Impact of fluorine plasma treatment on AlGaN/GaN high electronic mobility transistors by simulated and experimental results

Abstract

This paper demonstrates the effect of fluorine plasma treatment on the performance of AlGaN/GaN high electronic mobility transistors. The impact of ion implantation depth on threshold voltage is simulated using the Silvaco software. The simulated results declare that fluorine ions neutralize the positive polarization charge at AlGaN/GaN interface and weaken the polarization electric field. Experimental results confirm that a larger shift of threshold voltage will be achieved at a higher induced fluorine plasma bias voltage, due to the increasing depth of ion implantation. The fluorine plasma treatment is also found to be effective in lowering the gate reverse leakage current and enhance the Schottky barrier height of the metal gate. The influence of fluorine ions on the Schottky barrier height only counts for a small portion of the large shift in threshold voltage.