The deposition of sputtered films

The object of nearly all other work on cathode sputtering has been the investigation of the processes by which the metal is removed from the cathode. The primary object of the present work is to investigate the deposition of the sputtered material on glass and metal surfaces placed near the cathode. It is known from the experiments of Knudsen and other workers that a stream of atoms will not condense on a glass or metal surface unless the density of the stream (i. e., the number of atoms striking 1 sq. cm. of the surface per second) exceeds a certain critical value. This critical density does not depend much on the nature of the surface unless the surface is entirely free from a gas layer, but it is a rapidly varying function of the temperature. The first of the present experiments was designed to see if these critical densities existed for metal sputtered on to insulated surfaces. No trace of this phenomenon was found, and further experiments were made to test different explanations of this result. 2. General Notes on Experimental Conditions. Before describing the conditions of individual experiments it may be convenient to give the following information relevant to all or most of the experiments.