Abstract

Two techniques of transmission microscopy were used to examine films of aluminum oxide made by ion-assisted deposition with a Kaufman hot cathode ion gun. The films were bombarded during their growth by oxygen ions of 500-eV energy at an ion current density of 100 μA/cm². Substrate temperatures were nominally 100°C. The films were grown in the same pumpdown cycle with and without bombardment. The surfaces of shadowed replicas of the films were examined by a technique involving the microdensitometry of micrographs,¹ and statistical parameters were derived. With ion bombardment, there appeared to be a reduction in the incidence of large nodular features but a slight increase in very fine roughness. Direct micrographs were obtained by first depositing films over carbon and then stripping them; they showed that the films were completely amorphous.

© 1987 Optical Society of America