Methods and systems for pattern design with tailored response to wavefront aberration

• US 10,423,075 B2
• Filed: 12/18/2014
• Issued: 09/24/2019
• Est. Priority Date: 07/08/2011
• Status: Active Grant

• Current Assignee: ASML Netherlands BV (ASML Holding NV)
• Original Assignee: ASML Netherlands BV (ASML Holding NV)
• Inventors: Feng, Hanying, Cao, Yu, Ye, Jun, Zhang, Youping
• Primary Examiner(s): Rossoshek, Helen
• Application Number:
  US14/575,609
• Publication Number:
  US 20150153651A1
• Time in Patent Office: 1,741 Days
• CPC Class Codes: G03F 7/70125 Use of illumination settings tailored to particular mask patterns details of setting means G03F7/70091
• CPC Class Codes: G03F 7/70258 Projection system adjustments, e.g. adjustments during exposure or alignment during assembly of projection system
• CPC Class Codes: G03F 7/70483 Information management; Active and passive control; Testing; Wafer monitoring, e.g. pattern monitoring
• CPC Class Codes: G03F 7/705 Modelling or simulating from physical phenomena up to complete wafer processes or whole workflow in wafer productions
• CPC Class Codes: G03F 7/706 Aberration measurement
• CPC Class Codes: G03F 7/70683 Mark designs
• CPC Class Codes: G06F 17/10 Complex mathematical operations function generation by table look-up G06F1/03; evaluation of elementary functions by calculation G06F7/544

Abstract

The present invention relates to methods and systems for designing gauge patterns that are extremely sensitive to parameter variation, and thus robust against random and repetitive measurement errors in calibration of a lithographic process utilized to image a target design having a plurality of features. The method may include identifying most sensitive line width/pitch combination with optimal assist feature placement which leads to most sensitive CD (or other lithography response parameter) changes against lithography process parameter variations, such as wavefront aberration parameter variation. The method may also include designing gauges which have more than one test patterns, such that a combined response of the gauge can be tailored to generate a certain response to wavefront-related or other lithographic process parameters. The sensitivity against parameter variation leads to robust performance against random measurement error and/or any other measurement error.

Claims

1. A non-transitory computer-readable medium configured to cooperate with a processor system connected to a physical patterning device or to a physical patterning device manufacturing process or apparatus, the computer-readable medium comprising data representing a set of one or more test patterns for a projection lithography system, the data, or information derived from that data, arranged such that, when processed by the processor system, the processor system causes physical configuration of the patterning device to produce the set of one or more test patterns as part an imaging process using the projection lithography system or causes the patterning device manufacturing process or apparatus to manufacture a physical patterning device to produce the set of one or more test patterns as part an imaging process using the projection lithography system, wherein wavefront aberration terms mathematically represent characteristics of wavefront aberration in the projection lithography system, and the set of one or more test patterns comprises a test pattern that, when imaged, produces an essentially linear or quadratic desired response in a lithographic imaging parameter measured from the imaged test pattern with respect to variation of a certain one of the wavefront aberration terms that mathematically represent characteristics of wavefront aberration in the projection lithography system.

2. The non-transitory computer-readable medium according to claim 1, wherein the wavefront aberration terms comprise Zernike coefficients.

3. The non-transitory computer-readable medium according to claim 1, wherein the desired response is an essentially linear response.

4. The non-transitory computer-readable medium according to claim 1, wherein the desired response is an essentially linear response, and wherein the test pattern includes a pair of sub-patterns having offsetting non-linear responses.

5. The non-transitory computer-readable medium according to claim 1, wherein the test pattern includes a pair of sub-patterns that have a geometric relationship with each other that has been determined in accordance with the desired response.

6. The non-transitory computer-readable medium according to claim 5, wherein the desired response is an essentially linear response, and wherein the geometric relationship is mirror symmetry.

7. The non-transitory computer-readable medium according to claim 5, wherein the desired response is an essentially linear response, and wherein the geometric relationship is rotational.

8. The non-transitory computer-readable medium according to claim 1, wherein the certain one of the wavefront aberration terms is an odd-symmetric Zernike term.

9. The non-transitory computer-readable medium according to claim 1, wherein the certain one of the wavefront aberration terms is a spherical Zernike term.

10. The non-transitory computer-readable medium according to claim 1, wherein the desired response is an essentially quadratic response.

11. The non-transitory computer-readable medium according to claim 1, wherein the desired response includes a desired signal-to-noise ratio.

12. The non-transitory computer-readable medium according to claim 1, wherein the test pattern comprises substantially binary structures.

13. The non-transitory computer-readable medium according to claim 1, wherein the test pattern comprises phase-shifting structures.

14. The non-transitory computer-readable medium according to claim 1, wherein the test pattern has been derived from one or more other patterns in the layout.

15. The non-transitory computer-readable medium according to claim 1, wherein the imaging of the layout via the lithography process causes formation of structures on a substrate corresponding to the layout.

16. A reticle comprising one or more physical structures that, when irradiated, are configured to produce a set of one or more test patterns for a projection lithography system, wherein wavefront aberration terms mathematically represent characteristics of wavefront aberration in the projection lithography system, the set of one or more test patterns comprising:

a test pattern that, when imaged, produces an essentially linear or quadratic response in a lithographic imaging parameter measured from the imaged test pattern with respect to variation of a certain one of the wavefront aberration terms that mathematically represent characteristics of wavefront aberration in the projection lithography system.

17. The reticle of claim 16, wherein the desired response is an essentially linear response.

18. The reticle of claim 16, wherein the desired response is an essentially linear response, and wherein the test pattern includes a pair of sub-patterns having offsetting non-linear responses.

19. The reticle of claim 16, wherein the test pattern includes a pair of sub-patterns that have a geometric relationship with each other that has been determined in accordance with the desired response.

20. The reticle of claim 16, wherein the desired response is an essentially quadratic response.

21. A non-transitory computer-readable medium comprising instructions, that when executed, are configured to cause a processor system to at least:

evaluate a response in a lithographic imaging parameter, expected to result from imaging of a plurality of test pattern designs, with respect to variation of a certain wavefront aberration term that mathematically represents characteristics of wavefront aberration in a projection lithography system; and

based on the evaluation, identify a set of one or more test patterns from the evaluated plurality of test pattern designs, the set of one or more test patterns comprises a test pattern that, when imaged, produces an essentially linear or quadratic desired response in the lithographic imaging parameter measured from the imaged test pattern with respect to variation of the certain wavefront aberration term.

22. The non-transitory computer-readable medium of claim 21, wherein the desired response is an essentially linear response.

23. The non-transitory computer-readable medium of claim 21, wherein the desired response is an essentially linear response, and wherein the test pattern includes a pair of sub-patterns having offsetting non-linear responses.

24. The non-transitory computer-readable medium of claim 21, wherein the test pattern includes a pair of sub-patterns that have a geometric relationship with each other that has been determined in accordance with the desired response.

25. The non-transitory computer-readable medium according to claim 21, wherein the certain wavefront aberration term is an odd-symmetric Zernike term.

26. The non-transitory computer-readable medium according to claim 21, wherein the certain wavefront aberration term is a spherical Zernike term.