Substrates for in particular microlithography
AssigneeSchott AG
InventorsJochen Alkemper, Lutz Aschke, Hrabanus Hack
Life of this patent
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Abstract
The present invention relates to a substrate in particular of EUV microlithography, to the production of a substrate of this type and to the use of this substrate as a substrate for mirrors and/or masks or mask blanks in particular in EUV microlithography.
Claims20
Substrate for EUV microlithography, comprising a base layer and at least one covering layer, the base layer having a coefficient of thermal expansion of at most 0.1 ppm/° C. and the covering layer having a coefficient of thermal expansion of at most 1 ppm/° C.
Substrate for EUV microlithography, comprising a base layer and at least one covering layer, in which the base layer comprises ceramic and/or glass-ceramic and the covering layer comprises silicon dioxide.
Process for producing a substrate wherein the substrate comprises at least one covering layer and at least one base layer, the base layer having a coefficient of thermal expansion of at most 0.1 ppm/° C. and the covering layer having a coefficient of thermal expansion of at most 1.0 ppm/° C.,
- wherein the process comprises the steps of
- a) providing a base layer which has a coefficient of thermal expansion of at most 0.1 ppm/° C.,
- (b) applying a covering layer which has a coefficient of thermal expansion of at most 1.0 ppm/° C., and
- (c) if appropriate, polishing the covering layer.
An element for EUV microlithography, comprising a substrate and a reflective layer, provided on the substrate;
- wherein the substrate comprises at least one covering layer and at least one base layer, the base layer having a coefficient of thermal expansion of at most 0.1 ppm/° C. and the covering layer having a coefficient of thermal expansion of at most 1.0 ppm/° C.
A process of producing an element for EUV microlithography, wherein the element comprises a substrate and a reflective layer, provided on the substrate;
- and wherein the substrate comprises at least one covering layer and at least one base layer, the base layer having a coefficient of thermal expansion of at most 0.1 ppm/.° C. and the covering layer having a coefficient of thermal expansion of at most 1.0 ppm/° C.;
- the process comprising the steps of
- (A) providing at least one base layer which has a coefficient of thermal expansion of at most 0.1 ppm/° C.,
- (B) applying-at least one covering layer which has a coefficient of thermal expansion of at most 1.0 ppm/° C.,
- (C) if appropriate, polishing the covering layer, and
- (D) providing a reflective layer on the covering layer of the substrate.
A substrate for precision components comprising a base layer and at least one covering layer, the base layer having a coefficient of thermal expansion of at most 0.1 ppm/° C. and the covering layer having a coefficient of thermal expansion of at most 1 ppm/° C.;
- wherein the surface roughness of the covering layer is at most 1 nm rms.
Dependencies are inferred from the claim text.