Fabrication method of wiring structure for improving crown-like defect

A method of fabricating a wiring structure for improving a crown-like defect, the method comprising the steps of:

• providing a substrate on which a seed layer and a patterned photoresist layer with an opening are formed;
• forming a copper layer in the opening, wherein the copper layer has a bottom covering the seed layer;
• forming a barrier layer on the copper layer, wherein the barrier layer covers at least a top portion of the copper layer, and an oxidation potential of the barrier layer is greater than an oxidation potential of the copper layer;
• removing the patterned photoresist layer to perform an etching process, wherein the copper layer and a portion of the seed layer exposed are etched to form a wiring layer;
• and
• performing an immersion process to form an anti-oxidation layer comprehensively on exposed surfaces of the barrier layer and the wiring layer, wherein the exposed surfaces of the barrier layer comprise an exposed bottom surface.