System and method for inhibiting VUV radiative emission of a laser-sustained plasma source

Patent metadata

Field	Value
Publication number	US-9899205-B2
Application number	US-201615223335-A
Country	US
Kind code	B2
Filing date	Jul 29, 2016
Priority date	May 25, 2016
Publication date	Feb 20, 2018
Grant date	Feb 20, 2018

Abstract

A system for forming a laser-sustained plasma includes a gas containment element, an illumination source configured to generate pump illumination, and a collector element configured to focus the pump illumination from the pumping source into the volume of the gas mixture in order to generate a plasma within the volume of the gas mixture that emits broadband radiation. The gas containment element may be configured to contain a volume of a gas mixture including a first gas component and a second gas component. The second gas component suppresses at least one of a portion of the broadband radiation associated with the first gas component or radiation by one or more excimers associated with the first gas component from a spectrum of radiation exiting the gas mixture.

First claim

What is claimed:

1. A system for forming a laser-sustained plasma, comprising:
a gas containment element, wherein the gas containment element is configured to contain a volume of a gas mixture, wherein the gas mixture includes a first gas component and a second gas component;
an illumination source configured to generate pump illumination; and
a collector element configured to focus the pump illumination from the pumping source into the volume of the gas mixture in order to generate a plasma within the volume of the gas mixture, wherein the plasma emits broadband radiation, wherein the second gas component suppresses at least one of a portion of the broadband radiation associated with the first gas component or radiation by one or more excimers associated with the first gas component from a spectrum of radiation exiting the gas mixture.

2. The system of claim 1 , wherein the second gas component suppresses radiation including wavelengths within an absorption spectrum of one or more propagation elements from the spectrum of radiation exiting the gas mixture.

3. The system of claim 2 , wherein the one or more propagation elements comprise:
at least one of the collector element, a transmission element, a reflective element, or a focusing element.

4. The system of claim 2 , wherein the one or more propagation elements are formed from at least one of crystalline quartz, sapphire, fused silica, calcium fluoride, lithium fluoride, or magnesium fluoride.

5. The system of claim 1 , wherein the gas mixture suppresses radiation including wavelengths within an absorption spectrum of one or more additional elements from the spectrum of radiation exiting the gas mixture.

6. The system of claim 5 , wherein the one or more additional elements comprise:
at least one of a flange or a seal.

7. The system of claim 1 , wherein the broadband radiation emitted by the plasma includes at least one of infrared wavelengths, visible wavelengths, UV wavelengths, DUV wavelengths, VUV wavelengths, or EUV wavelengths.

8. The system of claim 1 , wherein the second gas component suppresses a portion of the broadband radiation by the plasma associated with the first gas component including VUV wavelengths from the spectrum of radiation exiting the gas mixture.

9. The system of claim 1 , wherein the second gas component suppresses a portion of the broadband radiation of the plasma associated with the first gas component including wavelengths lower than 600 nm from the spectrum of radiation exiting the gas mixture.

10. The system of claim 1 , wherein the second gas component absorbs the at least one of a portion of the broadband radiation associated with the first gas component or radiation by one or more excimers associated with the first gas component.

11. The system of claim 1 , wherein the second gas component quenches radiative emission by excimers associated with the first gas component.

12. The system of claim 11 , wherein the second gas component quenches radiative emission of excimers associated with the first gas component by at least one of collisional dissociation, a photolytic process, or resonant energy transfer.

13. The system of claim 1 , wherein the second gas component comprises:
less than 25% of the gas mixture.

14. The system of claim 13 , wherein the second gas component comprises:
0.5% to 20% of the gas mixture.

15. The system of claim 13 , wherein the second gas component comprises:
less than 5% of the gas mixture.

16. The system of claim 13 , wherein the second gas component comprises:
10% to 15% of the gas mixture.

17. The system of claim 1 , wherein the gas mixture further includes a third gas component, wherein the third gas component suppresses at least one of a portion of the broadband radiation associated with the second gas component or radiation by one or more excimers associated with the second gas component from the spectrum of radiation exiting the gas mixture.

18. The system of claim 17 , wherein the third gas component comprises:
less than 5 mg per cubic centimeter of the gas mixture.

19. The system of claim 18 , wherein the third gas component comprises:
less than 2 mg per cubic centimeter of the gas mixture.

20. The system of claim 17 , wherein the first gas component comprises:
argon.

21. The system of claim 20 , wherein the second gas component comprises:
xenon.

22. The system of claim 21 , wherein the third gas component comprises:
mercury.

23. The system of claim 1 , wherein the gas containment element includes at least one of a chamber, a plasma bulb or a plasma cell.

24. The system of claim 1 , wherein the collector element is arranged to collect at least a portion of the broadband radiation emitted by the plasma and direct the broadband radiation to one or more additional optical elements.

25. The system of claim 1 , wherein suppressing radiation from the spectrum of radiation exiting the gas mixture inhibits damage to one or more components of the system.

26. The system of claim 25 , wherein the damage includes solarization.

27. The system of claim 1 , wherein the illumination source comprises:
one or more lasers.

28. The system of claim 27 , wherein the one or more lasers comprise:
one or more infrared lasers.

29. The system of claim 27 , wherein the one or more lasers comprise:
at least one of a diode laser, a continuous wave laser, or a broadband laser.

30. The system of claim 1 , wherein the illumination source comprises:
an illumination source configured to emit pump illumination at a first wavelength and illumination at an additional wavelength different from the first wavelength.

31. The system of claim 1 , wherein the illumination source comprises:
an adjustable illumination source, wherein a wavelength of the pump illumination emitted by the illumination source is adjustable.

32. The system of claim 1 , wherein the collector element is positioned external to the gas containment element.

33. The system of claim 1 , wherein the collector element is positioned internal to the gas containment element.

34. The system of claim 1 , wherein the collector element comprises:
at least one of an ellipsoid-shaped collector element or a spherical-shaped collector element.

35. A plasma lamp for forming a laser-sustained plasma, comprising:
a gas containment element, wherein the gas containment element is configured to contain a volume of a gas mixture, wherein the gas mixture includes a first gas component and a second gas component, wherein the gas mixture is further configured to receive pump illumination in order to generate a plasma within the volume of the gas mixture, wherein the plasma emits broadband radiation, wherein the second gas component suppresses at least one of a portion of the broadband radiation associated with the first gas component or radiation by one or more excimers associated with the first gas component from a spectrum of radiation exiting the gas mixture.

36. The system of claim 35 , wherein the broadband radiation emitted by the plasma includes at least one of infrared wavelengths, visible wavelengths, UV wavelengths, DUV wavelengths, VUV wavelengths, or EUV wavelengths.

37. The system of claim 35 ,

Assignees

• Kla Tencor Corp

Inventors

• Bezel Ilya
• Gross Kenneth P
• Wilson Lauren
• Yadav Rahul
• Wittenberg Joshua
• Bhuiyan Aizaz
• Shchemelinin Anatoly
• Chimmalgi Anant
• Solarz Richard

Classifications

• H01J61/20

  mercury vapour · CPC title

• H01J65/04

  Lamps in which a gas filling is excited to luminesce by an external electromagnetic field or by external corpuscular radiation, e.g. for indicating {plasma display panels} · CPC title

• H01J61/16

  having helium, argon, neon, krypton, or xenon as the principle constituent · CPC title

• H01J61/36

  Seals between parts of vessels; Seals for leading-in conductors; Leading-in conductors · CPC title

• H01J61/12 Primary

  Selection of substances for gas fillings; Specified operating pressure or temperature · CPC title