Enhanced barrier seed metallization for integration of high-density high aspect-ratio copper-filled 3D through-silicon via interconnects

Higher performance, higher operation speed and volume shrinkage require high 3D interconnect densities. A way to meet the density specifications is to further increase the A.R. of the TSV interconnection. This requires the integration of highly conformal thin films deposition techniques in TSV flows, particularly for metallization. In this study, seed layer enhancement is applied to regular PVD Cu seed for metalizing TSV of diameter of 2μm and aspect-ratio 15:1. The results reported in this paper open a new path for process integration of high A.R. TSVs and provide a versatile and reliable building block for achieving the high density interconnects required for tomorrow's 3D electronics devices.