Atomic structure of the epitaxial Al–Si interface

The atomic structure of the Al–Si epitaxial interface has been investigated by high-resolution transmission electron microscopy combined with computer image-simulation techniques. A stable epitaxial structure was observed at the Al(111)–Si(111) interface with a matching of four Al to three Si lattice planes, corresponding to a misfit of 30%. The formation of an epitaxial interface with such a large misfit is unexpected and its Occurrence can be attributed to the optimum energy of this interface. Atomic models consistent with these observations are proposed.