A serial electrochemical process consist of copper via filling, electropolishing, electroless copper plating and electroless tin plating is presented for the TSV 3D SiP application. Defect-free copper via filling was achieved by controlling current modes and additives. After via filling, electropolishing was performed to planarize over-plated copper. Electropolishing within the potential of mass-transfer region and with the assistance of additives, fine polished surface without thickness disparity was achieved. For bump formation process, electroless copper and tin plating which is a self-aligned process was applied. Consequently, Cu/Sn bump on via patterned wafer was obtain without using the conventional CMP and lithographic processes.
展开▼
机译：对于TSV 3D SiP应用，提出了一系列的电化学工艺，该工艺包括通孔填充铜，电抛光，化学镀铜和化学镀锡。通过控制电流模式和添加剂可以实现通孔填充的无缺陷铜。在通孔填充之后，进行电抛光以平坦化过镀的铜。在传质区域的电位范围内进行电抛光，并在添加剂的辅助下，实现了没有厚度差异的精细抛光表面。对于凸点形成工艺，采用了自对准工艺的化学镀铜和锡。因此，无需使用常规的CMP和光刻工艺就可以在通孔图案化的晶片上获得Cu / Sn凸块。
展开▼
