Dummy fill Insertion considering the effect on high-frequency characteristics of spiral inductors

This paper discusses the effect of dummy fills on spiral inductors. In fabrication processes that use copper wire, metal dummy fills are required to prevent thickness fluctuation in CMP stage. Dummy fills have been thought to affect the wire capacitance, however in high frequency, dummy fills also affect the wire resistance and the wire inductance due to the eddy current in dummy fills. This work evaluates the effect of the dummy fills by 3D field solver and proposes a method to suppress the effect of dummy fills. Experimental results show that the proposed method can decrease the effect of dummy fills on quality factor by 55%.