Substrate for an euv-lithography mirror

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 ).

1 . A substrate for a mirror for extreme-ultraviolet (EUV) lithography comprising:
 a base body consisting essentially of a precipitation-hardened alloy.   
     
     
         2 . The substrate according to  claim 1 , wherein the base body consists essentially of a precipitation-hardened copper or aluminum alloy. 
     
     
         3 . A substrate for a mirror for EUV lithography comprising:
 a base body consisting essentially 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.   
     
     
         4 . The substrate according to  claim 3 , wherein the alloy is an alloy with a substitution lattice. 
     
     
         5 . The substrate according to  claim 3 , wherein the alloy is precipitation-hardened. 
     
     
         6 . The substrate according to  claim 3 , wherein the alloy is a copper or aluminum alloy. 
     
     
         7 . A substrate for a mirror for EUV lithography comprising:
 a base body consisting essentially of a particulate composite.   
     
     
         8 . The substrate according to  claim 7 , wherein the particulate composite has dispersoids of an extent of between 1 nm and 20 nm. 
     
     
         9 . The substrate according to  claim 7  wherein the particulate composite has a metallic matrix. 
     
     
         10 . The substrate according to  claim 9 , wherein the particulate composite has spheroidal dispersoids. 
     
     
         11 . The substrate according to  claim 9 , wherein the metallic matrix is a copper matrix or an aluminum matrix. 
     
     
         12 . The substrate according to  claim 7 , wherein the particulate composite has a ceramic matrix. 
     
     
         13 . The substrate according to  claim 12 , wherein the ceramic matrix is a silicon matrix or a carbon matrix with silicon carbide dispersoids. 
     
     
         14 . A substrate for a mirror for EUV lithography comprising:
 a base body consisting essentially of an intermetallic phase of an alloy system.   
     
     
         15 . The substrate according to  claim 14 , wherein the base body consists essentially of an intermetallic phase in which the stoichiometric standard composition is observed. 
     
     
         16 . The substrate according to  claim 14 , wherein the base body consists essentially of an intermetallic phase having a composition which corresponds to a phase stability line in the phase diagram of the alloy system. 
     
     
         17 . The substrate according to  claim 14 , wherein the alloy has a composition which, in the phase diagram of the corresponding alloy system, lies in a region which is bounded by phase stability lines. 
     
     
         18 . The substrate according to  claim 14 , wherein the base body consists essentially of an intermetallic phase having the same Bravais lattice as components of the base body in crystalline form. 
     
     
         19 . The substrate according to  claim 14 , wherein the alloy system is a binary system, one component of which is copper. 
     
     
         20 . The substrate according to  claim 14 , wherein the alloy system is a binary aluminum-copper system. 
     
     
         21 . The substrate according to  claim 1 , wherein the base body has a face-centered cubic material structure. 
     
     
         22 . The substrate according to  claim 1 , wherein the base body experiences essentially no changes in microstructure in response to changes in temperature from 20° C. to 150° C. over a period of time of at least one year. 
     
     
         23 . The substrate according to  claim 1 , further comprising a polishing layer arranged on the base body. 
     
     
         24 . The substrate according to  claim 23 , further comprising an adhesion-promoter layer arranged between the base body and the polishing layer. 
     
     
         25 . A mirror for an EUV projection exposure apparatus, comprising:
 a substrate according to  claim 1 , and   a highly reflective layer on the substrate.   
     
     
         26 . A mirror for an EUV projection exposure apparatus, comprising:
 a substrate according to  claim 1 ,   a polishing layer arranged on the base body, and   a highly reflective layer on the polishing layer.