Lithographic apparatus and device manufacturing method

• US 9,436,096 B2
• Filed: 12/30/2014
• Issued: 09/06/2016
• Est. Priority Date: 12/30/2005
• Status: Active Grant

• Current Assignee: ASML Netherlands BV (ASML Holding NV)
• Original Assignee: ASML Netherlands BV (ASML Holding NV)
• Inventors: Zaal, Koen Jacobus Johannes Maria, Ottens, Joost Jeroen
• Primary Examiner(s): NGUYEN, HUNG
• Application Number:
  US14/586,333
• Publication Number:
  US 20150116676A1
• Time in Patent Office: 616 Days
• Field of Search: 355/30.M, 355/53, 355 72- 76, 355/30, 310/10, 310/12, 165/46, 165/86, 165/80.2
• US Class Current: 1/1
• CPC Class Codes: G03F 7/70341 Details of immersion lithography aspects, e.g. exposure media or control of immersion liquid supply chemical composition of immersion liquids G03F7/2041
• CPC Class Codes: G03F 7/70716 Stages
• CPC Class Codes: G03F 7/70725 control
• CPC Class Codes: G03F 7/70775 Position control, e.g. interferometers or encoders for determining the stage position
• CPC Class Codes: G03F 7/70783 Handling stress or warp of chucks, masks or workpieces, e.g. to compensate for imaging errors or considerations related to warpage of masks or workpieces due to their own weight
• CPC Class Codes: G03F 7/7085 Detection arrangement, e.g. detectors of apparatus alignment possibly mounted on wafers, exposure dose, photo-cleaning flux, stray light, thermal load
• CPC Class Codes: G03F 7/70858 Environment aspects, e.g. pressure of beam-path gas, temperature pollution aspects G03F7/70916
• CPC Class Codes: G03F 7/70875 Temperature, e.g. temperature control of masks or workpieces via control of stage temperature

Abstract

A lithographic apparatus with a cover plate formed separately from a substrate table and means for stabilizing a temperature of the substrate table by controlling the temperature of the cover plate is disclosed. A lithographic apparatus with thermal insulation provided between a cover plate and a substrate table so that the cover plate acts as a thermal shield for the substrate table is disclosed. A lithographic apparatus comprising means to determine a substrate table distortion and improve position control of a substrate by reference to the substrate table distortion is disclosed.

Claims

1. A lithographic apparatus, comprising:

a substrate table arranged to support a substrate, the substrate table comprising a two-dimensional array of protrusions;

a projection system configured to project a modulated radiation beam onto a substrate;

a liquid supply system configured to provide a liquid in a region between the projection system and the substrate during exposure;

a single cover plate having an opening wider than the substrate, the cover plate removably supported on the array of protrusions during exposure, and configured to provide a surface facing the projection system that is substantially adjacent to the substrate.

2. The apparatus according to claim 1, wherein the array of protrusions comprises low thermal conductance burls on which the cover plate is mounted.

3. The apparatus according to claim 2, wherein the low conductance burls are arranged to have low thermal conductivity, minimal contact area with the cover plate, minimal contact area with the substrate table, or any combination of the foregoing.

4. The apparatus according to claim 1, further comprising a reflective surface of the substrate table, the cover plate, or both.

5. The apparatus according to claim 1, wherein the array of protrusions extend under the cover plate and under the substrate when supported by the substrate table.

6. The apparatus according to claim 5, wherein the tops of the plurality of protrusions under the cover plate and the substrate arranged in a substantially flat plane.

7. The apparatus according to claim 1, further comprising a plurality of electric heaters configured to heat at least part of the cover plate, the substrate table, or both.

8. A lithographic apparatus, comprising:

a substrate table arranged to support a substrate;

a projection system configured to project a modulated radiation beam onto a substrate;

a liquid supply system configured to provide a liquid in a region between the projection system and the substrate during exposure;

a plurality of cover plates;

a two-dimensional array of protrusions between the cover plates and the substrate table, wherein the cover plates are removably supported on the array of protrusions around the substrate during exposure to provide a surface facing the projection system.

9. The apparatus according to claim 8, wherein the array of protrusions is provided on the substrate table to support the cover plate.

10. The apparatus according to claim 9, wherein the array of protrusions extend under the cover plates and under the substrate when supported by the substrate table.

11. The apparatus according to claim 10, wherein the tops of the plurality of protrusions under the cover plates and the substrate arranged in a substantially flat plane.

12. The apparatus according to claim 8, wherein the array of protrusions is provided on the cover plates.

13. The apparatus according to claim 8, further comprising a reflective surface of the substrate table, the cover plates, or both.

14. The apparatus according to claim 8, further comprising a plurality of electric heaters configured to heat at least part of the cover plate, the substrate table, or both.

15. A lithographic apparatus, comprising:

a substrate table arranged to support a substrate;

a projection system configured to project a modulated radiation beam onto a substrate;

a liquid supply system configured to provide a liquid in a region between the projection system and the substrate during exposure;

a cover plate configured to be to the side of the substrate during exposure; and

a two-dimensional array of protrusions, the array of protrusions arranged to extend under the cover plate and under the substrate when supported by the substrate table and the tops of the plurality of protrusions under the cover plate and the substrate are arranged in a substantially flat plane.

16. The apparatus according to claim 15, wherein the cover plate has an aperture wider than the substrate.

17. The apparatus according to claim 15, wherein the array of protrusions comprises low thermal conductance burls on which the cover plate is mounted.

18. The apparatus according to claim 15, further comprising a reflective surface of the substrate table, the cover plate, or both.

19. The apparatus according to claim 15, wherein the cover plate is detachably mounted on the plurality of protrusions.

20. The apparatus according to claim 15, comprising a plurality of cover plates configured to be to the side of the substrate during exposure.