Abstract: The invention provides optical projection lithography methods, photolithography photomasks, and optical photolithography mask blanks for use in optical photolithography systems utilizing deep ultraviolet light (DUV) wavelengths below 300 nm, such as DUV projection lithography systems utilizing wavelengths in the 248 nm region and the 193 nm region. The invention provides improved production of lithography patterns by inhibiting polarization mode dispersion of lithography light utilizing low birefringence mask blanks and photomasks.

Abstract: The invention provides optical projection lithography methods, photolithography photomasks, and optical photolithography mask blanks for use in optical photolithography systems utilizing deep ultraviolet light (DUV) wavelengths below 300 nm, such as DUV projection lithography systems utilizing wavelengths in the 248 nm region and the 193 nm region. The invention provides improved production of lithography patterns by inhibiting polarization mode dispersion of lithography light utilizing low birefringence mask blanks and photomasks.

Abstract: The invention provides optical projection lithography methods, photolithography photomasks, and optical photolithography mask blanks for use in optical photolithography systems utilizing deep ultraviolet light (DUV) wavelengths below 300 nm, such as DUV projection lithography systems utilizing wavelengths in the 248 nm region and the 193 nm region. The invention provides improved production of lithography patterns by inhibiting polarization mode dispersion of lithography light utilizing low birefringence mask blanks and photomasks.

Abstract: An optical member includes a fused silica glass having a concentration of ≡SiH moiety below detection limit as measured by Raman spectroscopy and a concentration of molecular hydrogen of at least 1×1017 molecules/cm3. The fused silica glass exhibits an induced absorption level which quickly attains an initial peak upon exposure to irradiation and rapidly decays to a low value. The induced absorption level after decaying to the low value remains substantially unchanged by further irradiation.

Abstract: These glass bodies are light weight porous structures such as a boules of high purity fused silica or ultra-low expansion glass. More specifically, the porous structures are supports for mirror blanks. Porous glass is made utilizing flame deposition of pure silica or doped silica in a manner similar to the production of high purity fused silica. Bubbles or seeds are formed in the glass during laydown. Several means of creating and controlling these seeds are available. The processes use incomplete combustion to create the bubbles. There are a number of different steps to create the incomplete combustion. One such step is a short distance between the hydrolysis flame and the glass precursor.

Abstract: A method and a burner for manufacturing silica-containing soot is disclosed. The method includes providing a liquid silicon-containing feedstock and a gas mixture and ejecting the liquid-gas mixture from an orifice into a combustion site to convert the silica-containing feedstock into silica containing soot. The burner includes a plurality of channels for delivering a gas to provide a flame, an effervescent atomizer for atomizing a liquid, silicon-containing feedstock and a rail for guiding the atomized liquid, silicon-containing feedstock into the burner flame. The method and burner can be used to produce silica-containing articles such as high purity fused silica optical members and waveguides.

Abstract: An article of relatively pure silica, and a furnace and method of producing the article. The article is produced by collecting molten silica particles (24) in a refractory furnace in which at least a portion of the refractory has been exposed to a halogen-containing gas to react with contaminating metal ions in the refractory.

Abstract: A method of producing, by flame hydrolysis, a fused silica glass containing titania which comprises delivering a mixture of a silica precursor and a titania precursor in vapor form to a flame, passing the vapor mixture through the flame to form SiO.sub.2 --TiO.sub.2 particles, and depositing the particles within a furnace where they melt to form a solid glass body.

Abstract: A method of producing a fused silica glass by thermally converting a polymethylsiloxane precursor, the lens transmitting ultraviolet radiation at wavelengths below 300 nm. without undergoing a marked absorption transition, the lens so produced, and a microlithography system employing a lens of such glass.

Abstract: A method of producing a fused silica product comprising introducing a silicon-containing, organometallic compound into a flame to form molten silica particles, and collecting the molten silica particles in a furnace having a crown and cup such that a fused silica product is obtained, wherein at least the furnace crown is formed from a porous, fired, zircon refractory having a sodium ion content of less than 30 ppm. The fused silica product produced by the method has a sodium ion contamination level below 100 parts per billion.

Abstract: A fired, porous, zircon refractory body consisting essentially of zircon and having a sodium ion content, as an impurity, of less than 30 ppm. A furnace for making fused silica constructed with a crown and cup of such zircon refractory, and a method of making fused silica using such furnace.

Abstract: A composite article, such as a telescope mirror blank, comprising a solid glass body and a supporting network structure, the structure being composed of a network of interlocking struts frit sealed to one another and to the face plate. The article is characterized in that sufficient of the glass body is incorporated in particulate form in the struts to maintain an average expansion mismatch (-50.degree. C. to +50.degree. C.) between the network structure and the glass body of no more than 0.15 ppm/.degree.C.

Abstract: A telescope mirror blank having a supporting network core composed of sintered ceramic struts, and a method of forming such core from a thermally crystallizable, powdered glass and as a separate component from the faceplate, are disclosed. Optionally, the mirror faceplate may be formed in a similar manner.