Method and apparatus for measurement of crossfield chromatic response of projection imaging systems

• US 7,544,449 B1
• Filed: 11/14/2005
• Issued: 06/09/2009
• Est. Priority Date: 11/12/2004
• Status: Expired due to Fees

• Current Assignee: Litel Instruments Incorporated
• Original Assignee: Litel Instruments Incorporated
• Inventors: Smith, Adlai H., Bendik, Joseph, Hunter, Jr., Robert O.
• Primary Examiner(s): Young, Christopher G
• Application Number:
  US11/280,531
• Time in Patent Office: 1,303 Days
• Field of Search: 430/30, 430/312, 430/328, 356/515, 356/521
• US Class Current: 430/30
• CPC Class Codes: G03F 7/706 Aberration measurement

Abstract

A method and apparatus for measuring the chromatic response of lithographic projection imaging systems is described. An apparatus for determining the lens aberrations for a lithographic projection lens is provided. A substrate coated with a suitable recording media is provided. A series of lithographic exposures are performed using an exposure source with variable spectral settings. The exposures are measured, and the measurements are used to determine a chromatic response of the projection imaging system.

Claims

1. A method of determining chromatic response of a projection imaging system, the method comprising:

exposing a first pattern with an illumination source configured at a first wavelength onto a substrate with a recording media;

exposing a second pattern with the illumination source configured at a second wavelength onto the substrate;

measuring the exposed patterns; and

determining chromatic response of the projection imaging system based upon the measurements.

2. A method as defined in claim 1, further comprising repeating exposing patterns at different wavelengths a desired number of times.

3. A method as defined in claim 1, wherein measuring the exposed patterns comprises ISI01, ISI02, SPIN, ARTEMIS, ISIS, multi-wavelength scatterometry, multi-angle scatterometry, Nomura, or FE matrix.

4. A method as defined in claim 1, wherein exposing the patterns comprises ILIAS, P-PMI, or PMI.

5. A method as defined in claim 1, wherein the substrate is a semiconductor surface, a silicon wafer, a flat panel display, a reticle, a photolithographic mask, or an electronic recording media.

6. A method as defined in claim 1, wherein the projection imaging system is used in a photolithographic stepper system, a photolithographic scanner system, a one dimensional scanner, a two dimensional scanner, an electronic beam imaging system, an extreme ultra-violet photolithographic tool, an EPL machine, or an image side immersion lens, or an x-ray imaging system.

7. A method as defined in claim 1, wherein the recording media is a negative resist material, a positive resist material, an electronic CCD, a liquid crystal material, or an optically sensitive material.

8. A method of determining chromatic response of a projection imaging system, the method comprising:

exposing a first pattern with an illumination source with a first spectral setting onto a substrate with a recording media;

exposing a second pattern with the illumination source configured with a second spectral setting onto the substrate;

measuring the exposed patterns; and

determining chromatic response of the projection imaging system based upon the measurements.

9. A method as defined in claim 8, further comprising repeating exposing patterns at different spectral settings a desired number of times.

10. A method as defined in claim 8, wherein spectral settings comprise the illumination source nominal wavelength, spectral shape, bandwidth, pulse duration, pulse number, polarization, or spatial energy distribution.

11. A method as defined in claim 8, wherein spectral settings comprise a focus matrix.

12. A method as defined in claim 8, wherein spectral settings comprise an exposure matrix.

13. A method as defined in claim 8, wherein measuring the exposed patterns comprises ISI01, ISI02, SPIN, ARTEMIS, ISIS, multi-wavelength scatterometry, multi-angle scatterometry, Nomura, or FE matrix.

14. A method as defined in claim 8, wherein exposing the patterns comprises ILIAS, P-PMI, or PMI.

15. A method as defined in claim 8, wherein the substrate is a semiconductor surface, a silicon wafer, a flat panel display, a reticle, a photolithographic mask, or an electronic recording media.

16. A method as defined in claim 8, wherein the projection imaging system is used in a photolithographic stepper system, a photolithographic scanner system, a one dimensional scanner, a two dimensional scanner, an electronic beam imaging system, an extreme ultraviolet photolithographic tool, an EPL machine, or an image side immersion lens, or an x-ray imaging system.

17. A method as defined in claim 8, wherein the recording media is a negative resist material, a positive resist material, an electronic CCD, a liquid crystal material, or an optically sensitive material.

18. A method of determining chromatic response of a projection imaging system, the method comprising:

providing a reticle with a pattern;

exposing a first reticle pattern with an illumination source with a first spectral setting 15 onto a substrate with a recording media;

exposing a second reticle pattern with the illumination source configured with a second spectral setting onto the substrate, wherein the exposures comprise a focus and exposure matrix;

measuring the exposed reticle patterns, wherein measuring comprising critical dimension measurements of the exposed patterns; and

determining chromatic response of the projection imaging system based upon the measurements.

19. A method as defined in claim 18, wherein the reticle pattern comprises a line/space pattern or a contact hole pattern.

20. A method as defined in claim 18, wherein determining chromatic response comprises determining the optimum focus for each spectral setting using an interferometer system.

21. A method as defined in claim 20, wherein the projection imaging system comprises the interferometer system.

22. A method of determining chromatic response of a projection imaging system, the method comprising:

providing a first reticle with an ISIO pattern and a second reticle with an ISII pattern;

exposing the ISIO pattern with an illumination source with a first spectral setting onto a substrate with a recording media;

exposing the ISII pattern with the illumination source configured with a second spectral setting onto the substrate, wherein the exposed ISII pattern overlays the exposed ISIO pattern thereby forming completed alignment attributes;

measuring the exposed completed alignment attributes; and

determining chromatic response of the projection imaging system based upon the 20 measurements.

23. Method of determining chromatic response of a projection imaging system, the method comprising:

providing a reticle with a first set of alignment attributes and a second set of alignment attributes, wherein the first and second sets of alignment attributes are complementary;

exposing the first set of alignment attributes with an illumination source with a first spectral setting onto a substrate with a recording media;

exposing the second set of alignment attributes with the illumination source configured with a second spectral setting onto the substrate, wherein the exposed second set of alignment

attributes overlays the exposed first set of alignment attributes thereby forming completed alignment attributes;

measuring the exposed completed alignment attributes; and

determining chromatic response of the projection imaging system based upon the measurements.

24. A method as defined in claim 23, wherein the first set of alignment attributes comprise inner overlay targets and the second set of alignment attributes comprise outer alignment attributes.

25. A method as defined in claim 23, wherein the first set of alignment attributes comprise outer overlay targets and the second set of alignment attributes comprise inner alignment attributes.

26. A method as defined in claim 23, wherein spectral settings are adjusted to minimize coma effects of the illumination source.

27. A method as defined in claim 23, wherein the chromatic response is in terms of Zernike expansions.

28. A method of optimizing a chromatic photolithographic chip mask work from a lithographic machine, the method comprising:

exposing a first pattern with an illumination source with a first spectral setting onto a substrate with a recording media;

exposing a second pattern with the illumination source configured with a second spectral setting onto the substrate;

measuring the exposed patterns;

determining chromatic response of the projection imaging system based upon the measurements;

determining a set of spectral settings that optimize lithographic performance metrics of the lithographic machine.

29. A method as defined in claim 28, wherein the spectral settings comprise depth of focus or iso-dense bias.

30. A method as defined in claim 28, wherein determining the set of spectral settings that optimize lithographic performance metrics comprises a lithography process simulator.

31. A method as defined in claim 28, wherein the lithographic machine comprises a stepper, a one dimensional scanner, a two dimensional scanner, an E V scanner, an EPL machine, or an image side immersion lens.