INTERNAL-STRESS AND STRUCTURE OF ULTRAHIGH-VACUUM EVAPORATED CHROMIUM AND IRON FILMS AND THEIR DEPENDENCE ON SUBSTRATE-TEMPERATURE AND OXYGEN PARTIAL-PRESSURE DURING DEPOSITION

The internal stress of chromium and iron films was measured in situ by a cantilever beam technique under ultrahigh vacuum conditions. At room temperature only tensile stresses are built up with increasing thickness in chromium as well as iron films. Using a previously published model for the origin of the film stress such a stress vs. thickness curve is characteristic for materials with high melting point (i.e. low material mobility) and columnar grain growth. At elevated substrate temperatures the mobility of both types of material increases, which manifests itself in a more and more pronounced island growth during the early growth stage. The corresponding stress vs. thickness curve shows tensile as well as compressive stresses. Reducing the high chromium mobility at elevated substrate temperature by oxygen incorporation in the film during its deposition gives rise to changes in the stress curve expected from our stress model. © 1990.