系统级测试下静电防护器件的失效机理分析  

Study on Failure Mechanism of ESD Protection Devices under System-level Tests

作　　者：刘进[1] 陈永光[2] 

机构地区：[1]中国空气动力研究与发展中心,四川绵阳621000 [2]北京跟踪与通信技术研究所,北京100094

出　　处：《半导体光电》2016年第5期698-702,724,共6页Semiconductor Optoelectronics

基　　金：国家自然科学基金项目(51177174);国防科技重点实验室项目(9140C87020410JB3403)

摘　　要：为满足系统级电磁兼容测试标准IEC61000-4-2,许多航空电子设备中都有静电放电(ESD)防护器件,其功能的失效直接影响到被保护电路和整机的安全性。在分析该类器件的失效机理时考虑到典型性,选择双极性ESD防护器件0603ESDA-TR作为受试对象,研究了系统级ESD注入对器件性能的影响,并对器件内部温度分布进行了仿真分析。研究表明ESD脉冲注入时雪崩电流在整个pn结面分布不均匀,仅集中在边缘几个点上,局部过热点的温度甚至达到硅熔融温度,将破坏原有的晶格结构,导致器件二次击穿而发生硬损伤。当ESD电压达到25kV后,器件的性能参数开始退化,但反向漏电流几乎不变;连续100次脉冲后器件完全失效。分析后得出的结论是:ESD防护器件遭受系统级静电放电冲击时具有累积效应,其失效是由性能退化引起的,并且传统的漏电流检测无法探测到ESD引起的损伤。In order to satisfy the IEC61000-4-2 system-level ESD standard, discrete ESD protection devices were used in the electronic systems to guarantee the ESD robustness, and the failure of such devices may result in the destruction of the whole system. Investigated are the behavior and the failure mechanism of bidirectional ESD protection device 0603ESDA-TR under system-level ESD pulses, and simulated is the lattice temperature distribution, clamping voltages, failure location based on two-dimensional device simulation tool Medici. In the case of negative differential resistance, the avalanche current distribution in the pn junction is in general spatially unstable and results in the formation of current crowding effects and crystal defects. Then, the local hot spots begin to occur and the peak temperature in these regions reaches the silicon melt temperature （about 1 413 ℃） quickly, as a result permanent damage is incurred. When the ESD level increased to 25 kV, even though no change in leakage current observed, degradation of V-T behavior has been found. Finally, the device became destruction completely after 100 pulses. The result has been indicated that accumulative effect is obvious during system- level ESD test. So the failure of bidirectional ESD protection device is caused by performance degradation, and leakage current measurements alone fail to detect such ESD damage.

关 键 词：系统级测试 ESD防护器件 性能退化 瞬变电压抑制器 二次击穿 

分 类 号：O441.1[理学—电磁学]