Method and apparatus for determining feature characteristics using scatterometry
First Claim
1. A method for characterizing features, comprising:
- measuring a dimensional characteristic of a first grating structure;
illuminating at least a portion of a first feature and the first grating structure, the first feature being formed over at least a portion of the first grating structure;
measuring light reflected from the illuminated portion of the first feature and the first grating structure to generate a reflection profile;
selecting at least one reference reflection profile based on the measured dimensional characteristic of the first grating structure;
comparing the generated reflection profile to the selected reference reflection profile; and
determining a characteristic of the first feature based on the comparison between the measured reflection profile and the selected reference reflection profile.
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Accused Products
Abstract
A method for characterizing features includes measuring a dimensional characteristic of a first grating structure; illuminating at least a portion of a first feature and the first grating structure, the first feature being formed over at least a portion of the first grating structure; measuring light reflected from the illuminated portion of the first feature and the first grating structure to generate a reflection profile; selecting at least one reference reflection profile based on the measured dimensional characteristic of the first grating structure, comparing the generated reflection profile to the selected reference reflection profile; and determining a characteristic of the first feature based on the comparison between the measured reflection profile and the selected reference reflection profile.
53 Citations
70 Claims
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1. A method for characterizing features, comprising:
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measuring a dimensional characteristic of a first grating structure;
illuminating at least a portion of a first feature and the first grating structure, the first feature being formed over at least a portion of the first grating structure;
measuring light reflected from the illuminated portion of the first feature and the first grating structure to generate a reflection profile;
selecting at least one reference reflection profile based on the measured dimensional characteristic of the first grating structure;
comparing the generated reflection profile to the selected reference reflection profile; and
determining a characteristic of the first feature based on the comparison between the measured reflection profile and the selected reference reflection profile. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 65)
selecting the at least one reference reflection profile further comprises generating a library of reference reflection profiles based on the measured dimension of the first grating structure, each reference reflection profile having an associated characteristic metric;
comparing the generated reflection profile to the selected reference reflection profile further comprises selecting a reference reflection profile from the library closest to the generated reflection profile; and
determining the characteristic of the first feature further comprises determining the characteristic of the first feature based on the characteristic metric associated with the selected reference reflection profile from the library.
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11. The method of claim 1, wherein:
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selecting the at least one reference reflection profile further comprises selecting a set of reference reflection profiles from a library of reference reflection profiles based on the measured dimension of the first grating structure, each reference reflection profile in the selected set having an associated characteristic metric;
comparing the generated reflection profile to the selected reference reflection profile further comprises selecting a reference reflection profile from the set closest to the generated reflection profile; and
determining the characteristic of the first feature further comprises determining the characteristic of the first feature based on the characteristic metric associated with the selected reference reflection profile from the set.
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12. The method of claim 1, wherein:
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selecting the at least one reference reflection profile further comprises generating a target reflection profile based on the measured dimension of the first grating structure;
comparing the generated reflection profile to the selected reference reflection profile further comprises comparing the generated reflection profile to the target reflection profile; and
determining the characteristic of the first feature further comprises determining the second characteristic of the first feature based on the comparison of the generated reflection profile and the target reflection profile.
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13. The method of claim 1, wherein:
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selecting the at least one reference reflection profile further comprises selecting a target reflection profile from a library of reference reflection profiles based on the measured dimension of the first grating structure;
comparing the generated reflection profile to the selected reference reflection profile further comprises comparing the generated reflection profile to the target reflection profile; and
determining the characteristic of the first feature further comprising determining the characteristic of the first feature based on the comparison of the generated reflection profile and the target reflection profile.
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14. The method of claim 1, wherein generating the reflection profile comprises generating the reflection profile based on at least one of intensity and phase of the reflected light.
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15. The method of claim 1, further comprising identifying a fault condition associated with the first feature based on the determined characteristic of the first feature.
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16. The method of claim 1, wherein forming the first grating and the first feature further comprises forming the first grating and the first feature in a test structure on a wafer.
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17. The method of claim 1, wherein forming the first grating and the first feature further comprises forming the first grating and the first feature in a production device on a wafer.
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18. The method of claim 1, wherein measuring the dimension of the first grating structure further comprises measuring the dimension using at least one of a scatterometry tool, a scanning electron microscope, an atomic force microscope, and a thickness measuring tool.
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65. The processing line of claim 5, further comprising a controller adapted to identify a fault condition associated with the first feature based on the determined characteristic of the first feature.
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19. A method for characterizing features, comprising:
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measuring a dimensional characteristic of a first grating structure;
illuminating at least a portion of a first feature and the first grating structure, the first feature being formed over at least a portion of the first grating structure;
measuring light reflected from the illuminated portion of the first feature and the first grating structure to generate a reflection profile;
generating at least one reference reflection profile based on the measured dimensional characteristic of the first grating structure;
comparing the generated reflection profile to the generated reference reflection profile; and
determining a characteristic of the first feature based on the comparison between the measured reflection profile and the generated reference reflection profile. - View Dependent Claims (20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34)
generating the at least one reference reflection profile further comprises generating a library of reference reflection profiles based on the measured dimension of the first grating structure, each reference reflection profile having an associated characteristic metric;
comparing the generated reflection profile to the generated reference reflection profile further comprises selecting a reference reflection profile from the library closest to the generated reflection profile; and
determining the characteristic of the first feature further comprises determining the characteristic of the first feature based on the characteristic metric associated with the selected reference reflection profile from the library.
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29. The method of claim 19, wherein:
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generating the at least one reference reflection profile further comprises generating a target reflection profile based on the measured dimension of the first grating structure;
comparing the generated reflection profile to the generated reference reflection profile further comprises comparing the generated reflection profile to the target reflection profile; and
determining the characteristic of the first feature further comprises determining the second characteristic of the first feature based on the comparison of the generated reflection profile and the target reflection profile.
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30. The method of claim 19, wherein generating the reflection profile comprises generating the reflection profile based on at least one of intensity and phase of the reflected light.
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31. The method of claim 19, further comprising identifying a fault condition associated with the first feature based on the determined characteristic of the first feature.
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32. The method of claim 19, wherein forming the first grating and the first feature further comprises forming the first grating and the first feature in a test structure on a wafer.
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33. The method of claim 19, wherein forming the first grating and the first feature further comprises forming the first grating and the first feature in a production device on a wafer.
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34. The method of claim 19, wherein measuring the dimension of the first grating structure further comprises measuring the dimension using at least one of a scatterometry tool, a scanning electron microscope, an atomic force microscope, and a thickness measuring tool.
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35. A processing line, comprising:
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a first metrology tool adapted to measure a dimensional characteristic of a first grating structure;
a second metrology tool, comprising;
a light source adapted to illuminating at least a portion of a first feature and the first grating structure, the first feature being formed over at least a portionof the first grating structure;
a detector adapted to measure light reflected from the illuminated portion of the first feature and the first grating structure to generate a reflection profile; and
a data processing unit adapted to select at least one reference reflection profile based on the measured dimensional characteristic of the first grating structure, comparing the generated reflection profile to the selected reference reflection profile, and determine a characteristic of the first feature based on the comparison between the measured reflection profile and the selected reference reflection profile. - View Dependent Claims (36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52)
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53. A processing line, comprising:
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a first metrology tool adapted to measure a dimensional characteristic of a first grating structure;
a second metrology tool, comprising;
a light source adapted to illuminating at least a portion of a first feature and the first grating structure, the first feature being formed over at least a portion of the first grating structure;
a detector adapted to measure light reflected from the illuminated portion of the first feature and the first grating structure to generate a reflection profile; and
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a data processing unit adapted to generate at least one reference reflection profile based on the measured dimensional characteristic of the first grating structure, compare the generated reflection profile to the generated reference reflection profile, and determine a characteristic of the first feature based on the comparison between the measured reflection profile and the generated reference reflection profile. - View Dependent Claims (54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 66, 67, 68)
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69. A processing line, comprising:
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means for measuring a dimensional characteristic of a first grating structure;
means for illuminating at least a portion of a first feature and the first grating structure, the first feature being formed over at least a portion of the first grating structure;
means for measuring light reflected from the illuminated portion of the first feature and the first grating structure to generate a reflection profile;
means for selecting at least one reference reflection profile based on the measured dimensional characteristic of the first grating structure;
means for comparing the generated reflection profile to the selected reference reflection profile; and
means for determining a characteristic of the first feature based on the comparison between the measured reflection profile and the selected reference reflection profile.
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70. A processing line, comprising:
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means for measuring a dimensional characteristic of a first grating structure;
means for illuminating at least a position of a first feature and the first grating structure, the first feature being formed over at least a portion of the first grating structure;
means for measuring light reflected from the illuminated portion of the first feature and the first grating structure to generate a reflection profile;
means for generating at least one reference reflection profile based on the measured dimensional characteristic of the first grating structure;
means for comparing the generated reflection profile to the generated reference reflection profile; and
means for determining a characteristic of the first feature based on the comparison between the measured reflection profile and the generated reference reflection profile.
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Specification