Selection of Optimum Patterns in a Design Layout Based on Diffraction Signature Analysis
First Claim
1. A method of selecting a subset of target patterns from a design layout configured to be imaged onto a substrate via a lithographic process, the method comprising the steps of:
- generating a respective diffraction map for a plurality of target patterns from an initial larger set of target patterns from the design layout;
identifying diffraction signatures from the various diffraction maps of the plurality of target patterns from the initial larger set of target patterns;
grouping the plurality of target patterns from the initial larger set of target patterns into diffraction-signature groups, the target patterns in a specific diffraction-signature group having similar diffraction signature; and
selecting the subset being a representative set of target patterns to cover a predefined number of diffraction-signature groups, such that the representative set of target patterns represents at least a part of the design layout for the lithographic process.
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Abstract
The present invention relates generally to selecting optimum patterns based on diffraction signature analysis, and more particularly to, using the optimum patterns for mask-optimization for lithographic imaging. A respective diffraction map is generated for each of a plurality of target patterns from an initial larger set of target patterns from the design layout. Diffraction signatures are identified from the various diffraction maps. The plurality of target patterns is grouped into various diffraction-signature groups, the target patterns in a specific diffraction-signature group having similar diffraction signature. A subset of target patterns is selected to cover all possible diffraction-signature groups, such that the subset of target patterns represents at least a part of the design layout for the lithographic process. The grouping of the plurality of target patterns may be governed by predefined rules based on similarity of diffraction signature. The predefined rules comprise coverage relationships existing between the various diffraction-signature groups.
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Citations
21 Claims
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1. A method of selecting a subset of target patterns from a design layout configured to be imaged onto a substrate via a lithographic process, the method comprising the steps of:
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generating a respective diffraction map for a plurality of target patterns from an initial larger set of target patterns from the design layout; identifying diffraction signatures from the various diffraction maps of the plurality of target patterns from the initial larger set of target patterns; grouping the plurality of target patterns from the initial larger set of target patterns into diffraction-signature groups, the target patterns in a specific diffraction-signature group having similar diffraction signature; and selecting the subset being a representative set of target patterns to cover a predefined number of diffraction-signature groups, such that the representative set of target patterns represents at least a part of the design layout for the lithographic process. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
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Specification