Study on the electrodeposition of Fe-Ni UBM films in modified watts bath

The electroplating process of Fe-Ni UBM thin film has been developed using modified Watts bath and customized wafer electroplating system. The main factors which can affect the Fe content in the UBM film have been thoroughly investigated. Two kinds of chemical analysis methods, titration and spectrophotography, were used to monitor the variation of bath component content under working condition. The deposition speed under different plating conditions had been investigated by measuring the thickness of Fe-Ni deposited layer.