Investigation of random rough surface effects in interconnect resistance extraction utilizing effective conductivity

Abstract

Due to the decreasing skin depth in high-frequency analog and digital circuits, surface roughness is playing an increasingly important role in interconnect parasitic extraction. However, the inaccessibility of explicit surface expression and the complicated electromagnetic (EM) nature baffle the satisfactory solution to this kind of problems. In this paper, the impact of random surface roughness on the frequency-dependent resistance extraction for interconnects is quantitively evaluated by the concept of effective conductivity. The surface information is given in terms of statistical description instead of explicit functions. We combine the equivalent source method with the Monte Carlo simulation, called generalized equivalent source method (GESM), to analyze the behavior of EM wave on random rough surfaces. These techniques simplify the investigation of rough surface effects in interconnect parasitic extractions and full-wave analyses for signal integrity. © 2006 IEEE.