Design Considerations for BEOL MIM Capacitor Modeling in RF CMOS Processes

Modeling of MIM capacitors in high frequency RF applications depends heavily on the design of test structures. An external substrate ring is shown to be essential in capturing and modeling the inherent inductance of the MIM capacitor. Additionally, deembedding of series parasitics plays a very important role in modeling of MIM capacitors since these devices have very low series resistance. Various short structures were studied and their impact on the MIM characteristics are reported. It is shown that a short structure with the shortest path to ground is best suited to deembed the series parasitics.