US 9,382,151 B2 · Low expansion silica-titania articles with a Tzc gradient by compositional variation

Abstract

A glass article for use in Extreme Ultra-Violet Lithography (EUVL) is provided. The glass article includes a silica-titania glass having a compositional gradient through the glass article, the compositional gradient being defined by the functions: [TiO2]=(c+f(x,y,z)), and [SiO2]=(100−{c+f(x,y,z)}−δ(x,y,z)) wherein [TiO2] is the concentration of titania in wt. %, [SiO2] is the concentration of silica in wt. %, c is the titania concentration in wt. % for a predetermined zero crossover temperature (Tzc), f(x, y, z) is a function in three-dimensional space that defines the difference in average composition of a volume element centered at the coordinates (x, y, z) with respect to c, and δ(x, y, z) is a function in three-dimensional space that defines the sum of all other components of a volume element centered at the coordinates (x, y, z).

Claims14

Dependent claims

A glass article for use in Extreme Ultra-Violet Lithography (EUVL), the glass article comprising a silica-titania glass having a compositional gradient through the glass article, the compositional gradient being defined by the functions:

[TiO2]=(c+f(x,y,z)), and
[SiO2]=(100−{c+f(x,y,z)}−δ(x,y,z))
wherein [TiO2] is the concentration of titania in wt. % , [SiO2] is the concentration of silica in wt. % , c is the titania concentration in wt. % for a predetermined zero crossover temperature (Tzc), f(x,y,z) is a function in three-dimensional space that defines the difference in average composition of a volume element centered at the coordinates (x,y,z) with respect to c, and δ(x,y,z) is a function in three-dimensional space that defines the sum of all other components of a volume element centered at the coordinates (x,y,z);
and
wherein f(x,y,z) is independent of z, and the glass article comprises multidirectional variations in the x,y plane.

2 more elements

A method for forming a silica-titania glass article having a compositional gradient, the method comprising:

mixing silica precursors and titania precursors to form at least two mixed precursor compositions sufficient to form at least two glass portions, each of the at least two glass portions having different titania concentrations;
converting with at least two burners the at least two mixed precursor compositions into at least two silica-titania soot compositions;
depositing the at least two silica-titania soot compositions in a vessel;
and
consolidating the at least two silica-titania soot compositions to form a silica-titania glass article having a compositional gradient through the glass article, the compositional gradient being defined by the functions:
[TiO2]=(c+f(x,y,z)), and
[SiO2]=(100−{c+f(x,y,z)}−δ(x,y,z))
wherein [TiO2] is the concentration of titania in wt. % , [SiO2] is the concentration of silica in wt. %, c is the titania concentration in wt. % for a predetermined zero crossover temperature (Tzc), f(x,y,z) is a function in three-dimensional space that defines the difference in average composition of a volume clement centered at the coordinates (x,y,z) with respect to c, and δ(x,y,z) is a function in three-dimensional space that defines the sum of all other components of a volume element centered at the coordinates (x,y,z);
and
wherein f(x,y,z)is independentis of z, and the glass article comprises multidirectional variations in the x,y plane.

7 more elements

Dependencies are inferred from the claim text.

Low expansion silica-titania articles with a Tzc gradient by compositional variation

Life of this patent

Low expansion silica-titania articles with a Tzc gradient by compositional variation

Life of this patent

Abstract

Claims14