Substrate for a reflective optical element
AssigneeCarl Zeiss SMT GmbH
InventorEric Eva
Life of this patent
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Abstract
In order to reduce the degree of relaxation after an optical substrate has been compacted, in particular after a longer period, substrates (51) or reflective optical elements (50), in particular for EUV lithography, with substrates (51) of this type, are proposed. These substrates (51), which have a surface region (511) with a reflective coating (54), are characterised in that, at least near to the surface region (511), the titanium-doped quartz glass has a proportion of Si—O—O—Si bonds of at least 1*1016/cm3 and/or a proportion of Si—Si bonds of at least 1*1016/cm3 or, along a notional line (513) perpendicular to the surface region (511), over a length (517) of 500 nm or more, a hydrogen content of more than 5×1018 molecules/cm3.
Claims19
A substrate for an optical element configured to reflect extreme ultraviolet wavelength light,
- wherein the substrate is made of titanium-doped quartz glass that has a surface region configured to be coated, and
- wherein the titanium-doped quartz glass has, at least in a vicinity of the surface region, a proportion of Si—O—O—Si bonds of at least 1*1016/cm3 or a proportion of Si—Si bonds of at least 1*1016/cm3.
A substrate for an optical element configured to reflect extreme ultraviolet wavelength light,
- wherein the substrate is made of titanium-doped quartz glass that has a surface region configured to be coated,
- wherein the titanium-doped quartz glass has a hydrogen content of more than 5×1018 molecules/cm3 along an imaginary line perpendicular to the surface region over a length of at least 500 nm, and
- wherein the titanium-doped quartz glass has, at least in the vicinity of the surface region, a proportion of Si—O—O—Si bonds of at least 1*1016/cm3 or a proportion of Si—Si bonds of at least 1*1016/cm3.
Dependencies are inferred from the claim text.