Projection exposure apparatus, device manufacturing method, and sensor unit

• US 20050200815A1
• Filed: 02/08/2005
• Published: 09/15/2005
• Est. Priority Date: 02/09/2004
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Akamatsu, Takahiro
• Granted Patent: US 7,256,868 B2
• Time in Patent Office: Days
• US Class Current: 353/53
• 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 7/7085 Detection arrangement, e.g. detectors of apparatus alignment possibly mounted on wafers, exposure dose, photo-cleaning flux, stray light, thermal load

Abstract

A projection exposure apparatus which has a projection optical system and projects a pattern onto a substrate through the projection optical system is disclosed. This apparatus includes a sensor unit which comprises a light-receiving element for detecting light incident through the projection optical system, a vessel in which the light-receiving element is arranged, and a sealing window which transmits the incident light and seals the vessel. A space between the sealing window and the light-receiving element is filled with a medium having a refractive index greater than 1.

Claims

1. A projection exposure apparatus which has a projection optical system and projects a pattern onto a substrate through said projection optical system, said apparatus comprising:

a sensor unit which comprises a light-receiving element for detecting light incident through said projection optical system, a vessel in which said light-receiving element is arranged, and a sealing window which transmits the incident light and seals said vessel,

wherein a space between said sealing window and said light-receiving element is filled with a medium having a refractive index which is greater than 1.

2. An apparatus according to claim 1, wherein said sensor unit is arranged not to include an interface at which total reflection of the incident light entering said sensor unit occurs.

3. An apparatus according to claim 1, wherein the medium comprises a liquid.

4. An apparatus according to claim 3, wherein the liquid is an inert liquid.

5. An apparatus according to claim 3, wherein the liquid includes one of PFE (perfluoroether), PFPE (perfluoropolyether), HFE (hydrofluoroether), and HFPE (hydrofluoropolyether).

6. An apparatus according to claim 1, wherein said sensor unit comprises a member covering said light-receiving element.

7. An apparatus according to claim 6, wherein said member comprises one of fluoroplastic and glass.

8. An apparatus according to claim 3, further comprising a supply unit which supplies the liquid to said sensor unit.

9. An apparatus according to claim 3, further comprising a recovery unit which recovers the liquid from said sensor unit.

10. An apparatus according to claim 1, further comprising a liquid supply unit which supplies the liquid to a space between said projection optical system and one of the substrate and said sensor unit.

11. An apparatus according to claim 3, further comprising a liquid supply unit which supplies the liquid to a space between said projection optical system and one of the substrate and said sensor unit, and a tank which stores the liquid, wherein the liquid in the tank is supplied to both said sensor unit and said liquid supply unit.

12. An apparatus according to claim 3, further comprising driving means for aligning the substrate, wherein the liquid also serves as a coolant for cooling the driving means.

13. An apparatus according to claim 1, wherein the medium comprises a solid.

14. An apparatus according to claim 13, wherein the solid comprises one of fluoroplastic and glass.

15. An apparatus according to claim 1, wherein said sensor unit comprises a light-shielding member with a predetermined shape at an incident portion for the incident light.

16. An apparatus according to claim 1, wherein the sealing window comprises a predetermined light-shielding pattern.

17. A device manufacturing method comprising steps of:

projecting a pattern onto a substrate using a projection exposure apparatus as defined in claim 1;

and

developing the substrate onto which the pattern has been projected.

18. A projection exposure apparatus which has a projection optical system and projects a pattern onto a substrate through said projection optical system, said apparatus comprising:

a sensor unit which comprises a light-receiving element for detecting light incident through said projection optical system, and a vessel in which said light-receiving element is arranged,

wherein said vessel is filled with a solid which has a refractive index greater than 1 and transmits the incident light.

19. A sensor unit comprising a light-receiving element which detects light, said unit comprising:

a vessel in which said light-receiving element is arranged; and

a sealing window which transmits light incident thereon and seals said vessel,

wherein a space between said sealing window and said light-receiving element is filled with a medium having a refractive index which is greater than 1.

20. A unit according to claim 19, wherein said unit is arranged not to include an interface at which total reflection of the incident light entering the unit occurs.

21. A unit according to claim 19, wherein the medium comprises a liquid.

22. A unit according to claim 19, wherein the medium comprises a solid.

23. A unit according to claim 22, wherein the solid comprises one of fluoroplastic and glass.

24. A sensor unit comprising a light-receiving element which detects light, said unit comprising:

a vessel in which said light-receiving element is arranged,

wherein said vessel is filled with a solid which has a refractive index greater than 1 and transmits the light.

25. A projection exposure apparatus which has a projection optical system and projects a pattern onto a substrate through said projection optical system, said apparatus comprising:

a sensor unit which comprises a light-receiving element which detects light incident through said projection optical system, a vessel in which said light-receiving element is arranged, and a sealing window which transmits the incident light and seals said vessel,

wherein a space between said sealing window and said light-receiving element is filled with a liquid.

28. A device manufacturing method comprising steps of:

projecting a pattern onto a substrate using a projection exposure apparatus as defined in claim 25;

and

developing the substrate onto which the pattern has been projected.

26. A projection exposure apparatus which has a projection optical system and projects a pattern onto a substrate through said projection optical system, said apparatus comprising:

a sensor unit which comprises a light-receiving element which detects light incident through said projection optical system, and a vessel in which said light-receiving element is arranged,

wherein said vessel is filled with a solid which transmits the incident light.

27. An apparatus according to claim 26, wherein the solid comprises one of fluoroplastic and glass.

29. A device manufacturing method comprising steps of:

projecting a pattern onto a substrate using a projection exposure apparatus as defined in claim 26;

and

developing the substrate onto which the pattern has been projected.

30. A sensor unit comprising a light-receiving element which detects light, said unit comprising:

a vessel in which said light-receiving element is arranged, and

a sealing window which transmits the incident light and seals said vessel,

wherein a space between said sealing window and said light-receiving element is filled with a liquid.

31. A sensor unit comprising a light-receiving element which detects light, said unit comprising:

a vessel in which said light-receiving element is arranged, and

a solid which fills said vessel and transmits the light.

32. A unit according to claim 31, wherein said solid comprises one of fluoroplastic and glass.