Etchant composition for forming metal interconnects

The present invention provides an etchant composition for a metal film comprising at least one film selected from an indium-based transparent conductive film, an aluminum-based metal film and a titanium-based metal film, used for the interconnect of a pixel electrode, a gate electrode, a source electrode and a drain electrode. The etchant composition is excellent in etching characteristics to an indium-based transparent conductive film, an aluminum-based metal film and a titanium-based metal film, respectively, and particularly to an Al-La-based alloy film. In addition, the etchant composition can effectively etch a tri-layered film comprising an indium-based transparent conductive film, an Al-La-based alloy film and a titanium-based metal film at a time.