Comparison of the DC and microwave performance of AlGaN/GaN HEMTs with sputter PVD or plasma enhanced CVD grown silicon nitride (SiNx) passivation layer

Sputter and plasma enhanced chemical vapor deposition (PECVD) processed SiNx passivation layer on AlGaN/GaN high electron mobility transistors (HEMTs) was compared in this investigation. The both samples were process on the same wafer and the same process besides the passivation process in the same batch. From the data of DC, mimicked class B quiescent bias point pulse measurement, transient pulse measurement are showing that the sputter passivation HEMTs have better performance because there are fewer surface traps. The power sweep data from load pull measurement were in accordance with the pulsed measurement data. Without cooling, continuous wave power densities of 4W/mm and 3.1W/mm was measured at 3GHz on the sputter and PECVD passivation HEMTs, respectively