Toshiba Ceramics Co., Ltd.

Covalent Materials Corporation

Masanobu Ezaki

Sachiko Kato

Masashi Kobata

Seiji Taniike

Lian-Sheng Pan

To provide titania-silica glass which is transparent glass of low thermal expansion, in particular, is of a low thermal expansion coefficient over a wide range of temperatures of 0 to 100&#xb0; C. (an operating temperature range) when it is used as a photomask or a mirror material in extreme ultraviolet ray lithography, and which is excellent in homogeneity within the field and stability. Titania-silica glass is used which has 8 to 10% by weight of titania and 90 to 92% by weight of silica, where a Ticoncentration is 10 to 60 ppm by weight.

Titania-silica glass

A silica glass member for semiconductor in which each concentration of Fe, Cu, Cr and Ni is 5 ppb or less and the concentration of an OH group is 30 ppm or less and which has a viscosity of 10poise or more at 1200&#xb0; C. is provided as a silica glass member for semiconductor having high heat-resistance and higher purity.

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Hadano, Japan

Masanobu Ezaki