Abstract: First of all, there is provided a production process of a synthetic quartz glass which has less impurity, has a high-temperature viscosity characteristic equal to or more than that of a natural quartz glass, and hardly deforms even in a high-temperature environment, and especially a production process of a highly heat resistant synthetic quartz glass which is free from the generation of bubbles and is dense. Secondly, there is provided a highly heat resistant synthetic quartz glass body which is easily obtained by the production process of the present invention, and especially a transparent or black quartz glass body which is free from the generation of bubbles, is dense, has high infrared absorption rate and emission rate, and has an extremely high effect for preventing diffusion of alkali metal. The process is a process of producing a highly heat resistant quartz glass body having an absorption coefficient at 245 nm of 0.

Abstract: An object of the present invention is to provide an improved blank such that an optical member of a high homogeneity can be obtained therefrom, and to provide a vessel and a heat treatment method for heat-treating a highly uniform synthetic quartz blank. In a first aspect of the invention a special designed blank is provided showing a concave shaped outer surface. In a second aspect of the invention a special designed vessel for heat-treating blanks is provided, whereby the degree of heat emission at the center is set higher than that of the surroundings.

Abstract: It is an object of the present invention to provide synthetic quartz glass optical materials suitable for use in YAG of higher order harmonics. The damage threshold value in J/cm2 (energy density at which cracks occur generated by irradiation) is to be considered when synthetic quartz glass material is irradiated with YAG laser of third or higher order harmonics with single pulses or continuously. Regarding a synthetic quartz glass optical material in use for the optical parts constituting the prism and lens used in a laser beam machine, this invention provides a synthetic quartz glass material suitably used for the YAG laser with the third or higher order of harmonic, choosing the following conditions: OH group concentration is in the range of ?1 to ?300 ppm; contained hydrogen molecule concentration is in the range of ?2×1018 to ?2×1019 molecules/cm3; transmittance of ultraviolet rays at 245 nm of wavelength is 99.9% or more; and the fictive temperature is in the range of ?880 to ?990° C.

Abstract: An object of the present invention is to provide a quartz glass body, especially a quartz glass jig for plasma reaction in producing semiconductors having excellent resistance against plasma corrosion, particularly, excellent corrosion resistance against F-based gaseous plasma; and a method for producing the same. A body made of quartz glass containing a metallic element and having an improved resistance against plasma corrosion is provided that contains bubbles and crystalline phase at an amount expressed by projected area of less than 100 mm2 per 100 cm3.

Abstract: In the light of the disadvantages of the prior art technology, an object of the present invention is to provide a method for producing a synthetic quartz glass member for excimer lasers, which comprises, while suppressing the generation of reductive defects which impairs the resistance against laser radiations, incorporating a sufficient amount of hydrogen molecules capable of achieving a high resistance against laser radiation into the quartz glass, yet uniformly incorporating the hydrogen molecules to realize a flat distribution in refractive indices attributed to the distribution in the density of hydrogen molecules. It is also an object of the present invention to provide a synthetic quartz glass member for excimer lasers obtained by the production method above, which yields high resistance against laser radiations and homogeneity.

Abstract: An object of the present invention is to provide a transparent ceramics which exhibits favorable slope efficiency well comparable to that of a single crystal when employed in solid lasers, yet having a uniform quality and internally free from pores, foreign matters, or granular structures. Another object of the present invention is to provide a production method therefor. The above problems have been overcome by a transparent YAG—ceramics (YAG: Y3Al5O12) the physical properties thereof is improved by doping a metallic element, provided that the concentration of the doped metallic elements is in a range of from 0.1 to 20% by weight, that the concentration of nitrogen is 500 ppm or lower, that said ceramics has pores and foreign matters accounting for less than 100 mm2 per 100 cm3 as expressed by their projected area, and that it has an internal transmittance for visible radiations of 50 %/cm of higher. The metallic element for doping the YAG—ceramic is Nd.

Abstract: A cylindrical, chlorine-free synthetic quartz glass blank of a specific size obtained by homogenizing a synthetic quartz glass ingot having periodic striae along a direction of growth has (a) striae grades in the working and off-axis directions which meet grade A of U.S. military specification MIL-G-174B, (b) average hydroxyl group concentrations in the working and off-axis directions of 700 to 1,000 ppm each, (c) average fictive temperatures in the working and off-axis directions of 850 to 950° C. each, and (d) a refractive index distribution for 633 nm wavelength light in the working direction of at most 1×10−6. The blank has a good transmittance to laser light, undergoes little deterioration when irradiated with laser light, and is particularly suitable for ArF excimer laser-related applications.

Abstract: An object of the present invention is to provide a transparent ceramics which exhibits favorable slope efficiency well comparable to that of a single crystal when employed in solid lasers, yet having a uniform quality and internally free from pores, foreign matters, or granular structures. Another object of the present invention is to provide a production method therefor. The above problems have been overcome by a transparent ceramices the physical properties thereof is improved by doping a metallic element, provided that the concentration of the doped metallic elements is in a range of from 0.1 to 20% by weight, that a body of said ceramics has pores and foreign matters accounting for less than 100 mm2 per 100 cm3 as expressed by their projected area, and that is has an internal transmittance for visible radiations of 50%/cm or higher.

Abstract: An object of the present invention is to provide an improved blank such that an optical member of a high homogeneity can be obtained therefrom, and to provide a vessel and a heat treatment method for heat-treating a highly uniform synthetic quartz blank. In a first aspect of the invention a special designed blank is provided showing a concave shaped outer surface. In a second aspect of the invention a special designed vessel for heat-treating blanks is provided, whereby the degree of heat emission at the center is set higher than that of the surroundings.

Abstract: An object of the present invention is to provide a synthetic quartz glass optical material having a high optical transmittance for a radiation 157 nm in wavelength emitted from F2 excimer laser and a high resistance against irradiation of a F2 excimer laser radiation, yet having a uniformity suitable for such a fine patterning using a F2 excimer laser, and to provide an optical member using the same. The problems above are solved by a synthetic quartz glass optical material for F2 excimer lasers having an OH group concentration of 0.5 ppm or lower, a fluorine concentration of 0.1 to 2 mol %, a hydrogen molecule concentration of 5×1016 molecules/cm3 or lower, a difference between the maximum and minimum fluorine concentrations within 20 mol ppm, and a difference between the maximum and minimum refraction indices of 2×10−5 or lower.

Abstract: 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.

Abstract: A cylindrical, chlorine-free synthetic quartz glass blank of a specific size obtained by homogenizing a synthetic quartz glass ingot having periodic striae along a direction of growth has (a) striae grades in the working and off-axis directions which meet grade A of U.S. military specification MIL-G-174B, (b) average hydroxyl group concentrations in the working and off-axis directions of 700 to 1,000 ppm each, (c) average fictive temperatures in the working and off-axis directions of 850 to 950° C. each, and (d) a refractive index distribution for 633 nm wavelength light in the working direction of at most 1×10−6. The blank has a good transmittance to laser light, undergoes little deterioration when irradiated with laser light, and is particularly suitable for ArF excimer laser-related applications.

Abstract: An object of the present invention is to overcome the problems of the prior art technique, and to provide a heat treatment method as well as a heat treatment apparatus capable of heat treating, with higher efficiency, a synthetic quartz glass for optical use having higher homogeneity and higher purity. Another object of the present invention is to provide and a synthetic quartz glass for optical use.

Abstract: A method for heat treating a synthetic quartz glass for optical use in a heating furnace, that comprises covering the surroundings of a synthetic quartz glass body with a SiO2 powder having a mean dissolved hydrogen molecule concentration of 1×1019 molecules/cm3 or higher, and then heat treating the body.

Abstract: A method for heat treating a synthetic quartz glass for optical use in a heating furnace, that comprises covering the surroundings of a synthetic quartz glass body with a SiO2 powder having a mean dissolved hydrogen molecule concentration of 1×1019 molecules/cm3 or higher, and then heat treating the body.

Abstract: A synthetic quartz glass member having (i) a change of transmittance at 193 nm of up to 0.002 cm−1 as expressed in extinction coefficient when 4×104 shots of ArF excimer laser light are irradiated at 2 mJ/cm2/pulse, (ii) an initial transmittance of at least 99.6% at 193 nm, (iii) a hydrogen molecule content of at least 5×1017 molecules/cm3, (iv) a refractive index amplitude of up to 1×10−6, and (v) a birefringence of up to 1 nm/cm finds use in an excimer laser because it experiences a minimized change of light transmittance.

Abstract: In the light of the disadvantages of the prior art technology, an object of the present invention is to provide a method for producing a synthetic quartz glass member for excimer lasers, which comprises, while suppressing the generation of reductive defects which impairs the resistance against laser radiations, incorporating a sufficient amount of hydrogen molecules capable of achieving a high resistance against laser radiation into the quartz glass, yet uniformly incorporating the hydrogen molecules to realize a flat distribution in refractive indices attributed to the distribution in the density of hydrogen molecules. It is also an object of the present invention to provide a synthetic quartz glass member for excimer lasers obtained by the production method above, which yields high resistance against laser radiations and homogeneity.

Abstract: A method for producing an optical quartz glass for use in excimer lasers, comprising a step of forming a porous silica preform by depositing silica in a soot-like form formed by flame hydrolysis of a high-purity volatile silicon compound, followed by a step of vitrifying said porous silica preform into transparent glass in an atmosphere containing water vapor and hydrogen, and a vertical type heating furnace for carrying out the production method therein.

Abstract: The present invention relates to a synthetic quartz glass, which is a material for producing an optical member having an excellent excimer laser resistance, and a production method thereof with a good productivity. That is, the synthetic quartz glass produced by vitrifying glass fine particles obtained by flame hydrolysis of an organodisilazane compound directly on a substrate having a birefringence index of 5 nm/cm or less, a refractive index difference (&Dgr;n) of 2×10−6/cm or less, and an ArF saturated absorbance of 0.05/cm or less at a pulse energy density of 100 mJ/cm2/pulse.

Abstract: An optical system for integrated circuit fabrication comprises optical members made of synthetic quartz glass and fluorite, wherein: an optical member disposed in a position through which laser light is transmitted at a high light energy density, is made of single crystal fluorite; and an optical member in a position through which laser light is transmitted at a low light energy density, is made of synthetic quartz glass containing approximately such a hydrogen molecule concentration as can be doped under atmospheric pressure.