| abstract |
The present invention uses a novel approach to copper metallization of workpieces, such as semiconductor workpieces. According to the present invention, the alkaline electrolyte copper bath 35 electroplats copper on the seed layer 30 and electroplats copper directly on the barrier layer material, or using a deposition process such as PVD. It is used to reinforce the ultra-thin copper seed layer deposited on the barrier layer. The resulting copper layer provides a good conformal copper coating that fills the trenches, vias, and other microstructures of the workpiece. When used for seed layer reinforcement, the resulting copper seed layer provides an excellent conformal copper coating that allows the microstructure to be filled with a copper layer with good uniformity using electrochemical deposition techniques. In addition, the copper layer electroplated in the described manner exhibits low sheet resistance and is easily cooled at low temperatures. |