Laser-sustained plasma light source

Patent metadata

Field	Value
Publication number	US-9526158-B1
Application number	US-201514814622-A
Country	US
Kind code	B1
Filing date	Jul 31, 2015
Priority date	May 28, 2009
Publication date	Dec 20, 2016
Grant date	Dec 20, 2016

Abstract

A laser sustained plasma light source having a cell with a gas volume contained within the cell. At least one laser is directed into the gas volume, for sustaining a plasma within the gas volume, which plasma produces a light. Means are provided for continuously providing the gas volume to the plasma in a laminar flow. A reflector collects the light and provides the light to a desired location.

First claim

What is claimed is:

1. A laser sustained plasma light source, comprising:
a cell,
a gas volume contained within the cell,
at least one laser directed into the gas volume, for sustaining a plasma within the gas volume, the plasma producing a light,
means for continuously providing the gas volume to the plasma in a laminar flow, and
a reflector for collecting the light and providing the light to a desired location.

2. The laser sustained plasma light source of claim 1 , further comprising means for continuously removing the gas volume from the plasma in a unidirectional flow.

3. The laser sustained plasma light source of claim 1 , further comprising means for cooling the gas volume that is provided to the plasma in the stable laminar flow.

4. The laser sustained plasma light source of claim 1 , further comprising a cooling jacket disposed around the cell, for further cooling walls of the cell and the gas volume.

5. The laser sustained plasma light source of claim 1 , further comprising a hollow upper electrode disposed within the cell to receive a heated gas volume leaving the plasma, whereby the hollow upper electrode thermally shields the cell from the heated gas volume and maintains a unidirectional flow of the heated gas volume leaving the plasma.

6. The laser sustained plasma light source of claim 5 , further comprising a dam formed between the hollow upper electrode and the cell so as to cause all of the gas volume to flow through the hollow upper electrode.

7. The laser sustained plasma light source of claim 5 , further comprising passive cooling means disposed in the hollow upper electrode for cooling the heated gas volume leaving the plasma.

8. The laser sustained plasma light source of claim 5 , further comprising active cooling means disposed in the hollow upper electrode for cooling the heated gas volume leaving the plasma.

9. The laser sustained plasma light source of claim 1 , further comprising a hollow lower electrode disposed within the cell to provide a cooled gas volume to the plasma, whereby the hollow lower electrode maintains a laminar flow of the cooled gas volume entering the plasma.

10. A laser sustained plasma light source, comprising:
a cell,
a gas volume contained within the cell,
at least one laser directed into the gas volume, for sustaining a plasma within the gas volume, the plasma producing a light,
means for continuously removing the gas volume from the plasma in a unidirectional flow,
means for continuously providing the gas volume to the plasma in a laminar flow,
means for cooling the gas volume that is provided to the plasma in the laminar flow and
a reflector for collecting the light and providing the light to a desired location.

11. The laser sustained plasma light source of claim 10 , further comprising a cooling jacket disposed around the cell, for further cooling walls of the cell and the gas volume.

12. The laser sustained plasma light source of claim 10 , further comprising a hollow upper electrode disposed within the cell to receive a heated gas volume leaving the plasma, whereby the hollow upper electrode thermally shields the cell from the heated gas volume and maintains a unidirectional flow of the heated gas volume leaving the plasma.

13. The laser sustained plasma light source of claim 12 , further comprising a dam formed between the hollow upper electrode and the cell so as to cause all of the gas volume to flow through the hollow upper electrode.

14. The laser sustained plasma light source of claim 12 , further comprising passive cooling means disposed in the hollow upper electrode for cooling the heated gas volume leaving the plasma.

15. The laser sustained plasma light source of claim 12 , further comprising active cooling means disposed in the hollow upper electrode for cooling the heated gas volume leaving the plasma.

16. The laser sustained plasma light source of claim 10 , further comprising a hollow lower electrode disposed within the cell to provide a cooled gas volume to the plasma, whereby the hollow lower electrode maintains a laminar flow of the cooled gas volume entering the plasma.

17. A laser sustained plasma light source, comprising:
a cell,
a gas volume contained within the cell,
at least one laser directed into the gas volume, for sustaining a plasma within the gas volume, the plasma producing a light,
a hollow upper electrode disposed within the cell to receive a heated gas volume leaving the plasma, whereby the hollow upper electrode thermally shields the cell from the heated gas volume and maintains a unidirectional flow of the heated gas volume leaving the plasma,
a hollow lower electrode disposed within the cell to provide a cooled gas volume to the plasma, whereby the hollow lower electrode maintains a laminar flow of the cooled gas volume entering the plasma, and
a reflector for collecting the light and providing the light to a desired location.

18. The laser sustained plasma light source of claim 17 , further comprising a cooling jacket disposed around the cell, for further cooling walls of the cell and the gas volume.

19. The laser sustained plasma light source of claim 17 , further comprising passive cooling means disposed in the hollow upper electrode for cooling the heated gas volume leaving the plasma.

20. The laser sustained plasma light source of claim 5 , further comprising active cooling means disposed in the hollow upper electrode for cooling the heated gas volume leaving the plasma.

Assignees

• Kla Tencor Corp

Inventors

• Bezel Ilya
• Shchemelinin Anatoly
• Zhao Yanming
• Delgado Gildardo R

Classifications

• H01J61/28 Primary

  Means for producing, introducing, or replenishing gas or vapour during operation of the lamp · CPC title

• H05H1/4697 Primary

  using glow discharges · CPC title

• H01J23/033

  Collector cooling devices · CPC title

• H05H1/24 Primary

  Generating plasma {(nuclear fusion reactors G21B1/00; gas-filled discharge reactors H01J37/32)} · CPC title

• H01J1/025

  Hollow cathodes · CPC title