Increasing pulse-to-pulse radiation beam uniformity

• US 7,453,551 B2
• Filed: 11/14/2006
• Issued: 11/18/2008
• Est. Priority Date: 11/14/2006
• Status: Expired due to Fees

• Current Assignee: ASML Netherlands BV (ASML Holding NV)
• Original Assignee: ASML Netherlands BV (ASML Holding NV)
• Inventors: Noordman, Oscar Franciscus Jozephus, Buurman, Erik Petrus
• Primary Examiner(s): Rutledge; Della J.
• Application Number:
  US11/598,834
• Publication Number:
  US 20080111982A1
• Time in Patent Office: 735 Days
• Field of Search: 355/69, 355/67, 372/50.22, 372/57
• US Class Current: 355/69
• CPC Class Codes: G03B 27/72 Controlling or varying light intensity, spectral composition, or exposure time in photographic printing apparatus
• CPC Class Codes: G03F 7/70041 by pulsed sources, e.g. multiplexing, pulse duration, interval control or intensity control

Abstract

A system is used to substantially reduce divergence of a beam traveling between master and power oscillators, for example in a laser beam source. The system comprises the first and second oscillators and a beam conditioning device. The first oscillator is configured to generate a radiation beam. The beam conditioning device is configured to stabilize a position, a direction, a size, or a divergence of the radiation beam to produce a conditioned beam. The second oscillator configured to amplify the conditioned beam to produce an amplified beam.

Claims

1. A system, comprising:

a first oscillator configured to generate a radiation beam;

a beam conditioning device configured to stabilize the radiation beam to produce a conditioned beam; and

a second oscillator configured to amplify the conditioned beam to produce an amplified beam having substantially less divergence than the radiation beam,

wherein a divergence of the conditioned beam, as received at the second oscillator, is substantially equivalent to a divergence of the radiation beam, as transmitted from the first oscillator.

2. The system of claim 1, wherein the first oscillator is configured to generate the radiation beam through random spontaneous emissions.

3. The system of claim 1, wherein the second oscillator is configured to operate at saturation, whereby output energy is substantially independent from input energy.

4. The system of claim 1, wherein the second oscillator is configured to perform the amplification of the conditioned beam using stimulated emissions.

5. The system of claim 1, wherein the second oscillator is a power oscillator.

6. The system of claim 1, further comprising:

a patterning device configured to pattern the amplified beam; and

a projection system configured to project the patterned beam onto a target portion of a substrate.

7. The system of claim 6, further comprising:

an illumination system that processes the amplified beam and directs the amplified beam onto the patterning device.

8. The system of claim 7, wherein the illumination system comprises the first and second oscillator and the beam conditioning device.

9. The system of claim 1, wherein the beam conditioning device is configured to stabilize at least one of a position, a direction, or a size of the radiation beam.

10. A lithography system, comprising:

an illumination system configured to generate an illumination beam of radiation, comprising,

a first oscillator configured to generate a radiation beam having a first divergence;

a beam conditioning device configured to stabilize the radiation beam to produce a conditioned beam having a second divergence substantially equivalent to the first divergence; and

a second oscillator configured to amplify the conditioned beam to produce an illumination beam of radiation having a third divergence, the third divergence being substantially smaller than the first divergence and the second divergence;

a patterning device that patterns the illumination beam of radiation; and

a projection system that projects the patterned beam onto a target portion of a substrate.

11. The lithography system of claim 10, wherein the first oscillator is configured to generate the radiation beam through random spontaneous emissions.

12. The lithography system of claim 10, wherein the second oscillator is configured to operate at saturation, whereby output energy is substantially independent from input energy.

13. The lithography system of claim 10, wherein the second oscillator is configured to perform the amplification of the conditioned beam using stimulated emissions.

14. The lithography system of claim 10, wherein the second oscillator is a power oscillator.

15. The lithography system of claim 10, wherein a divergence of the conditioned beam, as received at the second oscillator, is substantially equivalent to a divergence of the radiation beam, as transmitted from the first oscillator.

16. The lithography system of claim 10, wherein the beam conditioning device is configured to stabilize at least one of a position, a direction, or a size of the radiation beam.

17. A method, comprising:

(a) generating a radiation beam using a first oscillator;

(b) maintaining a divergence of the radiation beam to produce a conditioned beam having a divergence substantially equivalent the divergence of the radiation beam; and

(c) amplifying the conditioned beam using a second oscillator such that an amplified beam has substantially less divergence than the radiation beam.

18. The method of claim 17, wherein step (a) comprises generating the radiation beam through random spontaneous emissions.

19. The method of claim 17, wherein step (c) comprises operating the second oscillator at saturation, whereby output energy is substantially independent from input energy.

20. The method of claim 17, wherein step (c) comprises performing the amplification of the conditioned beam using stimulated emissions.

21. The method of claim 17, further comprising:

patterning the amplified beam; and

projecting the patterned beam on a target portion of a substrate.

22. The method of claim 17, wherein step (b) comprises stabilizing at least one of a position, direction, or size of the radiation beam.

23. A laser, comprising:

a first oscillator configured to generate a radiation beam;

a beam conditioning device configured to stabilize the radiation beam to produce a conditioned beam; and

a second oscillator configured to amplify the conditioned beam to produce an amplified beam having substantially less divergence than the radiation beam,

wherein a divergence of the conditioned beam, as received at the second oscillator, is substantially equivalent to a divergence of the conditioned beam, as transmitted from the first oscillator.

24. The laser of claim 23, wherein the second oscillator is configured to operate at saturation, whereby output energy is substantially independent from input energy.

25. The laser of claim 23, wherein the second oscillator is a power oscillator.

26. The laser of claim 23, wherein the beam conditioning device is configured to stabilize at least one of a position, a direction, or a size of the radiation beam.

27. An illuminator, comprising:

a first oscillator configured to generate a radiation beam having a first divergence;

a beam conditioning device configured to stabilize the radiation beam to produce a conditioned beam having a second divergence substantially equivalent to the first divergence;

a second oscillator configured to amplify the conditioned beam to produce an amplified beam having a third divergence, the third divergence being substantially smaller than the first divergence and the second divergence; and

an optical system configured to process the amplified beam to produce a processed beam.

28. The illuminator of claim 27, wherein the first oscillator is configured to generate the radiation beam through random spontaneous emissions.

29. The illuminator of claim 27, wherein the second oscillator is configured to operate at saturation, whereby output energy is substantially independent from input energy.

30. The illuminator of claim 27, wherein the second oscillator is configured to perform the amplification of the conditioned beam using stimulated emissions.

31. The illuminator of claim 27, wherein the second oscillator is a power oscillator.

32. The illuminator of claim 27, wherein a divergence of the conditioned beam, as received at the second oscillator, is substantially equivalent to a divergence of the radiation beam, as transmitted from the first oscillator.

33. The illuminator of claim 27, wherein the beam conditioning device is configured to stabilize at least one of a position, a direction, or a size of the radiation beam.