Process for preventing the formation of ring defects

Abstract

The prevention of the formation of undesired defects formed during the etching of etched metal interconnect lines on an integrated circuit during an integrated circuit manufacturing process that involves laying down on a semiconductor wafer a thin film such as an anti-reflective coating (ARC) on a layer of metal to be patterned into the metal interconnects of the individual integrated circuits. To do this the anti-reflective coating layer is covered with an oxide layer prior to applying and patterning subsequent photoresist. The specific metalization layer disclosed can be of aluminum, copper or copper-aluminum alloy. The ARC as disclosed is a nitride layer, such as titanium nitride. The oxide may be formed on the ARC in a number of known ways and may be etched subsequently alone or in combination with the underlying ARC and metal after subsequent photoresist deposit upon the oxide layer.