Apparatus and methods for modeling process effects and imaging effects in scanning electron microscopy
First Claim
1. A method of generating a test recipe for a metrology tool, the method comprising:
- providing a plurality of first reference images that are designed to be used to fabricate a plurality of structures on a sample, each of the plurality of structures being imageable to form a plurality of target image patterns; and
generating or modifying a test recipe for use by a metrology tool in locating the structures on the sample, wherein generating or modifying the test recipe includes forming a plurality of second references images from at least some of the first reference images and associating the second reference images with the test recipe, the second reference images being formed to at least partially simulate one or more process effect(s) associated with fabricating the structures of the sample.
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Abstract
Disclosed are methods and apparatus for generating a test recipe for a metrology tool is disclosed. A plurality of first reference images that are designed to be used to fabricate a plurality of structures on a sample are provided. Each structure is imageable to form a plurality of target image patterns. A test recipe for use by a metrology tool in locating the structures on the sample is generated or modified. Generating or modifying the test recipe includes forming a plurality of second references images from the first reference images and associating the second reference images with the test recipe. The second reference images are formed to at least partially simulate one or more process effect(s) associated with fabricating the structures of the sample. Additionally, the second reference images may also be formed to simulate one or more imaging effects.
79 Citations
32 Claims
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1. A method of generating a test recipe for a metrology tool, the method comprising:
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providing a plurality of first reference images that are designed to be used to fabricate a plurality of structures on a sample, each of the plurality of structures being imageable to form a plurality of target image patterns; and
generating or modifying a test recipe for use by a metrology tool in locating the structures on the sample, wherein generating or modifying the test recipe includes forming a plurality of second references images from at least some of the first reference images and associating the second reference images with the test recipe, the second reference images being formed to at least partially simulate one or more process effect(s) associated with fabricating the structures of the sample. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
for a particular process type and a particular type of metrology tool, analyzing a plurality of combinations of different degree parameter values for each processing and imaging effect to determine which combination most accurately simulates the process and imaging effects of the particular process type and the particular type of metrology tool, respectively.
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10. A method as recited in claim 9, wherein the analysis is accomplished by:
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analyzing a plurality of combinations of different degree parameter values for each processing effect to determine which combination most accurately simulates the process effect of the particular process type; and
analyzing a plurality of combinations of different degree parameter values for each imaging effect to determine which combination most accurately simulates the imaging effect of the particular metrology tool, wherein the processing effect combinations are analyzed separately from the imaging effects.
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11. A method as recited in claim 1, wherein the metrology tool is a scanning electron microscope designed to measure and/or inspect samples selected from a group consisting of a reticle and an integrated circuit and the structures are selected from a group consisting of integrated circuit structures, resist pattern structures utilizable for fabricating integrated circuit structures, reticle structures, and resist pattern structures utilizable for fabricating reticle structures.
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12. A method as recited in claim 1, wherein locating the structures on the sample is accomplished by a pixel based search.
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13. A method as recited in claim 1, wherein locating the structures on the sample is accomplished by a geometric feature based search.
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14. A method as recited in claim 1, wherein locating the structures on the sample is accomplished by finding a first structure on the sample that is significantly correlated with a first one of the second reference images.
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15. A method as recited in claim 1, wherein each reference image is associated with an offset value from the corresponding target image to a test structure which is to be tested and information regarding how to test the test structure.
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16. A method as recited in claim 15, wherein the information includes a test structure type and a measurement type.
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17. A method as recited in claim 16, wherein the test structure type specifies whether the test structure is a hole, a post, a line, or a trench and the measurement type specifies whether to measure from the inside edges or the outside edges of such test structure.
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18. A computer system operable to generate a test recipe for a metrology tool, the computer system comprising:
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one or more processors;
one or more memory, wherein at least one of the processors and memory are together operable to;
provide a plurality of first reference image patterns that are designed to be used to fabricate a plurality of structures on a sample, each of the plurality of structures being imageable to form a plurality of target image patterns; and
generate or modify a test recipe for use by a metrology tool in locating the structures on the sample, wherein generating or modifying the test recipe includes forming a plurality of second references images from the first reference images and associating the second reference images with the test recipe, the second reference images being formed to at least partially simulate one or more process effect(s) associated with fabricating the structures of the sample. - View Dependent Claims (19, 20, 21, 22, 23, 24, 25, 26, 27, 28)
for a particular process type and a particular type of metrology tool, analyze a plurality of combinations of different degree parameter values for each processing and imaging effect to determine which combination most accurately simulates the process and imaging effects of the particular process type and the particular type of metrology tool, respectively.
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25. A computer system as recited in claim 24, wherein the analysis is accomplished by:
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analyzing a plurality of combinations of different degree parameter values for each processing effect to determine which combination most accurately simulates the process effect of the particular process type; and
analyzing a plurality of combinations of different degree parameter values for each imaging effect to determine which combination most accurately simulates the imaging effect of the particular metrology tool, wherein the processing effect combinations are analyzed separately from the imaging effects.
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26. A computer system as recited in claim 18, wherein the metrology tool is a scanning electron microscope designed to measure and/or inspect samples selected from a group consisting of a reticle and an integrated circuit and the structures are selected from a group consisting of integrated circuit structures, resist pattern structures utilizable for fabricating integrated circuit structures, reticle structures, and resist pattern structures utilizable for fabricating reticle structures.
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27. A computer system as recited in claim 18, wherein locating the structures on the sample is accomplished by a pixel based search.
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28. A computer system as recited in claim 18, wherein locating the structures on the sample is accomplished by finding a first structure on the sample that is significantly correlated with a first one of the second reference images.
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29. A computer program product for generating a test recipe for a metrology tool, the computer program product comprising:
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at least one computer readable medium;
computer program instructions stored within the at least one computer readable product configured to cause a combining device to;
provide a plurality of first reference image patterns that are designed to be used to fabricate a plurality of structures on a sample, each of the plurality of structures being imageable to form a plurality of target image patterns; and
generate or modify a test recipe for use by a metrology tool in locating the structures on the sample, wherein generating or modifying the test recipe includes forming a plurality of second references images from the first reference images and associating the second reference images with the test recipe, the second reference images being formed to at least partially simulate one or more process effect(s) associated with fabricating the structures of the sample. - View Dependent Claims (30, 31, 32)
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Specification