The Structural Studies of Amorphous Ge Films Prepared by Vacuum Deposition

Abstract

Structural studies on vacuum-deposited amorphous Ge films have been carried out by high resolution electron microscopy using an axial beam illumination. Crossed lattice images are observed in the films, which show that the amorphous films consist of micro-crystallites. The micro-crystallite size is about 14 A in diameter. It is shown that the 14 A micro-crystallite has a minimum value of the surface energy. An oriented and a distorted micro-crystallite models based on the diamond structure are proposed for the amorphous Ge and Si. The distorted micro-crystallite model interprets the diffraction intensity over the wide scattering angle, much better than any model that has ever been reported.