Dilute H2SO4 solution for copper seed cleaning in electroplating
(1. Department of Information Communication Engineering, Hanbat National University, Daejeon 305-719, Korea;
2. School of Materials Science and Engineering, Pusan National University, Busan 609-73)
2. School of Materials Science and Engineering, Pusan National University, Busan 609-73)
Abstract: The effects of surface cleaning to eliminate the surface oxides formed on Cu seed layer with dilute H2SO4 solution were investigated. Cu seed layer formed on Ti/Si(100) wafer by sputter deposition was exposed to air to grow native Cu oxide. Dilute H2SO4 solutions and/or TS-40A alkaline soak cleaner were used to remove the native Cu-oxide. After mainly carbon groups (such as C=O) on surface of Cu seed layer were removed by pretreatment of TS-40A alkaline solution, subsequently, dilute H2SO4 acid solution removed Cu-oxides (Cu2O and CuO) as well as a lot of O=C and Cu(OH)2.
Key words: pretreatment; copper-oxide; H2SO4; XPS; sheet resistance