Methods for improved monitor and control of lithography processes
First Claim
1. A computer-implemented method, comprising:
- controlling one or more parameters of features within an entire printed area on a product wafer using a limited number of wafer measurements performed on the product wafer or another wafer, wherein the wafer measurements comprise one or more parameters of horizontal features and vertical features printed on the product wafer or the other wafer using a lithoaraphy system;
determining exposure conditions applied to the product wafer or the other wafer based on the wafer measurements;
predicting one or more parameters of one or more feature types printed on the product wafer using a tuned simulation model with the exposure conditions and design data for the product wafer, wherein the one or more feature types comprise at least one feature type on which the wafer measurements were not performed;
determining errors in performance of a lens of the lithography system across a field of the lens based on the wafer measurements and separating the errors into correctable and non-correctable errors across the field, wherein the errors comprise dose errors, focus errors, or dose and focus errors; and
determining astigmatism errors in the lens using the errors, wherein said controlling, said determining the exposure conditions, said predicting, said determining the errors, and said determining the astigmatism errors are performed by a computer having one or more processors executing instructions from a memory medium.
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Abstract
Various computer-implemented methods are provided. One method includes determining errors across a field of a lens of a lithography system based on wafer measurements. In addition, the method includes separating the errors into correctable and non-correctable errors across the field. The errors may include dose errors, focus errors, or dose and focus errors. In another embodiment, the method may include determining correction terms for parameter(s) of the lithography system, which if applied to the parameter(s), the correctable errors would be eliminated resulting in approximately optimal imaging performance of the lithography system. Another method includes controlling one or more parameters of features within substantially an entire printed area on a product wafer using a limited number of wafer measurements performed on a test wafer. The wafer measurements may be performed on a first feature type, and the features that are controlled may include a second, different feature type.
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Citations
27 Claims
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1. A computer-implemented method, comprising:
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controlling one or more parameters of features within an entire printed area on a product wafer using a limited number of wafer measurements performed on the product wafer or another wafer, wherein the wafer measurements comprise one or more parameters of horizontal features and vertical features printed on the product wafer or the other wafer using a lithoaraphy system; determining exposure conditions applied to the product wafer or the other wafer based on the wafer measurements; predicting one or more parameters of one or more feature types printed on the product wafer using a tuned simulation model with the exposure conditions and design data for the product wafer, wherein the one or more feature types comprise at least one feature type on which the wafer measurements were not performed; determining errors in performance of a lens of the lithography system across a field of the lens based on the wafer measurements and separating the errors into correctable and non-correctable errors across the field, wherein the errors comprise dose errors, focus errors, or dose and focus errors; and determining astigmatism errors in the lens using the errors, wherein said controlling, said determining the exposure conditions, said predicting, said determining the errors, and said determining the astigmatism errors are performed by a computer having one or more processors executing instructions from a memory medium. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A non-transitory computer-readable medium, comprising program instructions executable on a processor to perform a computer-implemented method, wherein the computer-implemented method comprises:
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controlling one or more parameters of features within an entire printed area on a product wafer using a limited number of wafer measurements performed on the product wafer or another wafer, wherein the wafer measurements comprise one or more parameters of horizontal features and vertical features printed on the product wafer or the other wafer using a lithography system; determining exposure conditions applied to the product wafer or the other wafer based on the wafer measurements; predicting one or more parameters of one or more feature types printed on the product wafer using a tuned simulation model with the exposure conditions and design data for the product wafer, wherein the one or more feature types comprise at least one feature type on which the wafer measurements were not performed; determining errors in performance of a lens of the lithography system across a field of the lens based on the wafer measurements and separating the errors into correctable and non-correctable errors across the field, wherein the errors comprise dose errors, focus errors, or dose and focus errors; and
determining astigmatism errors in the lens using the errors.
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15. A system, comprising:
- a measurement device configured to perform wafer measurements; and
a computer configured for;controlling one or more parameters of features within an entire printed area on a product wafer using a limited number of the wafer measurements performed on the product wafer or another wafer, wherein the wafer measurements comprise one or more parameters of horizontal features and vertical features printed on the product wafer or the other wafer using a lithography system; determining exposure conditions applied to the product wafer or the other wafer based on the wafer measurements; predicting one or more parameters of one or more feature types printed on the product wafer using a tuned simulation model with the exposure conditions and design data for the product wafer, wherein the one or more feature types comprise at least one feature type on which the wafer measurements were not performed; determining errors in performance of a lens of the lithography system across a field of the lens based on the wafer measurements and separating the errors into correctable and non-correctable errors across the field, wherein the errors comprise dose errors, focus errors, or dose and focus errors; and determining astigmatism errors in the lens using the errors, wherein the computer has one or more processors executing instructions from a memory medium. - View Dependent Claims (16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27)
- a measurement device configured to perform wafer measurements; and
Specification