Investigation of Nitrogen-Based Plasma Passivation on GaN RF HEMTs Using Various Precursors

This study investigates the DC and RF performance of RF GaN High Electron Mobility Transistors (HEMTs) subjected to surface pretreatments by N2 and N2O plasma. The filling of nitrogen vacancies or the passivation effect introduced by the thin GaON layer result in enhanced DC characteristics and RF performance for devices treated with nitrogen-based plasma. Compared to the untreated device, the device treated with N2 plasma exhibited a significant improvement in performance i.e. the saturated current increased by approximately 16%, the characteristic frequency (fT) had an increase of 27.6 GHz, the maximum oscillating frequency (fmax) increased by 60.4 GHz. Furthermore, the breakdown voltage had a 10.7% increase, and the dynamic/static on-resistance ratio decreased from 1.34 to 1.18. These results highlight the potential of nitrogen-based plasma treatments in improving the performance of RF GaN HEMTs.