High-speed and high-quality TSV filling with the direct ultrasonic agitation for copper electrodeposition

In this paper, the influential factors of the silent and ultrasonic electroplating using 3-mercapto-1-propanesulfonate (MPS), polyethylene glycol (PEG), and Polyethylenimine alkyl salt (PN) on the TSV filling are investigated. The effects of different accelerator concentration, current density and ultrasonic agitation on TSV filling are studied. The accelerative effect of MPS on TSV filling by the copper electrodeposition is studied to find out the optimal condition of the accelerator concentration. Using the plating bath with same additive conditions, the effects of different current densities on the TSV filling under the silent and ultrasonic conditions are investigated. The results show that the quality of TSV filling under ultrasonic electroplating has improved by 23% compared with the silent condition at the same current density.