EUV optical element having blister-resistant multilayer cap

Patent metadata

Field	Value
Publication number	US-11215736-B2
Application number	US-201515038430-A
Country	US
Kind code	B2
Filing date	Jan 29, 2015
Priority date	Feb 7, 2014
Publication date	Jan 4, 2022
Grant date	Jan 4, 2022

Abstract

A multilayer mirror having a cap with a multilayer structure including a top layer and a series of bilayers each having an absorber layer and a spacer layer, where the materials for the top layer, absorber layers, and spacer layers are chosen to resist blistering.

First claim

The invention claimed is:

1. A multilayer mirror comprising:
a substrate;
a multilayer coating on the substrate; and
a capping layer on the multilayer coating, the capping layer comprising
an outermost layer comprising Nb2O5 or TiO2, and
a multilayer structure positioned between the outermost layer and the multilayer coating, the multilayer structure comprising a plurality of bilayers, each of the bilayers comprising a spacer layer comprising a first material and an absorber layer comprising a second material different from the first material, one of the first material and the second material comprising ZrN.

2. The multilayer mirror as claimed in claim 1 wherein the other of the first material and the second material comprises B4C.

3. A multilayer mirror comprising:
a substrate;
a multilayer coating on the substrate; and
a capping layer on the multilayer coating, the capping layer comprising:
an outermost layer comprising Ta2O5 and
a multilayer structure positioned between the outermost layer and the multilayer coating, the multilayer structure comprising a plurality of bilayers, each of said bilayers comprising a spacer layer comprising a spacer layer nitride material resistant to hydrogen diffusion and blistering and an absorber layer comprising an oxide material resistant to ion penetration.

4. A multilayer mirror comprising:
a substrate;
a multilayer coating on the substrate; and
a capping layer on the multilayer coating, the capping layer comprising
an outermost layer comprising ZrN, and
a multilayer structure positioned between the outermost layer and the multilayer coating, the multilayer structure comprising a plurality of bilayers, each of the bilayers comprising a spacer layer comprising a first material and an absorber layer comprising a second material different from the first material, at least one of the bilayers comprising ZrN.

5. A multilayer mirror comprising:
a substrate;
a multilayer coating on the substrate; and
a capping layer on the multilayer coating, the capping layer comprising
an outermost layer comprising Nb2O5 or TiO2, and
a multilayer structure positioned between the outermost layer and the multilayer coating, the multilayer structure comprising a plurality of bilayers, each of the bilayers comprising a spacer layer comprising a first material and an absorber layer comprising a second material different from the first material, one of the first material and the second material comprising ZrO2 and the other of the first material and the second material comprising ZrN.

Assignees

• Asml Netherlands Bv

Inventors

• Bowering Norbert

Classifications

• G21K1/062 Primary

  Devices having a multilayer structure · CPC title

• G02B5/0891

  Ultraviolet [UV] mirrors (apparatus for microlithography exposure G03F7/70; X-ray multilayer structures G21K1/06) · CPC title

• G02B5/0875

  the reflecting layers comprising two or more metallic layers · CPC title

• G02B5/0816

  Multilayer mirrors, i.e. having two or more reflecting layers (G02B5/0883, G02B5/0891 take precedence) · CPC title

• G02B1/14 Primary

  Protective coatings, e.g. hard coatings · CPC title