Multi-Layer Chips on Wafer Stacking Technologies with Carbon Nano-Tubes as Through-Silicon Vias and it’s potential applications for Power-Via technologies

In this work, carbon nanotubes (CNTs) are grown as advanced filler materials in through-silicon via (TSV). Electrical and thermal properties of CNTs are extracted by experiments and the implementation of multi-layer stacking is proposed. The resistance and thermal conductivity of CNT are measured as 10.5 ohm and 49 W/mK respectively. In accordance with its superior properties over copper, Carbon nanotubes as TSVs (CNT-TSV) have several advantages in three-dimensional integrated circuit (3DIC) technology. Signal integrity index, namely return loss and insertion loss have been evaluated by ANSYS HFSS (High frequency Structure Simulator). Within the high frequency interval (10~20 GHz), CNT-TSV has better electrical characteristics than copper. In summary, CNTs can be a promising material used in future chip on wafer stacking process.