Abstract: An etchant for a metal is described. In one example, the etchant includes ammonium persulfate ((NH4)2S2O8), an azole compound and water. The etchant does not include hydrogen peroxide. Thus, the etchant may etch a metal layer including copper so that an etched copper layer has a tapered profile. Furthermore, the etchant may have a high stability to maintain etching ability for a longer time. Thus, manufacturing margins may be improved so that manufacturing costs may be reduced.