Test structure definition for dummy metal filling strategy dedicated to advanced integrated RF inductors

A complete strategy to manage dummy fills inside a large spectrum of integrated RF inductors realized in a 0.13 μm CMOS technology using a dual damascene copper back end of line (BEOL) is presented here. Thanks to the developed test structures, their RF characterization, and a design of experiment (DOE) modeling analysis, it has been possible to determine the right metal fill density to insert inside inductors in order to be compliant with digital metal density rules without degrading their electrical performances.