METHOD OF FORMING METAL LINE FOR SEMICONDUCTOR DEVICE

PURPOSE: A method for forming metal lines of semiconductor devices is provided to avoid the generation of voids or seams in the metal lines by forming the upper side of etching stop patterns to be wider than the lower side of the trench. CONSTITUTION: A first interlayer insulating film(102), an etching stop film, and a second interlayer insulating film are successively formed on a semiconductor substrate. A first etching process in which the second interlayer insulating film is patterned to form a trench(TC) is performed. The etching stop film is patterned to form etching stop patterns. A second etching process is performed to form the etching stop patters. A part of the first interlayer insulating film which is exposed to the inside of the trench is removed. Metal lines are formed in the trench.