DC/RF and Statistic Modeling of Four Terminal InGap/GaAs Bifet for wireless application

InGaP-GaAs based BIFET is a novel technology that integrates HBT and FET onto a single wafer. The technique expands functionality of circuits and reduces the cost. A novel four-terminal large-signal model was developed for accurate DC and RF applications. The device has a p-layer as backgate that has significant impact on the DC/RF characteristics and therefore, the drain current, gate current, leakage current and all charges/capacitances are 3-dimensional functions, which increases the complexity of the model. The model predicts very well IV/leakage curves for all configurations, including the cases when backgate is connected to source or to gate in that the device reduces to three-terminal. For the three terminal cases, the model also predicts RF performances. Statistic model is also presented to predict the variation of Idss/Vp as well as the corner models that define the extremes of characteristics in terms of epi-layer structure