Some embodiments relate to a method for processing a workpiece. In the method, an anti-reflective coating layer is provided over the workpiece. A first patterned photoresist layer, which has a first photoresist tone, is provided over the anti-reflective coating layer. A second patterned photoresist layer, which has a second photoresist tone opposite the first photoresist tone, is provided over the first patterned photoresist layer. An opening extends through the first and second patterned photoresist layers to allow a treatment to be applied to the workpiece through the opening. Other embodiments are also disclosed.