Analysis of AlGaN/GaN high electron mobility transistors failure mechanism under semi-on DC stress  

作　　者：杨振 王金延 徐哲 李晓平 张波 王茂俊 于民 张进城 马晓华 李用兵 

机构地区：[1]Institute of Microelectronics, Peking University [2]School of Microelectronics, Xidian University [3]The 13th Research Institute of CETC

出　　处：《Journal of Semiconductors》2014年第1期56-60,共5页半导体学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(Nos.60406004,60890193,60736033);the National Key Micrometer/Nanometer Processing Lab

摘　　要：Semi-on DC stress experiments were conducted on A1GaN/GaN high electron mobility transistors （HEMTs） to find the degradation mechanisms during stress. A positive shift in threshold voltage （VT） and an increase in drain series resistance （RD） were observed after semi-on DC stress on the tested HEMTs. It was found that there exists a close correlation between the degree of drain current degradation and the variation in VT and RD. Our analysis shows that the variation in Vx is the main factor leading to the degradation of saturation drain current （IDs）, while the increase in RD results in the initial degradation of Ios in linear region in the initial several hours stress time and then the degradation of VT plays more important role. Based on brief analysis, the electron trapping effect induced by gate leakage and the hot electron effect are ascribed to the degradation of drain current during semi-on DC stress. We suggest that electrons in the gate current captured by the traps in the A1GaN layer under the gate metal result in the positive shift in VT and the trapping effect in the gate-drain access region induced by the hot electron effect accounts for the increase in RD.Semi-on DC stress experiments were conducted on A1GaN/GaN high electron mobility transistors （HEMTs） to find the degradation mechanisms during stress. A positive shift in threshold voltage （VT） and an increase in drain series resistance （RD） were observed after semi-on DC stress on the tested HEMTs. It was found that there exists a close correlation between the degree of drain current degradation and the variation in VT and RD. Our analysis shows that the variation in Vx is the main factor leading to the degradation of saturation drain current （IDs）, while the increase in RD results in the initial degradation of Ios in linear region in the initial several hours stress time and then the degradation of VT plays more important role. Based on brief analysis, the electron trapping effect induced by gate leakage and the hot electron effect are ascribed to the degradation of drain current during semi-on DC stress. We suggest that electrons in the gate current captured by the traps in the A1GaN layer under the gate metal result in the positive shift in VT and the trapping effect in the gate-drain access region induced by the hot electron effect accounts for the increase in RD.

关 键 词：A1GaN/GaN HEMT reliability semi-on DC stress hot electron effect 

分 类 号：TN32[电子电信—物理电子学] TH49[机械工程—机械制造及自动化]