Electrochemical Analysis of Aged Copper Plating Bath in Wafer Level Packaging (Part 1)

Abstract Copper electroplating processes are widely used in semiconductor manufacturing, particularly during the packaging stage [1]. Copper deposition is used to build various structures including TSV, RDL, Pillars, and Micro and Mega Bumps. Those processes utilize plating solutions that contain inorganic components and organic additives [2]. During the electroplating process, the additives can partially transform into compounds that are so-called breakdown products. The presence of such breakdown products can interfere with the electrochemical analysis of organic additives. This article presents results of plating tests that show the influence of freshly produced breakdown products on analysis of organic additives. In addition, several options to eliminate this effect are presented.