Systems and methods for minimizing scattered light in multi-SLM maskless lithography

• US 20060146308A1
• Filed: 01/06/2005
• Published: 07/06/2006
• Est. Priority Date: 01/06/2005
• Status: Active Grant

• Current Assignee: ASML Holding NV
• Original Assignee: ASML Holding NV
• Inventors: Vladimirsky, Yuli, Cebuhar, Wenceslao A., Hintersteiner, Jason D., Janik, Stan
• Granted Patent: US 7,567,368 B2
• Time in Patent Office: Days
• US Class Current: 355/67
• 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

The present invention is directed to a lithography system in which scattered light from a pattern generator, having one or more pattern generating devices, is blocked from an object, such as a wafer or display. The system includes a pattern generator with multiple pattern generating devices, a projection system for directing light from the pattern generating device, and an aperture located at or near an object window. The aperture has a profile that matches the configuration of the pattern generating devices. A method for blocking scattered light in a lithography system using multiple pattern generating devices is also provided.

Claims

1. A system, comprising

one or more pattern generating devices having a pattern generating configuration;

a projection optics system for directing light from said one or more pattern generating devices to a substrate or work surface; and

an aperture within said projection optics system having a profile that matches the pattern generating configuration.

2. The system of claim 1, wherein said one or more pattern generating devices are spatial light modulators.

3. The system of claim 2, wherein said spatial light modulators are digital micromirror devices.

4. The system of claim 2, wherein said spatial light modulators are transmissive liquid crystal light valves.

5. The system of claim 2, wherein said spatial light modulators are grating light values.

6. The system of claim 1, wherein said aperture is an aperture plate.

7. The system of claim 1, wherein said aperture is etched onto a window near an object plane of the projection optics system.

8. The system of claim 1, wherein said aperture is etched onto a window near an image plane of the projection optics system.

9. The system of claim 1, wherein said aperture is etched onto a lens within the projection optics system.

10. A projection optics system for use with one or more pattern generating devices having a pattern generating configuration, comprising

one or more optical elements for directing light;

an aperture having a profile with openings that correspond to locations of the one or more pattern generating devices.

11. The projection optic system of claim 10, wherein said aperture is etched onto a window near an object plane of the projection optics system.

12. The projection optic system of claim 10, wherein said aperture is etched onto a window near an image plane of the projection optics system.

13. The projection optic system of claim 10, wherein said aperture is etched onto a lens within the projection optics system.

14. A method, comprising:

(a) generating a beam of radiation;

(b) patterning portions of the beam of radiation;

(c) projecting the patterned beam of radiation towards a substrate; and

(d) blocking scattered light from the beam of radiation from the object.

15. The method of claim 14, further comprising providing a display device as the substrate.

16. The method of claim 14, further comprising providing a wafer as the substrate.

17. The method of claim 14, further comprising providing a camera as the substrate.