METHOD OF FORMING A SEMICONDUCTOR DEVICE HAVING A METAL LAYER

摘要

A metal layer (24) is formed over a metal oxide (14), where the metal oxide is formed over a semiconductor substrate (12). A predetermined critical dimension of the metal layer is determined. A first etch is performed to etch the metal layer down to the metal oxide and form footings (26) at the sidewalls of the metal layer. A second etch to remove the footings to target a predetermined critical dimension, wherein the second etch is selective to the metal oxide. In one embodiment, a conductive layer (22) is formed over the metal layer. The bulk of the conductive layer may be etched leaving a portion in contact with the metal layer. Next, the portion left in contact with the metal layer may be etched using chemistry selective to the metal layer.