On-die Decoupling Capacitor Measurement Using Vector Network Analyzer

This paper describes a technique for characterizing on-die core power networks using package level vector network analyzer (VNA) S₂₁ measurements. The technique uses the two-port self-impedance measurement concept for low impedance power distribution networks (PDN) (Novak, 2000). It is validated mathematically through network analysis and makes use of an auxiliary test fixture to de-embed the chip packaging parasitic resistance and inductance. The nature of the device under test (DUT) requires specific calibration and measurement considerations to ensure accurate low impedance (sub-milliohm) measurements. Measurements and equivalent circuit models of a sample are presented to show the effectiveness of the methodology