THz Characterization and Modeling of SiGe HBTs: Review (Invited)

This article presents a state-of-art review of on-wafer S-parameter characterization of THz silicon transistors for compact modelling purpose. After, a brief review of calibration/de-embedding techniques, the paper focuses on the on-wafer calibration techniques and especially on the design and dimensions of lines built on advanced silicon technologies. Other information such as the pad geometry, the ground plane and the floorplan of the devices under test are also compared. The influence of RF probe geometry on the coupling with the substrate and adjacent structures is also considered to evaluate the accuracy of the measurement, especially using EM simulation methodology. Finally, the importance of measuring above 110 GHz is demonstrated for SiGe HBT parameter extraction. The validation of the compact model is confirmed thanks to an EM-SPICE co-simulation that integrates the whole calibration cum de-embedding procedure.