Wet etching method in multilayer metal patterning process

The invention provides a wet etching method in the multilayer metal patterning process. According to the method, etching is performed on Ag and Ni by utilizing the mixed liquor of glacial acetic acid (CH3COOH), nitric acid (HNO3) and water, etching is performed on Ti by utilizing diluted hydrofluoric acid, etching is performed on Al by utilizing an Al etching solution, and finally, etching is performed on TiN and Ti by utilizing an APM solution. According to the invention, the photoetching process needs only once, so the cost is greatly reduced, and the advantage of good etching window morphology control can be realized in all wet etching steps, so the quality of the patterning process can be improved, and Ag, Ni, Al as well as TiN and Ti are etched in one step separately, so the flow of the wet etching process can be simplified, and the efficiency of the process can be improved.