The transport mechanism of gate leakage current in AlGaN/GaN high electron mobility transistors

¹ Materials Science Center, Institute of Semiconductors, Chinese Academy of Sciences, P.O. Box 912, Beijing 100083, P.R. China
² Key Laboratory of Semiconductor Materials Science, Institute of Semiconductors, Chinese Academy of Sciences, P.O. Box 912, Beijing 100083, P.R. China
³ ISCAS-XJTU Joint Laboratory of Functional Materials and Devices for Informatics, P.O. Box 912, Beijing 100083, P.R. China

^a e-mail: dflin@semi.ac.cn

Received: 5 May 2011
Revised: 31 May 2011
Accepted: 8 June 2011
Published online: 18 August 2011

Abstract

The temperature dependence of the I-V characteristics on Au/Ni-HEMT Schottky contacts was measured and analyzed. Large deviations from the thermionic emission and thermionic-field emission model were observed in the I-V-T characteristics. The thin surface barrier model only fits the measured curves in the high bias region, but deviates drastically in the low bias region. Using a revised thin surface barrier model, the calculated curves match well with the measured curves. It is also found that tunneling emission model is the dominant current transport mechanism at low temperature, yet thermionic-field emission model is the dominant current transport mechanism at high temperature.