Schottky forward current transport mechanisms in AlGaN/GaN HEMTs over a wide temperature range  

作　　者：武玫 郑大勇 王媛 陈伟伟 张凯 马晓华 张进成 郝跃 

机构地区：[1]School of Microelectronics,Xidian University [2]Key Laboratory for Wide Band-Gap Semiconductor Materials and Devices,School of Microelectronics,Xidian University [3]The Fifth Electronics Research Institute of Ministry of Industry and Information Technology

出　　处：《Chinese Physics B》2014年第9期409-413,共5页中国物理B（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant No.61334002);the Opening Project of Science and Technology on Reliability Physics and Application Technology of Electronic Component Laboratory of China(Grant No.ZHD201206)

摘　　要：The behavior of Schottky contacts in AlGaN/GaN high electron mobility transistors （HEMTs） is investigated by temperature-dependent current-voltage （T-I-V） measurements from 300 K to 473 K. The ideality factor and barrier height determined based on the thermionic emission （TE） theory are found to be strong functions of temperature, while present a great deviation from the theoretical value, which can be expounded by the barrier height inhomogeneities. In order to determine the forward current transport mechanisms, the experimental data are analyzed using numerical fitting method, considering the temperature-dependent series resistance. It is observed that the current flow at room temperature can be attributed to the tunneling mechanism, while thermionic emission current gains a growing proportion with an increase in temperature. Finally, the effective barrier height is derived based on the extracted thermionic emission component, and an evaluation of the density of dislocations is made from the I-V characteristics, giving a value of 1.49 × 10^7 cm^-2.The behavior of Schottky contacts in AlGaN/GaN high electron mobility transistors （HEMTs） is investigated by temperature-dependent current-voltage （T-I-V） measurements from 300 K to 473 K. The ideality factor and barrier height determined based on the thermionic emission （TE） theory are found to be strong functions of temperature, while present a great deviation from the theoretical value, which can be expounded by the barrier height inhomogeneities. In order to determine the forward current transport mechanisms, the experimental data are analyzed using numerical fitting method, considering the temperature-dependent series resistance. It is observed that the current flow at room temperature can be attributed to the tunneling mechanism, while thermionic emission current gains a growing proportion with an increase in temperature. Finally, the effective barrier height is derived based on the extracted thermionic emission component, and an evaluation of the density of dislocations is made from the I-V characteristics, giving a value of 1.49 × 10^7 cm^-2.

关 键 词：AlGaN/GaN HEMTs Schottky contacts forward current transport mechanism temperature dependence 

分 类 号：O441[理学—电磁学]