Modeling of the Lateral Emitter-Current Crowding Effect in SiGe HBTs

Two-section models for capturing the lateral ac emitter-current crowding effect, which is also known as the lateral nonquasi-static (NQS) effect, are presented following a consistent approach based on a model formulation for ac operating condition. Following the theoretical results, model formulations suitable for implementation in the large-signal domain are developed. The proposed two-section model performs better than the state-of-the-art model in both the large-signal and small-signal domains and appears to be suitable for accurately capturing the lateral NQS effect.