Investigation of the stresses in continuous thin films and patterned lines by x-ray diffraction

Abstract

Strains and stresses in aluminum thin films and patterned lines were measured using x-ray diffraction. Measurements were performed on pure aluminum and on ion-implanted aluminum, as annealed and six months after an annealing treatment. The results suggest that stresses in passivated lines, starting from an unequitriaxial state of stress, show the tendency to relax in the direction of an equitriaxial state of stress, depending on the ratio of grain size and linewidth or film thickness. The relaxation is particularly rapid in ion-implanted aluminum lines, in contradiction to the expected strengthening effect. Possible implications for electromigration resistance are discussed.