Lithographic method

Patent metadata

Field	Value
Publication number	US-11029610-B2
Application number	US-201816650520-A
Country	US
Kind code	B2
Filing date	Sep 4, 2018
Priority date	Sep 28, 2017
Publication date	Jun 8, 2021
Grant date	Jun 8, 2021

Abstract

A method for determining one or more optimized values of an operational parameter of a sensor system configured for measuring a property of a substrate. The method includes: determining a quality parameter for a plurality of substrates; determining measurement parameters for the plurality of substrates obtained using the sensor system for a plurality of values of the operational parameter; comparing a substrate to substrate variation of the quality parameter and a substrate to substrate variation of a mapping of the measurement parameters; and determining the one or more optimized values of the operational parameter based on the comparing.

First claim

The invention claimed is:

1. A method for determining one or more optimized values of an operational parameter of a sensor system configured for measuring a property of a substrate, the method comprising:
obtaining first values of a quality parameter for a plurality of substrates;
obtaining second values of a measurement parameter for the plurality of substrates, wherein the second values of the measurement parameter are measured values obtained by using the sensor system for a plurality of values of the operational parameter;
comparing, by a hardware computer system, a substrate to substrate variation of the first values to a substrate to substrate variation of a mapping of the second values; and
determining the one or more optimized values of the operational parameter based on the comparing.

2. A non-transitory computer-readable medium comprising computer-readable instructions therein, the instructions, upon execution by a computer system, configured to cause the computer system to at least:
obtain first values of a quality parameter for a plurality of substrates;
obtain second values of a measurement parameter for the plurality of substrates, wherein the second values of the measurement parameter are measured values obtained by using a sensor system configured for measuring a property of a substrate, for a plurality of values of an operational parameter of the sensor system;
compare a substrate to substrate variation of the first values to a substrate to substrate variation of a mapping of the second values; and
determine one or more optimized values of the operational parameter based on the comparing.

3. The computer-readable medium of claim 2 , wherein the mapping is a weighted sum, a non-linear mapping or a trained mapping based on a machine learning method.

4. The computer-readable medium of claim 2 , wherein the instructions are further configured to cause the computer system to determine an optimal set of weight factors for weighting the measurement parameter associated with a first value of the operational parameter and the measurement parameter associated with a second value of the operational parameter based on the comparison.

5. The computer-readable medium of claim 2 , wherein the first values of the quality parameter are determined using a simulation model predicting the quality parameter based on one or more selected from: context information, measurement data, reconstructed data, and/or hybrid metrology data.

6. The computer-readable medium of claim 2 , wherein the measurement parameter comprises a measured position of a mark and the quality parameter comprises a mark-to-device shift, the optimized values of the operational parameter being determined so as to optimize the quality parameter such that a substrate to substrate variation is minimal.

7. The computer-readable medium of claim 6 , wherein the instructions are further configured to cause the computer system to determine weightings for the operational parameter for measuring sub-segmented marks using measurements obtained from substrates having sub-segmented marks that have intentional mark-to-device shifts applied thereto so as to determine a sensitivity of the operational parameter to mark-to-device shifts.

8. The computer-readable medium of claim 2 , wherein the first values of the quality parameter and the second values of the measurement parameter are associated with a particular layer associated with the plurality of substrates.

9. The computer-readable medium of claim 8 , wherein the particular layer is selected based on evaluation of: i) a first substrate to substrate variation between the first values of the quality parameter associated with the particular layer and ii) a second substrate to substrate variation between the second values of the measurement parameter associated with the particular layer.

10. The computer-readable medium of claim 9 , wherein the particular layer is selected in case the first substrate to substrate variation and the second substrate to substrate variation exceed a threshold.

11. The computer-readable medium of claim 2 , wherein the one or more optimized values of the operational parameter comprise a first set of values of the operational parameter associated with a first coordinate of the measurement parameter and a second set of values of the operational parameter associated with a second coordinate of the measurement parameter.

12. The computer-readable medium of claim 11 , wherein the instructions are further configured to cause the computer system to:
determine a third coordinate parallel to a first preferential direction of a mark;
determine a fourth coordinate parallel to a second preferential direction of a mark;
determine a third set of optimized values of the operational parameter associated with the third coordinate and a fourth set of optimized values of the operational parameter associated with the fourth coordinate;
determine a transformation from the third and fourth coordinates to the first and second coordinates; and
transform the determined optimized values of the operational parameter in the third and fourth coordinates to optimized values of the operational parameter in the first and second coordinates, using the determined transformation.

13. The computer-readable medium of claim 11 , wherein the first set of values of the operational parameter are optimized independently of the second set of values of the operational parameter.

14. The computer-readable medium of claim 2 , wherein the quality parameter comprises an overlay or focus parameter.

15. The computer-readable medium of claim 2 , wherein the measurement parameter comprises a position of a feature provided to the plurality of substrates or an out-of-plane deviation of a location on the substrate.

16. The computer-readable medium of claim 2 , wherein the instructions configured to cause the computer system to determine the one or more optimized values of the operational parameter based on the comparison are arranged to do so for different zones of the substrate.

17. The computer-readable medium of claim 16 , wherein the different zones comprise a zone proximate an edge of the substrate and a zone proximate a center of the substrate.

18. A method of optimizing measurement data from a sensor system configured for measuring a property of a substrate, the method comprising:
obtaining overlay data for a plurality of substrates, wherein the overlay represents a deviation between a measured and an expected position of an alignment marker on a substrate and comprises a plurality of measurements of the alignment marker position made by a sensor system, each measurement of the plurality of measurements utilizing a different value of the operational parameter and/or a different operational parameter of the sensor system;
based on the obtained overlay data, and for each of the different values of the operational parameter and/or different operational parameters, determining a weight for adjusting the measurements obtained utilizing the different values of the operational parameter and/or different operational parameters such that the weighted adjustments to the measurements made by the sensor system for all of the different values of the operational parameter and/or different operational parameters are combined to minimize the overlay.

19. A non-transitory computer-readable medium comprising computer-readable instructions therein, the instructions, upon execution by a computer system, configured to cause the computer system to at least:
obtain overlay data

Assignees

• Asml Netherlands Bv

Inventors

• Tinnemans Patricius Aloysius Jacobus
• Hulsebos Edo Maria
• Megens Henricus Johannes Lambertus
• Erdamar Ahmet Koray
• Verhees Loek Johannes Petrus
• Roelofs Willem Seine Christian
• Van De Ven Wendy Johanna Martina
• Yagubizade Hadi
• Cekli Hakki Ergün
• Brinkhof Ralph
• Vu Tran Thanh Thuy
• Goosen Maikel Robert
• Van T Westeinde Maaike
• Kou Weitian
• Rijpstra Manouk
• Cox Matthijs
• Bijnen Franciscus Godefridus Casper

Classifications

• G03F9/7046 Primary

  Strategy, e.g. mark, sensor or wavelength selection · CPC title

• G03F9/7073

  Alignment marks and their environment (marks specific to masks G03F1/42; marks specific to molds or stamps G03F7/0002; overlay marks G03F7/70633; marks applied to semiconductor devices H10W46/00) · CPC title

• G03F7/70633

  Overlay, i.e. relative alignment between patterns printed by separate exposures in different layers, or in the same layer in multiple exposures or stitching · CPC title

• G03F7/70516 Primary

  Calibration of components of the microlithographic apparatus, e.g. light sources, addressable masks or detectors · CPC title

• G03F9/7069

  Alignment mark illumination, e.g. darkfield, dual focus · CPC title