Analysis of buffer-trapping effects on current reduction and pulsed I-V curves of GaN FETs

摘要

Two-dimensional transient analyses of GaNMESFETs are performed in which a three level compensation model is adopted for a semi-insulating bufferlayer, where a shallow donor, a deep donor and adeepacceptorare included. Quasi-pulsedI-V curves are derivedfromthe transient characteristics. It is shown that so called current collapse or current reduction is more pronounced foracase with higher acceptor density in the buffer layer,because trapping effects become more significant. It is also shown that the current reduction is more pronounced when the drain voltage is lowered from a higher drain bias during turn-on.