开态应力下电压和电流对AlGaN/GaN高电子迁移率晶体管的退化作用研究  

Degradation induced by voltage and current for AlGaN/GaN high-electron mobility transistor under on-state stress

作　　者：石磊[1] 冯士维[1] 石帮兵 闫鑫[1] 张亚民[1] 

机构地区：[1]北京工业大学电子信息与控制工程学院,北京100124

出　　处：《物理学报》2015年第12期367-371,共5页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:61376077);北京市自然科学基金(批准号:4132022;2132023)资助的课题~~

摘　　要：通过采集等功率的两种不同开态直流应力作用下Al Ga N/Ga N高电子迁移率晶体管(HEMTs)漏源电流输出特性、源区和漏区大信号寄生电阻、转移特性、阈值电压随应力时间的变化,并使用光发射显微镜观察器件漏电流情况,研究了开态应力下电压和电流对Al Ga N/Ga N高电子迁移率晶体管的退化作用.结果表明,低电压大电流应力下器件退化很少,高电压大电流下器件退化较明显.高电压是HEMTs退化的主要因素,栅漏之间高电场引起的逆压电效应对参数的永久性退化起决定性作用.除此之外,器件表面损坏部位的显微图像表明低电压大电流下器件失效是由于局部电流密度过高,出现热斑导致器件损伤引起的.Voltage and current degrade the A1GaN/GaN high electron mobility transistors （HEMTs） under on-state stress. To determine which one dominates the degradation, two on-state stresses which have equal power are exerted on A1GaN/GaN HEMTs： high voltage and low current on sample A, low voltage and high current on sample B. In the former stress, drain-source voltage （VDs） is 28 V, drain-source current （IDs） is 75 mA/mm. In the latter stress, VDS is 14 V and IDS is 150 mA/mm. The package temperatures of samples A and B are kept at 150℃. The samples are measured every 24 hours, with an extra measurement at the 8th hour in the first 24 hours （note that the time refers to the stressing time）. There is an interval of 4 hours between the stressing and the measurement. The device parameters include drain-source current-voltage （IDs-VDs） characteristics, large-signal parasitic source resistance （Rs）, large-signal parasitic drain resistance （RD）, and transfer characteristics between IDS and gate-source voltage （VGs）. The emission microscope （EMMI） is used to study the leakage current after experiment. The IDs-VDs characteristics of sample B are kept constant after being stressed, while that of device A shifts downward after being stressed. Rs of sample A, Rs of sample B, and RD of sample B increase slightly, RD of sample A increases more obviously with most change happening in the first 8 hours. IDs-Vcs characteristics of sample B kept constant, IDs-VGs characteristics of sample A shift downward. The changes of threshold voltage （VGs（th）） is obtained from the transfer characteristics, and it is similar to the changes of transfer characteristics. The YGs（th） that of sample B decreases slightly. The magnitude （absolute value） of sample A decreases obviously while Lts show that the device under low voltage and high current stress degrades little and the device under high voltage and low current stress degrades more obviously. The EMMI images show that the leakage of sample A i

关 键 词：ALGAN/GAN高电子迁移率晶体管 电压 电流 退化 

分 类 号：TN386[电子电信—物理电子学]