Surface Leakage Currents in SiN and Al$_{2}$O$_{3}$ Passivated AlGaN/GaN High Electron Mobility Transistors
Long Bai1, Wei Yan1, Zhao-Feng Li1, Xiang Yang1, Bo-Wen Zhang1, Li-Xin Tian2,3, Feng Zhang2,3, Grzegorz Cywinski4, Krzesimir Szkudlarek4, Czesław Skierbiszewski4, Wojciech Knap4,5, Fu-Hua Yang1**
1 Engineering Research Center for Semiconductor Integration Technology, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 2Key Laboratory of Semiconductor Material Sciences, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 3Beijing Key Laboratory of Low-Dimensional Semiconductor Materials and Devices, Beijing 100083 4Institute of High Pressure Physics, Polish Academy of Sciences, ul. Sokolowska 29/37, Warsaw 01142, Poland 5Laboratoire Charles Coulomb (L2C), UMR 5221 CNRS-Univ., Montpellier 2, pl. Eugene Bataillon, Montpellier 34095, France
Surface leakage currents of AlGaN/GaN high electron mobility transistors are investigated by utilizing a circular double-gate structure to eliminate the influence of mesa leakage current. Different mechanisms are found under various passivation conditions. The mechanism of the surface leakage current with Al$_{2}$O$_{3}$ passivation follows the two-dimensional variable range hopping model, while the mechanism of the surface leakage current with SiN passivation follows the Frenkel–Poole trap assisted emission. Two trap levels are found in the trap-assisted emission. One trap level has a barrier height of 0.22 eV for the high electric field, and the other trap level has a barrier height of 0.12 eV for the low electric field.
2016, Vol. 33 
