Methodology for multi-layer interdigitated power and ground network design

Higher operating frequencies and greater power demands have increased the requirements on the power and ground network. Simultaneously, due to the larger current loads, current densities are increasing, making electromigration an important design issue. The optimal wire width for an interdigitated power and ground network is based on the resistive and inductive (both self- and mutual) impedance. In this paper, a methodology for optimizing a multi-layer interdigitated power and ground network is presented, reducing the current density and impedance of a network. Based on 65 nm, 45 nm, and 32 nm CMOS technologies, the optimal width as a function of metal layer is determined for different frequencies, suggesting important trends for interdigitated power and ground networks.