The improvement of Al₂O₃/AlGaN/GaN MISHEMT performance by N₂ plasma pretreatment

This paper discusses the effect of N₂ plasma treatment before dielectric deposition on the electrical performance of a Al₂O₃/AlGaN/GaN metal-insulator-semiconductor high electron mobility transistor (MISHEMT), with Al₂O₃ deposited by atomic layer deposition. The results indicated that the gate leakage was decreased two orders of magnitude after the Al₂O₃/AlGaN interface was pretreated by N₂ plasma. Furthermore, effects of N₂ plasma pretreatment on the electrical properties of the AlGaN/Al₂O₃ interface were investigated by x-ray photoelectron spectroscopy measurements and the interface quality between Al₂O₃ and AlGaN film was improved.