An investigation of smooth nano-sized copper seed layers on TiN and TaSiN by new non-toxic electroless plating

The purpose of this research is to explore the properties of a copper seed layer grown by electroless plating on TiN. We have developed a displacement layer made of amorphous silicon (a-Si) and copper contact displacement process to improve the island structure of copper activated layer which can then be grown directly on the surface of TiN. Furthermore, this research proposes glyoxylic acid as replacements to formaldehyde, which is commonly used at present as a reductant but regarded as a carcinogen, and is of high volatility. The copper seed layer has been grown by electroless plating on an activated surface of TiN, at the set temperature of 60 °C with the plating bath consisting of the copper source, complexing agent, stabilizer and surfactant. The existence of a copper seed layer provides not only the conduction layer, but also the copper nucleation layer, to help the growth of electroplated copper on the surface of TiN. Moreover, based on the results of the studies can lead us to grow a smooth nano-sized Cu seed layer on the top of a TaSiN layer.