THERMAL-STRESSES IN MULTILEVEL INTERCONNECTIONS - ALUMINUM LINES AT DIFFERENT LEVELS

Numerical results on the evolution of thermal stresses in multilevel i nterconnects are presented. Two levels of aluminum lines with an aspec t ratio of unity, aligned vertically or arranged in a staggered manner , are considered by recourse to the finite element analysis. The stres ses are found to be significantly higher in the lower-level lines than in the upper-level lines, for both the aligned and staggered arrangem ents. The stress magnitudes are generally smaller in lines of staggere d arrangement, compared to the case of aligned lines. Implications of the present findings are discussed, with directions of future studies highlighted.