Numerical simulation of the copper electroplating of TSV with additives under megasound effect

In order to meet the reliability requirement for through silicon via (TSV), the void-free electroplating of TSV should be achieved in its fabrication process. Megasonic has shown noticeable improvement on the void-free electroplating of TSV. However, the megasonic electroplating is a complex multi-physics coupling process. It is necessary to establish the numerical model of TSV megasonic electroplating for further mechanisms study. In this paper, the numerical model is established. The effects of megasonic power density and aspect ratio of TSV on the TSV electroplating are investigated. The simulation results indicate that filling quality of TSV has been greatly improved with the megasonic electroplating. For the simulated parameter range, filling ratio of TSV increases with the applied megasound power density, and improvement decreases with the aspect ratio. The paper provides an effective method of mechanisms study for TSV electroplating under megasonic effect.