InP/GaAsSb Double Heterojunction Bipolar Transistor Characterization and Compact Modeling up to 500 GHz

This article presents a new methodology to accurately characterize indium phosphide (InP) bipolar transistors up to 500 GHz. Following design optimization of RF test structures specifically developed for the on-wafer thru-reflect-line (TRL) calibration technique, InP/GaAsSb double heterojunction bipolar transistors have been successfully characterized up to 500 GHz. Moreover, the high current model (HICUM) compact model was validated against measurements for different operating conditions and various geometries for the first time up to 500 GHz. The physics-based compact model and the associated scalable parameter extraction flow allowed us to demonstrate the scalability of this terahertz (THz) InP double heterojunction transistor (DHBT) technology, offering possibilities for further design-level explorations. State-of-the-art cut-off frequencies of this THz transistor technology featuring <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${f}_{\text {MAX}}$ </tex-math></inline-formula> reaching 1 THz for transistor geometries with 0.15-<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text {m}$ </tex-math></inline-formula> emitter widths were experimentally verified and confirmed by the compact model predictions.