A new approach to the high-quality epitaxial growth of lattice- mismatched materials.

We have reconsidered the problem of the critical layer thickness h(c) for growth of strained heterolayers on lattice-mismatched substrates, using a new approach which allows to determine the spatial distribution of stresses in a bi-material assembly and include the effects of a finite size of the sample. The possibility of dislocation-free growth of lattice-mismatched materials on porous silicon substrates is discussed as an example of a more general problem of heteroepitaxial growth on small seed pads of lateral dimension l, having a uniform crystal orientation over the entire substrate wafer.