TEM), and photoluminescence (PL) characterizations. The critical thickness of InAs layers grown on InAs 0.25 P 0.75 templates is enhanced from 15 Å to 60 Å when compared to InP substrates.

High structural and high optoelectronic quaby In0.65Ga0.35As layers have been grown on InP substrates using the paramorphk approach. Full relaxation is achieved by growing the In0.65Ga0.3sA.s layers lattice matched to an InAs0.25P0.75 seed membrane of predetermined lattice parameter. The InAs0.25P0.75 seed membrane, originally grown pseudomorphically strained on the InP substrate coated with a sacrificial layer, is separated by chemical etching fkom its original substrate and subsequently deposited on the bottom substrate after being elastically relaxed.