Growth of Si1-xGex heterostructures using gas-source molecular beam epitaxy

Abstract

Si1-xGex/Si heterostructures have been grown using Si gas-source molecular beam epitaxy. Growth from gaseous hydride sources not only provides a clean growth process but also pioneers new processing technologies and hence holds great promise for future applications in Si-based devices. Here, its characteristic advantages over conventional solid source molecular beam epitaxy have been investigated through surface chemistry studies of Si1-xGex growth using reflection high-energy electron diffraction. Surface hydrogen, which is produced by the dissociation of hydride source gases on the surface during growth, gives rise to several interesting effects on the growing surface and has been found to provide an inherent advantage over evaporation sources in providing a more precise control of the interface.