Metallic nanofilms on single crystal silicon: Growth, properties and applications

Abstract

The metal–silicon thin-film system is not isostructural and furthermore exhibits pronounced interdiffusion and chemical reactions. Therefore the growth of metallic films on silicon leads to a nanosize nonhomogenity of films and a high concentration of defects, especially at interface. The material also contains stressed transition layer, which can contain alloys and/or compounds (silicides).We have considered theoretical viewpoints and reviewed experimental data on the growth and properties of metallic nanofilms (including multilayered ones) on silicon, and also provided a brief review of their applications. The films consist either of atomic-sized, quabquantum sized and quantum sized layers. We have suggested a low temperature film growth technology based on freezing growing layers during deposition by maintaining a low temperature of the substrate and using an atomic beam with a reduced heat power. The technology uses a specially shaped deposition system in which the distance between the source and the substrate is comparable to their size or smaller. Furthermore, we use a special time sequence of deposition that provides for a reduced substrate surface temperature due to greater intervals between deposition pulses. This growth method of atomically thin films and multilayered nanofilms excludes interdiffusion between the layers, reduces three-dimensional growth rate and relatively increases lateral layer growth rate.