Properties of Dc Magnetron Sputtered Nickel-Chromium Alloy Thin Films

Abstract

ABSTRACT The properties of dc magnetron sputtered nickel-chromium alloy thin films are examined for changes in intrinsic stress, stoichiometry and grain size as a result of heat treatment. We find that a large change in stress from compressive to tensile occurs above 300°C in air ambient for films deposited under nominally low stress. Auger depth profilometry of as-deposited and heat treated films shows that a minimal change in Ni:Cr stoichiometry occurs along with a small increase in oxygen and carbon content for the heat treated film. The accompanying change in grain size of the two types of films is also examined in addition to the large change in intrinsic stress as a function of rf substrate bias on the films during deposition. Atomic Force Microscopy of a heat-treated film shows the presence of voids, which along with the increased grain size, may account for changes in film stress. It appears that the voids are formed by evolution of impurities.