Systems and Methods for Minimizing Scattered Light in Multi-SLM Maskless Lithography

• US 20100002221A1
• Filed: 07/09/2009
• Published: 01/07/2010
• Est. Priority Date: 01/06/2005
• Status: Active Grant

• Current Assignee: ASML Holding NV
• Original Assignee: ASML Holding NV
• Inventors: VLADIMIRSKY, Yuli, JANIK, Stan, HINTERSTEINER, Jason D., CEBUHAR, Wenceslao A.
• Granted Patent: US 7,859,735 B2
• Time in Patent Office: Days
• US Class Current: 355/77
• CPC Class Codes: G03F 7/70291 Addressable masks, e.g. spatial light modulators [SLMs], digital micro-mirror devices [DMDs] or liquid crystal display [LCD] patterning devices
• CPC Class Codes: G03F 7/70308 Optical correction elements, filters or phase plates for manipulating imaging light, e.g. intensity, wavelength, polarisation, phase or image shift
• CPC Class Codes: G03F 7/70941 Stray fields and charges, e.g. stray light, scattered light, flare, transmission loss

Abstract

A lithography method is provided. The method includes generating a beam of radiation, patterning portions of the beam of radiation, projecting the patterned beam of radiation towards a substrate, and blocking scattered light from the beam of radiation from the substrate.

Claims

1. A method, comprising:

projecting a patterned beam of radiation towards a substrate; and

blocking scattered light before the beam of radiation interacts with the substrate.

2. The method of claim 1, further comprising providing a display device substrate as the substrate.

3. The method of claim 1, further comprising providing a wafer as the substrate.

4. The method of claim 1, further comprising providing a camera substrate as the substrate.

5. The method of claim 1, wherein the patterned beam is patterned with one or more pattern generating devices.

6. The method of claim 1, wherein the one or more pattern generating devices are spatial light modulators.

7. The method of claim 6, wherein the spatial light modulators are digital micromirror devices.

8. The method of claim 6, wherein the spatial light modulators are transmissive liquid crystal light valves.

9. The method of claim 6, wherein the spatial light modulators are grating light values.

10. The method of claim 1, wherein blocking comprises blocking the scattered light using an aperture.

11. The method of claim 1, wherein:

the projecting comprises using a projection optics system; and

the blocking comprises using an aperture etched onto a window near an object plane of the projection optics system.

12. The method of claim 1, wherein:

the projecting comprises using a projection optics system; and

the blocking comprises using an aperture etched onto a window near an image plane of the projection optics system.

13. The method of claim 1, wherein:

the projecting comprises using a projection optics system; and

the blocking comprises using an aperture etched onto a lens within the projection optics system.

14. A method, comprising:

generating beams using respective patterning devices, each of the respective patterning devices comprising a reflecting portion, the reflecting portion including an array of programmable elements that each are configured to produce a beam, and a non-reflecting portion, wherein respective beams form a patterned beam and wherein the non-reflecting portion is configured to produce stray beams;

directing the patterned beams onto a surface; and

blocking the stray beams from reaching the surface using an aperture device comprising a number of openings, the number corresponding to a number of the patterning devices, the openings arranged in a configuration to correspond to locations of the patterning devices, the openings being arranged in a configuration to transmit the patterned beam, while substantially blocking the stray beams;

wherein a spacing between adjacent ones of the elements in each of the array of programmable elements is smaller than a spacing between adjacent ones of the patterning devices.

15. The method of claim 14, wherein the non-reflecting portions scatter incident light.

16. The method of claim 14, wherein the surface is a surface of a display device, a wafer, or a camera.

17. The method of claim 14, wherein each of the pattern generating devices comprise a spatial light modulator.

18. The method of claim 17, wherein the spatial light modulator comprises a digital micromirror device, a transmissive liquid crystal light valve, or a grating light valve.

19. The method of claim 14, wherein the aperture is an aperture plate.

20. The method of claim 14, wherein:

the directing comprises directing the patterned beams towards the surface using a projection optics system; and

the aperture is etched onto a window near an object plane or image plane of the projection optics system.

21. The method of claim 14, wherein:

the directing comprises directing the patterned beams towards the surface using a projection optics system; and

the aperture is etched onto a lens within the projection optics system.