基于异质金属接触电化学腐蚀的MMIC阻性衰减器失效分析

Failure Analysis of MMIC Resistive Attenuator Based on Electrochemical Corrosion for Heterometal Contact

针对某单片微波集成电路(MMIC)阻性衰减器断路故障进行了失效分析。开封后,利用扫描电子显微镜(SEM)、能谱仪(EDS)和聚焦离子束(FIB)等对失效样品进行检测。经检测发现W电阻薄膜断裂导致器件断路失效。W电阻薄膜断裂的原因是W-Au异质金属直接接触的区域暴露在空气中形成腐蚀原电池发生电化学腐蚀。利用质量分数3%的NaCl溶液对同批次器件进行腐蚀实验,复现了失效模式。检测和复现实验证明了该器件的失效机理为基于异质金属接触的电化学腐蚀。

Failure analysis of open circuit fault for a monolithic microwave integrated circuit(MMIC)resistive attenuator was carried out.The failure samples were detected by scanning electron microscopy(SEM), energy disperse spectroscopy(EDS) and focused ion beam(FIB) after decap.It is found that the fracture of W resistor thin film leads to open circuit failure of the device.The reason for the fracture of W resistor thin film is that the area in direct contact with W-Au heterogeneous metals is exposed to the air to form corroded galvanic cell structure and lead to electrochemical corrosion.Corrosion experiment of the same batch of devices with the mass fraction of 3% NaCl solution was carried out, and the failure mode was reproduced.Detections and reproduction experiments show that the failure mechanism of the device is electrochemical corrosion based on heterometal contact.