초록 ▼

The invention relates to a synthetic quartz glass preform which is produced according to the flame hydrolysis technique with subsequent cooling and is suitable for the application of high-energy DUV radiation in the wave length range under 250 nm. Said preform has a core area which contains ≥1150 pp

The invention relates to a synthetic quartz glass preform which is produced according to the flame hydrolysis technique with subsequent cooling and is suitable for the application of high-energy DUV radiation in the wave length range under 250 nm. Said preform has a core area which contains ≥1150 ppm OH, a strain double refraction of .ltoreq.5 nm/cm and a resistance to high-energy DUV radiation as a result of a transmission reduction of .DELTA. T .ltoreq.0.1 %/cm thickness. The quartz glass has been exposed to the following radiation: wavelength .lambda.1=248 nm, laser shot frequency ≥300 Hz, laser shot value ≥109 and rumination .ltoreq.10 mJ/cm2, and wavelength .lambda.2=193 nm, laser shot frequency ≥300 Hz, laser shot value ≥109 and rumination .ltoreq.5 mJ/cm2. A device for producing said preform comprises a horizontally positioned muffle with two different-sized openings facing each other. The larger of said openings is for removing the preform, the smaller opening being for introducing a burner. The internal chamber of the muffle narrows from the larger opening to the smaller opening.

대표청구항 ▼

1. A synthetic quartz glass preform for application of high-energy DUV radiation having a wavelength of less than 250 nm, comprising:a core area having an OH content of ≥1150 ppm, a strain birefringence of .ltoreq.5 nm/cm, an H2 content of ≥1?1018 molecules/cm3, a Cl content of .ltoreq.20 ppm, and a

1. A synthetic quartz glass preform for application of high-energy DUV radiation having a wavelength of less than 250 nm, comprising:a core area having an OH content of ≥1150 ppm, a strain birefringence of .ltoreq.5 nm/cm, an H2 content of ≥1?1018 molecules/cm3, a Cl content of .ltoreq.20 ppm, and a total concentration of elements Cr, Cb, Fe, Ni, Cu, V, Zn, Al, Li, K, Na of 500 ppb or less; said core area being substantially free of stratifications; said core area having a stability with respect to high-energy DUV radiation that is defined by a transmission reduction of .DELTA.T.ltoreq.0.1%/cm thickness, when the synthetic quartz glass preform is subjected to radiation at a wavelength .lambda.1=248 nm, a laser shot frequency ≥300 Hz, a laser shot number ≥109, and an energy density .ltoreq.10 mJ/cm2, and when the synthetic quartz glass preform is subjected to radiation at a wavelength .lambda.1=193 nm, a laser shot frequency ≥300 Hz, a laser shot number ≥2 109, and an energy density .ltoreq.5 mJ/cm2; and said preform being produced by a method comprising the steps of: applying a flame combusting a fuel comprising H and O to a Si compound to form the preform without doping with F, and cooling the preform.