Embodiments of the present disclosure provide methods for etching a metal layer, such as a copper layer, to form an interconnection structure in semiconductor devices. In one example, a method of patterning a metal layer on a substrate includes supplying a first etching gas mixture comprising a hydro-carbon gas and a hydrogen containing gas into a processing chamber having a substrate disposed therein, the substrate having a metal layer disposed thereon, supplying a second gas mixture comprising the hydrogen containing gas to a surface of the etched metal layer disposed on the substrate, and supplying a third gas mixture comprising an inert gas into the processing chamber to sputter clean the surface of the etched metal layer.