Abstract: In this paper the basic knowledge of copper corrosion defects in IC BEOL copper interconnect process were summarized, and the formation process of copper corrosion in post Dual-Damascus structure all in one(AIO) etch clean process was introduced. The copper under the AIO cavity is corroded, which leads to the short circuit and the failure of circuit connection, resulting in yield loss. Based on the key influence factors of AIO cleaning process, the copper corrosion phenomenon is studied by experiments, and the defects are analyzed according to the characteristics of the layout design. This paper also points out that ESD components in wet cleaning machine have an important impact on copper corrosion defects. In view of insufficient ESD design, we cooperated with vendor to design and improve the ability of electrostatic removal, which are applied to production successfully.