A FULLY INTEGRATED ALUMINUM DUAL DAMASCENE PROCESS USING A NEW DOUBLESTOPPER STRUCTURE

A fully integrated aluminum dual damascene process is presented. The p rocess incorporates a double silicon nitride etch stopper structure to achieve better etching control. Use of silicon nitride etch stoppers usually results in increased wire capacitance. However, the new proces s presented here succeeds in significantly reducing the impact of the silicon nitride stopper layers on wire capacitance by arranging for th e stopper layers to be away from the wire corners. The integration of this process with a previously reported aluminum reflow process to obt ain an integrated aluminum dual damascene process is described and the results obtained are discussed.