US 12,306,539 B2
Optical element, EUV lithography system, and method for forming nanoparticles
Anastasia Gonchar, Ulm (DE)
Assigned to CARL ZEISS SMT GMBH, Oberkochen (DE)
Filed by Carl Zeiss SMT GmbH, Oberkochen (DE)
Filed on Nov. 14, 2022, as Appl. No. 17/986,329.
Application 17/986,329 is a continuation of application No. PCT/EP2021/060921, filed on Apr. 27, 2021.
Claims priority of application No. 10 2020 206 117.3 (DE), filed on May 14, 2020.
Prior Publication US 2023/0076667 A1, Mar. 9, 2023
Int. Cl. G03F 7/00 (2006.01)
CPC G03F 7/7015 (2013.01) [G03F 7/70316 (2013.01)] 19 Claims
OG exemplary drawing
 
1. An optical element, comprising:
a substrate,
applied to the substrate, a multilayer system which reflects extreme ultraviolet (EUV) radiation, and
applied to the multilayer system, a protective layer system having an uppermost layer, wherein nanoparticles containing at least one metallic material are embedded into the uppermost layer of the protective layer system, and
wherein the embedded nanoparticles reduce a reflectivity (RVUV) of the optical element for radiation at wavelengths greater than wavelengths of the EUV radiation.