The Interaction of Oxygen with Clean Chromium Films and its Influence on the Electrical Film Properties

An outline is given of an approach to the investigation of ageing mechanisms in thin film resistors. The programme includes the separation of most of the deterioration processes by using single crystal and polycrystalline chromium films deposited at ultra-high vacuum and the detailed study of the various gas-metal interaction stages during oxidation, which is considered to be one of the most important ageing mechanisms. The experimental procedures are described and results Presented from the first stage of the investigations giving the process kinetics and their impact on the electrical properties of chromium films. The results are consistent with Mott and Cabrera´s theory for thin oxide films, where the growth is determined by a field dependent cation diffusion through the oxide and indicate any improvement of the resistor stability against oxidation to be dependent on the control of this diffusion process. *Supported in part under RADC Contract AF61(052)-923 through the European Office of Aerospace Research, OAR, United States Air Force.