Ultra-Deep Annular Cu Through-Silicon-Vias Fabricated Using Single-Sided Process

Ultra-deep through-silicon-vias (TSVs) are of great demand for 3D heterogeneous integration. However, most reported deep TSVs adopt double-sided silicon etching and electroplating, which dramatically increases the complexity and cost of the fabrication process. This letter focuses on how to achieve a high-quality Cu seed layer in ultra-deep vias, which is the key technology for the fabrication of ...