Method for filling cobalt into through vias of a semiconductor wafer

Abstract

A method for filling cobalt into through vias of a semiconductor wafer is disclosed. The method comprises preparing a cobalt-based electroplating solution, performing wetting treatment on the through vias, and electroplating cobalt into the wetting-treated vias. The wetting treatment includes immersing the wafer in an organic solvent, immersing the wafer in deionized water, and placing the wafer in a vacuum container containing the electroplating solution to enhance wettability by releasing trapped air from the through-silicon via (TSV) holes. Incorporating a leveling agent and an inhibitor in the electroplating solution enables void-free filling of high aspect ratio TSVs. The process can be further tailored with electrolyte additives to improve trench filling, broaden the process window, and lower manufacturing costs. Compared with conventional CVD and PVD methods, the disclosed method provides improved filling performance and enhanced industrial applicability.

Dependencies are inferred from the claim text.