<p>Methods for fabricating semiconductor structures are provided. A first layer may be deposited onto a substrate followed by the deposition of a second layer onto the first layer. A plurality of line structures may be etched in the second layer. A third layer, deposited onto the plurality of line structures of the second layer, may subsequently be etched to expose the plurality of line structures in the second layer. The plurality of line structures in the second layer may be removed, leaving an etched third layer. The etched third layer may be used as a mask to etch the first layer to form a semiconductor structure in the first layer. In some respects, the methods may include steps for etching the substrate using the etched first layer. The methods may also provide annealing the etched substrate to form a corrugate substrate surface.</p>