US Patent 8003305 Method for patterning a semiconductor wafer

A method for etching a pattern on a surface is disclosed. A mask layer is disposed over a surface and a resist is disposed over the mask layer. The resist is exposed to light through the mask exposing primary pattern and sidelobe regions. The resist is developed and the mask layer is etched according to the resist pattern. A first material is deposited over the mask layer, wherein a gap is formed beneath the material and over the primary pattern region. The material is etched back so that the gap is exposed, and the primary pattern region is etched using the first material as a mask.