Dynamic void formation in a DD-copper-structure with different metallization geometry

摘要

In this study the degradation phenomena in dual-damascene copper (DD-Cu) metallizations will be investigated due to high current densities and substrate temperatures by finite element modeling. The static and dynamic simulations and calculations will show the suitability of the method in comparison to experimental results from the literature. Different geometry variations, like overlap and via height as well as a variation of the stress free temperature of the metallization will be carried out. It will be found, that if the maximum temperature in the metallization is near the stress free temperature the electromigration is dominant. If the temperatures differ from the stress free level stress migration will be predominant. Out of this it will be found that the knowledge of the stress free temperature in the metallization is very important for a sufficient migration determination.