EPITAXIAL GROWTH OF ALKALINE EARTH FLUORIDE FILMS ON Si SUBSTRATES.

Heteroepitaxial growth of alkaline earth fluoride films (CaF//2, SrF//2, BaF//2 and their mixed crystals) on Si substrates and growth of Si films on the fluoride/Si structures have been reviewed. It has been found that single crystal CaF//2 films grow on both (111) and (100) substrates, but that lattice-mismatched fluoride films such as SrF//2 and BaF//2 do not grow as single crystals. It has also been found that crystal orientations of the lattice-mismatched fluoride films can be controlled by depositing intermediate CaF//2 films between the top mismatched films and the Si substrates. In the epitaxial growth of Si overlayers, it has been found that the interface between the top Si and underlying CaF//2 films is successfully stabilized by depositing a thin Si layer at room temperature, prior to the growth of a thick Si film at high temperature. Finally, electrical characteristics of MOSFETs fabricated in the Si/CaF//2/Si structure have been presented.