Dynamic through-silicon-via filling process using copper electrochemical deposition at different current densities

Fuliang Wang,Zhipeng Zhao,Wenhui Zhu,Nantian Nie,Feng Wang

doi:10.1038/srep46639

Abstract

This work demonstrates the dynamic through-silicon-via (TSV) filling process through staged electrodeposition experiments at different current densities. Different morphologies corresponding to TSV filling results can be obtained by controlling the applied current density. Specifically, a low current density (4 mA/cm2) induces seam defect filling, a medium current density (7 mA/cm2) induces defect-free filling, and a high current density (10 mA/cm2) induces void defect filling. Analysis of the filling coefficient indicates that the effect of current density on the TSV filling models is triggered by the coupling effect of consumption and diffusion of additives and copper ions. Further, the morphological evolution of plating reveals that the local deposition rate is affected by the geometrical characteristics of the plating.

Highlights

This work demonstrates the dynamic through-silicon-via (TSV) filling process through staged electrodeposition experiments at different current densities
The morphological evolution of the plating revealed that the local deposition rate was affected by the geometrical characteristics of the plating
Staged TSV filling experiments using the electrochemical deposition (ECD) method were conducted in this work at different current densities

Summary

Introduction

This work demonstrates the dynamic through-silicon-via (TSV) filling process through staged electrodeposition experiments at different current densities. Different morphologies corresponding to TSV filling results can be obtained by controlling the applied current density. The optimum electrodeposition parameters corresponding to specific additives and via structure have been widely studied[12,13,14,15,16,17] Among these parameters, the effect of current density on the filling morphology is pronounced. Specific additives effectively allow for defect-free filling, the required steps are complex, deposition rate is low, and associated costs are high. We demonstrate the TSV dynamic filling process through staged electrodeposition experiments at different current densities. The morphological evolution of the plating revealed that the local deposition rate was affected by the geometrical characteristics of the plating

Methods

Results

Discussion

Conclusion