Direct Parameter Extraction of SiGe HBTs for the VBIC Bipolar Compact Model

TLDR

The paper develops an improved direct parameter extraction method for SiGe HBTs in the VBIC hybrid‑/π/ model. The method extracts all equivalent circuit elements analytically from S‑parameter data, correcting pad de‑embedding errors, introducing a new parasitic substrate network, and refining the extraction of intrinsic base resistance, transconductance, rπ, and Cπ. The extracted parameters are frequency‑independent, match measured data excellently from 0.2 to 10.2 GHz across many bias points, and provide a simple, reliable routine for transistor design, process control, and VBIC model improvement.

Abstract

An improved direct parameter extraction method of SiGe heterojunction bipolar transistors (HBTs) for the vertical bipolar intercompany (VBIC)-type hybrid-/spl pi/ model is developed. All the equivalent circuit elements are extracted analytically from S-parameter data only and without any numerical optimization. The proposed technique of the parameter extraction, differing from the previous ones, focuses on correcting the pad de-embedding error for an accurate and invariant extraction of intrinsic base resistance (R/sub bi/), formulating a new parasitic substrate network, and improving the extraction procedure of transconductance (g/sub m/), dynamic base-emitter resistance (r/sub /spl pi//), and base-emitter capacitance (C/sub /spl pi//) using the accurately extracted R/sub bi/. The extracted parameters are frequency-independent and reliable due to elimination of any de-embedding errors. The agreements between the measured and model-calculated data are excellent in the frequency range of 0.2-10.2 GHz over a wide range of bias points. Therefore, we believe that the proposed extraction method is a simple and reliable routine applicable to the optimization of transistor design, process control, and the improvement of VBIC compact model, especially for SiGe HBTs.