System and method to compensate for static and dynamic misalignments and deformations in a maskless lithography tool

• US 7,102,733 B2
• Filed: 08/13/2004
• Issued: 09/05/2006
• Est. Priority Date: 08/13/2004
• Status: Active Grant

• Current Assignee: ASML Holding NV
• Original Assignee: ASML Holding NV
• Inventors: Latypov, Azat M., Poultney, Sherman K., Mason, Christopher J., Bleeker, Arno J.
• Primary Examiner(s): NGUYEN, HUNG
• Application Number:
  US10/917,380
• Publication Number:
  US 20060033902A1
• Time in Patent Office: 753 Days
• Field of Search: 355/53, 355/55, 355 67- 71, 430/5, 430/20, 359290-292
• US Class Current: 355/67
• CPC Class Codes: G03F 7/70291 Addressable masks, e.g. spatial light modulators [SLMs], digital micro-mirror devices [DMDs] or liquid crystal display [LCD] patterning devices
• CPC Class Codes: G03F 7/70433 Layout for increasing efficiency or for compensating imaging errors, e.g. layout of exposure fields for reducing focus errors; Use of mask features for increasing efficiency or for compensating imaging errors
• CPC Class Codes: G03F 7/70508 Data handling in all parts of the microlithographic apparatus, e.g. handling pattern data for addressable masks or data transfer to or from different components within the exposure apparatus
• CPC Class Codes: G03F 7/70616 Monitoring the printed patterns

Abstract

The present invention provides systems and methods for maskless lithographic printing that compensate for static and/or dynamic misalignments and deformations. In an embodiment, a misalignment of a pattern formed by a spatial light modulator is measuring during printing. Rasterizer input data is generated based on the measured misalignment and passed the rasterizer. The rasterizer generates pattern data, based on the rasterizer input data, that is adjusted to compensate for the measured misalignment. The pattern data generated by the rasterizer is passed to the spatial light modulator and used to form a second pattern, which includes compensation for the measured misalignment. In an embodiment, deformations caused, for example, by a warping a surface of the spatial light modulator are measured and used by the rasterizer to generate pattern data that compensates for the deformations.

Claims

1. A system for maskless lithographic printing, comprising:

a spatial light modulator that forms patterns, the spatial light modulator including a plurality of spatial light modulator arrays and a reference reticle;

a substrate stage;

at least one optical element that images the patterns onto a substrate held by the substrate stage;

a rasterizer, coupled to the spatial light modulator, that generates pattern data used by the spatial light modulator to form the patterns; and

a sensor, coupled to the rasterizer, that provides a signal to the rasterizer related to misalignment of a first spatial light modulator array relative to a frame of reference,

wherein the rasterizer uses the signal from the sensor in generating the pattern data to compensate for misalignment of the first spatial light modulator array relative to the frame of reference.

2. The system of claim 1, wherein the sensor is a positional sensor.

3. The system of claim 1, wherein the sensor provides a signal to the rasterizer related to a displacement of the first spatial light modulator array relative to the frame of reference.

4. The system of claim 3, wherein the displacement is within a plane of the frame of reference.

5. The system of claim 3, wherein the displacement is normal to a plane of the frame of reference.

6. The system of claim 1, wherein the sensor provides a signal to the rasterizer related to a tilting of the first spatial light modulator array relative to the frame of reference.

7. The system of claim 1 wherein the sensor provides a signal to the rasterizer related to a rotation of the first spatial light modulator array relative to the frame of reference.

8. The system of claim 1, wherein the sensor provides a signal to the rasterizer related to an aerial image of a pattern formed by the first spatial light modulator array.

9. The system of claim 1, wherein the sensor provides a signal to the rasterizer related to field-varying defocus of a pattern formed by the first spatial light modulator array.

10. The system of claim 1, wherein the sensor provides a signal to the rasterizer related to a warping of a surface of the first spatial light modulator array.

11. The system of claim 1, wherein the rasterizer compensates for static misalignment of the first spatial light modulator array relative to the frame of reference.

12. The system of claim 1, wherein the rasterizer compensates for dynamic misalignment of the first spatial light modulator array relative to the frame of reference.

13. The system of claim 1, wherein the rasterizer compensates for mechanical misalignment of the first spatial light modulator array.

14. The system of claim 1, wherein the rasterizer compensates for misalignments or imperfections caused by aberrations and distortions induced by the projection optics.

15. The system of claim 1, wherein the rasterizer calculates the pattern data during exposure of the substrate.

16. The system of claim 1, wherein the rasterizer retrieves pre-computed pattern data from a memory during exposure of the substrate.

17. A method for maskless lithographic printing with a tool including a spatial light modulator, which has a plurality of spatial light modulator arrays and a reference reticle, and a rasterizer, comprising:

(a) comparing a first pattern formed using the reference reticle to a second pattern formed using a first spatial light modulator array to determine a misalignment of the first spatial light modulator array relative to a frame of reference;

(b) generating rasterizer input data based on the misalignment determined in step (a);

(c) providing the rasterizer input data to the rasterizer;

(d) generating pattern data with the rasterizer, the pattern data being adjusted based on the rasterizer input data provided in step (c);

(e) providing the pattern data to the spatial light modulator; and

(f) forming a third pattern with the spatial light modulator and the pattern data that compensates for the misalignment measured in step (a).

18. The method of claim 17, wherein step (a) comprises determining a displacement misalignment of the first spatial light modulator array relative to the frame of reference.

19. The method of claim 18, wherein the displacement is within a plane of the frame of reference.

20. The method of claim 18, wherein the displacement is normal to a plane of the frame of reference.

21. The method of claim 17, wherein step (a) comprises determining a tilting misalignment of the first spatial light modulator array relative to the frame of reference.

22. The method of claim 17, wherein step (a) comprises determining a rotational misalignment of the first spatial light modulator array relative to the frame of reference.

23. The method of claim 17, wherein step (a) comprises determining field-varying defocus of a pattern formed by the first spatial light modulator array.

24. The method of claim 17, wherein step (d) comprises generating pattern data that compensates for static misalignment of the first spatial light modulator array.

25. The method of claim 17, wherein step (d) comprises generating pattern data that compensates for dynamic misalignment of the first spatial light modulator array.

26. The method of claim 17, wherein step (d) comprises generating pattern data that compensates for misalignment caused by aberrations and distortions induced by the projection optics.

27. The method of claim 17, wherein step (d) comprises calculating the pattern data.

28. The method of claim 17, wherein step (d) comprises retrieving pre-computed pattern data from a memory.

29. The method of claim 17, wherein

step (a) further comprises determining a warping of a surface of the first spatial light modulator array;

step (b) further comprises generating rasterizer input data based on the warping measured in step (a); and

step (f) further comprises forming the third pattern with the spatial light modulator and the pattern data that compensates for the warping measured in step (a).