Coalescence of Thin Films of Gold Condensed on Glass

Abstract

Thin films of gold were deposited by evaporation onto glass surfaces generated by slow fracture in a vacuum. Such films characteristically show an agglomerated or coalesced structure. Deliberate contamination of the substrate and growing films with O2, CO2, H2O, and Ar by exposure to a pressure of 0.0013 Pa (1×10−5 torr) of the gas had no effect on the structure of films of an average thickness of 5 nm (50 Å). Similar treatment of the films with N2 resulted in a decrease in the extent of agglomeration of the gold. Treatment of the substrate with N2 prior to the deposition caused an even greater decrease in agglomeration. Films of an average thickness of 2 nm (20 Å) were not affected detectably by the N2 treatment. The available evidence indicated that the N2 acted directly on the glass and that the structure of the films was unaffected by minor variations in the age of the surface or by differences in the speed of the fracture which generated the surface. The film structure was not changed by extended exposure to the atmosphere.