Mask Treatment for Double Patterning Design

A method of forming a semiconductor device, the method comprising:

• forming a first pattern in a mask layer;
• forming a second pattern in the mask layer, a combined pattern of the first pattern and the second pattern including one or more corners between sections of the first pattern and sections of the second pattern;
• rounding the one or more corners, thereby creating a rounded pattern;
• and
• transferring rounded pattern to an underlying layer.

A method of forming a semiconductor device, the method comprising:

• providing a substrate having an overlying first mask layer;
• forming a pattern in the first mask layer using a plurality of exposures, the pattern having one or more sharp corners;
• treating the pattern to round the one or more sharp corners, thereby forming a rounded pattern;
• and
• etching the substrate using the rounded pattern as a mask, the rounded pattern comprising remaining portions of the first mask layer.