Method to determine the value of process parameters based on scatterometry data
First Claim
1. A method for determining at least one process parameter related to a lithographic apparatus, the method comprising:
- obtaining calibration measurement data, with an optical detection apparatus, from a plurality of marker structure sets provided on a calibration substrate, each of said plurality of marker structure sets including at least one calibration marker structure created using different known values of said at least one process parameter;
determining a mathematical model by using said known values of said at least one process parameter and by employing a regression technique on said calibration measurement data, said mathematical model comprising a number of regression coefficients;
obtaining measurement data, with said optical detection apparatus, from at least one marker structure provided on a substrate, said at least one marker structure being exposed with an unknown value of said at least one process parameter; and
determining the unknown value of said at least one process parameter for said substrate from said obtained measurement data by employing said regression coefficients of said mathematical model.
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Abstract
A method according to an embodiment includes obtaining calibration measurement data, with an optical detection apparatus, from a plurality of marker structure sets provided on a calibration substrate. Each marker structure set includes at least one calibration marker structure created using different known values of the process parameter. The method includes obtaining measurement data, with the optical detection apparatus, from at least one marker structure provided on a substrate and exposed using an unknown value of the process parameter; and determining the unknown value of the process parameter from the obtained measurement data by employing regression coefficients in a model based on the known values of the process parameter and the calibration measurement data.
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Citations
36 Claims
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1. A method for determining at least one process parameter related to a lithographic apparatus, the method comprising:
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obtaining calibration measurement data, with an optical detection apparatus, from a plurality of marker structure sets provided on a calibration substrate, each of said plurality of marker structure sets including at least one calibration marker structure created using different known values of said at least one process parameter;
determining a mathematical model by using said known values of said at least one process parameter and by employing a regression technique on said calibration measurement data, said mathematical model comprising a number of regression coefficients;
obtaining measurement data, with said optical detection apparatus, from at least one marker structure provided on a substrate, said at least one marker structure being exposed with an unknown value of said at least one process parameter; and
determining the unknown value of said at least one process parameter for said substrate from said obtained measurement data by employing said regression coefficients of said mathematical model. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A system for determining at least one process parameter related to a lithographic apparatus, the system comprising:
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an optical detection apparatus configured to provide measurement data related to said at least one process parameter; and
a processor unit comprising a mathematical model defining how said at least one process parameter can be derived from said measurement data, wherein said optical detection apparatus is further configured to;
obtain calibration data from a plurality of marker structure sets provided on a calibration substrate, each of said plurality of marker structure sets comprising at least one calibration marker structure created using different known values of said at least one process parameter;
provide said calibration data to said processor unit;
obtain measurement data on at least one marker structure provided on a substrate, said at least one marker structure being made using an unknown value of said at least one process parameter to be determined; and
provide said measurement data to said processor unit;
and wherein said processor unit is further configured to;
determine said mathematical model by using said known values of said at least one parameter and by employing a regression technique on said calibration data, received from said optical detection apparatus, said mathematical model comprising a number of regression coefficients; and
determine the unknown value of said at least one process parameter for said substrate from said obtained measurement data, received from said optical detection apparatus, by employing said regression coefficients in said mathematical model. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20, 21, 22, 23)
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24. A method for determining at least one process parameter related to a lithographic apparatus, the method comprising:
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obtaining calibration data, with an optical detection apparatus, from at least two calibration marker structures provided on a calibration substrate, at least one of said at least two calibration marker structures being created using multiple known values of said at least one process parameter;
preprocessing said calibration data by performing at least one mathematical operation upon said calibration data;
determining a mathematical model by using said known values of said at least one parameter and by employing a regression technique on said preprocessed calibration data, said mathematical model comprising a number of regression coefficients;
obtaining measurement data, with said optical detection apparatus, from at least one measurement marker provided on a substrate, said at least one measurement marker being created using an unknown value of said at least one process parameter; and
determining the unknown value of said at least one process parameter for said substrate from said measurement data by preprocessing said measurement data, said preprocessing including performing said at least one mathematical operation, and employing said regression coefficients of said mathematical model. - View Dependent Claims (25, 26, 27, 28)
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29. A system for determining at least one process parameter related to a lithographic apparatus, the system comprising:
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an optical detection apparatus configured to provide measurement data related to said at least one process parameter; and
a processor unit comprising a mathematical model defining how said at least one process parameter can be derived from said measurement data, wherein said optical detection apparatus is configured to;
obtain calibration data from at least two different calibration marker structures provided on a calibration substrate, at least one of said at least two calibration marker structures being created using multiple known values of said at least one process parameter;
provide said calibration data to said processor unit;
obtain measurement data on at least one marker structure provided on a substrate, exposed with an unknown value of said at least one process parameter to be determined; and
provide said measurement data to said processor unit;
and wherein said processor unit is configured to;
preprocess said calibration data by performing at least one mathematical operation upon the calibration data obtained on said at least two different calibration marker structures;
determine said mathematical model by using said known values of said at least one parameter and by employing a regression technique on said preprocessed calibration data, said mathematical model comprising a number of regression coefficients; and
determine the unknown value of said at least one process parameter for said substrate from said measurement data, by preprocessing said measurement data by performing said at least one mathematical operation and employing said regression coefficients in said mathematical model. - View Dependent Claims (30, 31, 32, 33)
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34. A method for determining at least one parameter of a lithographic apparatus, the method comprising:
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measuring a plurality of calibration spectra obtained from a plurality of calibration structures, each of the plurality of calibration structures being created using a different known value of said at least one parameter;
performing a regression analysis on said plurality of calibration spectra to determine a mathematical model that defines a relationship between a spectrum and a value of said at least one parameter;
measuring a spectrum obtained with a marker structure provided on a substrate, said marker structure being exposed with said lithographic apparatus using an unknown value of said at least one parameter; and
determining said unknown value of said at least one parameter using said mathematical model. - View Dependent Claims (35, 36)
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Specification