Electrochemical and in situ SERS study of the role of an inhibiting additive in selective electrodeposition of copper in sulfuric acid

Abstract

The role of an inhibiting additive in selective copper (Cu) deposition was investigated using linear sweep and cyclic voltammetry and in situ SERS. Both the normalized SERS peak intensity of Basic Red 12 and the Cu deposition current showed hysteresis. These results indicate that Basic Red 12 desorbs or decomposes on the surface during electrodeposition of Cu. Therefore the concentration of Basic Red 12 on the patterned area decreases more than that on the flat area. This inhomogeneity of concentration leads to the preferential growth of Cu on the patterned area. Keywords: Anisotropic deposition, Selective deposition, Copper electroplating, Overburden, Copper interconnects