Other

Heraeus Quarzglas Gmbh & Co Kg

Shin-etsu Quartz Products Co., Ltd.

Takayuki Oshima

Akira Fujinoki

Hiroyuki Nishimura

Yasuyuki Yaginuma

An object is to provide a method for producing an optical synthetic quartz glass and an optical synthetic glass, having a birefringence of lower than 0.5 nm/cm and having favorable refractive index distribution, yet without lowering the productivity, as well as to provide an annealing furnace suitably used in practicing said method. In a step of raising the temperature of a columnar optical synthetic quartz glass preform to a temperature of from 800&#xb0; C. to 1200&#xb0; C., and after keeping for a definite time, lowering the temperature, the temperature is lowered with a temperature difference of from 1 to 20&#xb0; C. between the temperature of the light transmitting surface of the optical synthetic quartz glass preform and the temperature of the outer peripheral side surface of the optical synthetic quartz glass preform at temperature-lowering rates of from 2 to 50&#xb0; C./hour, respectively.

Production method of optical synthetic quartz glass, optical synthetic quartz glass, and annealing furnace

A synthetic glass member for use in excimer laser lithography, having superior homogeneity, high transmittance for ArF excimer laser beams and an excellent resistance against lasers is made from high purity synthetic quartz glass, and it is characterized in that layered structures, striae in three directions and internal strains are thermally and mechanically removed, the distribution of refractive index (&Dgr;n) in a plane orthogonal to the optical axis is up to about 1&times;10 , the distribution of refractive index (&Dgr;n) in a plane parallel to the optical axis is up to about 5&times;10 , the birefringence is up to about 2 nm/cm, the hydrogen molecule concentration is at least about 2&times;10 molecules/cm , and the internal transmittance is at least about 99.8% at a wavelength of 193.4 nm.

Synthetic quartz glass member for use in ArF excimer laser lithography

Method for producing synthetic quartz glass for use in ArF excimer laser lithography

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Koriyama, Japan

Takayuki Oshima