Mask treatment for double patterning design

摘要

A method of forming a semiconductor device, and a product formed thereby, is provided. The method includes forming a pattern in a mask layer using, for example, double patterning or multi-patterning techniques. The mask is treated to smooth or round sharp corners. In an embodiment in which a positive pattern is formed in the mask, the treatment may comprise a plasma process or an isotropic wet etch. In an embodiment in which a negative pattern is formed in the mask, the treatment may comprise formation of conformal layer over the mask pattern. The conformal layer will have the effect of rounding the sharp corners. Other techniques may be used to smooth or round the corners of the mask.

主权项

1. A method of forming a semiconductor device, the method comprising:
forming a first mask layer directly over and contacting an underlying layer; forming a first pattern in the first mask layer; after the forming the first pattern in the first mask layer, performing a smoothing process on the first mask layer, the smoothing process rounding corners of the first mask layer in a plan view; and after completing the smoothing process, patterning the underlying layer using the first mask layer as a mask.