Substrate for an EUV-lithography mirror

Patent metadata

Field	Value
Publication number	US-10935704-B2
Application number	US-201715399495-A
Country	US
Kind code	B2
Filing date	Jan 5, 2017
Priority date	Jan 21, 2011
Publication date	Mar 2, 2021
Grant date	Mar 2, 2021

Abstract

Substrates suitable for mirrors used at wavelengths in the EUV wavelength range have substrates (1) including a base body (2) made of a precipitation-hardened alloy, of an intermetallic phase of an alloy system, of a particulate composite or of an alloy having a composition which, in the phase diagram of the corresponding alloy system, lies in a region which is bounded by phase stability lines. Preferably, the base body (2) is made of a precipitation-hardened copper or aluminum alloy. A highly reflective layer (6) is preferably provided on a polishing layer (3) of the substrate (1) of the EUV mirror (5).

First claim

The invention claimed is:

1. A mirror for Extreme Ultraviolet (EUV) lithography comprising:
a base body consisting essentially of a particulate composite, wherein the particulate composite comprises dispersoids dispersed in a matrix in which the dispersoids are insoluble, wherein the matrix comprises a metallic copper matrix;
a polishing layer arranged on the base body; and
a reflective layer configured to reflect EUV radiation arranged on the polishing layer.

2. The mirror according to claim 1 , wherein the dispersoids have an extent of between 1 nm and 20 nm.

3. The mirror according to claim 1 , wherein the dispersoids comprise spheroidal dispersoids.

4. The mirror according to claim 1 , wherein the dispersoids comprise titanium oxide particles.

5. The mirror according to claim 1 , wherein the dispersoids comprise silicon oxide particles.

6. The mirror according to claim 1 , wherein the dispersoids comprise graphite particles.

7. The mirror according to claim 1 , wherein the dispersoids comprise diamond-like carbon particles.

8. The mirror according to claim 1 , wherein the reflective layer comprises a multilayer system of alternating layers of high index of refraction layers and low index of refraction layers.

9. The mirror according to claim 1 , wherein the reflective layer comprises a multilayer system of alternating layers of molybdenum and silicon.

10. The mirror according to claim 1 , wherein the dispersoids comprise titanium carbide particles.

Assignees

• Zeiss Carl Smt Gmbh

Inventors

• Ekstein Claudia
• Maltor Holger

Classifications

• C22C14/00

  Alloys based on titanium · CPC title

• C22C9/00 Primary

  Alloys based on copper · CPC title

• G02B5/08

  Mirrors {(vehicle mirrors involving special optical features B60R1/08)} · CPC title

• C22C21/00

  Alloys based on aluminium · CPC title

• C22C29/00

  Alloys based on carbides, oxides, nitrides, borides, or silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides, sulfides {(C22C26/00 takes precedence)} · CPC title