Characterization of Partially Overlapped Inductors for Compact Layout Design in 130nm RFCMOS and 22nm FinFET Processes

Based on the principle of magnetic flux cancellation, partially overlapped spiral inductors can achieve nearly zero magnetic coupling with ultra-compact footprint. This paper presents a study of the characteristics of partially overlapped spiral inductor configurations fabricated in 130nm RFCMOS and 22nm FinFET processes. The viability of the compact inductor layout with controlled very low magnetic coupling is demonstrated by on-wafer measurement and full-wave simulations. Negligible degradation in isolation due to metal fill is observed for both processes, demonstrating the feasibility of the compact layout design methodology even at lower technology nodes with stringent metal density requirements.