Low-loss mesh-type coplanar waveguides for high-current, high-frequency CMOS circuits

Current-handling capability of interconnection lines must be considered to avoid electromigration. In monolithic design, all design rules have to be rigorously followed which indicates that the maximum metal width is limited. In order to handle high current and simultaneously obey the design rules, stacked and mesh interconnections are employed. In this paper five coplanar waveguides (CPWs) for high current-handling are investigated using a commercial CMOS technology. The measurement shows that a mesh CPW reaches lower attenuation constant than stacking of metals under similar current carrying capability. The lowest measured attenuation is 0.81 dB/mm at 10 GHz and 1.46 dB/mm at 40 GHz in a mesh CPW, which can continuously flow a DC current of 145 mA without electromigration.