GaN基Micro-LED反向漏电流失效机理分析  

Analysis of Failure Mechanism of Reverse Leakage Current in GaN-based Micro-LEDs

作　　者：王伟 张腾飞 王绶玙 WANG Wei;ZHANG Tengfei;WANG Shouyu(Jiangsu Province Integrated Circuit Reliability Technology and Testing System Engineering Research Center,Wuxi University,Wuxi 214105,China;College of Electronic and Information Engineering,Nanjing University of Information Science and Technology,Nanjing 210044,China)

机构地区：[1]无锡学院江苏省集成电路可靠性技术及检测系统工程研究中心,江苏无锡214105 [2]南京信息工程大学电子与信息工程学院,江苏南京210044

出　　处：《发光学报》2024年第9期1539-1546,共8页Chinese Journal of Luminescence

基　　金：南京信息工程大学滨江学院人才启动科研项目(2019 r005,550219005);企业横向(2021320205000041,2023320205000242,2023320205000242,560124081)。

摘　　要：针对GaN基蓝光Micro-LED芯片,采用温度应力和电压应力的实验方法研究了其反向漏电流失效机理。结果表明,在温度应力下,Micro-LED芯片退化前的反向漏电流主要由多步热辅助隧穿电流构成,且受Poole-Frenkel(PF)隧穿机制影响;电压应力(-85V)退化后,反向漏电流会随着应力时间的延长而增大,此时由多步热辅助隧穿电流转换为空间电荷限制电流机制(SCLC)。通过分析退化前后的能带图得知,长时间的电压应力会发生击穿现象,导致Micro-LED芯片内部电场剧烈变化,电子能够以高能量碰撞到晶格原子,产生大量的载流子,从而增加了非辐射复合率,使得反向漏电流由原来的1.9766×10^(-7)A增大到1.5834×10^(-4)A。For GaN-based blue Micro-LED chips,experimental methods involving temperature and voltage were used to investigate the reverse leakage current failure mechanism in this paper.The results demonstate that,under temperature stress,the reverse leakage current of Micro-LED chips,prior to degradation,is primarily composed of multi-step thermal-assisted tunneling current,which is significantly influenced by the Poole-Frenkel(PF)tunneling mechanism.After degradation under voltage stress(-85 V),the reverse leakage current increases with the extension of stress time,transitioning from a multi-step thermal-assisted tunneling current to a space-charge-limited current(SCLC).Through analyzing the band diagrams before and after degradation,it was determined that prolonged volt-age stress leads to breakdown phenomenon,resulting a drastic change in the internal electric field of the Micro-LED chip.Electrons are then able to collide with lattice atoms with high energy,generating numerous carriers.Conse-quently,this increase the rate of non-radiative recombination,causing the reverse leakage current to increase from an original value of 1.9766×10^(-7) A to 1.5834×10^(-4) A.

关 键 词：Micro-LED 失效机制 非辐射复合 遂穿通道 反向漏电流 

分 类 号：TN312.8[电子电信—物理电子学]