Experimental study of current density in copper filling process within deep through-silicon vias with high aspect ratio

Abstract

Current density is one of the process parameters with the most significant effect on throughsilicon via (TSV) filling. However, the mechanism analysis of the influence of current density on TSV filling morphology lacks experimental demonstration. In this work, electrochemical deposition experiments and electrochemical analysis experiments were carried out to investigate the effect of current density on the copper filling within deep TSV with high aspect ratio. Three typical filling morphologies and corresponding evolution of the plating were observed. Additionally, the influence of current density on the competitive adsorption relationship between accelerator and suppressor was discussed based on the electrochemical measurement results. Furthermore, the diffusion time of additives was measured. The indirect effect of the current density on the local concentration of additives was discussed. Finally, three filling patterns were proposed to explain the effect current density on the filling process of deep TSV with high aspect ratio.

The effect of quaternary ammonium salts with different chain lengths on copper filling behavior in blind holes of printed circuit board

“…In order to further explore the large blind hole filling ability of the quaternary ammonium, GMs experiment [30][31][32][33] under two different rotation speeds are carried out to analyze the effect of the synergistic effect of these suppressor s and accelerators on the copper deposition behavior at the bottom and surface of the blind holes and the corresponding results are shown in figure 8, where the GMs curve of traditional additives also provides for comparison. Here, the high rotation speed simulates the high current region of the surface of blind hole of PCB, while the low rotation speed referred to the low current region of the bottom of the blind holes.…”