Electrochemical mechanisms of hydrogen incorporation in electroless copper films

Abstract

Hydrogen incorporation in electroless copper films is a well-known source of void formation and embrittlement, which reduces the ductility of copper films and can lead to circuit failure. A non-invasive method for measuring hydrogen incorporation in electroless Cu films was utilized, and a method for driving the surface potential of the substrate is implemented. Films with rougher substrate surfaces incorporate more hydrogen, and take significantly longer to release it, than smoother surfaces of the same substrate. The stabilizer system is the fundamental driver of hydrogen incorporation into electroless Cu films. Additionally, a method for investigating the mechanism by which nickel lowers hydrogen incorporation is put forward.