Through glass via (TGV) copper metallization and its microstructure modification

Through glass via (TGV) copper metallization and its microstructure modification

Citation

Chang, Y.-H., Lin, Y.-M., Lee, C.-Y., Hsu, P.-C., Chen, C.-M., & Ho, C.-E. (2024). Through glass via (TGV) copper metallization and its microstructure modification. Journal of Materials Research and Technology, 31, 1008–1016. https://doi.org/10.1016/j.jmrt.2024.06.137* 

Keywords

  • Through glass via (TGV)
  • Electroplating
  • Uniformity
  • Throwing power (TP)
  • Single-step electroplating
  • Multiple-step electroplating
  • Current density (j)
  • Microstructure
  • Electron backscatter diffraction (EBSD)
  • Finite element analysis (FEA)
  • Mechanical properties 

Brief

This article describes how using a multiple-step electroplating process, as opposed to a single-step process, can improve the uniformity of electroplated copper for through glass via (TGV) metallization. A multiple-step process with lower current density applied at the beginning enhances the uniformity of Cu deposition and reduces the total electroplating time. 

Summary

The article, published in the Journal of Materials Research and Technology, examines the use of a multiple-step electroplating process to improve the uniformity of copper metallization in through glass vias (TGVs). The uniformity of copper metallization is important for the thermal and mechanical reliability of TGVs. The authors found that using a lower current density (j) at the beginning of the multiple-step electroplating process resulted in a more uniform distribution of electric current and copper ions in the via structure, leading to a higher throwing power (TP) value. TP is a measure of the uniformity of copper metallization. The authors also found that the multiple-step electroplating process resulted in larger grain sizes and a higher fraction of high angle grain boundaries (HAGBs), including twin boundaries (TBs). HAGBs and TBs are beneficial to the mechanical and electrical properties of copper interconnects. The authors conclude that the multiple-step electroplating process is a time- and energy-efficient method for improving the uniformity and mechanical properties of copper metallization in TGVs.

Origin: https://www.sciencedirect.com/science/article/pii/S2238785424014480

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