Radiation beam pulse trimming

• US 7,738,079 B2
• Filed: 11/14/2006
• Issued: 06/15/2010
• 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: Vink, Henri Johannes Petrus, Visser, Huibert, Noordman, Oscar Franciscus Jozephus
• Primary Examiner(s): Mathews; Alan A
• Application Number:
  US11/598,837
• Publication Number:
  US 20080112030A1
• Time in Patent Office: 1,309 Days
• Field of Search: 355/53, 355/67, 355/71, 355/77, 359/238, 359/245, 359/248, 359/251, 359/315, 359/318, 359/321, 359/322, 359/257
• US Class Current: 355/71
• 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:

a radiation source configured to generate a polarized beam of radiation;

an electro-optical modulator configured to modulate the beam of radiation;

a compensation wedge configured to adjust the modulated beam of radiation; and

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

4. The system of claim 1, wherein the compensation wedge comprises a moveable crystalline quartz wedge.

5. The system of claim 1, wherein the compensation wedge is configured to have zero transmission if zero voltage is applied to the electro-optical modulator.

6. The system of claim 1, wherein the compensation wedge is configured to compensate for phase retardation changes caused by wavelength or temperature variation.

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

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

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

10. 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.

11. The system of claim 10 further comprising:

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

12. The system of claim 11, wherein the illumination system comprises the electro-optical modulator, the compensation wedge, and the beam splitter.

13. 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, configured to modulate the beam of radiation;

a compensation wedge configured to adjust the modulated beam of radiation; and

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

a patterning device configured to pattern the illumination beam of radiation; and

a projection system configured to project 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 compensated beam from a first polarization direction of the polarized beam and the second portion of the compensated beam from a second polarization direction of the polarized beam.

17. The lithography system of claim 14, wherein the compensation wedge comprises a moveable crystalline quartz wedge.

18. The lithography system of claim 14, wherein the compensation wedge is configured to compensate for phase retardation changes caused by wavelength or temperature variation.

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

20. A method, comprising:

modulating a polarized beam of radiation using an electro-optical modulator;

adjusting the modulated beam using a compensation wedge;

directing a first portion of the compensated beam to a beam dump using a beam splitter; and

forming an output beam from a second portion of the compensated beam using the beam splitter.

21. The method of claim 20, wherein the modulating comprises using a Pockels cell for the electro-optical modulator.

22. The method of claim 20, wherein the directing and forming 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.

23. The method of claim 20, further comprising using a moveable crystalline quartz wedge as the compensation wedge.

24. The method of claim 20, further comprising:

patterning the output beam; and

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

25. The method of claim 20, wherein the modulating modulates polarization characteristics of the beam of radiation.