Kit of parts for assembling an optical element, method of assembling an optical element, optical element, lithographic apparatus, and device manufacturing method

• US 20040012764A1
• Filed: 05/29/2003
• Published: 01/22/2004
• Est. Priority Date: 05/31/2002
• Status: Active Grant

• Current Assignee: ASML Netherlands BV (ASML Holding NV)
• Original Assignee: ASML Netherlands BV (ASML Holding NV)
• Inventors: Van Greevenbroek, Hendrikus Robertus Marie, Mulder, Heine Melle
• Granted Patent: US 7,038,763 B2
• Time in Patent Office: Days
• US Class Current: 355/53
• CPC Class Codes: G03F 7/70075 Homogenization of illumination intensity in the mask plane by using an integrator, e.g. fly's eye lens, facet mirror or glass rod, by using a diffusing optical element or by beam deflection
• CPC Class Codes: G03F 7/70108 Off-axis setting using a light-guiding element, e.g. diffractive optical elements [DOEs] or light guides
• CPC Class Codes: G03F 7/70158 Diffractive optical elements
• CPC Class Codes: G03F 7/70566 Polarisation control
• CPC Class Codes: G03F 7/70825 Mounting of individual elements, e.g. mounts, holders or supports workpiece or mask holders G03F7/707

Abstract

A kit of parts for assembling an optical element for use in a lithographic apparatus comprises a large number of different small pieces which direct light into respective regions of the pupil plane of the radiation system and/or change the polarization state of incident radiation. The previously manufactured pieces are selected and assembled into an optical element to rapidly create a desired intensity distribution. The optical element may also be disassembled and the pieces reused.

Claims

1. A kit of parts for assembling an optical element for effecting a desired change in incident radiation at a plane of a radiation system of a lithographic apparatus, the kit of parts comprising:

a plurality of previously manufactured optical components, each component having an effect on the incident radiation, wherein the effect of at least some of the optical components is different than the effect of others of the optical components; and

a support constructed and arranged to hold a user selectable subset of the plurality of optical components in an array.

2. A kit of parts according to claim 1, wherein the effect of at least some of the optical components is a change of direction of incident radiation.

3. A kit of parts according to claim 2, wherein all of the optical components direct incident radiation into four mutually symmetric directions.

4. A kit of parts according to claim 2, wherein all of the optical components direct incident radiation into respective regions of one quadrant of a pupil plane of the lithographic apparatus.

5. A kit of parts according to claim 2, wherein all of the optical components are square in shape and direct incident radiation into respective regions of one half of one quadrant of a pupil plane of the lithographic apparatus.

6. A kit of parts according to claim 2, wherein the optical components are selected from a group of optical components comprising diffractive, refractive, reflective, and diffusive optical components.

7. A kit of parts according to claim 1, wherein the effect of the at least some of the optical components is a change of polarization state of the incident radiation.

8. A kit of parts according to claim 7, wherein the optical components are selected from a group of optical components comprising optical components that effect a rotation of the polarization state and optical components that effect an at least partial polarization of the incident radiation.

9. A kit of parts according to claim 1, wherein the effect of the at least some of the optical components is a change of both direction and polarization state of the incident radiation.

10. A kit of parts according to claim 1, wherein the support is partially transmissive for the incident radiation.

11. A kit of parts according to claim 10, wherein the support comprises a plate-like optical element for directing the incident radiation into a narrow range of angles.

12. A kit of parts according to claim 11, wherein the optical components comprise refractive wedges.

13. A method of assembling an optical element for effecting a desired change in incident radiation at a plane of a radiation system of a lithographic apparatus, the method comprising:

selecting, from a plurality of previously manufactured optical components which have different effects on the incident radiation, optical components to effect the desired change; and

mounting the selected optical components in an array on a support to form the optical element.

14. A method according to claim 13, wherein the plurality of previously manufactured optical components comprise a plurality of first optical components that effect a change of direction of the incident radiation and a plurality of second optical components that effect a change of polarization state of the incident radiation.

15. A method according to claim 13, wherein the optical components are releasably mounted on the support.

16. An optical element for effecting a desired change in incident radiation at a plane of a radiation system of a lithographic apparatus, the optical element comprising:

a plurality of previously manufactured optical components, each component having an effect on the incident radiation, wherein the effect of at least some of the optical components is different than the effect of others of the optical components; and

a support constructed and arranged to hold a user selectable subset of the plurality of optical components in an array.

17. An optical element according to claim 16, wherein the optical components are selected from a group of optical components comprising redirective optical components, polarization changing optical components, and optical components that effect both direction and polarization state of incident radiation.

18. An optical element according to claim 16, wherein the support comprises a plate-like optical element for directing incident radiation into a narrow range of angles.

19. An optical element according to claim 16, wherein the plurality of previously manufactured optical components comprises a first layer of optical components that effect a change of polarization state of the incident radiation and a second layer of optical components that effect a change of direction of the incident radiation.

20. An optical element according to claim 16, wherein the optical components are releasably mounted on the support.

21. A lithographic apparatus, comprising:

a radiation system constructed and arranged to provide a projection beam of radiation;

a support structure constructed and arranged to support a patterning device, the patterning device constructed and arranged to pattern the projection beam according to a desired pattern;

a substrate table constructed and arranged to hold a substrate; and

a projection system constructed and arranged to project the patterned beam onto a target portion of the substrate, wherein the radiation system comprises an optical element for effecting a desired change in incident radiation at a plane of the radiation system, the optical element having been assembled by mounting a user selectable subset of a plurality of previously manufactured optical components having different effects on the incident radiation in an array on a support.

22. A device manufacturing method, comprising:

providing a substrate;

providing a projection beam of radiation using a radiation system;

using a patterning device to endow the projection beam with a pattern in its cross-section;

projecting the patterned beam of radiation onto a target portion of the substrate; and

placing in the radiation system an optical element for effecting a desired change in incident radiation at a plane of the radiation system, the optical element having been assembled by mounting a user selectable subset of a plurality of previously manufactured optical components having different effects on the incident radiation in an array on a support.