High-Resolution Electron Microscope Observation of Voids in Amorphous Ge

Electron micrographs have been obtained which clearly show the existence of a void network in amorphous Ge films formed at substrate temperatures of 25 and 150^∘{}C, and the absence of a void network in films formed at higher substrate temperatures of 200 and 250^∘{}C. These results correlate quite well with density measurements and predictions of void densities by indirect methods.