Carbon-Induced Deep Traps Responsible for Current Collapse in AlGaN/GaN HEMTs  

碳致深能级引起的AlGaN/GaN HEMT电流崩塌现象(英文)

作　　者：庞磊[1] 李诚瞻[1] 王冬冬[1] 黄俊[1] 曾轩[1] 刘新宇[1] 刘键[1] 郑英奎[1] 和致经[1] 

机构地区：[1]中国科学院微电子研究所,北京100029

出　　处：《Journal of Semiconductors》2008年第6期1066-1069,共4页半导体学报（英文版）

基　　金：国家重点基础研究发展计划(批准号:2002CB311903);中国科学院重点创新(批准号: KGCX2-SW-107)资助项目~~

摘　　要：Although outstanding microwave power performance of AlGaN/GaN HEMTs has been reported,drain current collapse is still a problem. In this paper,an experiment was carried out to demonstrate one factor causing the collapse. Two AlGaN/GaN samples were annealed under N2-atmosphere with and without carbon incorporation, and the XPS measurement technique was used to determine that the concentration of carbon impurity in the latter sample was far higher than in the former. From the comparison of two Id- Vds characteristics,we conclude that carbon impurity incorporation is responsible for the severe current collapse. The carbon impurity-induced deep traps under negative gate bias stress can capture the channel carriers, which release slowly from these traps under positive bias stress,thus causing the current collapse.AlGaN/GaN HEMT良好的功率特性虽然被大量报导,但其电流崩塌现象仍是一个令人困扰的问题,作者通过实验证明了导致其电流崩塌的一个因素.两个AlGaN/GaN样片被分别放在纯氮气和掺碳的氮气气氛中快速退火,利用XPS证明了后者中的碳元素含量远远大于前者.比较二者的I-V特性曲线,可发现碳杂质的引入可使AlGaN/GaN HEMT电流崩塌程度大大增加.分析表明:由碳杂质引入导致的深能级使得负栅压下俘获沟道中的载流子在正栅压下不能立刻释放,从而引起AlGaN/GaN HEMT中的电流崩塌现象.

关 键 词：AlGaN/GaN HEMT current collapse carbon impurity deep trap 

分 类 号：TN386[电子电信—物理电子学]