a method for patterning an aluminum - containing layer . a tungsten - containing layer is provided over an aluminum - containing layer . the tungsten - containing layer is patterned to form an opening therein , so that the opening exposes an underlying portion of the aluminum - containing layer . the patterned tungsten - containing layer is exposed to an etch having a substantially higher etch rate of the aluminum - containing layer than of the tungsten - containing layer to remove the exposed portion of the aluminum - containing layer .