Material supply apparatus for extreme ultraviolet light source having a filter constructed with a plurality of openings fluidly coupled to a plurality of through holes to remove non-target particles from the supply material

Patent metadata

Field	Value
Publication number	US-9669334-B2
Application number	US-201514674724-A
Country	US
Kind code	B2
Filing date	Mar 31, 2015
Priority date	May 20, 2011
Publication date	Jun 6, 2017
Grant date	Jun 6, 2017

Abstract

A filter is used in a target material supply apparatus and includes a sheet having a first flat surface and a second opposing flat surface, and a plurality of through holes. The first flat surface is in fluid communication with a reservoir that holds a target mixture that includes a target material and non-target particles. The through holes extend from the second flat surface and are fluidly coupled at the second flat surface to an orifice of a nozzle. The sheet has a surface area that is exposed to the target mixture, the exposed surface area being at least a factor of one hundred less than an exposed surface area of a sintered filter having an equivalent transverse extent to that of the sheet.

First claim

What is claimed is:

1. An apparatus comprising:
a supply system comprising an orifice;
a holder that houses the supply system, the holder comprising a face that opens to the orifice; and
a filter comprising a plurality of channels extending from a first channel end at a first surface of the filter to a second channel end at a second, opposing surface of the filter, the first channel end of each channel being configured to be fluidly coupled at a first end to a reservoir, and the second channel end of each channel being configured to be fluidly coupled to the orifice, each channel comprising:
a plurality of through holes extending from the second surface of the filter; and
an opening extending from the first surface of the filter toward the plurality of through holes, the opening being between the first channel end and the plurality of through holes such that the opening fluidly couples the reservoir to the through holes; wherein
the opening has a cross-sectional width, and each through hole has a cross-sectional width that is smaller than the width of the opening, the through holes are sized to remove at least some non-target particles from a target mixture, the through holes are within the cross-sectional width of the opening, and the filter is hermetically sealed to the face of the holder,
the channel has a width no larger than the cross-sectional width of the opening, and
the plurality of through holes and the opening are fluidly coupled such that substantially all fluid that flows into the first end of the channel flows in the channel.

2. The apparatus of claim 1 , wherein the through holes have a uniform cross-sectional width along an axial length of the through hole.

3. The apparatus of claim 1 , wherein the through holes are a capillary array.

4. The apparatus of claim 1 , further comprising:
a radiation source that supplies radiation to a target location; and wherein the supply system supplies the target mixture to the target location such that a plasma is formed when a target material within the target mixture is irradiated by the supplied radiation.

5. The apparatus of claim 2 , wherein the through holes and the opening are cylindrically shaped.

6. The apparatus of claim 1 , wherein the filter comprises tungsten.

7. The apparatus of claim 1 , wherein the filter comprises silicon nitride.

8. The apparatus of claim 1 , wherein the filter comprises a bulk structure, and the first and second surfaces of the filter are flat.

9. The apparatus of claim 8 , wherein the openings are arranged in a regular pattern on the first flat surface.

10. A filter for use in a target material supply apparatus, the filter comprising:
a sheet having a first flat surface and a second opposing flat surface, the first flat surface being in fluid communication with a reservoir that holds a target mixture that includes a target material and non-target particles;
a plurality of groups of through holes extending from the second flat surface and being fluidly coupled at the second flat surface to an orifice of a nozzle; and
a plurality of openings extending from the first flat surface, each opening fluidly coupling a group of through holes to the reservoir such that one opening couples one group of through holes to the reservoir, wherein
the sheet has a surface area that is exposed to the target mixture, the through holes have a uniform cross sectional width along an axial length of the through hole, each of the through holes is part of one group of through holes, each group of through holes is within a cross-sectional width of the opening that couples the group of through holes to the reservoir,
the through holes are arranged in a regular pattern on the second flat surface, and
the sheet comprises a single piece of a solid phase bulk material.

11. The filter of claim 10 , wherein a cross-sectional width of each through hole of the plurality of through holes varies no more than 20% from the cross-sectional width of each of the other through holes of the plurality of through holes and the cross-sectional width of each hole of the plurality of through holes is less than a height of the hole.

12. The filter of claim 10 , wherein each through hole has a height along a direction that is parallel to a longitudinal axis of the through hole and a width in a direction that is perpendicular to the direction, the height being at least 75% of the width.

13. The filter of claim 10 , wherein the openings have a uniform cross sectional width along an axial length of the opening.

14. The apparatus of claim 10 , wherein the filter comprises tungsten.

15. The apparatus of claim 10 , wherein the filter comprises silicon nitride.

16. The apparatus of claim 1 , wherein the through holes are in direct fluid communication with the opening.

17. The apparatus of claim 1 , wherein a cross-sectional width of each through hole of the plurality of through holes varies no more than 20% from the cross-sectional width of each of the other through holes of the plurality of through holes and the cross-sectional width of each hole of the plurality of through holes is less than a height of the hole.

18. The apparatus of claim 1 , wherein the filter is hermetically sealed to the face of the holder with one or more of an O-ring and a gasket.

19. The apparatus of claim 1 , wherein the filter defines an edge, and the edge of the filter is hermetically sealed to the face of the holder.

20. A filter for use in a target material supply apparatus of an extreme ultraviolet (EUV) light source, the filter comprising: a bulk material comprising a plurality of channels extending from a first channel end at a first surface of the bulk material to a second channel end at a second surface of the bulk material, the first channel end of each channel being configured to be fluidly coupled at a first end to a reservoir, and the second channel end of each channel being configured to be fluidly coupled to an orifice, each channel comprising: a plurality of through holes extending from the second surface of the filter; and an opening extending from the first surface of the filter toward the plurality of through holes, the opening being between the first channel end and the plurality of through holes such that the opening fluidly couples the reservoir to the through holes; wherein the opening has a cross-sectional width, and each through hole has a cross-sectional width that is smaller than the width of the opening, the through holes are sized to remove at least some non-target particles from a target mixture, the through holes are within the cross-sectional width of the opening, and the channel is configured to contain a fluid that flows into the first end of the channel in a channel width, the channel width being no larger than the cross-sectional width of the opening.

21. The filter of claim 20 , wherein the bulk material is a single, non-layered piece of a solid phase bulk material.

22. The filter of claim 21 , wherein the bulk material comprises tungsten.

23. The filter of claim 21 , wherein the filter comprises silicon nitride.

24. The filter of claim 20 , wherein the bulk material comprises tungsten.

25. The filter of claim 20 , wherein the filter comprises silicon nitride.

26. The filter of claim 20 , wherein each through hole has a height along a direction that is parallel to a longitudinal axis of the through hole and a width in a direction that is perpendicu

Assignees

• Asml Netherlands Bv

Inventors

• Fomenkov Igor V
• Partlo William N
• Vaschenko Gregory O
• Oldham William

Classifications

• H10P76/00 Primary

  Manufacture or treatment of masks on semiconductor bodies, e.g. by lithography or photolithography · CPC title

• H05G2/002

  Supply of the plasma generating material · CPC title

• H05H1/46

  using applied electromagnetic fields, e.g. high frequency or microwave energy (H05H1/26 takes precedence) · CPC title

• B01D29/56 Primary

  in series connection · CPC title

• H05G2/008

  involving an energy-carrying beam in the process of plasma generation · CPC title