Metrology method and system and lithographic system

Patent metadata

Field	Value
Publication number	US-2024094643-A1
Application number	US-202118269983-A
Country	US
Kind code	A1
Filing date	Dec 20, 2021
Priority date	Jan 19, 2021
Publication date	Mar 21, 2024
Grant date	—

Abstract

A method for measuring a parameter of interest from a target and associated apparatuses. The method includes obtaining measurement acquisition data relating to measurement of the target and finite-size effect correction data and/or a trained model operable to correct for at least finite-size effects in the measurement acquisition data. At least finite-size effects in the measurement acquisition data is corrected for using the finite-size effect correction data and/or the trained model to obtain corrected measurement data and/or obtain a parameter of interest; and where the correcting does not directly determine the parameter of interest, determining the parameter of interest from the corrected measurement data.

First claim

1 . A method for measuring a parameter of interest from a target, the method comprising:
obtaining measurement acquisition data relating to measurement of the target; obtaining finite-size effect correction data and/or a trained model operable to correct for at least finite-size effects in the measurement acquisition data; correcting for at least finite-size effects in the measurement acquisition data using the finite-size effect correction data and/or the trained model to obtain corrected measurement data and/or determine a parameter of interest which is corrected for at least the finite-size effects; and where the correcting does not directly determine the parameter of interest, determining the parameter of interest from the corrected measurement data.

2 . The method as claimed in claim 1 , wherein the measurement acquisition data comprises at least one acquisition local parameter distribution.

3 . The method as claimed in claim 2 , wherein the at least local parameter distribution comprises an acquisition local phase distribution and/or an acquisition local amplitude distribution.

4 . The method as claimed in claim 2 , wherein the at least one local parameter distribution comprises at least one simulated local parameter distribution.

5 . The method as claimed in claim 2 , wherein the at least one local parameter distribution and/or at least one correction local parameter distribution is obtained by an extraction step which extracts the local parameter distribution from the measurement acquisition data and/or the at least one correction local parameter distribution from calibration measurement acquisition data.

6 . The method as claimed in claim 5 , wherein the extraction step comprises a pattern recognition step to determine one or more global quantities from the raw metrology signal.

7 . The method as claimed in claim 1 , further comprising:
obtaining calibration data comprising a plurality of calibration images, the calibration images comprising images of calibration targets having been obtained with at least one physical parameter of the measurement varied between acquisitions; determining one or more basis functions from the calibration data, each basis function encoding the effect of the variation of the at least one physical parameter on the calibration images; determining a respective expansion coefficient for each basis function; and correcting at least one measurement image comprised within the measurement acquisition data and/or a respective value for the parameter of interest derived from each the at least one measurement image using the expansion coefficients.

8 . The method as claimed in claim 7 , comprising determining a component image for each of the basis functions, wherein each expansion coefficient is obtained from a combination of each respective component image and each at least one measurement image.

9 . The method as claimed in claim 7 , comprising determining each expansion coefficient from a combination of; each at least one measurement image, a scalar mean of the at least one measurement image and an averaged zero-mean image comprising the average zero-mean of the at least one measurement image.

10 . The method as claimed in claim 7 , wherein the correcting each at least one measurement image and/or a value for the parameter of interest comprises:
obtaining ground truth data for the parameter of interest; and constructing a correction model and using the correction model to calibrate a function of the expansion coefficients which minimizes a residual between the value for the parameter of interest with respect to the ground truth data.

11 . A method for measuring a parameter of interest from a target, the method comprising:
obtaining calibration data comprising a plurality of calibration images, the calibration images comprising images of calibration targets having been obtained with at least one physical parameter of the measurement varied between acquisitions; determining one or more basis functions from the calibration data, each basis function encoding the effect of the variation of the at least one physical parameter on the calibration images; determining a respective expansion coefficient for each basis function; obtaining measurement acquisition data comprising at least one measurement image relating to measurement of the target; and correcting each said at least one measurement image and/or a value for the parameter of interest derived from each said at least one measurement image using the expansion coefficients.

12 . The method as claimed in claim 11 , comprising determining a component image for each of the basis functions, wherein each expansion coefficient is obtained from a combination of each respective component image and each at least one measurement image.

13 . The method as claimed in claim 11 , comprising determining each expansion coefficient from a combination of each at least one measurement image, a scalar mean of the at least one measurement image and an averaged zero-mean image comprising the average zero-mean of the at least one measurement image.

14 . The method as claimed in claim 1 , wherein the parameter of interest is aligned position.

15 . The method as claimed in claim 1 , wherein the parameter of interest is overlay or focus.

16 . (canceled)

17 . A non-transient computer program carrier comprising a computer program that, when executed by one or more processors, are configured to cause the one or more processors to at least:
obtain measurement acquisition data relating to measurement of a target; obtain finite-size effect correction data and/or a trained model operable to correct for at least finite-size effects in the measurement acquisition data; correct for at least finite-size effects in the measurement acquisition data using the finite-size effect correction data and/or the trained model to obtain corrected measurement data and/or determine a parameter of interest which is corrected for at least the finite-size effects; and where the correction does not directly determine the parameter of interest, determine the parameter of interest from the corrected measurement data.

18 . A processing arrangement comprising:
the non-transient computer program carrier of claim 17 ; and a processor operable to run the computer program.

19 . A metrology device comprising the processing arrangement of claim 18 .

20 . A lithographic apparatus comprising the metrology device of claim 19 .

21 . A lithographic apparatus comprising:
a patterning device support for supporting a patterning device; a substrate support for supporting a substrate; and a metrology device configured to perform the method of claim 14 .

22 . A non-transient computer program carrier comprising a computer program that, when executed by one or more processors, are configured to cause the one or more processors to at least perform the method of claim 11 .

Assignees

• Asml Netherlands Bv

Inventors

• Alpeggiani Filippo
• Belt Harm Jan Willem
• Goorden Sebatianus Adrianus
• Setija Irwan Dani
• Huisman Simon Reinald
• Pellemans Henricus Petrus Maria

Classifications

• G03F7/706845 Primary

  Calibration, e.g. tool-to-tool calibration, beam alignment, spot position or focus · 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

• G03F7/70641

  Focus · CPC title

• G03F7/706839

  Modelling, e.g. modelling scattering or solving inverse problems · CPC title

• G03F7/705 Primary

  Modelling or simulating from physical phenomena up to complete wafer processes or whole workflow in wafer productions · CPC title