Extreme ultraviolet reflective element with multilayer stack and method of manufacturing thereof

Patent metadata

Field	Value
Publication number	US-9581890-B2
Application number	US-201514696325-A
Country	US
Kind code	B2
Filing date	Apr 24, 2015
Priority date	Jul 11, 2014
Publication date	Feb 28, 2017
Grant date	Feb 28, 2017

Abstract

An apparatus and method of manufacture of an extreme ultraviolet reflective element includes: a substrate; a multilayer stack on the substrate, the multilayer stack includes a plurality of reflective layer pairs having a first reflective layer formed from silicon and a second reflective layer formed from niobium or niobium carbide for forming a Bragg reflector; and a capping layer on and over the multilayer stack for protecting the multilayer stack by reducing oxidation and mechanical erosion.

First claim

What is claimed is:

1. A method of manufacture for an extreme ultraviolet reflective element comprising:
providing a substrate;
forming a multilayer stack on the substrate, the multilayer stack includes a plurality of reflective layer pairs having a first reflective layer formed from silicon and a second reflective layer formed from niobium or niobium carbide for forming a Bragg reflector; and
forming a capping layer on and over the multilayer stack for protecting the multilayer stack by reducing oxidation and mechanical erosion.

2. The method as claimed in claim 1 , wherein forming the multilayer stack includes forming the first reflective layer from silicon having a thickness from 3.5 to 4.15 nanometers and the second reflective layer formed from niobium 3.5 nanometers thick or niobium carbide 2.8 nanometers thick.

3. The method as claimed in claim 1 , wherein forming the multilayer stack includes forming a barrier layer between the first reflective layer and the second reflective layer, the barrier layer formed from carbon having a thickness between 1 angstrom and 5 angstroms, and the barrier layer for reducing the formation of silicide.

4. The method as claimed in claim 1 , wherein forming the multilayer stack includes forming a barrier layer between the multilayer stack and the capping layer, the barrier layer formed from carbon having a thickness between 1 angstrom and 5 angstroms for reducing the formation of silicide.

5. The method as claimed in claim 1 , wherein forming the multilayer stack includes forming a barrier layer between the multilayer stack and the substrate, the barrier layer formed from carbon having a thickness between 1 angstrom and 5 angstroms for reducing the formation of silicide.

6. The method as claimed in claim 1 , wherein forming the multilayer stack includes:
forming a barrier layer between the first reflective layer and the second reflective layer, the barrier layer formed from carbon having a thickness of 5 angstroms; and
forming a boundary layer of silicide between the first reflective layer and the second reflective layer, the boundary layer having a reduced thickness based on the barrier layer.

7. The method as claimed in claim 1 , wherein forming the capping layer includes forming the capping layer from ruthenium or a ruthenium alloy and forming an absorber layer on and over the capping layer, the absorber layer formed from chromium, tantalum, nitrides, nickel, or a combination thereof.

8. An extreme ultraviolet reflective element comprising:
a substrate;
a multilayer stack on the substrate, the multilayer stack includes a plurality of reflective layer pairs having a first reflective layer formed from silicon and a second reflective layer formed from niobium or niobium carbide for forming a Bragg reflector; and
a capping layer on and over the multilayer stack for protecting the multilayer stack by reducing oxidation and mechanical erosion.

9. The extreme ultraviolet reflective element as claimed in claim 8 , wherein the multilayer stack includes the first reflective layer formed from silicon having a thickness from 3.5 to 4.15 nanometers and the second reflective layer formed from niobium 3.5 nanometers thick or niobium carbide 2.8 nanometers thick.

10. The extreme ultraviolet reflective element as claimed in claim 8 , wherein the multilayer stack includes a barrier layer between the first reflective layer and the second reflective layer, the barrier layer formed from carbon having a thickness between 1 angstrom and 5 angstroms, and the barrier layer for reducing the formation of silicide.

11. The extreme ultraviolet reflective element as claimed in claim 8 , wherein the multilayer stack includes a barrier layer between the multilayer stack and the capping layer, the barrier layer formed from carbon having a thickness between 1 angstrom and 5 angstroms for reducing the formation of silicide.

12. The extreme ultraviolet reflective element as claimed in claim 8 , wherein the multilayer stack includes a barrier layer between the multilayer stack and the substrate, the barrier layer formed from carbon having a thickness between 1 angstrom and 5 angstroms for reducing the formation of silicide.

13. The extreme ultraviolet reflective element as claimed in claim 8 , wherein the multilayer stack includes:
a barrier layer between the first reflective layer and the second reflective layer, the barrier layer formed from carbon having a thickness of 5 angstroms; and
a boundary layer of silicide between the first reflective layer and the second reflective layer, the boundary layer having a reduced thickness based on the barrier layer.

14. The extreme ultraviolet reflective element as claimed in claim 8 , wherein the capping layer includes the capping layer formed from ruthenium or a ruthenium alloy and an absorber layer on and over the capping layer, the absorber layer formed from chromium, tantalum, nitrides, nickel, or a combination thereof.

15. An extreme ultraviolet reflective element production system comprising:
a first deposition system for depositing a multilayer stack on the substrate, the multilayer stack including a plurality of reflective layer pairs having a first reflective layer formed from silicon and a second reflective layer formed from niobium or niobium carbide for forming a Bragg reflector; and
a second deposition system for forming a capping layer on the multilayer stack for protecting the multilayer stack by reducing oxidation and mechanical erosion.

16. The extreme ultraviolet reflective element production system as claimed in claim 15 , wherein the first deposition system is for forming the first reflective layer from silicon having a thickness from 3.5 to 4.15 nanometers and for forming the second reflective layer from niobium 3.5 nanometers thick or niobium carbide 2.8 nanometers thick.

17. The extreme ultraviolet reflective element production system as claimed in claim 15 , wherein the first deposition system is for forming a barrier layer between the first reflective layer and the second reflective layer, the barrier layer formed from carbon having a thickness between 1 angstrom and 5 angstroms, and the barrier layer for reducing the formation of silicide.

18. The extreme ultraviolet reflective element production system as claimed in claim 15 , wherein the first deposition system is for forming a barrier layer between the multilayer stack and the capping layer, the barrier layer formed from carbon having a thickness between 1 angstrom and 5 angstroms for reducing the formation of silicide.

19. The extreme ultraviolet reflective element production system as claimed in claim 15 , wherein the first deposition system is for forming a barrier layer between the multilayer stack and the substrate, the barrier layer formed from carbon having a thickness between 1 angstrom and 5 angstroms for reducing the formation of silicide.

20. The extreme ultraviolet reflective element production system as claimed in claim 15 , wherein second deposition system is for forming the capping layer from ruthenium or a ruthenium alloy and an absorber layer on and over the capping layer, the absorber layer formed from chromium, tantalum, nitrides, nickel, or a combination thereof.

Assignees

• Applied Materials Inc

Inventors

• Hofmann Ralf
• Hassan Vinayak Vishwanath
• Beasley Cara
• Foad Majeed A

Classifications

• H01J37/3429

  Plural materials · CPC title

• G03F7/70958

  Optical materials or coatings, e.g. with particular transmittance, reflectance or anti-reflection properties · CPC title

• C23C14/0635

  Carbides · CPC title

• G03F1/48

  Protective coatings · CPC title

• C23C16/44

  characterised by the method of coating (C23C16/04 takes precedence) · CPC title