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

• US 7,456,932 B2
• Filed: 07/09/2004
• Issued: 11/25/2008
• Est. Priority Date: 07/25/2003
• Status: Expired due to Fees

• Current Assignee: ASML Netherlands BV (ASML Holding NV)
• Original Assignee: ASML Netherlands BV (ASML Holding NV)
• Inventors: Kurt, Ralph, Bakker, Levinius Pieter
• Primary Examiner(s): FULLER, RODNEY EVAN
• Application Number:
  US10/887,329
• Publication Number:
  US 20050040345A1
• Time in Patent Office: 1,600 Days
• Field of Search: 355/67, 355/71, 355/77, 430/5
• US Class Current: 355/67
• 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

A filter window for EUV lithography includes a pellicle, and a wire structure for supporting the pellicle. The pellicle includes a first layer that includes at least one of AlN, Ru, Ir, Au, SiN, Rh. The pellicle has a very low EUV absorption in combination with a minimal oxidation rate. The thickness of the pellicle may be 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 and a second layer on top of the first layer, wherein the first layer comprising a material selected from the group consisting of AlN, Ru, Ir, Au, SiN, Rh, and combinations thereof, and wherein the second layer includes elevated bars; and

a wire structure configured to support 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 third layer arranged on top of the second layer.

5. 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.

6. A filter window according to claim 1, wherein said second layer comprises a material selected from the group consisting of Si, Be, B₄C, Mo, Zr, Nb, C, Al and combinations thereof.

7. A filter window according to claim 1, wherein said elevated bars comprise Si.

8. A filter window according to claim 1, wherein said bars have a pitch between 500 and 5000 nm and each bar has a height between 200 and 500 nm.

9. 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.

10. A filter window according to claim 1, wherein the first layer of the pellicle includes C.

11. A lithographic projection apparatus comprising:

an illumination system configured to condition a beam of radiation;

a mask table provided with a mask holder configured to hold a mask;

a substrate table provided with a substrate holder configured to hold a substrate;

a projection system configured to image an irradiated portion of the mask onto a target portion of the substrate, and

a filter window comprising;

a pellicle having a first layer and a second layer on top of the first layer, wherein the first layer comprising a material selected from the group consisting of AlN, Ru, Ir, Au, SiN, Rh and combinations thereof and wherein the second layer includes elevated bars; and

a wire structure configured to support 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.

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

14. A lithographic projection apparatus according to claim 11, wherein said filter window is arranged to shield a reticle from particle contamination.

15. A lithographic projection apparatus according to claim 11, wherein the first layer of the pellicle includes C.

16. 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, the filter including a pellicle comprising a first layer and a second layer on top of the first layer, wherein the first layer comprising a material selected from the group consisting of AlN, Ru, Ir, Au, SiN, Rh, and combinations thereof and wherein the second layer includes elevated bars, and a wire structure for supporting said pellicle.

17. A device manufactured in accordance with the method of claim 16.

18. A device manufacturing method according to claim 16, wherein the first layer of the pellicle includes C.