Ultra-wideband millimeter-wave on-wafer characterization of bipolar junction transistors with EM-based three-step de-embedding

On-wafer characterization implementing an electromagnetic (EM)-based three-step de-embedding technique is proposed for accurate determination of bipolar junction transistor´s (BJT´s) S-parameters over ultra-wide frequency ranges up to millimeter-wave region. The characterization is performed on a 0.18-µm SiGe BiCMOS BJT from DC-67 GHz. The common issue of narrow spacing between interconnects in typical on-wafer calibration standards that causes calibration error and difficulty in load-standard design, is overcome with the proposed EM-based three-step de-embedding. The parts of the interconnects including vias within the spacing, which have significant parasitics affecting the characterization accuracy at high frequencies and over wide frequency ranges, that remain non-calibrated after calibration, are extracted using the EM-based three-step de-embedding technique. The measured results up to 67 GHz show sizable differences in insertion loss and phase between the on-wafer characterizations with and without the EM-based de-embedding, demonstrating that the on-wafer characterization with EM-based three-step de-embedding is needed for accurate characterization of devices at millimeter-wave frequencies.