Vapor as a protectant and lifetime extender in optical systems

Patent metadata

Field	Value
Publication number	US-11624904-B2
Application number	US-201916533366-A
Country	US
Kind code	B2
Filing date	Aug 6, 2019
Priority date	Aug 6, 2019
Publication date	Apr 11, 2023
Grant date	Apr 11, 2023

Abstract

An enclosure surrounding the optical component can be connected with a vapor source. The vapor source can provide a vapor to the enclosure with a vapor level from 500 ppm to 15000 ppm. The concentration of vapor in the enclosure can increase the lifespan of the optical component in the enclosure.

First claim

What is claimed is:

1. A system comprising:
an optical component, wherein the optical component is CaF 2 ;
an enclosure surrounding the optical component; and
a vapor source in fluid communication with the enclosure, wherein the vapor source provides a vapor to the enclosure with a vapor level from greater than or equal to 5000 ppm to 15000 ppm, wherein the vapor is one of water, methanol, ethylene glycol, or ethanol.

2. The system of claim 1 , wherein the vapor is water.

3. The system of claim 1 , wherein the vapor source includes a bubbler.

4. The system of claim 1 , wherein the vapor source includes a permeable membrane, and wherein the permeable membrane includes Nafion or a polyamid.

5. The system of claim 1 , wherein the vapor source includes a semi-permeable membrane.

6. The system of claim 1 , wherein the vapor source includes a charge mosaic membrane or a bipolar membrane.

7. The system of claim 1 , wherein the vapor source includes a gas source, wherein the gas source provides nitrogen, helium, carbon monoxide, carbon dioxide, krypton, argon, xenon, hydrogen, oxygen, compressed dry air, or a mixture thereof, wherein the gas from the gas source is mixed with the vapor.

8. The system of claim 1 , further comprising a vapor sensor disposed in fluid communication with the enclosure, wherein the vapor sensor is one of a carbon monoxide detector, a carbon dioxide detector, a hygrometer, or a hydrogen sensor.

9. The system of claim 8 , further comprising a processor in electronic communication with the vapor sensor, wherein the processor is configured to adjust the vapor level in purge gas from the enclosure based on readings from the vapor sensor.

10. A method comprising:
flowing a vapor from a vapor source to an enclosure that surrounds an optical component, wherein the optical component is one of CaF 2 ; and
maintaining a vapor level in the purge gas from greater than or equal to 5000 ppm to 15000 ppm, wherein the vapor is one of water, methanol, ethylene glycol, or ethanol.

11. The method of claim 10 , further comprising measuring the vapor level in the enclosure using a vapor sensor disposed in the enclosure.

12. The method of claim 11 , wherein the maintaining is based on readings from the vapor sensor.

Assignees

• Kla Corp

Inventors

• Zare David Jalil
• Soto Eduardo
• Wu I-Fan
• Walsh Joseph
• Mckernan Kent
• Armstrong Joseph
• Davis Christopher
• Rose Garry
• Kvamme Damon
• Burfeindt Bernd
• Ehsani Ali

Classifications

• H10P74/27

  Structural arrangements therefor · CPC title

• G01N2021/151

  Gas blown · CPC title

• G02B27/0006 Primary

  with means to keep optical surfaces clean, e.g. by preventing or removing dirt, stains, contamination, condensation (G02B1/18 takes precedence; cleaning in general B08B) · CPC title

• G01N21/15

  Preventing contamination of the components of the optical system or obstruction of the light path · CPC title

• H01S3/036

  Means for obtaining or maintaining the desired gas pressure within the tube, e.g. by gettering, replenishing; Means for circulating the gas, e.g. for equalising the pressure within the tube {(H01S3/031 takes precedence)} · CPC title