Radiation beam pulse trimming

• US 20080112030A1
• Filed: 11/14/2006
• Published: 05/15/2008
• Est. Priority Date: 11/14/2006
• Status: Active Grant

• Current Assignee: ASML Netherlands BV (ASML Holding NV)
• Original Assignee: ASML Netherlands BV (ASML Holding NV)
• Inventors: Noordman, Oscar Franciscus Jozephus, Vink, Henri Johannes Petrus, Visser, Huibert
• Granted Patent: US 7,738,079 B2
• Time in Patent Office: Days
• US Class Current: 359/238
• CPC Class Codes: G03F 7/70041 by pulsed sources, e.g. multiplexing, pulse duration, interval control or intensity control
• CPC Class Codes: G03F 7/70558 Dose control, i.e. achievement of a desired dose

Abstract

A system is used to perform fast and slow applications, for example fast application can be pulse trimming. The system includes a radiation source, an electro-optical modulator, and a beam splitter. The radiation source is configured to generate a polarized beam of radiation. The electro-optical modulator, formed of crystalline quartz, is configured to modulate the beam of radiation. The beam splitter is configured to direct a first portion of the beam to a beam dump and to form an output beam from a second portion of the beam.

Claims

1. A system, comprising:

radiation source configured to generate a polarized beam of radiation;

an electro-optical modulator, formed of crystalline quartz, which is configured to modulate the beam of radiation; and

a beam splitter configured to direct a first portion of the beam to a beam dump and to form an output beam from a second portion of the beam.

2. The system of claim 1, wherein the electro-optical modulator comprises a Pockels cell.

3. The system of claim 1, wherein the beam splitter comprises a polarizing beam splitter, such that the polarizing beam splitter is configured to form the first portion of the beam from a first polarization direction of the polarized beam and the second portion of the beam from a second polarization direction of the polarized beam.

4. The system of claim 1, further comprising a compensation device positioned between the electro-optical modulator and the beam splitter.

5. The system of claim 4, wherein the compensation device comprises a moveable crystalline quartz wedge.

6. The system of claim 4, wherein the compensation device is configured to have zero transmission when zero voltage is applied to the electro-optical modulator.

7. The system of claim 4, wherein the compensation device is configured to compensate for phase retardation changes caused by wavelength or temperature variation.

8. The system of claim 1, wherein the beam of radiation has a wavelength of about 193 nm or less.

9. The system of claim 1, wherein the electro-optical modulator is biased between zero and a predetermined voltage.

10. The system of claim 1, wherein the electro-optical modulator transitions between about 100% and about 0% transmission in about 10 ns or less.

11. The system of claim 1, further comprising:

a patterning device configured to pattern the output beam; and

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

12. The system of claim 11 further comprising:

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

13. The system of claim 12, wherein the illumination system comprises the electro-optical modulator and the beam splitter.

57. The system of claim 1, wherein the electro-optical modulator is configured to modulate polarization characteristics of the beam of radiation.

14. A lithography system, comprising:

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

an electro-optical modulator, formed of crystalline quartz, which is configured to modulate the beam of radiation; and

a beam splitter configured to direct a first portion of the beam to a beam dump and to form the illumination beam from a second portion of the beam,

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.

15. The lithography system of claim 14, wherein the electro-optical modulator comprises a Pockels cell.

16. The lithography system of claim 14, wherein the beam splitter comprises a polarizing beam splitter, such that the polarizing beam splitter is configured to form the first portion of the beam from a first polarization direction of the polarized beam and the second portion of the beam from a second polarization direction of the polarized beam.

17. The lithography system of claim 14, further comprising a compensation device positioned between the electro-optical modulator and the beam splitter.

18. The lithography system of claim 17, wherein the compensation device comprises a moveable crystalline quartz wedge.

20. The lithography system of claim 17, wherein the compensation device is configured to compensate for phase retardation changes caused by wavelength or temperature variation.

58. The lithography system of claim 14, wherein the electro-optical modulator is configured to modulate polarization characteristics of the beam of radiation.

19. (canceled)

21-23. -23. (canceled)

24. A method, comprising:

(a) modulating a polarized beam of radiation using an electro-optical modulator formed of crystalline quartz;

(b) directing a first portion of the modulated beam to a beam dump using a beam splitter; and

(c) forming an output beam from a second portion of the modulated beam using the beam splitter.

25. The method of claim 24, wherein step (a) comprises using a Pockels cell for the electro-optical modulator.

26. The method of claim 24, wherein steps (b) and (c) comprise using a polarizing beam splitter, such that a first polarization direction of the polarized beam is used to form the first portion and a second polarization direction of the polarized beam is used to form the second portion of the beam.

27. The method of claim 24, further comprising positioning a compensation device between the electro-optical modulator and the beam splitter.

28. The method of claim 27, further comprising using a moveable crystalline quartz wedge as the compensation device.

34. The method of claim 24, further comprising:

(d) patterning the output beam; and

(e) projecting the patterned beam on a target portion of a substrate.

59. The method of claim 24, wherein step (a) modulates polarization characteristics of the beam of radiation.

29-33. -33. (canceled)

35-56. -56. (canceled)

60-62. -62. (canceled)