ABSTRACT
This chapter seeks to review the properties of semiconductors that bear on these aspects of heteroepitaxy, including crystallographic properties, elastic properties, surface properties, and defect structures. Semiconductors in common use today are nearly always single-crystal materials. A crystal is a periodic arrangement of atoms in space. Heteroepitaxial semiconductors typically contain elastic strains, due to lattice mismatch and thermal expansion mismatch. SiC exhibits over 250 different polytypes, including cubic, hexagonal, and rhombohedral variants. The surface free energies have been determined experimentally for only a few semiconductor crystals. The electronic properties of dislocations vary greatly among the different classes of semiconductor crystals. Dislocations have been found to act as nonradiative recombination centers in the arsenides, phosphides, nitrides, and II-VI semiconductors. Notable exceptions include thin-film transistors, made using polycrystalline or amorphous silicon, and the gates of metal oxide semiconductor field effect transistors, which are made using polycrystalline silicon.
