Cleanup method for optics in immersion lithography

• US 20080100813A1
• Filed: 12/19/2007
• Published: 05/01/2008
• Est. Priority Date: 04/11/2003
• Status: Active Grant

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Watson, Douglas, Kawai, Hidemi, Novak, W., Hazelton, Andrew
• Granted Patent: US 8,670,103 B2
• Time in Patent Office: Days
• US Class Current: 355/30
• CPC Class Codes: B08B 3/04 Cleaning involving contact with liquid
• CPC Class Codes: B08B 3/12 by sonic or ultrasonic vibrations washing or rinsing machines for crockery or tableware using sonic or ultrasonic waves A47L15/13; of natural teeth, of prostheses using ultrasonic techniques similar to those used for natural teeth A61C17/20; application of ultrasonic vibrations to chemical, physical or physico-chemical processes in general B01J19/10
• 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 7/70891 Temperature
• CPC Class Codes: G03F 7/70916 Pollution mitigation, i.e. mitigating effect of contamination or debris, e.g. foil traps
• CPC Class Codes: G03F 7/70925 Cleaning, i.e. actively freeing apparatus from pollutants, e.g. using plasma cleaning

Abstract

A liquid immersion exposure apparatus includes an optical system via which a substrate is exposed with an exposure beam, and a cleaning device which performs a cleaning operation by filling a space adjacent the optical system with a liquid including bubbles.

Claims

1. A liquid immersion exposure apparatus comprising:

an optical system via which a substrate is exposed with an exposure beam; and

a cleaning device which performs a cleaning operation by filling a space adjacent the optical system with a liquid including bubbles.

2. The apparatus according to claim 1, wherein the bubbles include cavitating bubbles.

3. The apparatus according to claim 1, wherein the cleaning operation is performed to clean a member which is in contact with the liquid including the bubbles.

4. The apparatus according to claim 3, wherein the space includes a gap between the optical system disposed on one side and an object positioned on the other side, and wherein the member is disposed at the one side.

5. The apparatus according to claim 3, wherein the member includes a last optical element of the optical system.

6. The apparatus according to claim 3, wherein the space includes a gap between the optical system disposed on one side and an object positioned on the other side, and wherein the cleaning operation is performed with the object being moved relative to the optical system.

7. The apparatus according to claim 6, wherein the cleaning device includes the object.

8. The apparatus according to claim 1, wherein the cleaning device generates the bubbles.

9. The apparatus according to claim 8, wherein the space includes a gap between the optical system disposed on one side and an object positioned on the other side, and wherein the cleaning device generates the bubbles by moving the object relative to the optical system.

10. The apparatus according to claim 8, wherein the cleaning device generates the bubbles by stirring the liquid.

11. The apparatus according to claim 8, wherein the space includes a gap between the optical system disposed on one side and an object positioned on the other side, and wherein the cleaning device includes the object.

12. The apparatus according to claim 1, wherein the space includes a gap between the optical system disposed on one side and an object positioned on the other side, and wherein the cleaning operation is performed with the object being moved relative to the optical system.

13. The apparatus according to claim 12, wherein the cleaning device includes the object.

14. The apparatus according to claim 1, wherein the cleaning device generates pressure waves in the liquid.

15. The apparatus according to claim 1, wherein the liquid includes an exposure liquid through which the substrate is exposed with the exposure beam in exposure operation.

16. The apparatus according to claim 1, wherein the cleaning operation is performed with ultraviolet light.

17. The apparatus according to claim 16, wherein the ultraviolet light includes the exposure beam.

18. A device manufacturing method comprising:

exposing a substrate via the optical system of the apparatus defined in claim 1;

and

developing the exposed substrate.

19. A cleaning method used in a liquid immersion exposure apparatus in which a substrate is exposed with an exposure beam via an optical system, the method comprising:

filling a space adjacent the optical system with a liquid including bubbles;

wherein a member of the apparatus which is in contact with the liquid is cleaned.

20. The method according to claim 19, wherein the bubbles include cavitating bubbles.

21. The method according to claim 19, wherein the space includes a gap between the optical system disposed on one side and an object positioned on the other side, and wherein the member is disposed at the one side.

22. The method according to claim 19, wherein the member includes a last optical element of the optical system.

23. The method according to claim 19, further comprising:

moving an object positioned opposite to the optical system,

wherein the space includes a gap between the optical system and the object.

24. The method according to claim 19, further comprising generating the bubbles.

25. The method according to claim 19, wherein the liquid includes an exposure liquid through which the substrate is exposed with the exposure beam in the apparatus.

26. A cleaning method used in a liquid immersion exposure apparatus in which a substrate is exposed with an exposure beam via an optical system, the method comprising:

filling a gap between the optical system disposed on one side and an object positioned on the other side with a liquid including bubbles; and

moving the object relative to the optical system in a state in which the liquid including the bubbles is filled in the gap between the optical system and the object.

27. The method according to claim 26, wherein the liquid including the bubbles is used for cleaning a member disposed at the one side in the apparatus.

28. The method according to claim 26, wherein the liquid including the bubbles is used for cleaning a last optical element of the optical system.