INTERNAL-STRESS OF VAPOR-DEPOSITED ALUMINUM ON ALUMINUM SUBSTRATE FILMS - EFFECT OF O-2 AND WATER INCORPORATED IN THE SUBSTRATE

Thin films of aluminium were evaporated at various oxygen and water partial pressures and then used as substrates for the deposition of a clean aluminium film. The effect of oxygen and water incorporated in the substrate on the internal film stress of the deposited clean aluminium film was measured in situ with a cantilever beam apparatus under ultrahigh vacuum conditions. When the clean aluminium film is evaporated onto a clean aluminium substrate, the film stress is only compressive. During the evaporation of aluminium onto substrates containing oxygen or water, compressive as well as tensile stresses are measured. We interpret the tensile stress as due to diffusion of oxygen and hydrogen from the substrate film into the clean aluminium film. © 1990.