Apparatus and method for analyzing an element of a photolithography process with the aid of a transformation model

Patent metadata

Field	Value
Publication number	US-12001145-B2
Application number	US-201916415510-A
Country	US
Kind code	B2
Filing date	May 17, 2019
Priority date	May 18, 2018
Publication date	Jun 4, 2024
Grant date	Jun 4, 2024

Abstract

An apparatus for analyzing an element of a photolithography process, said apparatus comprising: (a) a first measuring apparatus for recording first data of the element; and (b) means for transforming the first data into second, non-measured data, which correspond to measurement data of a measurement of the element with a second measuring apparatus; (c) wherein the means comprise a transformation model, which has been trained using a multiplicity of first data used for training purposes and second data corresponding therewith, which are linked to the second measuring apparatus.

First claim

What is claimed is:

1. An apparatus for analyzing a first photomask, the apparatus comprising:
a. a scanning particle microscope for measuring first image data of the first photomask; and
b. a computer system comprising a transformation model configured to transform the first image data into second image data that represents a prediction of an image of the first photomask measured by an optical measuring tool if the optical measuring tool were used to measure the first photomask, wherein the image represented by the first image data comprises at least 32×32 pixels, wherein the transformation model comprises at least one encoder block for determining information-carrying features from the first image data and at least one decoder block for producing the second image data, and wherein the transformation model enables an assessment of the first photomask without the first photomask needing to be transported and aligned with respect to the optical measuring tool;
c. wherein the transformation model has been trained using a multiplicity of first training data and second training data,
wherein the first training data comprise data obtained by using the scanning particle microscope to measure a set of at least one photomask, and the second training data comprise image data obtained by using the optical measuring tool to measure the set of at least one photomask,
wherein the transformation model is trained by:
applying the transformation model to the first training data to generate third image data that represents a prediction of at least one image of the set of at least one photomask measured by the optical measuring tool,
comparing the third image data with corresponding fourth image data in the second training data, wherein the fourth image data represents the at least one image of the set of at least one photomask measured by the optical measuring tool, and
modifying parameters of the transformation model based on the comparison of the third image data with the corresponding fourth image data.

2. An apparatus for transforming first image data of a first element of a photolithography process measured by use of a first measuring apparatus into second image data, the apparatus comprising:
a computer system comprising a transformation model;
wherein the second image data represents a prediction of an image of the first element measured by a second measuring apparatus if the second measuring apparatus were used to measure the first element, enabling an assessment of the first element without the first element needing to be transported and aligned with respect to the second measuring apparatus,
wherein the second measuring apparatus comprises at least one of: a first scanning particle microscope or an optical measuring tool,
wherein the transformation model has been trained using a multiplicity of first training data and second training data,
wherein the first training data comprise data obtained by using the first measuring apparatus to measure a set of at least one element of the photolithography process, and the second training data comprise image data obtained by using the second measuring apparatus to measure the set of at least one element of the photolithography process, and
wherein the apparatus is configured to use the transformation model to transform the first image data of the first element of the photolithography process into the second image data;
wherein the transformation model comprises at least one encoder block for determining information-carrying features from the first image data and at least one decoder block for producing the second image data; and
wherein the transformation model is trained by:
applying the transformation model to the first training data to generate third image data that represents a prediction of at least one image of the set of the at least one element of the photolithography process measured by use of the first measuring apparatus;
comparing the third image data with corresponding fourth image data in the second training data, wherein the fourth image data represents the at least one image of the at least one element of the photolithography process measured by the second measuring apparatus; and
modifying parameters of the transformation model based on the comparison of the third image data with the corresponding fourth image data.

3. The apparatus of claim 2 , wherein the second training data that is associated with the second measuring apparatus comprise data measured by the second measuring apparatus and/or comprise corresponding simulation data instead of second training data measured by the second measuring apparatus.

4. The apparatus of claim 2 , wherein the first measuring apparatus comprises at least one element from the group: a second scanning particle microscope, a scanning probe microscope, and an interferometer, and/or wherein the optical measuring tool comprises an AIMS™ tool, a WLCD tool and/or a PROVE® tool.

5. The apparatus of claim 2 , wherein the first image data comprise:
a. first measurement data of a region of the element of the photolithography process, which has at least one defect; and/or
b. first measurement data of a repaired region of the element of the photolithography process.

6. The apparatus of claim 2 , wherein the second image data comprise an image with a two-dimensional pixel representation.

7. The apparatus of claim 2 , wherein the second image data comprise an aerial image and/or an aerial image focus stack.

8. The apparatus of claim 2 , wherein the first image data comprise first measurement data that were recorded with different parameter settings of the first measuring apparatus.

9. The apparatus of claim 2 , wherein at least one of the first or the second measuring apparatus comprises a scanning electron microscope, which is embodied to scan the element of the photolithography process and which is further embodied to repair a defect of the element of the photolithography process.

10. The apparatus of claim 2 , wherein the transformation model comprises a machine learning model.

11. The apparatus of claim 2 , wherein the first element of the photolithography process comprises at least a first photomask, a first template of nanoimprint lithography, a first mold of nanoimprint lithography, or a first wafer;
wherein the set of at least one element of the photolithography process comprises at least one of (i) a set of at least one photomask, (ii) a set of at least one template of nanoimprint lithography, (iii) a set of at least one mold of nanoimprint lithography, or (iv) a set of at least one wafer.

12. The apparatus of claim 2 , wherein the first measuring apparatus comprises at least one of a scanning particle microscope, a scanning probe microscope, or an interferometer.

13. The apparatus of claim 2 wherein the image represented by the first image data comprises at least 32×32 pixels.

14. The apparatus of claim 2 wherein the image represented by the first image data comprises at least 224×224 pixels.

15. A method for analyzing a first element of a photolithography process, including the steps of:
a. measuring first image data of the first element with a first measuring apparatus; and
b. transforming the first image data into second image data that represents a prediction of an image of the first element measured by a second measuring apparatus if the second measuring apparatus were used to measure the first element, enabling an assessment of the first element without the first element needing to be transported and aligned with respect to the second measuring apparatus, wherein the second measuring apparatus comprises at

Assignees

• Zeiss Carl Smt Gmbh

Inventors

• Freytag Alexander
• Husemann Christoph
• Seidel Dirk
• Schmidt Carsten
• Scheruebl Thomas

Classifications

• G03F7/706837

  Data analysis, e.g. filtering, weighting, flyer removal, fingerprints or root cause analysis · CPC title

• G01Q30/02

  Non-SPM analysing devices, e.g. SEM [Scanning Electron Microscope], spectrometer or optical microscope · CPC title

• G06N20/00

  Machine learning · CPC title

• G03F7/705 Primary

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

• G03F1/72 Primary

  Repair or correction of mask defects · CPC title