A new method is provided for the creation of the trenches or line patterns of damascene structures. Under the first embodiment of the invention, the trenches that are created for the copper interconnect lines are sputter etched as a result of which the corners of the trenches around the top elevation of the trenches are rounded. Under the second embodiment of the invention a disposable hard mask is created over the surface of the dielectric after which the trenches for the interconnect lines are created. The surface of the hard mask layer including the created trenches are rf sputter etched resulting in a sharp reduction of the angle of incidence between sidewalls of the trenches around the perimeter of the trenches and the surface of the layer of dielectric. The barrier and seed layers are deposited over the surface of the disposable hard mask including the created trenches, the deposited copper is polished down to the surface of the dielectric.