Plasma cell for providing VUV filtering in a laser-sustained plasma light source

Patent metadata

Field	Value
Publication number	US-10976025-B2
Application number	US-201815895868-A
Country	US
Kind code	B2
Filing date	Feb 13, 2018
Priority date	Jan 17, 2012
Publication date	Apr 13, 2021
Grant date	Apr 13, 2021

Abstract

A plasma cell for use in a laser-sustained plasma light source includes a plasma bulb configured to contain a gas suitable for generating a plasma. The plasma bulb is transparent to light from a pump laser, wherein the plasma bulb is transparent to at least a portion of a collectable spectral region of illumination emitted by the plasma. The plasma bulb of the plasma cell is configured to filter short wavelength radiation, such as VUV radiation, emitted by the plasma sustained within the bulb in order to keep the short wavelength radiation from impinging on the interior surface of the bulb.

First claim

What is claimed:

1. A plasma cell comprising:
a plasma bulb configured to contain a gas suitable for generating a plasma, the bulb being substantially transparent to light emanating from a pump laser configured to sustain a plasma within the plasma bulb, wherein the plasma bulb is substantially transparent to at least a portion of a collectable spectral region of illumination emitted by the plasma;
a liquid inlet arranged at a first portion of the plasma bulb; and
a liquid outlet arranged at a second portion of the plasma bulb opposite the first portion of the plasma bulb, the liquid inlet and the liquid outlet configured to flow a liquid from the liquid inlet to the liquid outlet, the liquid configured to block a selected spectral region of the illumination emitted by the plasma; and
an actuation assembly configured to at least partially rotate the plasma bulb in order to distribute the liquid about at least a portion of the interior surface of the plasma bulb.

2. The plasma cell of claim 1 , wherein the liquid inlet and the liquid outlet are configured to flow a liquid from the liquid inlet to the liquid outlet in order to coat at least a portion of an internal surface of the plasma bulb with the liquid.

3. The plasma cell of claim 1 , wherein the liquid inlet and the liquid outlet are configured to flow a liquid from the liquid inlet to the liquid outlet in order to form a stand-alone sheath of the liquid within the volume of the plasma bulb.

4. The plasma cell of claim 1 , wherein the liquid comprises:
at least one of water, methanol, or ethanol.

5. The plasma cell of claim 1 , wherein the liquid includes at least one of nanocrystalline material and dye material.

6. The plasma cell of claim 1 , further comprising:
an active liquid distributor jet configured to transfer liquid from the liquid inlet to the liquid outlet along one or more pathways about at least one of a portion of the interior surface of the plasma bulb.

7. The plasma cell of claim 1 , further comprising:
an active liquid distributor jet configured to transfer liquid from the liquid inlet to the liquid outlet in order to form a stand-alone sheath within the volume of the plasma bulb.

8. A plasma cell comprising:
a plasma bulb configured to contain a gas suitable for generating a plasma, the plasma bulb being substantially transparent to light emanating from a pump laser configured to sustain the plasma within the plasma bulb, wherein the plasma bulb is substantially transparent to at least a portion of a collectable spectral region of illumination emitted by the plasma; and
a liquid filter established within the volume of the plasma bulb, wherein the liquid filter is established by an actuation assembly configured to at least partially rotate the plasma bulb in order to distribute the liquid about at least a portion of the interior surface of the plasma bulb.

Assignees

• Kla Tencor Corp
• Kla Corp

Inventors

• Bezel Ilya
• Shchemelinin Anatoly
• Shifrin Eugene
• Panzer Matthew
• Derstine Matthew
• Wang Jincheng
• Chimmalgi Anant
• Patil Rajeev
• Brunner Rudolf

Classifications

• H01J65/04 Primary

  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

• H01J61/523

  Heating or cooling particular parts of the lamp · CPC title

• H01J61/40

  by light filters; by coloured coatings in or on the envelope · CPC title

• H01J61/35

  provided with coatings on the walls thereof; Selection of materials for the coatings (using coloured coatings H01J61/40; using luminescent coatings H01J61/42) · CPC title

• H01J61/34

  Double-wall vessels or containers · CPC title