Radiation beam pulse trimming

• US 7,826,037 B2
• Filed: 08/30/2007
• Issued: 11/02/2010
• 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: De Bruijn, Cornelis Cornelia, Meijerink, Marcus Gerhardus Hendrikus, Noordman, Oscar Franciscus Jozephus, Vink, Henri Johannes Petrus, Visser, Huibert, Schreel, Koenraad Remi André Maria
• Primary Examiner(s): Mathews; Alan A
• Application Number:
  US11/847,928
• Publication Number:
  US 20080111981A1
• Time in Patent Office: 1,160 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
• 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 temperature controller configured to control a temperature of the electro-optical modulator;

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; and

a compensation device located between the electro-optical modulator and the beam splitter and configured to compensate for phase retardation changes.

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, wherein the compensation device comprises a moveable crystalline quartz wedge.

5. The system of claim 1, wherein the compensation device is configured to have zero transmission or substantially complete transmission when zero voltage is applied to the electro-optical modulator.

6. The system of claim 1, wherein the electro-optical modulator transitions between about 100% and about 0% transmission in about 10 ns to about 30 ns or less.

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

8. The system of claim 1, wherein the temperature controller is configured to operate the electro-optical modulator at an elevated temperature.

9. The system of claim 8, wherein the elevated temperature is about 300°

C.

10. 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 temperature controller configured to control a temperature of the electro-optical modulator;

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; and

a compensation device between the electro-optical modulator and the beam slitter and that is configured to compensate for phase retardation changes;

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.

11. The system of claim 10, wherein the compensation device comprises a moveable crystalline quartz wedge.

12. The system of claim 10, wherein the compensation device is configured to have zero transmission or substantially complete transmission when zero voltage is applied to the electro-optical modulator.

13. A method, comprising:

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

controlling a temperature of the electro-optical modulating using a temperature controller;

compensating for phase retardation changes using a compensation device between the electro-optical modulator and a beam splitter;

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

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

14. The method of claim 13, wherein the modulating comprises using a Pockels cell for the electro-optical modulator.

15. The method of claim 13, 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.

16. The method of claim 13, further comprising using a moveable crystalline quartz wedge as the compensation device.

17. The method of claim 13, wherein the compensation device has zero transmission or substantially complete transmission when zero voltage is applied to the electro-optical modulator.

18. The method of claim 13, further comprising transitioning the electro-optical modulator between about 100% to about 0% transmission in about 10 ns to about 30 ns or less.

19. The method of claim 13, wherein the modulating modulates polarization characteristics of the beam of radiation.

20. The method of claim 13, wherein the controlling the temperature further comprises maintaining the electro-optical modulated at an elevated temperature.

21. The method of claim 20, wherein the elevated temperature is about 300°

C.

22. A laser that outputs an output beam, comprising:

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

a temperature controller configured to control a temperature of the electro-optical modulator;

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

a compensation device positioned between the electro-optical modulator and the beam splitter and configured to compensate for phase retardation changes caused by wavelength or temperature variation.

23. An illuminator that outputs a processed beam, comprising:

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

a temperature controller configured to control a temperature of the electro-optical modulator;

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;

a compensation device between the electro-optical modulator and the beam splitter and configured to compensate for phase retardation changes based on wavelength or temperature variation; and

an optical system configured to process the output beam to produce the processed beam.