Temperature and Current Effects on Small-Geometry-Contact Resistance

Abstract-Tbe 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
nterface 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.