Paramorphic growth: A new approach in mismatched heteroepitaxy to prepare fully relaxed materials

We propose paramorphic growth as a new approach for growing thick, ideally relaxed, epitaxial layers on mismatched substrates. First, a thin seed layer, originally grown pseudomorphically strained on a mismatched substrate coated with a sacrificial layer, is separated by chemical etching from its original substrate and subsequently deposited on the final substrate after bring elastically relaxed. Consequently, thick layers, lattice matched to the cubic-relaxed seed layer, can be grown epitaxially without the introduction of any structural defects. The validity of this approach is demonstrated by growing fully relaxed In(0.65)Gi(0.35)As thick layers on 300 x 300 mu m(2) platforms deposited on an InP substrate, using molecular beam epitaxy.