Impact of Metal Dummy Fills on the Performance of CMOS Inductors

To meet the metal density and uniformity requirement, metal dummy fills are inserted on all metallization layers in modern CMOS technologies. These metal dummy fills can have a detrimental effect on the performance of IC components. In this paper, the impact of metal dummy fills on the equivalent circuit and the performance of on-chip spiral inductors is presented based on experimental data. A simple closed-form formula is further provided to account for the effect of metal dummy fills to update the model for inductors in the conventional environment without metal dummy fills.