High-Q On-Chip Capacitors Featuring “Self-Inductance Cancellation” for RF and mm-Wave Applications

In this paper, we are reporting on the characterization of the on-chip metal-oxide-metal (MOM) capacitors that use “self-inductance cancellation” technique resulting in high performance operation in RF/mm-wave regime, for the first time. The proposed method helps mitigate the mutual magnetic induction between the metal fingers of a MOM capacitor while they are placed in proximity to each other, by controlling the direction of the RF current flow. More than 2x inductance cancellation is achieved resulting in an increase of the self-resonance frequency and Q-factor of the RF capacitor. The test structures are fabricated using 16nm analog/RF CMOS technology where post-silicon data show a good agreement between the theory and simulation. The proposed methodology is CMOS compatible and is applicable to RF/mm-wave circuits that employ capacitors to improve the overall RF system performance.