Comparison of copper damascene and aluminum RIE metallization in BICMOS technology

Modern interconnect schemes will be using copper instead of aluminum as metallization material due to its better electrical conductivity and its superior electromigration resistance. Using a production worthy BICMOS process it could be revealed that especially for this kind of application a copper dual damascene metallization offers serious advantages versus an aluminum RIE/tungsten plug approach. Interconnect parameters which are very helpful for high-performance RF technologies like line and via resistances can be reduced showing equal leakage current properties. Current density can be increased and up to now no impact on Bipolar and only slight influence on CMOS devices, which needs to be investigated in more detail, is detected.