Apparatus and method for cross-flow purge for optical components in a chamber

Patent metadata

Field	Value
Publication number	US-9662688-B2
Application number	US-201313935960-A
Country	US
Kind code	B2
Filing date	Jul 5, 2013
Priority date	Jul 9, 2012
Publication date	May 30, 2017
Grant date	May 30, 2017

Abstract

An apparatus for cross-flow purging for optical components in a chamber, including: a housing with first and second axial ends, a side wall extending in an axial direction and connecting the first and second axial ends, and the chamber formed by the first and second axial ends and the side wall; an optical component disposed within the chamber and fixed with respect to the housing via at least one connecting point on the optical component; an inlet port aligned with the side wall, between the first and second axial ends in the axial direction, in a radial direction orthogonal to the axial direction and arranged to inject a purge gas into the chamber and across the optical component in a radial direction orthogonal to the axial direction; and an exhaust port aligned with the side wall in the radial direction and arranged to exhaust the purge gas from the chamber.

First claim

What is claimed is:

1. An apparatus for cross-flow purging for optical components in a chamber, comprising:
a housing including:
a first axial end and a second axial end;
a side wall extending in an axial direction and connecting the first and second axial ends; and,
the chamber formed by the first and second axial ends and the side wall;

a first optical component:
disposed within the chamber; and,
fixed with respect to the housing via at least one first connecting point on the first optical component;

at least two inlet ports:
aligned with the side wall, between the first and second axial walls in the axial direction, in a radial direction orthogonal to the axial direction; and,
arranged to inject a purge gas into the chamber and across the first optical component in a radial direction orthogonal to the axial direction; and,

an exhaust port:
aligned with the side wall in the radial direction; and,
arranged to exhaust the purge gas from the chamber.

2. The apparatus of claim 1 , wherein:
the at least two inlet ports and the exhaust port are each located, in the axial direction, between the first axial end and the at least one first connecting point.

3. The apparatus of claim 1 , wherein:
the at least two inlet ports are located, in the axial direction, between the first axial end and the at least one first connecting point; and,
the exhaust port is located, in the axial direction, between the second axial end and the at least first one connecting point.

4. The apparatus of claim 1 , wherein:
at least one of the at least two inlet ports or exhaust port passes through the side wall in the radial direction.

5. The apparatus of claim 1 , wherein:
the side wall includes:
an outer surface and an inside surface partially bounding the chamber;
first and second portions having at least a first thickness, in the radial direction, between the inner and outer surfaces; and,
a cutout in the inner surface between the first and second portions and having a second thickness, in the radial direction, less than the first thickness; and,

the at least two inlet ports or the exhaust port opens into the cutout.

6. The apparatus of claim 1 , further comprising:
at least one spacer:
located between the first optical component and the side wall; and,
including the at least two inlet ports and the exhaust port;

a purge gas supply line connected to a supply of the purge gas, passing through the chamber, and connected to the at least two inlet ports via the at least one spacer; and,
a purge gas exhaust line connected to the exhaust port via the at least one spacer, passing through the chamber, and passing through the side wall or the first or second axial end to exit the chamber.

7. The apparatus of claim 6 , further comprising:
a seal element; and,
a resilient element, wherein:
the at least one spacer includes a first spacer displaceable with respect to the housing in the axial direction;
the seal element is disposed between the first spacer and the first optical component in the axial direction; and,
the resilient element urges the first spacer in the axial direction to:
compressively engage the seal element with the first spacer and the first optical component;
urge the first optical component into engagement with the housing or a second spacer from the at least one spacer; and,
fix a position of the first optical component within the chamber.

8. The apparatus of claim 1 , further comprising:
a second optical component:
fixed with respect to the housing via at least one second connecting point on the second optical component; and,
located, in the axial direction, between the first optical component and the first axial end, wherein:

the at least two inlet ports and the exhaust port are located, in the axial direction, between the at least one first and second connecting points.

9. The apparatus of claim 1 , further comprising:
a second optical component:
fixed with respect to the housing via at least one second connecting point on the second optical component; and,
located, in the axial direction, between the first optical component and the first axial end, wherein:

the at least two inlet ports are located, in the axial direction between the at least one first and second connecting points; and,
the exhaust port is located, in the axial direction between:
the at least one first connecting point and the second axial end; or,
the at least one second connecting point and the first axial end.

10. The apparatus of claim 1 , further comprising:
a second optical component:
fixed with respect to the housing via at least one second connecting point on the second optical component; and,
located, in the axial direction, between the first optical component and the first axial end, wherein:

the exhaust port is located, in the axial direction between the at least one first and second connecting points; and,
the at least two inlet ports are located, in the axial direction between:
the at least one first connecting point and the second axial end; or,
the at least one second connecting point and the first axial end.

11. The apparatus of claim 1 , further comprising:
a plurality of optical components:
each optical component in the plurality of optical components:
fixed with respect to the housing via at least one respective connecting point on said each optical component; and,
located, in the axial direction, between the first optical component and the first axial end; and,

including:
a second optical component closest to the first optical component in the axial direction; and,
a third optical component closest to the first axial end in the axial direction, wherein:

the at least two inlet ports are located, in the axial direction between:
the at least one first connecting point and the at least one respective connecting point for the second optical component; or,
the second axial end and the at least one first connecting point; and,

the exhaust port is located, in the axial direction between:
the at least one respective connecting points for the second and third optical components; or,
the first axial end and the at least one respective connecting point for the third optical component.

12. The apparatus of claim 11 , wherein:
the side wall includes an inner surface forming a portion of the chamber and having an axis connecting the first and second axial ends;
the at least two inlet ports are disposed in a circumferential direction with respect to the axis; and,
the exhaust port includes a plurality of exhaust ports disposed in the circumferential direction with respect to the axis.

13. The apparatus of claim 11 , wherein:
the side wall includes an inside surface forming a portion of the chamber;
the first optical component has a circular outer circumference with a center axis connecting the first and second axial ends;
at the at least two inlet ports, the circular outer circumference is separated, in a radial direction, from the inside surface by a first distance; and,
at a point on the outer circumference circumferentially separated from the at least two inlet ports, the circular outer circumference is separated, in the radial direction, from the inside surface by a second distance, greater than the first distance.

14. The apparatus of claim 11 , further comprising:
a first diffusion plate:
connected to the side wall; and,
located between the first optical component and the second axial end;

a first channel in communication with the at least two inlet ports and formed between the first optical component and the diffusion plate;

Assignees

• Kla Tencor Corp

Inventors

• Rose Garry
• Delgado Gildardo
• Larson H Steven
• Hennigan Daniel R

Classifications

• B08B5/02 Primary

  Cleaning by the force of jets, e.g. blowing-out cavities {(airguns or nozzles per se B05B1/005)} · CPC title

• G02B27/0006

  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