Asahi Glass Company, Limited

Other

Akio Masui

Yoshiaki Ikuta

Shinya Kikugawa

Noriaki Shimodaira

Shuhei Yoshizawa

Hideo Hosono

Tohru Ogawa

Yoshiaki Asahi Glass Company Ltd Ikuta

Shuhei Asahi Glass Company Ltd Yoshizawa

Noriaki Asahi Glass Company Ltd Simodaira

Shinya Asahi Glass Company Ltd Kikugawa

A process for producing a synthetic silica glass optical component which contains at least 1&#xd7;10molecules/cmand has an OH concentration of at most 200 ppm and substantially no reduction type defects, by treating a synthetic silica glass having a hydrogen molecule content of less than 1&#xd7;10molecules/cmat a temperature of from 300 to 600&#xb0; C. in a hydrogen gas-containing atmosphere at a pressure of from 2 to 30 atms.

Synthetic silica glass optical component and process for its production

A synthetic quartz glass for optical use, to be used by irradiation with light within a range of from the ultraviolet region to the vacuum ultraviolet region, which contains fluorine, which has a ratio of the scattering peak intensity of 2250 cm(I) to the scattering peak intensity of 800 cm(I), i.e. I/I, of at most 1&#xd7;10in the laser Raman spectrum, and which has an absorption coefficient of light of 245 nm of at most 2&#xd7;10cm.

Synthetic quartz glass and process for producing it

An exposure apparatus, wherein at least one of optical members constituting an exposure light source system, an illuminating optical system, a photomask and a projection optical system, is made of a synthetic quartz glass for an optical member, which has an absorption coefficient of 0.70 cm or less at a wavelength of 157 nm and an infrared absorption peak attributable to SiOH stretching vibration at about 3640 cm .

Exposure apparatus, semiconductor device, and photomask

A synthetic quartz glass to be used for light with a wavelength of from 150 to 200 nm, wherein the OH group concentration is at most 100 ppm, the hydrogen molecule concentration is at most 1&times;10 molecules/cm , reduction type defects are at most 1&times;10 defects/cm , and the relation between &Dgr;k and &Dgr;k , as between before and after irradiation of ultraviolet rays, satisfies 0<&Dgr;k <&Dgr;k , and a process for its production.

Synthetic quartz glass and method for preparing the same

A process for producing a synthetic quartz glass for an optical member, which comprises a step of irradiating a synthetic quartz glass having an OH group content of 50 ppm or lower with vacuum ultraviolet light having a wavelength of 180 nm or shorter to improve the transmittance in a region of wavelengths of not longer than 165 nm.

Synthetic quartz glass for optical member, process for producing the same, and method of using the same

A synthetic quartz glass for optical use, to be used by irradiation with light within a range of from the ultraviolet region to the vacuum ultraviolet region, which contains fluorine, which has a ratio of the scattering peak intensity of 2250 cm (I ) to the scattering peak intensity of 800 cm (I ), i.e. I /I , of at most 1&times;10 in the laser Raman spectrum, and which has an absorption coefficient of light of 245 nm of at most 2&times;10 .

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Tokyo, Japan

Akio Masui