Influence of the Anode on the Degradation of the Additives in the Damascene Process for Copper Deposition
Abstract
The influence of both soluble and insoluble anodes on the kinetics and morphology of the copper deposit in the damascene process was investigated by voltammetry and impedance techniques. A plating bath known to provide conformal superfilling of trenches and vias in the microelectronic industry was used. It was shown that the use of a glassy carbon anode leads to faster degradation of the plating bath which is detrimental to the copper deposit. A copper anode decreases the aging rate by limiting the anodic potential compared to the glassy carbon anode where high anodic potentials prevail during the copper deposition process.