Influence of Interconnection Configuration on Thermal Dissipation of ULSI Interconnect Systems

The effects of adjacent metal layers and space between metal lines on the temperature rise of multilevel ULSI interconnect lines are investigated by modeling a three-layer interconnect.The heat dissipation of various metallization technologies concerning the metal and low-k dielectric employment is simulated in detail.The Joule heat generated in the interconnect is transferred mainly through the metal lines in each metal layer and through the path with the smallest thermal resistance in each Ield layer.The temperature rises of Al metallization are approximately ρAl／ρCu times higher than those of Cu metallization under the same conditions.In addition,a thermal problem in 0.13μm globe interconnects is studied for the worst case,in which there are no metal lines in the lower interconnect layers.Several types of dummy metal heat sinks are investigated and compared with regard to thermal efficiency,influence on parasitic capacitance,and optimal application by combined thermal and electrical simulation.