Copper corrosion issue and analysis on copper damascene process

Because copper is very difficult to etch by dry etching methods, copper metallization is created with a damascene process. In this process, chemical mechanical polishing (CMP) is the key step. The wet chemical treatment in CMP makes copper corrosion one of the critical issues for copper metallization. This paper addresses the three different types of copper corrosion; namely, copper chemical corrosion, copper galvanic corrosion and photo assisted copper corrosion. The failure analyses for how to differentiate them and identify their root causes are discussed in detail.