Temperature and current effects on small-geometry-contact resistance

The effects of temperature and current on the resistance of small geometry silicided contact structures have been characterized and modeled for the first time. Both, temperature and high current induced self heating have been shown to cause contact resistance lowering which can be significant in the performance of advanced ICs. It is demonstrated that contact-resistance sensitivity to temperature and current is controlled by the silicide thickness which influences the interface doping concentration, N. Behavior of W-plug and force-fill (FF) Al plug contacts have been investigated in detail. A simple model has been formulated which directly correlates contact resistance to temperature and N. Furthermore, thermal impedance of these contact structures have been extracted and a critical failure temperature demonstrated that can be used to design robust contact structures.