Reliability improvement achieved by N2O radical treatment for AlGaN/GaN heterojunction field-effect transistors

Recently, O₂ or N₂O plasma treatment has been extensively investigated about the passivation effect of AIGaN/GaN HFETs. However, the effect was not consistent. Due to ion bombardment on the sample surface, the devices might be significantly degraded , suggesting that it might be difficult to suppress the plasma damage. On the other hand, Tapajna et al have reported the reliability issue of such oxidation process. In this work, a method called N₂O radical treatment will be introduced. With this method, we suppressed the current collapse of AIGaN/GaN HFETs by ~40%. And the reliability was also improved by ~60%.