Alternating phase shift mask design conflict resolution

摘要

Methods and apparatuses for preparing layouts and masks that use phase shifting to enable production of subwavelength features on an integrated circuit in close (optical) proximity to other structures are described. One embodiment selects from several strategies for resolving conflicts between phase shifters used to define features and (optically) proximate structures that are being defined other than by phase shifting. One embodiment adds additional phase shifters to define the conflicting structures. Another embodiment corrects the shape of the phase shifters in proximity to a conflicting structure. Resulting integrated circuits can include a greater number of subwavelength features even in areas that are in close proximity to structures that were not initially identified for production using a phase shifting mask.