Qualifying patterns, patterning processes, or patterning apparatus in the fabrication of microlithographic patterns
First Claim
1. A method of qualifying a pattern, patterning process, or a patterning apparatus, comprising:
- providing a substrate having a surface covered by a pattern recording material;
causing multiple occurrences of irradiation of a reticle or a mask containing a design pattern, each of the occurrences of irradiation representing a value of a member of a set of lithographic operating variables, and the reticle or mask imparting to the occurrences of irradiation design pattern information corresponding to each of the values of the member of the set;
causing on the pattern recording material occurrences of irradiation carrying the design pattern information imparted by the reticle or mask;
recording in the pattern recording material a spatial pattern corresponding to the design pattern information imparted by the reticle or mask for each of the values of the member of the set, each spatial pattern recorded at a different region of the pattern recording material; and
determining from the recorded spatial patterns a presence of a pattern anomaly associated with the pattern, patterning process, or patterning apparatus.
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Abstract
The invention is a method of determining the presence of an anomaly in qualifying a pattern, patterning process, or patterning apparatus used in the fabrication of microlithographic patterns. A preferred implementation of the method qualifies incoming reticles and process conditions on test wafers to maximize the available usable process window for a given reticle exposure tool combination. Practicing this method on test wafers enables the identification of spatial areas where a process will fail first and candidate regions for carrying out defect inspection and metrology. Other preferred implementations of the method qualify masks, reticles, or other patterns characterized by data bases on which are stored image data acquired by practice of aerial image measurement system (AIMS) or design rule checking (DRC) techniques.
106 Citations
20 Claims
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1. A method of qualifying a pattern, patterning process, or a patterning apparatus, comprising:
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providing a substrate having a surface covered by a pattern recording material;
causing multiple occurrences of irradiation of a reticle or a mask containing a design pattern, each of the occurrences of irradiation representing a value of a member of a set of lithographic operating variables, and the reticle or mask imparting to the occurrences of irradiation design pattern information corresponding to each of the values of the member of the set;
causing on the pattern recording material occurrences of irradiation carrying the design pattern information imparted by the reticle or mask;
recording in the pattern recording material a spatial pattern corresponding to the design pattern information imparted by the reticle or mask for each of the values of the member of the set, each spatial pattern recorded at a different region of the pattern recording material; and
determining from the recorded spatial patterns a presence of a pattern anomaly associated with the pattern, patterning process, or patterning apparatus. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A method of qualifying a pattern, a patterning process, or a patterning apparatus, comprising:
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acquiring multiple spatial patterns corresponding to a lithographic pattern containing a design pattern, the multiple patterns acquired for different values of a member of a set of lithographic variables;
determining a presence of a design pattern anomaly by taking differences between different pairs of the acquired spatial patterns corresponding to different values of the member of the set; and
comparing the differences between the different pairs to determine which ones of the differences exhibit events that repeat and thereby isolate a possible pattern anomaly. - View Dependent Claims (15, 16, 17, 18, 19, 20)
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Specification