Fabrication and simulation of copper spiral on-chip inductors for RF wireless communication

This paper presents some new results of the simulation and fabrication of high-Q cascade inductor for the RF wireless communication circuits at 2.45 GHz and 5.5 GHz. The cascade inductor is introduced and analyzed in detail with the help of HP-ADS Momentum simulation tool. The Q values of the 3-turn cascade inductor are 16.8 and 8.5. while those of the 6-turn normal inductor are only 8 and 2.8, at 2.45 GHz and 5.5 GHz respectively, and their inductances are similar at 7.5 nH and 10 nH, respectively. The area consumed by the inductor is also reduced for miniaturization of the RF IC with same numbers of mask. A new way to tune the inductance by tuning via thickness is also shown here. The research is based on Momentum simulation and copper damascene interconnection process.