Dynamic fluid control system for immersion lithography

• US 20080309895A1
• Filed: 08/08/2008
• Published: 12/18/2008
• Est. Priority Date: 07/01/2004
• Status: Active Grant

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Sogard, Michael
• Granted Patent: US 8,194,229 B2
• Time in Patent Office: Days
• US Class Current: 355/30
• CPC Class Codes: C07K 14/005 from viruses
• CPC Class Codes: C12N 2740/15022 New viral proteins or individual genes, new structural or functional aspects of known viral proteins or genes
• CPC Class Codes: G01N 2333/155 Lentiviridae, e.g. visna-maedi virus, equine infectious virus, FIV, SIV
• CPC Class Codes: G01N 2469/20 Detection of antibodies in sample from host which are directed against antigens from microorganisms
• CPC Class Codes: G01N 33/56983 Viruses
• CPC Class Codes: G03D 3/02 Details of liquid circulation
• 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 7/70725 control
• 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 7/709 Vibration, e.g. vibration detection, compensation, suppression or isolation

Abstract

An apparatus includes a stage that supports a substrate, an optical system having a last optical element, that projects an image onto the substrate that is positioned spaced apart from the last optical element by a gap at least partly filled with an immersion liquid, and a pressure control system having an actuator, that controls pressure of the immersion liquid in the gap using the actuator.

Claims

1. An apparatus comprising:

a stage that supports a substrate;

an optical system having a last optical element, that projects an image onto the substrate that is positioned spaced apart from the last optical element by a gap at least partly filled with an immersion liquid; and

a pressure control system having an actuator, that controls pressure of the immersion liquid in the gap using the actuator.

2. The apparatus of claim 1, wherein the actuator comprises one from the following group of actuators:

pistons, diaphragms, bellows, pressure head partial vacuum tubes, or electrocapillary pressure elements.

3. The apparatus of claim 1, wherein the actuator is located adjacent to the last optical element.

4. The apparatus of claim 1, wherein the actuator is located adjacent to a periphery of the last optical element.

5. The apparatus of claim 1, wherein the actuator is located adjacent to a surface of the last optical element that contacts the immersion liquid in the gap.

6. The apparatus of claim 1, wherein the pressure control system includes a plurality of the actuators.

7. The apparatus of claim 6, wherein the plurality of actuators are arranged at different locations.

8. The apparatus of claim 7, wherein the different locations are adjacent to the last optical element.

9. The apparatus of claim 7, wherein the different locations are adjacent to a periphery of the last optical element.

10. The apparatus of claim 7, wherein the different locations are adjacent to a surface of the last optical element that contacts the immersion liquid in the gap.

11. The apparatus of claim 1, further comprising a liquid supply and recovery system that supplies the immersion liquid to the gap and that recovers the immersion liquid from the gap, wherein the actuator is not a part of the liquid supply and recovery system.

12. The apparatus of claim 1, wherein the pressure control system includes a sensor that communicates with the liquid in the gap, wherein the pressure control system controls the actuator based on an output of the sensor.

13. The apparatus of claim 12, wherein the sensor is located adjacent to the actuator.

14. The apparatus of claim 12, wherein the pressure control system includes a plurality of the actuators and a plurality of the sensors.

15. The apparatus of claim 14, wherein there is an equal number of the actuators and the sensors.

16. The apparatus of claim 12, wherein the sensor is a pressure sensor.

17. The apparatus of claim 16, wherein the last optical element defines a boundary surface that bounds the immersion liquid in the gap, and the sensor is positioned in a same plane as the boundary surface.

18. The apparatus of claim 12, wherein the sensor comprises one from the following group of sensors:

a manometer, a capacitance manometer, or a piezoelectric transducer.

19. A method of controlling an immersion lithography apparatus in which and optical system having a last optical element projects an image onto a substrate held by a stage and spaced from the last optical element, the image being projected through an immersion liquid disposed in at least a part of a gap between the last optical element and the substrate, the method comprising:

controlling a pressure of the immersion liquid in the gap using an actuator that communicates with the immersion liquid in the gap.

20. The method of claim 19, wherein the actuator comprises one from the following group of actuators:

pistons, diaphragms, bellows, pressure head partial vacuum tubes, or electrocapillary pressure elements.

21. The method of claim 19, wherein the actuator is located adjacent to the last optical element.

22. The method of claim 19, wherein the actuator is located adjacent to a surface of the last optical element that contacts the immersion liquid in the gap.

23. The method of claim 19, wherein the pressure is controlled using a plurality of the actuators.

24. The method of claim 19, wherein the actuator is controlled based on an output of a sensor that communicates with the liquid in the gap.

25. The method of claim 24, wherein the sensor is located adjacent to the actuator.