Optical projection system

Patent metadata

Field	Value
Publication number	US-9557653-B2
Application number	US-201514792837-A
Country	US
Kind code	B2
Filing date	Jul 7, 2015
Priority date	Oct 8, 2004
Publication date	Jan 31, 2017
Grant date	Jan 31, 2017

Abstract

An optical projection unit includes first and second optical element modules. The first optical element module includes a first housing unit and a first optical element received within the first housing unit and having an optically used first region defining a first optical axis. The second optical element module is located adjacent to the first optical element module and includes a second optical element which defines a second optical axis of the optical projection unit. The first housing unit has a central first housing axis and an outer wall extending in a circumferential direction about the first housing axis. The first optical axis is laterally offset and/or inclined with respect to the first housing axis. The first housing axis is substantially collinear with the second optical axis.

First claim

The invention claimed is:

1. An optical projection system having a light path, the optical projection system comprising:
a first lens unit configured to receive a first part of the light path;
a second lens unit configured to receive a second part of the light path;
a support unit supporting the first and second lens units,
wherein:
the first lens unit is an elongated lens unit comprising a plurality of lenses;
the second lens unit is an elongated lens unit comprising a plurality of lenses;
the support unit comprises a housing receiving a third part of the light path and enclosing a reflective element;
the housing comprises a first interface, a second interface and an internal support interface;
the first interface supports the first lens unit;
the second interface supports the second lens unit;
the internal support interface is located internal to the housing;
the internal support interface supports the reflective element internal to the housing; and
the optical projection system is a microlithography optical projection system.

2. The optical projection system according to claim 1 , wherein the internal support interface directly supports the reflective element internal to the housing.

3. The optical projection system according to claim 1 , wherein the support unit comprises a holder directly connected to the internal support interface, and the holder holds the reflective element.

4. The optical projection system according to claim 1 , wherein the internal support interface adjustably holds the reflective element internal to the housing.

5. The optical projection system according to claim 1 , wherein the reflective element is selected from the group consisting of a prism, a beam splitter, an optical element defining a shape of the light path within the housing, and an optical element defining a part of an optical axis of the optical projection system.

6. The optical projection system according to claim 1 , wherein the reflective element has optical power.

7. The optical projection system according to claim 1 , wherein:
the reflective element defines part of an optical sub-system of the optical projection system;
the first lens unit has a first optical axis;
the second lens unit has a second optical axis;
the optical sub-system has a third optical axis;
the third optical axis is at least one of inclined and perpendicular to at least one of the first optical axis and the second optical axis.

8. The optical projection system according to claim 7 , wherein the optical sub-system comprises a first and second reflective elements supported within the housing.

9. The optical projection system according to claim 1 , wherein the first lens unit has a first optical axis, and the second lens unit has a second optical axis which is collinear with the first optical axis or parallel to the first optical axis.

10. The optical projection system according to claim 1 , further comprising a third lens unit, wherein the support unit supports the third lens unit.

11. The optical projection system according to claim 10 , wherein the first lens unit has a first optical axis, and the third lens unit has a third optical axis which is inclined with respect to the first optical axis.

12. The optical projection system according to claim 10 , wherein the third lens unit comprises a reflective element.

13. The optical projection system according to claim 1 , wherein the support unit comprises a plurality of support interfaces, and each support interface supports one of the lens units.

14. The optical projection system according to claim 1 , wherein the support unit is monolithic.

15. The optical projection system according to claim 1 , wherein the support unit comprises a plurality of separate components.

16. The optical projection system according to claim 1 , wherein the support unit comprises a material having at least one property selected from the group consisting of a high modulus of elasticity, a high thermal conductivity, and a low thermal expansion coefficient.

17. The optical projection system according to claim 1 , wherein the support unit comprises a ceramic material.

18. The optical projection system according to claim 1 , wherein the support unit comprises SiC.

19. The optical projection system according to claim 1 , wherein the support unit comprises ceramically bonded sub-sections.

20. The optical projection system according to claim 1 , wherein the support unit is formed using at least one process selected from the group consisting of a low shrinkage near-net-shape casting process and a low shrinkage near-net-shape reaction infiltration process.

21. The optical projection system according to claim 1 , wherein the first interface comprises an air bearing unit.

22. The optical projection system according to claim 1 , further comprising a device configured to compensate a thermally induced shift between components of the optical projection system.

23. The optical projection system according to claim 1 , wherein the first interface is configured to adjust the first optical element unit.

24. The optical projection system according to claim 1 , wherein the second interface is configured to adjust the second optical element unit.

25. The optical projection system according to claim 1 , wherein:
the first interface includes a first passage for the light path;
the second interface includes a second passage for the light path;
the housing defines an envelope for the light path; and
the envelope, apart from the first passage and the second passage, is essentially gas tight.

26. The optical projection system according to claim 25 , wherein the envelope comprises a bellows.

27. The optical projection system according to claim 1 , wherein:
the housing has an outer wall and a housing axis; and
the outer wall is substantially symmetric with respect to the housing axis.

28. The optical projection system according to claim 27 , wherein:
the first lens unit has a first optical axis;
the second lens unit has a second optical axis; and
the housing axis is at least one of parallel and collinear to at least one of the first optical axis and the second optical axis.

29. An apparatus, comprising:
an illumination system; and
an optical projection system according to claim 1 ,
wherein the apparatus is an optical exposure apparatus.

30. A method of operating an optical exposure apparatus comprising an illumination system and an optical projection system, the method comprising:
using the illumination system to illuminate a pattern of a mask; and
using the optical exposure apparatus to transfer an image of the illuminated pattern of the mask onto a substrate,
wherein the optical projection system is an optical projection system according to claim 1 .

Assignees

• Zeiss Carl Smt Gmbh

Inventors

• Rau Johannes
• Schoeppach Armin
• Gellrich Bernhard
• Kugler Jens
• Mahlmann Martin
• Geuppert Bernhard
• Petasch Thomas
• Fuerter Gerhard

Classifications

• G02B7/22

  Extensible connections, e.g. bellows · CPC title

• G03F7/70825

  Mounting of individual elements, e.g. mounts, holders or supports (workpiece or mask holders G03F7/707) · CPC title

• G02B17/0812

  off-axis or unobscured systems in which all of the mirrors share a common axis of rotational symmetry · CPC title

• G02B17/0892

  specially adapted for the UV · CPC title

• G02B7/00 Primary

  Mountings, adjusting means, or light-tight connections, for optical elements · CPC title