An AlGaN/GaN HEMT with sputter-SiN passivation for the on-state performance improvement

An AlGaN/GaN high electron mobility transistor (HEMT) using the magnetron sputter to deposit silicon nitride (SiN) passivation layer is proposed in this paper. The AlGaN surface damage will be reduced due to the advantages of high vacuum and low temperature during the growing processes of the magnetron sputter. Therefore, compared to the conventional device adopting the passivation of the plasma-enhanced chemical vapor deposition (PECVD) SiN, the proposed HEMT shows the significantly improved on-state performance. Supported by the experiments of the PECVD/sputter-SiN dual-layer passivation, we demonstrate that the passivation/AlGaN interface quality is a key factor that affecting on-state characteristics of the devices. The results suggest that the magnetron sputter-SiN passivation is a promising candidate for AlGaN/GaN HEMT with the high on-state performance.