Lithographic apparatus, device manufacturing method and device manufactured thereby having an increase in depth of focus

• US 20070013889A1
• Filed: 07/12/2005
• Published: 01/18/2007
• Est. Priority Date: 07/12/2005
• Status: Abandoned Application

• Current Assignee: ASML Netherlands BV (ASML Holding NV)
• Original Assignee: ASML Netherlands BV (ASML Holding NV)
• Inventors: Bleeker, Arno, Baselmans, Johannes, Jorritsma, Laurentius, Klinkhamer, Jacob
• Application Number:
  US11/179,056
• Publication Number:
  US 20070013889A1
• Time in Patent Office: Days
• US Class Current: 355/67
• CPC Class Codes: G03F 7/70275 Multiple projection paths, e.g. array of projection systems, microlens projection systems or tandem projection systems
• CPC Class Codes: G03F 7/70575 Wavelength control, e.g. control of bandwidth, multiple wavelength, selection of wavelength or matching of optical components to wavelength
• CPC Class Codes: G03F 7/70641 Focus

Abstract

A lithographic apparatus comprises an illumination system for supplying a beam of radiation, an array of individually controllable elements serving to impart the beam with a pattern in its cross-section, a substrate table for supporting a substrate, and a projection system for projecting the patterned beam onto a target portion of the substrate. The beam of radiation comprises a plurality of beam components. The plurality of beam components includes a first beam component having a first frequency spectrum about a first frequency and at least a second beam component having a second frequency spectrum about a second frequency. The second frequency is different from the first frequency. The projection system focuses the first and second beam components at different heights with respect to the substrate table.

Claims

1. A lithographic apparatus, comprising:

an illumination system that supplies a beam of radiation, the beam of radiation comprising a plurality of beam components including,

a first beam component having a first frequency spectrum about a first frequency, and

a second beam component having a second frequency spectrum about a second frequency, the second frequency being different from the first frequency;

an array of individually controllable elements that pattern the beam of radiation;

a substrate table that supports a substrate; and

a projection system that projects the patterned beam onto a target portion of the substrate, the projection system focusing the first and second beam components at different heights with respect to the substrate table.

2. The lithographic apparatus of claim 1, wherein the beam of radiation further comprises third, fourth, and fifth beam components.

3. The lithographic apparatus of claim 1, wherein the projection system is arranged to focus at least one of the first and second beam components at a height corresponding to a surface of the target portion.

4. The lithographic apparatus of claim 1, wherein the frequency spectra of the first and second beam components overlap.

5. The lithographic apparatus of claim 1, wherein the difference between the first frequency and the second frequency is less than about 4×

10¹⁵ Hz.

6. The lithographic apparatus of claim 1, wherein the projection system comprises an array of lenses arranged to receive the patterned beam.

7. The lithographic apparatus of claim 6, wherein the projection system projects the patterned beam as an array of radiation spots based on the array of lenses.

8. The lithographic apparatus of claim 1, wherein the illumination system supplies the plurality of beam components simultaneously.

9. The lithographic apparatus of claim 1, wherein the illumination system supplies the plurality of beam components sequentially.

10. The lithographic apparatus of claim 1, wherein the illumination system supplies a series of pulses of radiation, each pulse of radiation comprising a respective one of the plurality of beam components.

11. The lithographic apparatus of claim 1, wherein the illumination system comprises a plurality of radiation sources, each source in the plurality of radiation sources being arranged to provide a respective one of the beam components.

12. The lithographic apparatus of claim 11, wherein each radiation source comprises a respective laser.

13. The lithographic apparatus of claim 11, wherein the illumination system further comprises a beam deflection system that receives the plurality of beam components and directs each of the plurality of beam components along a single common beam path.

14. The lithographic apparatus of claim 1, wherein the illumination system supplies the beam of radiation to a plurality of the array of individually controllable elements.

15. The lithographic apparatus of claim 1, further comprising:

a control system that controls the substrate table to vary the focus height while a constant pattern is imparted to the beam.

16. A device manufacturing method, comprising:

supplying a beam of radiation from an illumination system comprising a plurality of beam components including a first beam component having a first frequency spectrum about a first frequency and at least a second beam component having a second frequency spectrum about a second frequency, the second frequency being different from the first frequency;

using an array of individually controllable elements to pattern the beam; and

projecting the patterned beam onto a target portion of a substrate supported by a substrate table, such that the first and second beam components are focused at different heights with respect to the substrate table.

17. The device manufacturing method of claim 16, wherein the projecting step comprises projecting the plurality of beam components simultaneously.

18. The device manufacturing method of claim 16, wherein the projecting step comprises projecting the plurality of beam components sequentially.

19. The device manufacturing method of claim 16, wherein the beam of radiation comprises a series of pulses of radiation, each pulse of radiation comprising a separate one of the plurality of beam components.

20. The device manufacturing method of any claim 16, further comprising:

receiving the plurality of beam components from a plurality of respective radiation sources; and

deflecting each one of the plurality of beam components along a single common beam path to the array of individually controllable elements.

21. A device manufactured using a method according to claim 16.

22. A flat panel display manufactured using a method according to claim 16.

23. A device manufacturing method, comprising:

using an array of individually controllable elements to impart a beam of radiation with a pattern; and

projecting the patterned beam of radiation onto a target portion of a substrate, the projecting comprising,

sequentially focusing the patterned beam at a plurality of different heights with respect to a surface of the substrate, and

projecting the patterned beam onto a common target portion of the substrate as a corresponding array of radiation spots for each of the plurality of different heights.

24. The device manufacturing method of claim 23, further comprising:

using a projection system to focus and project the patterned beam; and

moving the projection system relative to the substrate to focus the patterned beam at the plurality of different heights.

25. The device manufacturing method of claim 24, further comprising:

supporting the substrate on a substrate table and moving the substrate table to achieve the relative movement.

26. A device manufactured using a method according to claim 23.

27. A flat panel display manufactured using a method according to claim 23.