Analysis of the buffer trap induced Kink effect in GaN High Electric Mobility Transistor

Jia-Hong Lin^1*, Ting-Chang Chang¹, Fong-Min Ciou¹, Yu-Shan Lin¹

¹Physics, National Sun Yat-Sen University, Kaohsiung, Taiwan

* Presenter:Jia-Hong Lin, email:jhlin880406@gmail.com

In this study, the mechanism of the kink effect in GaN high electron mobility transistor is thoroughly analyzed. The Kink effect was observed during the switching operation. The electrons were captured by the buffer trap and lead to the I_D decrease in the next operation. Through different illumination experiments, the kink effect is caused by the recombination of hot holes generated by impact ionization with buffer trap. In addition, the location of the buffer trap is also confirmed by the threshold voltage (V_th) correction of the I_D-V_GS curve and UV light irradiation. After identifying the mechanism of Kink effect, silvaco simulation was used to verify the trap location, confirming that it is under the gate.

Keywords: GaN HEMT, Kink effect, Impact ionization