State-of-the-art and future perspectives in calibration and de-embedding techniques for characterization of advanced SiGe HBTs featuring sub-THz fT/fMAX

This paper presents an overview of RF calibration and pad de-embedding techniques, discusses limitations and demonstrates methods for accuracy improvement applicable for the characterization of advanced BiCMOS HBTs. The impact of the reference plane location is discussed. Numerous experiments with different device geometries showed that the in-situ (on-wafer) calibration yields the most accurate results. For a probe-tip calibration, a multiple-dummy de-embedding is crucial to improve measurement accuracy. A comparison with the compact model (HICUM V2.30) confirmed the findings.