METHOD FOR FORMING METAL INTERCONNECTION OF SEMICONDUCTOR DEVICE TO MINIMIZE GENERATION OF REACTION PRODUCT CAUSED BY REACTION OF ETCH GAS AND OBJECT TO BE ETCHED AND FORM METAL INTERCONNECTION OF MICRO LINE WIDTH

摘要

PURPOSE: A method for forming a metal interconnection of a semiconductor device is provided to minimize generation of a reaction product caused by reaction of etch gas and an object to be etched and form a metal interconnection of a fine line width by performing a physical etch process using inert gas while a chemical etch process is performed to dry-etch the metal interconnection. CONSTITUTION: A metal layer is deposited on an interlayer dielectric(401) of a semiconductor substrate. Mixture gas of BCl3, Cl2 and inert gas of 0-30 weight percent is used as the first etch gas to selectively etch the metal layer so that a main etch process for forming a metal interconnection(402a) is performed. Mixture gas of BCl3, Cl2 and inert gas of 65-100 weight percent is used as the second etch gas to perform an over-etch process in which a predetermined thickness of the interlayer dielectric in the periphery of the metal interconnection is etched.