METHOD OF DETERMINING A VALUE OF A PARAMETER OF INTEREST OF A PATTERNING PROCESS, DEVICE MANUFACTURING METHOD

• US 20200133140A1
• Filed: 10/15/2019
• Published: 04/30/2020
• Est. Priority Date: 10/31/2018
• Status: Active Grant

• Current Assignee: ASML Netherlands BV (ASML Holding NV)
• Original Assignee: ASML Netherlands BV (ASML Holding NV)
• Inventors: WARNAAR, Patrick, BOS, Hilko Dirk, SMILDE, Hendrik Jan Hidde, HAJIAHMADI, Mohammadreza, MACHT, Lukasz Jerzy, VAN DEN BOS, Karel Hendrik Wouter, SOKOLOV, Sergei, KUNNEMAN, Lucas Tijn
• Granted Patent: US 11,181,828 B2
• Time in Patent Office: Days
• CPC Class Codes: G01N 21/21 Polarisation-affecting properties G01N21/19 takes precedence
• CPC Class Codes: G01N 21/4788 Diffraction for sizing particles G01N15/0205
• CPC Class Codes: G01N 21/9501 Semiconductor wafers manufacturing processes per se of semiconductor devices implementing a measuring step H01L22/10
• CPC Class Codes: G03F 7/70516 Calibration of components of the microlithographic apparatus, e.g. light sources, addressable masks or detectors
• CPC Class Codes: G03F 7/70616 Monitoring the printed patterns
• CPC Class Codes: G03F 7/70625 Dimensions, e.g. line width, critical dimension [CD], profile, sidewall angle or edge roughness
• CPC Class Codes: G03F 7/70633 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 Class Codes: G03F 7/70641 Focus
• CPC Class Codes: G03F 7/7065 Defects, e.g. optical inspection of patterned layer for defects
• CPC Class Codes: H01L 22/12 for structural parameters, e.g. thickness, line width, refractive index, temperature, warp, bond strength, defects, optical inspection, electrical measurement of structural dimensions, metallurgic measurement of diffusions electrical measurement of diffusions H01L22/14

Abstract

Techniques for determining a value of a parameter of interest of a patterning process are described. One such technique involves obtaining a plurality of calibration data units from one or more targets in a metrology process. Each calibration data unit of at least two of the calibration data units represents detected radiation obtained using different respective polarization settings in the metrology process, each polarization setting defining a polarization property of incident radiation of the metrology process and of detected radiation of the metrology process. The calibration data units are used to obtain calibration information about the metrology process. A measurement data unit representing detected radiation scattered from a further target is obtained, the further target having a structure formed using the patterning process on the substrate or on a further substrate. A value of the parameter of interest is determined using the measurement data unit and the obtained calibration information.

Claims

1. A method comprising:

obtaining a plurality of calibration data units, each calibration data unit representing detected radiation scattered from a respective target in a metrology process, the target comprising a structure formed on a substrate using the patterning process, wherein each of at least two of the calibration data units represents detected radiation obtained using different respective polarization settings in the metrology process, each polarization setting defining a polarization property of incident radiation of the metrology process and a polarization property of detected radiation of the metrology process;

using the calibration data units to obtain calibration information about the metrology process;

obtaining a measurement data unit representing detected radiation scattered from a further target, the further target comprising a structure formed using the patterning process on the substrate or on a further substrate; and

determining a value of a parameter of interest using the measurement data unit and the obtained calibration information.

2. The method of claim 1, wherein:

the different polarization settings used to obtain the calibration data units comprise at least a first polarization setting and a second polarization setting; and

the incident radiation of the first polarization setting is polarized differently to the incident radiation of the second polarization setting.

3. The method of claim 2, wherein the incident radiation of the first polarization setting is polarized orthogonally to the incident radiation of the second polarization setting

4. The method of claim 2, wherein the detected radiation of the first polarization setting is polarized differently to the detected radiation of the second polarization setting.

5. The method of claim 4, wherein the detected radiation of the first polarization setting is polarized orthogonally to the detected radiation of the second polarization setting.

6. The method of claim 2, further comprising:

obtaining a calibration information unit using a pair of calibration data units,

wherein a first calibration data unit of the pair of calibration data units is obtained with the substrate at a reference angular position using the first polarization setting, and

wherein a second calibration data unit of the pair of calibration data units is obtained with the substrate rotated through a certain angle away from the reference angular position using the second polarization setting.

7. The method of claim 6, wherein the certain angle is equal to an angle between a direction of polarization of incident radiation of the first polarization setting and a direction of polarization of incident radiation of the second polarization setting.

8. The method of claim 6, wherein the certain angle is equal to an angle between a direction of polarization of detected radiation of the first polarization setting and a direction of polarization of detected radiation of the second polarization setting.

9. The method of claim 6, wherein the certain angle equals 90 degrees.

10. The method of claim 6, wherein a calibration information unit is obtained for each reference angular position of a plurality of different reference angular positions.

11. The method of claim 10, wherein the different reference angular positions comprise at least two angular positions separated from each other by 180 degrees.

12. The method of claim 10, wherein the obtaining of the calibration information comprises averaging over two or more of the calibration information units.

13. The method of claim 6, wherein at least a subset of the calibration information units comprises a calibration information unit for each pair of calibration data units of a plurality of pairs of calibration data units of which each pair is obtained using a periodic structure with a different respective bias relative to each other pair, wherein each bias represents a deliberately applied nominal shift between different layers of the periodic structure.

14. The method of claim 6, wherein:

calibration data units are obtained for each orientation of a plurality of different orientations of the target; and

at least one separate calibration information unit is obtained for each of the different orientations.

15. A device manufacturing method, comprising:

using a patterning process to form a structure on a substrate, wherein the patterning process forms part of a lithographic manufacturing process;

performing the method of claim 1 to determine a value of a parameter of interest of the patterning process; and

adjusting the patterning process based on the determined value of the parameter of interest.

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

obtain a plurality of calibration data units, each calibration data unit representing detected radiation scattered from a respective target in a metrology process, the target comprising a structure formed on a substrate using the patterning process, wherein each of at least two of the calibration data units represents detected radiation obtained using different respective polarization settings in the metrology process, each polarization setting defining a polarization property of incident radiation of the metrology process and a polarization property of detected radiation of the metrology process;

use, by a hardware computer system, the calibration data units to obtain calibration information about the metrology process;

obtain a measurement data unit representing detected radiation scattered from a further target, the further target comprising a structure formed using the patterning process on the substrate or on a further substrate; and

determine a value of a parameter of interest using the measurement data unit and the obtained calibration information.

17. The computer-readable medium of claim 16, wherein:

the different polarization settings used to obtain the calibration data units comprise at least a first polarization setting and a second polarization setting; and

the incident radiation of the first polarization setting is polarized differently to the incident radiation of the second polarization setting.

18. The computer-readable medium of claim 16, wherein the instructions are further configured to cause the computer system to obtain a calibration information unit using a pair of calibration data units,

wherein a first calibration data unit of the pair of calibration data units is obtained with the substrate at a reference angular position using the first polarization setting, and

wherein a second calibration data unit of the pair of calibration data units is obtained with the substrate rotated through a certain angle away from the reference angular position using the second polarization setting.

19. The computer-readable medium of claim 16, wherein at least a subset of the calibration information units comprises a calibration information unit for each pair of calibration data units of a plurality of pairs of calibration data units of which each pair is obtained using a periodic structure with a different respective bias relative to each other pair, wherein each bias represents a deliberately applied nominal shift between different layers of the periodic structure.

20. The computer-readable medium of claim 16, wherein:

calibration data units are obtained for each orientation of a plurality of different orientations of the target; and

at least one separate calibration information unit is obtained for each of the different orientations.