Effects of Deposition Thickness and Substrate Type on the Properties of GaAs-on-Si

The heteroepitaxial growth of GaAs substrates offers the potential for the eventual integration of optical devices with electrical circuits, and on a shorter time scale, the replacement of brittle GaAs substrates with larger diameter mechanically stronger Si wafers. The growth of a polar semiconductor (GaAs) on a non-polar substrate (Si) has two major impediments - the difference in lattice constant between the two systems, and the dissimilar thermal expansion coefficients.