Patent ID: 7945869

Claim:
A method for generating mask patterns, the method comprising: transforming a target lithographic pattern into a transformed lithographic pattern, wherein the target lithographic pattern comprises a plurality of mask elements, regions between the plurality of mask elements comprise spaces, and transforming comprises identifying critical spaces from the target lithographic pattern, wherein the critical spaces comprise spaces that comprise at least one dimension measuring a critical distance; identifying intermediate critical spaces, wherein the intermediate critical spaces comprise critical spaces which are separated from an adjoining critical space by an intermediate dimension; identifying intermediate mask elements, wherein the intermediate mask elements comprise mask elements immediately adjacent to at least one critical space; and identifying odd and even intermediate mask elements, wherein odd intermediate mask elements comprise every other intermediate mask element along an axis, and wherein even intermediate mask elements comprise remaining intermediate mask elements not designated as odd intermediate mask elements; and decomposing the transformed lithographic pattern into a first decomposed pattern and into a second decomposed pattern, wherein transforming and decomposing is performed by a computer having a non-transitory computer-readable storage medium with an executable program stored thereon.