Passivation effects on step AlCu/TiN line electromigration performance

Electromigration performance of AlCu/TiN with topography lines has been investigated and the results show a dependence of their behaviour on overlayer. When cross section reduction alone nearly account for the lifetime decrease of uncoated samples relative to flat structureO, it is insufficient to account for coated samples one. The simulations that were performed indicate that thermal gradients along the line are not important. Different microstructural fluctuations for both cases may be considered as supported by grain size analysis.