A Numerical Method for Modeling the Effects of Irregular Shape on Interconnect Resistance

Abstract

When clock frequencies exceed gigahertz, the skin depth in analog and digital circuits greatly decreases. The irregular shape of the cross section of the interconnect plays an increasingly important role in interconnect parasitic extraction. However, existing methods only focus on the rough surface of the interconnect, while ignoring other irregular shapes, such as the trapezoidal cross section. In this work, a new simulation method is proposed for irregular interconnects, which is applicable to arbitrary irregular shapes and to a wide range of frequencies. The method involves generating a mesh information file firstly and then extracting the frequency-dependent resistance based on a numerical solution of scalar wave modeling by using the method of moments. The singularity extraction method is used to calculate the self-inductors. The data from experiments verify the accuracy of our proposed method.