Effective Methods Controlling Cu Overburdens for Cu RDL Process

Microcontact printing (µCP) and electrochemical polishing (ECP) were proceeded for the Cu overburden thickness reduction and Cu planarization during the redistribution layer process. The suppressing property of µCP and the polishing effect of ECP were confirmed by electrochemical analysis. Suppressing effect of top surface of trench was confirmed after the µCP and Cu filling, and the removal of Cu overburdens was also confirmed after the Cu filling and the ECP.