On reliable modeling of substrate/buffer loading effects in a gallium nitride high-electron-mobility transistor on silicon substrate

摘要

Currently, gallium nitride (GaN) on silicon (Si) high-electron-mobility transistors (HEMT) are a promising candidate for designing improved power electronic circuits. The lattice mismatch between GaN and Si induces buffer/substrate leakage currents that impact the performance of the device. In this paper, four different model topologies have been demonstrated to simulate the buffer/substrate loading effect in GaN on a Si HEMT. A particle swarm optimization-based procedure has been developed to extract reliable values for the model elements. The models are evaluated in term of reliability of extraction and accuracy of S-parameter fitting. The results showed that the RC-based model topologies have more accurate simulation for buffer/substrate leakage than the RLC-based topology. This will contribute to reliable and accurate small-/large-signal modeling of the device for designing efficient power circuits.