Interaction effect of suppressor concentration and current density on the copper deposition rate in TSV filling process

Abstract

Through‑silicon-via (TSV) is the key technology to realize the lower power consumption, higher performance, smaller packaging size in three-dimensional (3D) packaging process. In this study, the interaction effect of the suppressor concentration and the current density in the TSV filling process is investigated. The experiments of electroplate filling are performed using TSV with the size of 20 μm in width and 65 μm in depth. According to the test results, the filling rate, deposition rate and growth pattern are affected not only by the suppressor concentration but also by the current density. It is found that the optimal conditions for the TSV filling is at the current density of 0.5 ASD and the suppressor concentration of 0.1 g/L. The copper deposition rate is negatively correlated to the concentration of suppressor, and an inhibition limit of the suppressor exists for the copper deposition rate.