500 nm-sized Ni-TSVwith Aspect Ratio 20 for Future 3D-LSIs_A Low-Cost Electroless-Ni Plating Approach

A 500 nm-width nickel-through-Si-via (Ni-TSV) for future 3D-LSI/IC integration at chip-to-wafer/wafer-to-wafer level was proposed and fabricated successfully on 12-inch LSI wafer. An aspect ratio of 20 for 500 nm-width Ni-TSVs has been realized. A modified electroless-Ni plating process was employed to seamlessly and nearly completely fill these Ni-TSVs. We were able to fabricate Ni-TSVs successfully with reproducibility by using via-last approach.