Epitaxial Films of Semiconducting FeSi(2) on (001) Silicon

摘要

Beta-FeSi2 is a direct, narrow-band-gap semiconductor that offers the possibilityof epitaxial growth on (001) oriented silicon substrates. The material is of considerable interest for the development of near-infrared light sources and detectors within the silicon microelectronics technology. Its development for optoelectronic applications will depend, in all probability, upon the availability of epitaxial films on silicon. Although the Bravais lattice is orthorhombic and there is no close lattice parameter match to silicon in the conventional sense, an acceptable 'lattice matching' is still achievable via the formation of a coincidence net with a small mismatch and a reasonably sized unit mesh common to the matching crystallographic faces of the two materials. For growth on (111) oriented silicon substrates, the epitaxial tendencies of beta-FeSi2 were first noted by Cheng et al. and interfaces of impressive quality have been recently reported. 5 For growth on (001) oriented silicon substrates, epitaxy has been reported only for very thin films (corresponding to less than 25 angstroms of deposited metal). (JES)