Title :
Joule heating-assisted electromigration failure mechanisms for dual damascene Cu/SiO2 interconnects
Author :
Chang, C.W. ; Gan, C.L. ; Thompson, C.V. ; Pey, K.L. ; Choi, W.K. ; Chua, M.H.
Author_Institution :
Singapore-MIT Alliance, Singapore, Singapore
Abstract :
Failure mechanisms observed in electromigration (EM)-stressed dual damascene Cu/SiO2 interconnect trees were studied by stressing at fixed conditions for a short time followed by stressing with increasing current to induce Joule heating. Similar failure sites as those observed in samples stressed at normal EM conditions were found. This suggests that Joule heating can be used to accelerate some EM failure mechanisms that occur in normal EM experiments. Finite element method (FEM) simulation showed that the failure mechanisms could be due to Joule heating of Ta diffusion barrier after fully-spanning void was formed. The probabilistic existence of the post-stress ´volcano craters´ and melt patches is highly dependent on the void growth mechanism during EM stressing.
Keywords :
copper; dielectric materials; diffusion barriers; electromigration; failure analysis; finite element analysis; heat transfer; integrated circuit interconnections; silicon compounds; voids (solid); Cu-SiO2; Joule heating; Ta diffusion barrier; dual damascene Cu/SiO2 interconnects trees; electromigration failure; electromigration stressing; finite element method; melt patches; spanning void; void growth; volcano craters; Cathodes; Copper; Current density; Electromigration; Failure analysis; Heating; Integrated circuit interconnections; Optical microscopy; Scanning electron microscopy; Volcanoes;
Conference_Titel :
Physical and Failure Analysis of Integrated Circuits, 2003. IPFA 2003. Proceedings of the 10th International Symposium on the
Print_ISBN :
0-7803-7722-2
DOI :
10.1109/IPFA.2003.1222741
