增强型AlGaN/GaN MIS-HEMTs器件的质子辐照效应  

Effects of Proton Irradiation on Enhancement-ModeAlGaN/GaN MIS-HEMTs

作　　者：吕玲 林正兆[2] 郭红霞 潘霄宇 严肖瑶 LYU Ling;LIN Zheng-zhao;GUO Hong-xia;PAN Xiao-yu;YAN Xiao-yao(State Key Laboratory of Intense Pulsed Radiation Simulation and Effect,Xi’an 710024,China;School of Microelectronics,Xidian University,Xi’an 710071,China)

机构地区：[1]强脉冲辐射环境模拟与效应国家重点实验室,西安710024 [2]西安电子科技大学微电子学院,西安710071

出　　处：《现代应用物理》2021年第2期86-92,共7页Modern Applied Physics

基　　金：强脉冲辐射环境模拟与效应国家重点实验室专项经费资助项目(SKLIPR1711)。

摘　　要：利用70 keV和140 keV质子辐照增强型AlGaN/GaN绝缘栅高电子迁移率晶体管(MIS-HEMTs),得到了最大饱和电流线密度、阈值电压及栅泄漏电流线密度等关键参数的退化规律,并与常规HEMTs器件的辐照退化行为进行了比较,并通过SRIM计算结果和C-V测试结果进一步分析了MIS-HEMTs的退化机制。结果表明,质子辐照在栅介质层和栅介质/AlGaN界面引入的辐照缺陷会导致界面态充/放电效应,使阈值电压正向漂移;辐照缺陷增加了电子穿越势垒的概率,导致栅极泄漏电流线密度增大;2维电子气(2DEG)沟道层产生的辐照缺陷俘获电子,导致2DEG密度降低,使饱和漏电流线密度降低。与常规肖特基栅器件相比,栅介质的存在使器件对质子辐照更为敏感。结合仿真计算结果可知,器件中低能质子的非电离能损区接近2DEG沟道层,是导致低能质子辐照对器件损伤更为严重的主要原因。通过变频电容分析发现,质子辐照后器件界面电荷密度增加,并引入了大量深能级缺陷。The enhancement-mode AlGaN/GaN metal-insulator-semiconductor high electron mobility transistors(MIS-HEMTs)induced by 70 keV and 140 keV proton irradiation are studied and analyzed.The degradation laws of key parameters such as maximum saturation current line density,threshold voltage,and gate leakage current line density of MIS-HEMTs are obtained,which are compared with those of conventional HEMTs.The mechanism of degradation of MIS-HEMTs are further analyzed based on SRIM calculation results and C-V test results.The results show that the irradiation defects introduced by proton irradiation at gate dielectric layer and gate dielectric/AlGaN interface will lead to the charge/discharge effect of interface state,resulting in the threshold voltage shift to positive values.The irradiation defects increase the probability of electrons crossing the barrier,resulting in the increase of the line density of gate leakage current,and the irradiation defects in the channel layer of two-dimensional electron gas(2DEG)will capture electrons,resulting in the decrease of 2DEG density and the decrease of saturated drain current.Compared with the conventional Schottky gate devices,the presence of gate dielectric makes the device more sensitive to proton irradiation.Combined with the calculation and simulation,the non ionization energy loss region of low energy proton is close to the 2DEG channel layer,which is the main reason for the more serious damage of the device caused by low energy proton irradiation.It is found that the charge density of the device interface increases after proton irradiation,and a large number of deep-level defects are introduced by capacitance test at different frequencies.

关 键 词：ALGAN/GAN 增强型 绝缘栅高电子迁移率晶体管 质子辐照 缺陷 界面态 

分 类 号：TN386[电子电信—物理电子学]