EM performance upside of short BEOL interconnects in advanced process technologies: Electrical-thermal finite element simulations and silicon verifications

In this paper, thermal characteristics (Joule heating) induced by currents in short metal interconnect lines are studied. Electrical-thermal 3D-Finite Element Method (FEM) simulation is employed to model the property of temperature in short length metal lines and an empirical yet practical current model with metal line length effect is introduced. Consequently, the Irms current gain up to 25% in short length metal was achieved. This is attributed to the heat dissipation at the line end being much more effective in short metal lines compared to long metal lines. The material properties of interconnects for simulation was obtained using 64nm pitch BEOL process. The simulation results were verified with experiment silicon data using metal test structures.