Finite Element Analysis of Thermal-Mechanical Stress Induced Failure in Interconnects

Abstract

AbstractIn this work a study of the nature as well as an evalution of the thermal-mechanical stress in aluminum interconnects was carried out. A theoretical model discribes the atom flux which can be induced by the relaxation of the stress. Based on this theory an algorithm has been developed and integrated into the finite element simulation software. This algorithm allows the calculation of the mass flux divergence and prediction of the failure location before the damage occurs. For the verification of this algorithm an aluminum pad structure sputtered on thermal oxide layer was used. The failure location was correlated with in situ observation during the long term stress tests. Experimental results confirm that the observed structure degradations correspond with the simulations very well.