Contaminant and Alcohol Induced Electrochemical Migration of Au Bond in ICs During Low Temperature Operation Test

摘要

Electrochemical migration (ECM) of metal has been studied for decades, including Ag, Ni, Sn, Pb, Cu and Au. These metal materials are commonly used in microelectronics devices, both in package and die. According to the failure mechanisms, some of the root causes are easy to find out except Au, since contaminant element is hard to be detected, and electrolyte is various besides water. In a real failure analysis case, we developed a method to analysis contaminant and alcohol induced ECM of Au bond by combining ion chromatography and TOF-SIMS characterization, and IVA analysis. Based on the coupled analysis, the origin of Au ECM is related to chlorine ions and dominant electrolyte formed in low temperature (-45°C) is alcohol. These results indicate alcohol control in microcircuit plays an important role in sealed package.