FORMATION OF INTERCONNECTION

PROBLEM TO BE SOLVED: To remove such residue as AlCl3 generated after reactive ion etching of Al without extending a process period and to prevent corrosion of the Al for forming an interconnection without disconnection. SOLUTION: In this method, on a substrate, an indium-oxide tin conductor, an indium-oxide conductor, or a tin oxide conductor is selectively coated, and on the conductor of the substrate, a metal of multi-layer structure containing aluminum or Al is film-formed, then by etching this, an interconnection is formed. In this case, the metal of multi-layer structure on the substrate is etched with Cl based gas plasma, and then exposed in the plasma discharge of alcohol gas so that the reaction product generated at the etching is removed.