METHOD FOR ACHIEVING COMPLIANT SUB-RESOLUTION ASSIST FEATURES
First Claim
1. A process of forming a photomask pattern comprising one or more sub-resolution assist features (SRAF), the process comprising:
- generating a first set of SRAF patterns, each of the SRAF patterns in the first set having a first assigned mask position;
determining if the SRAF patterns of the first set comply with a preselected set of rules, wherein one or more of the SRAF patterns are found to be illegal because they do not comply with at least one of the preselected rules; and
reassigning one or more of the illegal SRAF patterns to second mask positions that are different from the first mask positions, the second mask positions allowing the illegal SRAF patterns to comply with the at least one preselected rule to form corrected SRAF patterns.
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Accused Products
Abstract
The present application is directed to a process of forming a photomask pattern comprising one or more sub-resolution assist features (SRAF). The process comprises generating a first set of SRAF patterns. Each of the SRAF patterns in the first set having a first assigned mask position. After the first set of SRAF patterns are generated, determining if the SRAF patterns of the first set comply with a preselected set of rules, wherein one or more of the SRAF patterns are found to be illegal because they do not comply with at least one of the preselected rules. One or more of the illegal SRAF patterns are reassigned to second mask positions that are different from the first mask positions, the second mask positions allowing the illegal SRAF patterns to comply with the at least one preselected rule to form corrected SRAF patterns. The present application also discloses systems for generating a sub-resolution assist feature pattern for a photomask, as well as SRAF modules embodied on a computer readable medium comprising instructions operable to carry out the processes of the present application.
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Citations
23 Claims
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1. A process of forming a photomask pattern comprising one or more sub-resolution assist features (SRAF), the process comprising:
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generating a first set of SRAF patterns, each of the SRAF patterns in the first set having a first assigned mask position; determining if the SRAF patterns of the first set comply with a preselected set of rules, wherein one or more of the SRAF patterns are found to be illegal because they do not comply with at least one of the preselected rules; and reassigning one or more of the illegal SRAF patterns to second mask positions that are different from the first mask positions, the second mask positions allowing the illegal SRAF patterns to comply with the at least one preselected rule to form corrected SRAF patterns. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A system for correcting a sub-resolution assist feature (SRAF) pattern for a photomask, the system comprising:
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a database operable to store data describing one or more integrated circuit features having target dimensions; and an SRAF module coupled to the database, wherein the SRAF module is embodied on a computer readable medium and comprises a set of instructions operable to reassign one or more illegal SRAF patterns having first assigned mask positions to second mask positions that are different from the first mask positions. - View Dependent Claims (15, 16, 17, 18)
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- 19. An SRAF module embodied on a computer readable medium, the SRAF module comprising a set of instructions operable to reassign one or more illegal SRAF patterns having first assigned mask positions to second mask positions that are different from the first mask positions.
Specification