A method for avoiding erosion of a conductor structure during a procedure of removing etching residues is provided. The method provides a semiconductor structure and the conductor structure formed therein. A cap layer is formed on the conductor structure and the semiconductor and a dielectric layer formed thereon. The dielectric layer and the cap layer are then etched to partially expose the conductor structure. The etching residues are removed with an amine-containing solution and the amine-containing solution is removed with an intermediate solvent to avoid erosion of the exposed conductor structure. As a key step of the present invention, the intermediate solvent comprises N-methylpyrrolidone or isopropyl alcohol and can protect the conductor structure from erosion.