Abstract:
A method for forming an optical fiber preform is provided. The method includes inserting a glass core cane (511) into a glass sleeve (32) such that the glass sleeve (32) surrounds a portion of the glass core cane (511) and such that there is a gap between the glass sleeve and the portion of the glass core cane surrounded by the glass sleeve. The method further includes depositing silica soot (36) onto at least a portion of the glass core cane (511) and at least a portion of the glass sleeve (32) to form a silica soot preform (28), and flowing gas through the gap during processing of the silica soot preform, e.g. sintering. The processing time can be reduced. Alternatively the glass core can can be attached to a handle comprising a hollow interior portion connected to the exterior of the handle by at least one opening in the handle wall. Soot is deposited onto a portion of the core cane and a portion of the handle and gas is flowed through the opening during processsing of the silica soot preform.
Abstract:
Embodiments of the invention relate to a hydrogen-resistant optical fiber with a core having a central axis. The core may include only silica, or only silica and fluorine, while a cladding region surrounding the core may be made of silica and fluorine, along with at least one of germanium, phosphorus, and titanium.
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: [TiO 2 ] = (c + f(x,y,z)), and [SiO 2 ] = (100 - {c + f(x,y,z)} - δ(x,y,z) ) wherein [TiO 2 ] is the concentration of titania in wt.%, [SiO 2 ] is the concentration of silica in wt.%, c is the titania concentration in wt.% for a predetermined zero crossover temperature (T zc ), 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).
Abstract:
Silica-titania glasses with small temperature variations in coefficient of thermal expansion over a wide range of zero-crossover temperatures and methods for making the glasses. The method includes a cooling protocol with controlled anneals over two different temperature regimes. A higher temperature controlled anneal may occur over a temperature interval from 750°C - 950°C or a sub-interval thereof. A lower temperature controlled anneal may occur over a temperature interval from 650°C - 875°C or a sub-interval thereof. The controlled anneals permit independent control over CTE slope and Tzc of silica-titania glasses. The independent control provides CTE slope and Tzc values for silica-titania glasses of fixed composition over ranges heretofore possible only through variations in composition.
Abstract:
To provide a blank of TiO2-SiO2 glass for a mirror substrate for use in EUV lithography, in which the need for adaptation to optimize the progression of the coefficient of thermal expansion, and consequently also the progression of the zero crossing temperature Tzc, is low, the TiO2-SiO2 glass has at a mean value of the fictive temperature Tf in the range between 920°C and 970°C a dependence of its zero crossing temperature Tzc on the fictive temperature Tf which, expressed as the differential quotient dTzc/dTf, is less than 0.3.
Abstract:
Es ist bekannt zur Herstellung eines Rohlings aus Titan-dotiertem, hochkieselsäurehaltigem Glas für ein Spiegelsubstrat für den Einsatz in der EUV-Lithographie, das Ti-dotierte Kieselglas mittels Flammenhydrolyse von Silizium und Titan enthaltenden Ausgangssubstanzen zu erzeugen und anschließend in dem Ti-dotierten Kieselglas einen vorgegebenen Wasserstoffgehalt einzustellen. Um hiervon ausgehend eine möglichst weitgehende Unempfindlichkeit der Oberfläche gegenüber Verwerfungen und Verformungen bei Bestrahlung mit EUV- Laserstrahlung zu erreichen, wird erfindungsgemäß ein Verfahrensweise vorgeschlagen, bei dem durch Flammenhydrolyse ein Sootkörper aus mit Titan dotiertem SiO 2 erzeugt wird, der Sootkörper durch Erhitzen auf eine Temperatur von mindestens 1150 °C unter Vakuum getrocknet wird, so dass sich ein mittlerer Hydroxylgruppengehalt von weniger als 150 Gew.-ppm einstellt, der getrocknete Sootkörper unter Bildung einer Vorform aus Ti-dotiertem Kieselglas gesintert wird, und das Ti-dotierte Kieselglas mit Wasserstoff beladen wird, so dass sich ein mittlerer Wasserstoffgehalt von mindestens 1 x 10 16 Molekülen/cm 3 einstellt.
Abstract:
The present invention provides a TiO2-SiO2 glass in which when used as an optical member for an exposure tool for EUVL, a thermal expansion coefficient is substantially zero at the time of irradiation with high-EUV energy light, and physical properties of a multilayer can be kept over a long period of time by releasing hydrogen from the glass. The present invention relates to a TiO2-containing silica glass having a fictive temperature of 1,100 °C or lower, a hydrogen molecule concentration of 1 x 10 16 molecules/cm3 or more, and a temperature, at which a linear thermal expansion coefficient is 0 ppb/°C, falling within the range of from 40 to 110 °C.