An improved model for InP/InGaAs double heterojunction bipolar transistors

An improved VBIC model for InP/InGaAs double heterojunction bipolar transistors (DHBTs) is proposed. The model accounts for the double heterojunction effect and current blocking effect with novel current expressions. New empirical formulas for the collector-base capacitance and transit time are developed to explain the mobile-charge modulation effect and the role of negative differential mobility. DC and S-parameter measurements are conducted in order to realize the whole extraction flow. The accuracy and validity of this new model and extraction strategy are demonstrated by comparisons of simulation to measurement data on DC, AC small-signal and large-signal characteristics over a wide bias region.

► An improved VBIC model for InP/InGaAs/InP DHBTs is developed.
► Double heterojunction effects are considered in current expressions.
► Collector capacitance and transit time are modified with the dependence on biases.
► The corresponding extraction procedure is developed.
► The model is verified with measured DC, AC small-signal and large-signal data.