Measurement apparatus and a method for determining a substrate grid

Patent metadata

Field	Value
Publication number	US-11079684-B2
Application number	US-201816229009-A
Country	US
Kind code	B2
Filing date	Dec 21, 2018
Priority date	Jan 30, 2018
Publication date	Aug 3, 2021
Grant date	Aug 3, 2021

Abstract

A measurement apparatus and method for determining a substrate grid describing a deformation of a substrate prior to exposure of the substrate in a lithographic apparatus configured to fabricate one or more features on the substrate. Position data for a plurality of first features and/or a plurality of second features on the substrate is obtained. Asymmetry data for at least a feature of the plurality of first features and/or the plurality of second features is obtained. The substrate grid based on the position data and the asymmetry data is determined. The substrate grid and asymmetry data are passed to the lithographic apparatus for controlling at least part of an exposure process to fabricate one or more features on the substrate.

First claim

The invention claimed is:

1. A method comprising:
obtaining position data, measured outside of a lithographic apparatus configured to fabricate one or more features on a substrate, for a plurality of first features and/or a plurality of second features on the substrate;
obtaining asymmetry data for at least a feature of the plurality of first features and/or the plurality of second features;
determining, by a hardware computer system, the substrate grid based on at least the position data, the determined substrate grid describing deformation across the substrate prior to exposure of the substrate in the lithographic apparatus; and
passing the substrate grid and asymmetry data to the lithographic apparatus for controlling at least part of an exposure process to fabricate one or more features on the substrate.

2. The method of claim 1 , wherein the determining of the substrate grid is additionally based on the asymmetry data, such that the passing the substrate grid and asymmetry data comprises passing an asymmetry corrected substrate grid.

3. The method of claim 1 , wherein the plurality of first features comprises alignment marks.

4. The method of claim 3 , further comprising obtaining the position data for the alignment marks using a low numerical aperture (NA) optical system, comprising a sensor, having a NA of less than or equal to 0.9.

5. The method of claim 1 , wherein the plurality of second features comprises metrology targets.

6. The method of claim 5 , wherein the plurality of first features comprises alignment marks and further comprising obtaining the asymmetry data for the alignment marks and/or metrology targets of the plurality of second features, using a high NA optical system, comprising a sensor, having a NA of greater than 0.9.

7. The method of claim 1 , further comprising calibrating at least a selection of position data associated with the plurality of second features towards position data associated with the plurality of first features.

8. The method of claim 7 , further comprising calibrating at least a selection of the position data towards further position data obtained during the aligning of the substrate in the lithographic apparatus.

9. The method of claim 1 , further comprising passing the asymmetry data to a metrology apparatus for measuring overlay.

10. The method of claim 1 , wherein the asymmetry data further comprises intensity data or energy data of diffraction orders scattered from the first features and/or second features at a plurality of wavelengths and/or polarization modes.

11. The method of claim 10 , further comprising:
obtaining, based on the asymmetry data, an integrated intensity or integrated energy comprised within a +Nth and/or −Nth order of diffraction at the plurality of wavelengths and/or polarization modes; and
configuring a metrology tool based on the dependency of the integrated intensity or integrated energy to the wavelength and/or polarization mode, wherein the configuring provides at least selection of a wavelength and/or polarization mode of a source of radiation within or for the metrology tool.

12. A lithographic apparatus configured to use the substrate grid and asymmetry data of claim 1 , wherein the lithographic apparatus is configured to align the substrate in the lithographic apparatus based on the position data and/or the asymmetry data.

13. A measurement apparatus comprising:
an optical system outside of a lithographic apparatus configured to fabricate one or more features on a substrate, the optical system configured to obtain position data for a plurality of first features and/or a plurality of second features on the substrate,
wherein the optical system is further configured to obtain asymmetry data for at least a feature of the plurality of first features and/or the plurality of second features, and
wherein the measurement apparatus is configured to determine the substrate grid based on at least the position data, the determined substrate grid describing deformation across the substrate prior to exposure of the substrate in the lithographic apparatus, and pass the substrate grid and asymmetry data to the lithographic apparatus for controlling at least part of an exposure process to fabricate one or more features on the substrate.

14. The measurement apparatus of claim 13 , wherein the optical system comprises a low numerical aperture (NA) optical system, comprising a sensor, having an NA of less than or equal to 0.9 which is configured to obtain the position data.

15. The measurement apparatus of claim 14 , further comprising a plurality of spatially distributed high NA sensor systems.

16. A computer program product comprising a non-transitory computer-readable medium having instructions, the instructions, upon execution by a computer system, configured to cause the computer system to at least:
obtain position data, measured outside of a lithographic apparatus configured to fabricate one or more features on a substrate, for a plurality of first features and/or a plurality of second features on the substrate;
obtain asymmetry data for at least a feature of the plurality of first features and/or the plurality of second features;
determine a substrate grid based on at least the position data, the determined substrate grid describing deformation across the substrate prior to exposure of the substrate in the lithographic apparatus; and
pass the substrate grid and asymmetry data toward the lithographic apparatus for controlling at least part of an exposure process to fabricate one or more features on the substrate.

17. The computer program product of claim 16 , wherein the instructions configured to cause the computer system to determine the substrate grid are further configured to determine the substrate grid additionally based on the asymmetry data, such that the passing of the substrate grid and asymmetry data comprises passing of an asymmetry corrected substrate grid.

18. The computer program product of claim 16 , wherein the plurality of first features comprises alignment marks and wherein the instructions configured to cause the computer system to obtain the position data are further configured to obtain the position data for the alignment marks as measured using a low numerical aperture (NA) optical system, comprising a sensor, having a NA of less than or equal to 0.9.

19. The computer program product of claim 16 , wherein the instructions are further configured to cause the computer system to obtain the asymmetry data for the plurality of second features as measured using a high NA optical system, comprising a sensor, having a NA of greater than 0.9.

20. The computer program product of claim 16 , wherein the instructions are further configured to cause the computer system to calibrate at least a selection of position data associated with the plurality of second features towards position data associated with the plurality of first features.

Assignees

• Asml Netherlands Bv

Inventors

• Bijnen Franciscus Godefridus Casper
• Hulsebos Edo Maria
• Megens Henricus Johannes Lambertus
• Socha Robert John
• Zhang Youping

Classifications

• G03F7/70516 Primary

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

• G03F9/7046

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

• G03F7/70425 Primary

  Imaging strategies, e.g. for increasing throughput or resolution, printing product fields larger than the image field or compensating lithography- or non-lithography errors, e.g. proximity correction, mix-and-match, stitching or double patterning · CPC title

• G03F7/705

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