典型ESD防护器件失效机理研究

Research on Failure Mechanisms of the Typical ESD Protection Devices

瞬态电压抑制管(TVS)是电子线路设计中常用的静电放电(ESD)防护器件,其可靠性将直接影响整个电路的安全。选取常见的TVS器件PESD5V0U1BA进行研究,通过实验和仿真分析了TVS器件的短路失效机理及其影响。研究表明,当TVS器件注入高压时,器件存在缺陷的SiO2层会发生自愈性击穿。当器件的pn结发生击穿时,器件将失效。如果两个pn结都被击穿,器件的I-V曲线表现为电阻特性。当TVS器件出现损伤后,器件仍具有箝位作用,且其表现的箝位电压更低,但由于器件的漏电流发生较大的增长,将影响被保护电路的正常工作。

Transient voltage suppression （TVS） is used commonly in electronic circuit design as the ESD protection device, and its reliability Would greatly impact on the safety of the whole circuit. The bidirectional TVS device PESD5VOU1BA is researched, the shortcircuit failure mechanism of the device and its effects were researched by experiment and simulation. The results show that while the TVS device is applied high voltage, the SiO2 with defects would occur self-healing punch -through; when the pn junctions of the device is punch-throughed, the TVS device would failure. After the two pn junctions of the TVS device are both punch-throughed, its I-V characteristic would performance as the resistance characteristic. While the TVS device is failure, its clamp function can still be observed, and the clamp voltage is even lower, but the leakage current of the device has increased and it would influence the normal working of the protected circuit.