Electroless copper plating using dimethylamine borane as reductant

Electroless copper plating was studied using dimethylamine borane (DMAB) as reductant and 1,5,8,12-tetraazadodecane as additive and triethanolamine (TEA) as buffer. The effects of pH, temperature and concentrations of reactants and additives on the anodic oxidation of DMAB and the cathodic reduction of copper ion were investigated. Experimental results indicate that high pH values (10-12.5) promote the oxidation of DMAB, and suppress the reduction of the copper ion, while high bath temperatures (55-70 °C) accelerate both anodic oxidation and cathodic reduction. Increase of the Cu 2+ and DMAB concentrations can improve the deposition rate of copper plating. Results for a dual-chelating-agent system indicate that 1,5,8,12-tetraazadodecane plays an important role in chelation, while the main effect of TEA is adsorption on copper surfaces to inhibit DMAB oxidation and to promote deposition. © 2012 Published by Elsevier B.V. on behalf of Chinese Society of Particuology and Institute of Process Engineering, Chinese Academy of Sciences.