Impact of $\hbox{CF}_{4}$ Plasma Treatment on GaN

We present a systematic study of the impact of CF
₄
plasma treatment on GaN. It was found that CF
₄
plasma etches GaN at a slow rate and yields a smooth etched surface. The effect of CF
₄
plasma on electrical characteristics of GaN metal-semiconductor field-effect-transistor structures shows that the CF
₄
plasma introduces acceptors into the near surface region of the GaN, which depletes mobile electrons. It was further demonstrated that leakage current of AlGaN/GaN (or GaN) Schottky diodes can be significantly suppressed by proper CF
₄
plasma treatment. These unique properties of CF
₄
plasma can be utilized for the advanced processing of GaN transistors.