Degradation mechanism of fluorine treated enhancement-mode AlGaN/GaN HEMTs under high reverse gate bias

摘要

The degradation mechanism of fluorine treated enhancement-mode (E-mode) AlGaN/GaN high electron mobility transistors (HEMTs) under high reverse gate bias was studied in this paper. The experimental results show that E-mode HEMTs using fluorine ion implantation shows a significant negative shift of threshold voltage (Vth) during the long-term high reverse gate bias. Three main degradation mechanisms are used to explain this phenomenon. In this paper, F ions impact ionization is found to be the main reason for the device degradation under high reverse gate bias. Moreover, it is also observed that the degradation of Vth can be partially recovered after temperature annealing.