US 9,810,993 B2
Mirror, in particular for a microlithographic projection exposure apparatus
Peter Huber, Heidenheim (DE)
Assigned to Carl Zeiss SMT GmbH, Oberkochen (DE)
Filed by CARL ZEISS SMT GMBH, Oberkochen (DE)
Filed on May 3, 2016, as Appl. No. 15/144,982.
Application 15/144,982 is a continuation of application No. PCT/EP2014/072576, filed on Oct. 21, 2014.
Claims priority of application No. 10 2013 222 330 (DE), filed on Nov. 4, 2013.
Prior Publication US 2016/0246179 A1, Aug. 25, 2016
Int. Cl. G03F 7/20 (2006.01); G02B 5/08 (2006.01); G02B 5/28 (2006.01); G21K 1/06 (2006.01); C23C 8/20 (2006.01); C23C 28/00 (2006.01); G02B 1/14 (2015.01)
CPC G03F 7/702 (2013.01) [C23C 8/20 (2013.01); C23C 28/322 (2013.01); C23C 28/341 (2013.01); G02B 1/14 (2015.01); G02B 5/085 (2013.01); G02B 5/0816 (2013.01); G02B 5/0891 (2013.01); G02B 5/28 (2013.01); G03F 7/70316 (2013.01); G03F 7/70958 (2013.01); G03F 7/70983 (2013.01); G21K 1/062 (2013.01); G21K 2201/067 (2013.01)] 18 Claims
OG exemplary drawing
1. A mirror having an optically effective surface, comprising
a mirror substrate;
a reflection layer stack configured to reflect electromagnetic radiation that is incident on the optically effective surface;
a metallic diffusion barrier layer arranged on a side of the reflection layer stack that faces toward the optically effective surface; and
a stabilization layer arranged on a side of the diffusion barrier layer that faces toward the optically effective surface,
wherein the stabilization layer reduces deformation of the diffusion barrier layer compared to an analogous mirror structure of the mirror without such a stabilization layer upon irradiation of the optically effective surface with electromagnetic radiation; and
wherein the stabilization layer has a porosity with a relative density, which is defined as a ratio between geometric density and true density, of at most 80% and is configured to decrease the absorption of electromagnetic radiation by the stabilization layer compared to an analogous layer structure having a higher true density.