Filter window, lithographic projection apparatus, filter window manufacturing method, device manufacturing method and device manufactured thereby

• US 20050040345A1
• Filed: 07/09/2004
• Published: 02/24/2005
• Est. Priority Date: 07/25/2003
• Status: Active Grant

• Current Assignee: ASML Netherlands BV (ASML Holding NV)
• Original Assignee: ASML Netherlands BV (ASML Holding NV)
• Inventors: Kurt, Ralph, Bakker, Levinius Pieter
• Granted Patent: US 7,456,932 B2
• Time in Patent Office: Days
• US Class Current: 250/492.200
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• CPC Class Codes: B82Y 40/00 Manufacture or treatment of nanostructures
• CPC Class Codes: G03F 1/24 Reflection masks; Preparation thereof
• CPC Class Codes: G03F 1/62 Pellicles, e.g. pellicle assemblies, e.g. having membrane on support frame; Preparation thereof
• CPC Class Codes: G21K 1/10 Scattering devices; Absorbing devices; Ionising radiation filters

Abstract

The invention relates to a filter window for EUV lithography comprising a pellicle, a wire structure for supporting the pellicle, characterized in that the pellicle comprises a first layer comprising at least one of AlN, Ru, Ir, Au, SiN, Rh, C. A pellicle with these materials has a very low EUV absorption in combination with a minimal oxidation rate. In a particular embodiment, the thickness of the pellicle is between 30 nm and 100 nm. It can be easily checked that absorption of EUV radiation of such a thin pellicle is equal to known filter windows, i.e. about 50% at a wavelength of 13.5 nm wavelength, but the oxidation of the pellicle according to the invention is much smaller. The filter window can for example be used to separate a Projection Optics box and a wafer compartment of the apparatus or to shield a reticle from particle contamination.

Claims

1. A filter window for EUV lithography comprising:

a pellicle comprising a first layer comprising a material selected from the group consisting of AlN, Ru, Ir, Au, SiN, Rh, C, and combinations thereof; and

a wire structure for supporting said pellicle.

2. A filter window according to claim 1, wherein a thickness of said pellicle is between about 30 nm and about 300 nm.

3. A filter window according to claim 2, wherein a thickness of said pellicle is between 30 nm and 100 nm.

4. A filter window according to claim 1, wherein said pellicle comprises a second layer and a third layer, and wherein said second layer is arranged between said first and said third layer.

5. A filter window according to claim 4, wherein said second layer comprises a material selected from the group consisting of Si, Be, B₄C, Mo, Zr, Nb, C, Al and combinations thereof.

6. A filter window according to claim 4, wherein said third layer comprises a material selected from the group consisting of AlN, Ru, Ir, Au, SiN, Rh, C and combinations thereof.

7. A filter window according to claim 4, wherein said second layer comprises elevated bars on top of a base layer.

8. A filter window according to claim 7, wherein said elevated bars comprise Si.

9. A filter window according to claim 7, wherein said bars have a pitch between 500 and 5000 nm and each bar has a height between 200 and 500 nm.

10. A filter window according to claim 1, wherein said wire structure comprises metal wires, the distance between said wires, in at least one direction, being of the magnitude of millimeters.

19. A device manufacturing method comprising:

patterning a beam of radiation with a pattern in its cross section;

projecting the patterned beam of radiation onto a target portion of a layer of radiation sensitive material on a substrate, and

filtering the beam of radiation using a filter according to claim 1.

20. A device manufactured in accordance with the method of claim 19.

11. A lithographic projection apparatus comprising:

an illumination system for conditioning a beam of radiation;

a mask table provided with a mask holder for holding a mask;

a substrate table provided with a substrate holder for holding a substrate;

a projection system for imaging an irradiated portion of the mask onto a target portion of the substrate, and

a filter window comprising;

a pellicle having a first layer comprising a material selected from the group consisting of AlN, Ru, Ir, Au, SiN, Rh, C and combinations thereof; and

a wire structure for supporting said pellicle.

12. A lithographic projection apparatus according to claim 11, wherein each wire of said wire structure is arranged such that each wire has at least a component perpendicular to a scan direction of said projection apparatus.

21. Apparatus according to claim 11, wherein said filter window is arranged to separate a projection optics box from a wafer compartment of said apparatus.

22. Apparatus according to claim 11, wherein said filter window is arranged to shield a reticle from particle contamination.

13. A filter window manufacturing method comprising:

fabricating a structure of wires on a substrate;

depositing a lacquer over the wires and the substrate;

depositing a first layer comprising a material selected from the group consisting of AlN, Ru, Ir, Au, SiN, Rh, C and combinations thereof;

removing said lacquer;

removing said substrate, and

baking said first layer.

14. A filter window manufacturing method as in claim 13 wherein said removing said lacquer comprises heating to vaporize said lacquer.

15. A filter window manufacturing method according to claim 13, said method further comprising:

fabricating a second layer comprising a material selected from the group consisting of Si, Be, B₄C, Mo, Zr, Nb, C, Al and combinations thereof; and

depositing a third layer comprising a material selected from the group consisting of AlN, Ru, Ir, Au, SiN, Rh, C and combinations thereof.

16. A filter window manufacturing method comprising:

depositing, onto a substrate soluble in a fluid, a first layer comprising a material selected from the group consisting of AlN, Ru, Ir, Au, SiN, Rh, C and combinations thereof;

dissolving said substrate in the fluid;

removing said first layer from the fluid by adhering said first layer to a wire structure; and

baking said first layer.

17. A filter window manufacturing method according to claim 16, said method further comprising:

fabricating a second layer comprising a material selected from the group consisting of Si, Be, B₄C, Mo, Zr, Nb, C, Al and combinations thereof; and

depositing a third layer comprising a material selected from the group consisting of AlN, Ru, Ir, Au, SiN, Rh, C and combinations thereof.

18. Filter window manufacturing method according to claim 17, wherein said fabricating said second layer comprises fabricating a base layer and elevated bars on top of said base layer.