Optical imaging device with thermal attenuation

• US 8,363,206 B2
• Filed: 11/07/2008
• Issued: 01/29/2013
• Est. Priority Date: 05/09/2006
• Status: Active Grant

• Current Assignee: CARL Zeiss SMT GmbH (Carl-Zeiss-Stiftung)
• Original Assignee: CARL Zeiss SMT GmbH (Carl-Zeiss-Stiftung)
• Inventors: Gellrich, Bernhard, Kugler, Jens, Ittner, Thomas, Hembacher, Stefan, Schimitzek, Karl-Heinz, Tayebati, Payam, Holderer, Hubert
• Primary Examiner(s): Kim, Peter B
• Assistant Examiner(s): Persaud, Deoram
• Application Number:
  US12/267,074
• Publication Number:
  US 20090135385A1
• Time in Patent Office: 1,544 Days
• Field of Search: 355/53, 355/30
• US Class Current: 355/30
• 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

Abstract

An optical imaging device, in particular for use in microlithography, includes a mask device for receiving a mask having a projection pattern, a projection device with an optical element group, a substrate device for receiving a substrate and an immersion zone. The optical element group is adapted to project the projection pattern onto the substrate and includes a plurality of optical elements with an immersion element to which the substrate is at least temporarily located adjacent to during operation. During operation, the immersion zone is located between the immersion element and the substrate and is at least temporarily filled with an immersion medium. A thermal attenuation device is provided, the thermal attenuation device being adapted to reduce fluctuations within the temperature distribution of the immersion element induced by the immersion medium.

Claims

1. An optical imaging device, comprising:

a mask device for receiving a mask comprising a pattern;

a substrate device for receiving a substrate;

an immersion liquid; and

a projection device comprising a plurality of optical elements and a thermal attenuation device, the optical imaging device being configured so that during operation the plurality of optical elements projects the pattern onto the substrate and the thermal attenuation device reduces fluctuations in a temperature distribution of an immersion element of the plurality of optical elements induced by the immersion liquid,

wherein the immersion element is the optical element closest to the substrate and adjacent to the immersion liquid so that the immersion liquid is located between the immersion element and the substrate, the immersion element comprising a first area and a second area where the first area is optically used during operation of the optical imaging device and the second area is optically unused during operation of the optical imaging device, the second area comprising a first section adjacent the immersion liquid during operation of the optical imaging device and a second section non-adjacent to the immersion liquid during operation of the optical imaging device, and

the thermal attenuation device comprises a first shielding which is a thermal decoupling device that thermally shields at least a part of the first section of the second area of the immersion element, and the first shielding is between the immersion element and the immersion liquid.

2. The optical imaging device according to claim 1, wherein the first shielding shields the entire first section of the second area of the immersion element.

3. The optical imaging device according to claim 1, wherein the projection device comprises a holding device that holds the immersion element and the thermal attenuation device comprises a second shielding, the second shielding being a thermal decoupling device that thermally shields at least a part of the holding device.

4. The optical imaging device according to claim 3, wherein the second shielding thermally shields at least a part of an area of the holding device located adjacent to an adjacent section of the projection device.

5. The optical imaging device according to claim 1, wherein the thermal attenuation device comprises a thermal decoupling device comprising at least one passive thermally insulating device.

6. The optical imaging device according to claim 5, wherein the passive thermally insulating device comprises an organic material.

7. The optical imaging device according to claim 1, wherein the thermal attenuation device comprises a thermal decoupling device comprising at least one active shielding having at least one shielding element and at least one temperature adjustment device connected to the shielding element, wherein the temperature adjustment device is arranged such that a selectable temperature distribution on at least one surface of the shielding element is substantially maintained during operation of the optical imaging device.

8. The optical imaging device of claim 1, wherein the thermal attenuation device comprises a thermal decoupling device comprises at least one active shielding element, the temperature adjustment device being adapted to provide a flow of a heat carrier medium in an area of the at least one shielding element.

9. The optical imaging device according to claim 1, wherein the thermal decoupling device includes at least one of at least one hydrophobic surface and a hydrophobic coating facing away from the immersion element.

10. The optical imaging device according to claim 1, wherein during operation a setpoint temperature distribution is given for the immersion element and the thermal attenuation device is adapted to keep a given maximum deviation from the setpoint temperature distribution.

11. The optical imaging device according to claim 10, wherein the maximum deviation is less than 10 mK.

12. The optical imaging device according to claim 1, wherein the during operation the immersion element has an actual temperature distribution and a setpoint temperature distribution given for the immersion element and the thermal attenuation device includes at least one establishing device, a control device connected to the establishing device and an influencing device connected to the control device, where the establishing device establishes at least one parameter P influencing the actual temperature distribution or being representative of the actual temperature distribution, the control device, as a function of the established parameter P and the setpoint temperature distribution, establishes at least one control value C, and the influencing device, as a function of the at least one established control value C, influences a control parameter that influences the actual temperature distribution so that a deviation of the actual temperature distribution from the setpoint temperature distribution is reduced.

13. The optical imaging device according to claim 12, wherein the parameter P is a local temperature of the immersion liquid or the immersion element.

14. The optical imaging device of claim 12, wherein the establishment device includes at least one temperature sensor for measuring a local temperature of the immersion liquid or the immersion element.

15. The optical imaging device of claim 12, wherein the establishment device comprises at least one estimation device for estimating a local temperature of the immersion liquid or the immersion element.

16. The optical imaging device according to claim 12, wherein the control parameter is one of

a temperature of the immersion liquid,

a flow rate of the immersion liquid,

a temperature of a gas atmosphere contacting the immersion liquid,

a humidity of a gas atmosphere contacting the immersion liquid,

a flow rate of a gas atmosphere contacting the immersion liquid, and

a temperature of at least one temperature adjustment element being in operative connection with the immersion element.

17. The optical imaging device according to claim 12, wherein the control device is adapted to use a temperature behavior model of the immersion element and/or of the immersion liquid for establishing the control value C.

18. The optical imaging device according to claim 12, wherein the control device comprises a memory storing model data representing the temperature behavior model or parameters for calculating model data representing the temperature behavior model and uses the model data for establishing the control value C.

19. The optical imaging device according to claim 12, wherein the influencing device comprises at least one first temperature adjustment device for adjusting the temperature of the immersion liquid.

20. The optical imaging device according to claim 19, wherein the control device establishes the control value C for the first temperature adjustment device as a function of an alteration Δ

TIE of the temperature distribution to be expected within the immersion liquid so that the first temperature adjustment device adjusts the temperature of the immersion liquid to a supply temperature, where the supply temperature is selected such that a given temperature distribution is expected within the immersion liquid.

21. The optical imaging device according to claim 19, wherein the first temperature adjustment device is arranged in the area of an inlet of the immersion liquid.

22. The optical imaging device according to claim 12, wherein the influencing device comprises an adjustment device for influencing the evaporation induced cooling of the immersion liquid in a contact area with an adjacent gas atmosphere, where the adjustment device adjusts at least one state parameter of a gas atmosphere contacting the immersion liquid and the at least one state parameter is a temperature of the gas atmosphere, a humidity of the gas atmosphere or a flow rate of the gas atmosphere.

23. The optical imaging device according to claim 22, wherein the control device establishes the control value C for the adjustment device as a function of the state of the immersion liquid in the contact area so that one of a given evaporation induced cooling and substantially no evaporation induced cooling of the immersion liquid is expected in the contact area.

24. The optical imaging device according to claim 22, wherein the contact area substantially extends over an entire free surface of the immersion liquid.

25. The optical imaging device according to claim 1, wherein the thermal attenuation device comprises a temperature adjustment device connected to the immersion element for adjusting the temperature of the immersion element.

26. The optical imaging device according to claim 25, wherein during operation the control device establishes a control value for the temperature adjustment device as a function of a temperature distribution within the immersion liquid and the temperature adjustment device adjusts the temperature of the immersion element so that a deviation of an actual temperature distribution from a setpoint temperature distribution that is due to the established temperature distribution within the immersion liquid is reduced.

27. The optical imaging device according to claim 25, wherein the temperature adjustment device is arranged in the area of a circumference of the immersion element.

28. The optical imaging device according to claim 25, wherein the temperature adjustment device comprises at least one Peltier-Element.

29. The optical imaging device according to claim 25,

wherein the temperature adjustment device comprises at least one resistance heating device embedded within the immersion element or covered with a protection layer against the immersion liquid.

30. The optical imaging device according to claim 25, wherein the temperature adjustment device comprises at least one radiation heating device.

31. The optical imaging device according to claim 1, wherein the immersion element comprises a material having a refractive index larger than a refractive index of quartz glass and having a refractive index having a higher temperature sensitivity than the refractive index of quartz glass.

32. The optical imaging device according to claim 1, wherein the immersion element is made of a spinel or a LuAG.

33. The optical imaging device according to claim 1, wherein a numerical aperture of the projection device during operation is at least one of at least 1.3.

34. The optical imaging device of claim 1, wherein the thermal attenuation device further comprises a second shielding which is a thermal decoupling device that thermally shields at least a part of the second section of the second area of the immersion element.

35. The optical imaging device according to claim 34, wherein the second shielding shields the entire second section of the second area of the immersion element.

36. The optical imaging device according to claim 1, wherein the first shielding is between the immersion liquid and the first section of the second area of the immersion element.

37. The optical imaging device according to claim 1, wherein the first shielding contacts the first section of the second area of the immersion element.

38. A method, comprising:

using a projection device to project a pattern from a mask onto a substrate, wherein the projection device comprises;

a plurality of optical elements comprising an immersion element, the immersion element being the optical element closest to the substrate and adjacent to an immersion liquid between the optical elements and the substrate, the immersion element comprising a first area and a second area where the first area is optically used and the second area is optically unused, the second area comprising a first section adjacent the immersion liquid and a second section non-adjacent to the immersion liquid, and

a thermal attenuation device comprising a first shielding-which thermally shields at least a part of the first section of the second area of the immersion element, and the first shielding is between the immersion element and the immersion liquid, and

using the thermal attenuation device to reduce fluctuations in a temperature distribution of the immersion element induced by the immersion liquid.

39. The method of claim 38, wherein the thermal attenuation device further comprises a second shielding which is a thermal decoupling device that thermally shields at least a part of the second section of the second area of the immersion element.

40. The method according to claim 38, wherein the first shielding is between the immersion liquid and the first section of the second area of the immersion element.

41. The method according to claim 38, wherein the first shielding contacts the first section of the second area of the immersion element.

42. An optical imaging device, comprising:

a mask device for receiving a mask comprising a pattern;

a substrate device for receiving a substrate;

an immersion liquid; and

a projection device comprising a holding device, a plurality of optical elements and a thermal attenuation device, the optical imaging device being configured so that during operation the plurality of optical elements projects the pattern onto the substrate and the thermal attenuation device reduces fluctuations in a temperature distribution of an immersion element of the plurality of optical elements induced by the immersion liquid,

wherein the immersion element is held by the holding device, the immersion element being the optical element closest to the substrate, the immersion liquid being located between the immersion element and the substrate, the immersion element comprising a first area and a second area where the first area is optically used during operation of the optical imaging device and the second area is optically unused during operation of the optical imaging device, the second area comprising a first section adjacent the immersion liquid during operation of the optical imaging device and a second section non-adjacent to the immersion liquid during operation of the optical imaging device, and

the thermal attenuation device comprises a shielding which is a thermal decoupling device that thermally shields the holding device and at least a part of the second section of the second area of the immersion element.

43. The optical imaging device of claim 42, wherein a portion of the immersion element is between the holding device and the immersion liquid.

44. The optical imaging device according to claim 42, wherein the first shielding is between the immersion liquid and the first section of the second area of the immersion element.

45. The optical imaging device according to claim 42, wherein the first shielding contacts the first section of the second area of the immersion element.

46. An optical imaging device, comprising:

a mask device for receiving a mask comprising a pattern;

a substrate device for receiving a substrate;

an immersion liquid; and

a projection device comprising a plurality of optical elements and a thermal attenuation device, the optical imaging device being configured so that during operation the plurality of optical elements projects the pattern onto the substrate and the thermal attenuation device reduces fluctuations in a temperature distribution of an immersion element of the plurality of optical elements induced by the immersion liquid,

wherein the immersion element is the optical element closest to the substrate and adjacent to the immersion liquid so that the immersion liquid is located between the immersion element and the substrate, the immersion element comprising a first area and a second area where the first area is optically used during operation of the optical imaging device and the second area is optically unused during operation of the optical imaging device, the second area comprising a first section adjacent the immersion liquid during operation of the optical imaging device and a second section non-adjacent to the immersion liquid during operation of the optical imaging device, and

wherein the thermal attenuation device comprises a first shielding which is a thermal decoupling device that contacts a surface of the immersion element over at least a part of the first section of the second area of the immersion element and thermally shields this contacted part.

47. The optical imaging device according to claim 46, wherein the first shielding is between the immersion liquid and the first section of the second area of the immersion element.

48. The optical imaging device according to claim 46, wherein the first shielding contacts the first section of the second area of the immersion element.