The effects of plasma etching substrates on the performance of group 11 metal thin films

Thin films are often created by a type of vapor deposition. In the case of chemical vapor deposition (CVD), chemicals and precursors are used to create a vapor; in physical vapor deposition (PVD), specific interactions with a metal or metal oxide target are created inside a vacuum system. In both cases, the vapor is allowed to condense onto a substrate and grow the thin film. One of the most common a reliable approaches for PVD is the use of an electron-beam (e-beam) gun, in which a focused electron beam strikes a target creating heat and causing the target to change phases. In this thesis, we describe both the renovation of a severely abused and damaged e-beam system and some of the initial results from its use. Specifically, in very thin Group 11 metal films with thicknesses of the same order of magnitude or smaller than the electron mean free path, the morphology of the film surface can affect the physical properties of the film. To investigate the effects of etching a substrate with a low-pressure argon plasma (as a surface “pre-treatment”) using a custom-built plasma etcher, we grew a set of Group 11 metal films in a custom-built electron-beam deposition system at room temperature on both “treated” and untreated c-cut Al2O3 substrates. We compared the properties expected to be most affected by surface morphology (i.e., roughness, conductivity, surface free energy, and adhesion) were for each film and were able to determine the relative effects of the pre-treatment on film adhesion for the gold films.