System and Method for Vacuum Ultraviolet Lamp Assisted Ignition of Oxygen-Containing Laser Sustained Plasma Sources

Patent metadata

Field	Value
Publication number	US-2021120659-A1
Application number	US-201916654230-A
Country	US
Kind code	A1
Filing date	Oct 16, 2019
Priority date	Oct 16, 2019
Publication date	Apr 22, 2021
Grant date	—

Abstract

An illumination system includes a gas containment vessel configured to contain a gas. The illumination system also includes one or more pump sources configured to generate one or more pump beams. The illumination system includes an ozone generation unit including one or more illumination sources. The one or more illumination sources are configured to generate a beam of illumination of an energy sufficient for converting a portion of diatomic oxygen (O 2 ) contained within the gas containment vessel to triatomic oxygen (O 3 ). One or more energy sources are configured to ignite the plasma within the gas contained within the gas containment vessel via absorption of energy of the one or more energy sources by a portion of the triatomic oxygen, wherein the plasma emits broadband radiation.

First claim

What is claimed:

1 . A system comprising:
a gas containment vessel configured to contain a gas; one or more pump sources configured to generate one or more pump beams for sustaining a plasma within the gas containment vessel; and an ozone generation unit including one or more illumination sources, wherein the one or more illumination sources are configured to generate a beam of illumination of an energy sufficient for converting a portion of diatomic oxygen (O 2 ) contained within the gas containment vessel to triatomic oxygen (O 3 ), wherein one or more energy sources are configured to ignite the plasma within the gas contained within the gas containment vessel via absorption of energy of the one or more energy sources by a portion of the triatomic oxygen, wherein the plasma emits broadband radiation.

2 . The system of claim 1 , wherein the one or more illumination sources of the ozone generation unit comprise: one or more ultraviolet light sources configured to generate one or more beams of ultraviolet light.

3 . The system of claim 2 , wherein the one or more ultraviolet light sources comprise: one or more vacuum ultraviolet light sources configured to generate one or more beams of vacuum ultraviolet light.

4 . The system of claim 3 , wherein the one or more vacuum ultraviolet light sources comprise:
a discharge lamp.

5 . The system of claim 4 , wherein the discharge lamp comprises:
a mercury discharge lamp or deuterium lamp.

6 . The system of claim 1 , wherein the one or more illumination sources of the ozone generation unit comprise:
a microwave.

7 . The system of claim 1 , wherein the one or more illumination sources of the ozone generation unit comprise:
one or more lasers.

8 . The system of claim 3 , further comprising:
one or more optical elements configured to focus a portion of the vacuum ultraviolet light into a region of the gas containment vessel proximate to a location of the plasma.

9 . The system of claim 1 , wherein the one or more pump sources comprises:
one or more lasers.

10 . The system of claim 9 , wherein the one or more pump sources comprises:
one or more infrared lasers.

11 . The system of claim 10 , wherein the one or more pump sources comprises:
one or more continuous wave (CW) infrared lasers, wherein infrared light from the one or more CW lasers is absorbed by the portion of the triatomic oxygen within the gas containment vessel to ignite the plasma.

12 . The system of claim 1 , wherein the one or more energy sources comprises:
at least one of an electrical ignition source, an electromagnetic ignition source, or a laser ignition source.

13 . The system of claim 12 , wherein the laser ignition source includes one or more start lasers.

14 . The system of claim 13 , wherein the one or more start lasers comprises:
one or more pulsed lasers, wherein light from the one or more pulsed lasers is absorbed by the portion of the triatomic oxygen within the gas containment vessel to ignite the plasma.

15 . The system of claim 1 , wherein the one or more pump sources act as the one or more energy sources to ignite the plasma within the gas contained within the gas containment vessel.

16 . The system of claim 1 , further comprising:
one or more illumination optics configured to direct the one or more pump beams into the gas contained within the gas containment vessel at a position proximate to a region of triatomic oxygen generation.

17 . The system of claim 1 , further comprising:
one or more collection optics configured to collect at least a portion of the broadband radiation emitted by the generated plasma and direct the broadband radiation to one or more additional optical elements.

18 . The system of claim 1 , wherein the gas comprises:
diatomic oxygen.

19 . The system of claim 1 , wherein the gas comprises:
a gas mixture containing diatomic oxygen.

20 . The system of claim 19 , wherein the gas mixture comprises:
at least one of argon, krypton, xenon, or triatomic oxygen mixed with diatomic oxygen.

21 . The system of claim 1 , wherein the gas containment vessel comprises:
at least one of a plasma bulb, a plasma cell, or a plasma chamber.

22 . An apparatus comprising:
an ozone generation unit including one or more illumination sources, wherein the one or more illumination sources are configured to generate a beam of illumination of an energy sufficient for converting a portion of diatomic oxygen (O 2 ) contained within a gas containment vessel of a broadband illumination source of a sample characterization system to triatomic oxygen (O 3 ).

23 . An apparatus comprising:
a gas containment vessel for containing a gas, wherein the gas includes at least some triatomic oxygen, wherein the gas containment vessel is configured to receive pump illumination from a pump source for sustaining a plasma within the gas containment vessel, wherein one or more portions of the gas containment vessel are transparent to the pump illumination and a portion of broadband light emitted by the plasma.

24 . The apparatus of claim 23 , further comprising:
an ozone generation unit including one or more illumination sources, wherein the one or more illumination sources are configured to generate a beam of illumination of an energy sufficient for converting a portion of diatomic oxygen (O 2 ) contained within the gas containment vessel to triatomic oxygen (O 3 ).

25 . A method comprising:
converting a portion of diatomic oxygen contained within a gas containment vessel to triatomic oxygen at a selected location within the gas containment vessel with one or more illumination beams; generating one or more pump beams; focusing the one or more pump beams to the selected location within the gas containment vessel to ignite a plasma via absorption of illumination of the one or more pump beams by a portion of the triatomic oxygen; and collecting a portion of broadband illumination emitted by the plasma.

26 . The method of claim 25 , wherein the converting a portion of diatomic oxygen contained within a gas containment vessel to triatomic oxygen at a selected location within the gas containment vessel with one or more illumination beams comprises:
converting a portion of diatomic oxygen contained within a gas containment vessel to triatomic oxygen at a selected location within the gas containment vessel with one or more beams of vacuum ultraviolet light beams.

27 . The method of claim 25 , wherein the generating one or more pump beams comprises:
generating one or more infrared pump beams.

28 . The method of claim 25 , further comprising:
performing at least one of inspection or metrology with the collection broadband illumination.

Assignees

• Kla Corp

Inventors

• Szilagyi John
• Bezel Ilya

Classifications

• H05H1/24 Primary

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

• H01J65/00

  Lamps without any electrode inside the vessel; Lamps with at least one main electrode outside the vessel · CPC title

• H01J61/30

  Vessels; Containers · CPC title

• C01B13/10 Primary

  Preparation of ozone · CPC title

• H01J61/22

  vapour of an alkali metal · CPC title