ACCELERATION OF ELECTROLESS COPPER DEPOSITION IN THE PRESENCE OF EXCESS TRIETHANOLAMINE

The effects of addition of various ligands, such as ethylenediaminetetraacetic acid (EDTA), nitrilotriacetic acid, N,N,N',N',-tetrakis (2-hydroxypropyl)ethylenediamine, N,N,N',N'-tetrakis (2-hydroxyethyl)ethylenediamine, triethanolamine (TEA), and triisopropanolamine on the electroless copper deposition rate were examined. TEA was found to be the most effective ligand for increasing the electroless copper deposition rate. At lower TEA concentrations, the deposition rate increased until it peaked. After peaking, it decreased with increasing concentrations. The maximum rate was over 20 times faster than the current rate observed in the EDTA system. A new deposition model was proposed to derive the adsorption kinetics and to understand the effects of excess ligand. The adsorption equilibrium constant of ligands on the reactive surface and that on the adsorbed complexes were also determined.