More Than 90 Percent By Weight Silica Patents (Class 501/54)

Patent number: 6471930
Abstract: A method for the production of silicon oxide particles includes the pyrolysis of a molecular stream with a silicon compound precursor, an oxygen source and a radiation absorbing gas. The pyrolysis is driven by a light beam such as an infrared laser beam. The method can be used in the production of nanoscale particles including highly uniform nanoscale particles.
Type: Grant
Filed: December 6, 2000
Issued: October 29, 2002
Assignee: NanoGram Corporation
Inventors: Nobuyuki Kambe, Xiangxin Bi
Application number: 20020151425
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.
Type: Application
Filed: January 29, 2002
Issued: October 17, 2002
Inventors: Akira Fujinoki, Hiroyuki Nishimura, Toru Yokota, Yasuyuki Yaginuma, Akira Sato, Tetsuji Ueda
Patent number: 6466365
Abstract: The invention provides coated optical lithography elements and methods of coating optical elements, and particularly optical photolithography elements for use in below 240 nm optical photolithography systems utilizing vacuum ultraviolet light (VUV) lithography wavelengths no greater than about 193 nm, such as VUV projection lithography systems utilizing wavelengths in the 193 nm or 157 nm region. The optical devices manipulate vacuum ultraviolet lithography light less than 250 nm utilizing a deposited silicon oxyfluoride film. The deposited silicon oxyfluoride optical coating assists in the manipulation of incident light and protects the underlying optical materials, layers, and surfaces.
Type: Grant
Filed: May 10, 2000
Issued: October 15, 2002
Assignee: Corning Incorporated
Inventors: Robert L. Maier, Lisa A. Moore, Charlene M. Smith
Patent number: 6451719
Abstract: A silica glass optical material for transmitting light with a wavelength of from 155 to 195 nm emitted from an excimer laser or an excimer lamp, which comprises silica glass optical material of ultrahigh purity, containing from 1 to 100 wtppm of OH groups, from 5×1016 to 5×1019 molecules/cm3 of H2, and from 10 to 10,000 wtppm of F, but substantially free from halogens other than F, and having a fluctuation in refractive index, &Dgr;n, of from 3×10−6 to 3×10−7.
Type: Grant
Filed: October 19, 2000
Issued: September 17, 2002
Assignees: Heraeus Quarzglas GmbH & Co. KG, Shin-Etsu Quartz Products Co., Ltd.
Inventor: Shigeru Yamagata
Patent number: 6442973
Abstract: A method is provided for manufacturing a synthetic silica glass. The method includes the steps of maintaining a silica glass member, which is formed using a flame hydrolysis method and having an OH group concentration of about 500 ppm to about 1300 ppm, at a predetermined holding temperature for a predetermined period of time so as to substantially relax the structure of the silica glass member. The method further includes the step of subsequently cooling the silica glass member to a first predetermined temperature at a cooling rate of about 10 K/hour or less, and thereafter, cooling the silica glass member to a second predetermined temperature at a cooling rate of about 1 K/hour or less. The method further includes the step of further cooling the silica glass member to a third predetermined temperature at a cooling rate of about 10 K/hour or less.
Type: Grant
Filed: January 22, 1999
Issued: September 3, 2002
Assignee: Nikon Corporation
Inventors: Norio Komine, Seishi Fujiwara, Akiko Yoshida, Hiroki Jinbo
Patent number: 6429577
Abstract: A discharge lamp comprising an arc tube containing a pair of electrodes in a light-emitting portion and an outer tube that envelops the light-emitting portion and is at least partly fused to the arc tube, wherein the outer tube comprises silicon dioxide in the range from 90 to 99.88 wt. % and boron in the range from 0.12 wt. % or more. The discharge lamp can inhibit the arc tube from deforming when the outer tube and arc tube are fused to each other by adjusting a softening temperature of the outer tube to an appropriate temperature and can realize a high accuracy of luminous intensity distribution.
Type: Grant
Filed: June 7, 1999
Issued: August 6, 2002
Assignee: Matsushita Electric Industrial Co., Ltd.
Inventors: Hideaki Kiryu, Kazuhisa Tanaka, Takeshi Saitoh
Patent number: 6423656
Abstract: 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 ≦5 nm/cm and a resistance to high-energy DUV radiation as a result of a transmission reduction of &Dgr; T ≦0.1 %/cm thickness. The quartz glass has been exposed to the following radiation: wavelength &lgr;1=248 nm, laser shot frequency ≧300 Hz, laser shot value ≧109 and rumination ≦10 mJ/cm2, and wavelength &lgr;2=193 nm, laser shot frequency ≧300 Hz, laser shot value ≧109 and rumination ≦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.
Type: Grant
Filed: September 10, 1999
Issued: July 23, 2002
Assignee: Schott ML GmbH
Inventors: Frank Coriand, Andreas Menzel, Andreas Voitsch
Application number: 20020082157
Abstract: A photolithography apparatus is constructed comprising an exposure light source that emits light with a wavelength of 400 nm or less as the exposure light, a reticle with a pattern original image formed therein, an illumination optical system that irradiates light outputted from the exposure light source onto the reticle, a projection optical system that projects the pattern image outputted from the reticle onto a photosensitive plate and an alignment system that positions the reticle and the photosensitive plate. At least some of the synthetic silica glass members composing the illumination optical system, the synthetic silica glass members composing the projection optical system and the reticle consist of synthetic silica glass members which, upon 1×104 pulse irradiation with an ArF excimer laser at an energy density from 0.1 &mgr;J/cm2·p to 200 mJ/cm2·p, have a loss factor of no greater than 0.0050 cm−1 at 193.
Type: Application
Filed: November 27, 2001
Issued: June 27, 2002
Assignee: Nikon Corporation
Inventors: Akiko Yoshida, Norio Komine, Hiroki Jinbo
Patent number: 6410467
Abstract: A glass consisting essentially of antimony oxide. An optically active glass consisting essentially of antimony oxide and up to about 4 mole % of an oxide of a rare earth element. A rare earth-doped, antimony oxide-containing glass including 0-99 mole % SiO2, 0-99 mole % GeO2, 0-75 mole % (Al, Ga)2O3, 0.5-99 mole % Sb2O3, and up to about 4 mole % of an oxide of a rare earth element. The oxide of the rare earth element may comprise Er2O3. The glass of the invention further includes fluorine, expressed as a metal fluoride. An optical energy-producing or light-amplifying device, in particular, an optical amplifier, comprising the above-described glass. The optical amplifier can be either a fiber amplifier or a planar amplifier, either of which may have a hybrid composition. Embodiments of the glass of the invention can be formed by conventional glass making techniques, while some of the high content antimony oxide embodiments are formed by splat or roller quenching.
Type: Grant
Filed: April 8, 1999
Issued: June 25, 2002
Assignee: Corning Incorporated
Inventors: James E. Dickinson, Adam J G Ellison, Alexandre M. Mayolet, Michel Prassas
Application number: 20020077244
Abstract: Lithographic methods are disclosed. In one such method, a pulsed ultraviolet radiation source for producing ultraviolet lithography radiation having a wavelength shorter than about 300 nm at a fluence of less than 10 mJ/cm2/pulse and a high purity fused silica lithography glass having a concentration of molecular hydrogen of between about 0.02×1018 molecules/cm3 and about 0.18×1018 molecules/cm3 are provided. A lithography pattern is formed with the ultraviolet lithography radiation; the lithography pattern is reduced to produce a reduced lithography pattern; and the reduced lithography pattern is projected onto a ultraviolet radiation sensitive lithography medium to form a printed lithography pattern. At least one of the forming, reducing, and projecting steps includes transmitting the ultraviolet lithography radiation through the high purity fused silica lithography glass. Lithography systems and high purity fused silica lithography glass are also described.
Type: Application
Filed: September 27, 2001
Issued: June 20, 2002
Inventors: Nicholas F. Borrelli, Charlene M. Smith, Johannes Moll
Patent number: 6403508
Abstract: An optical member includes a fused silica glass having a concentration of ≡SiH moiety below detection limit as measured by Raman spectroscopy and a concentration of molecular hydrogen of at least 1×1017 molecules/cm3. The fused silica glass exhibits an induced absorption level which quickly attains an initial peak upon exposure to irradiation and rapidly decays to a low value. The induced absorption level after decaying to the low value remains substantially unchanged by further irradiation.
Type: Grant
Filed: May 31, 2000
Issued: June 11, 2002
Assignee: Corning Incorporated
Inventors: Roger J. Araujo, Nicholas F. Borrelli, Robert E. McLay, Daniel R. Sempolinski, Charlene M. Smith
Patent number: 6399037
Abstract: A low-viscosity dental material contains a non-settling nanoscale filler. Improvements of the mechanical properties of the dental materials, including the abrasive resistance and the compressive strength are provided. Furthermore, the dental materials have increased resistance to microleakage and have increased bond strengths. The filler forms a stable sol with low-viscosity dental materials and the filler may be prepared by surface treatment of fillers having a primary particle size of from about 1 to about 100 nanometers.
Type: Grant
Filed: February 4, 1999
Issued: June 4, 2002
Assignee: Dentsply Detrey GmbH
Inventors: Kai Pflug, Christoph Weber
Patent number: 6399526
Abstract: A quartz glass which would not become a source for the contamination even if it contains metallic impurities. This quartz glass includes a region where a concentration of E′ center as measured by means of an. electron spin resonance analysis is 3×1019 cm−3 or more. This quartz glass can be manufactured by a method including the steps of forming an initial quartz glass by melting and quenching a raw material for quartz glass, and implanting therein an ion, which is capable of entering into an SiO2 network of the initial quartz glass and substantially incapable of externally diffusing, to increase a concentration of E′ center in at least part of the initial quartz glass. This quartz glass can be manufactured by a method making use of a quartz glass raw material containing 0.01 to 0.1% by weight of-silicon, by a method of irradiating ultraviolet ray to the initial quartz glass, or by a method of giving an abrasion damage to the surface of the initial quartz glass by means of sand blast.
Type: Grant
Filed: June 4, 2001
Issued: June 4, 2002
Assignees: Kabushiki Kaisha Toshiba, Toshiba Ceramics, Ltd.
Inventors: Hiroshi Tomita, Tsuneo Ishii, Chie Hongo
Application number: 20020064366
Abstract: A modified silica glass composition for providing a reduction in the multiphonon quenching for a rare-earth dopant comprising:
Type: Application
Filed: October 2, 2001
Issued: May 30, 2002
Inventors: Brian J. Cole, Michael L. Dennis
Application number: 20020061810
Abstract: A process of manufacturing a silica glass article comprising the steps of: (1) irradiating a silica glass article with electromagnetic waves to generate defects therein; and (2) immersing the thus irradiated silica glass article in an atmosphere comprising a hydrogen gas, thereby providing the resulting silica glass article with a characteristic that is effective for preventing it substantially from increasing its absorption within an ultraviolet region due to ultraviolet ray irradiation. Also disclosed are a silica glass article or a glass fiber produced according to the manufacturing process.
Type: Application
Filed: December 3, 2001
Issued: May 23, 2002
Assignee: Sumitomo Electric Industries, Ltd.
Inventors: Akira Urano, Toshio Danzuka, Tatsuhiko Saito, Yasuhiko Shishido, Masaharu Mogi, Michihisa Kyoto
Patent number: 6380109
Abstract: There is disclosed second-order nonlinear glass material wherein a part having second-order nonlinearity contain Ge, H and OH and second-order nonlinear optical constant d of 1 pm/V or more, and a method for producing second-order nonliner glass material comprising treating a porous class material containing Ge with hydrohen, sintering it and subjecting it to a ultraviolet poling treatment. There can be provided second-order nonlinger glass material having second-order nonlinearity which is a sufficiently high and has a sufficiently long lifetime for a practical purpose, in use of the glass material for optical elements or the like.
Type: Grant
Filed: February 23, 2000
Issued: April 30, 2002
Assignees: Shin-Etsu Chemical Co., Ltd., Toyota Tecnological Institute
Inventors: Jun Abe, Seiki Ejima, Akira J. Ikushima, Takumi Fujiwara
Patent number: 6380110
Abstract: In a known process for the production of opaque quartz glass a blank is formed from synthetic SiO2 granulate and is heated at a vitrification temperature to form a body of opaque quartz glass. In order to provide on this basis a process for the production of pure opaque quartz glass with a homogenous pore distribution, high density, high viscosity and a low tendency to devitrify, it is proposed according to the invention that the SiO2 granulate to be used is a SiO2 granulate (21; 31) composed of at least partially porous agglomerates of SiO2 primary particles, with a specific BET surface ranging from 1.5 m2/g to 40 m2/g and an apparent density of at least 0.8 g/cm3. A SiO2 granulate (21; 31) suitable for the implementation of the process is distinguished in that it is formed from at least partially porous agglomerates of SiO2 primary particles and in that it has a specific BET surface ranging from 1.5 m2/g to 40 m2/g and an apparent density of at least 0.6 g/cm3.
Type: Grant
Filed: January 14, 2000
Issued: April 30, 2002
Assignee: Heraeus Quarzglas GmbH & Co. KG
Inventors: Waltraud Werdecker, Heinz Fabian, Udo Gertig, Johann Leist, Rolf Göbel
Patent number: 6376401
Abstract: A synthetic silica glass having a high transmittance for vacuum ultraviolet rays, for example F2 excimer laser beam with a wavelength of 157 nm, a high uniformity and a high durability and useful for ultraviolet ray-transparent optical glass materials is produced from a high-purity silicon compound, for example silicon tetrachloride, by heat treating an accumulated porous silica material at a temperature not high enough to convert the porous silica material to a transparent silica glass in an inert gas atmosphere for a time sufficient to cause the OH groups to be condensed and removed from the glass, and exhibits substantially no content of impurities other than OH group a difference between highest and lowest fictional temperatures of 50° C.
Type: Grant
Filed: September 1, 1999
Issued: April 23, 2002
Assignees: Tosoh Corporation, Nippon Silica Glass Co., Ltd., Yamaguchi Nippon Silica Glass Co., Ltd.
Inventors: Shinichi Kondo, Takayuki Nakamura, Kazuhiko Fukuda, Naoyoshi Kamisugi, Nobu Kuzuu, Yoshinao Ihara, Hidetoshi Wakamatsu
Patent number: 6366404
Abstract: In a projection optical system having at least two silica glass optical members, a birefringence value is measured at each of points in a plane normal to the optical axis with the center at an intersection of each optical member with the optical axis, a distribution of signed birefringence values in each optical member is obtained by assigning a positive sign to each birefringence value when a direction of the fast axis thereof is a radial direction to the intersection with the optical axis and assigning a negative sign to each birefringence value when the direction of the fast axis thereof is normal to the radial direction, and the optical members are combined with each other so as to satisfy such a placement condition that a signed birefringence characteristic value of the entire projection optical system calculated based on the distributions of signed birefringence values is between −0.5 and +0.5 nm/cm both inclusive.
Type: Grant
Filed: September 1, 2000
Issued: April 2, 2002
Assignee: Nikon Corporation
Inventors: Hiroyuki Hiraiwa, Issey Tanaka
Application number: 20020037797
Abstract: Fluorine-containing glass which comprises silica and contains, in said silica, not more than 10 ppm of OH group, not more than 10 ppm of Cl and not less than 1000 ppm of F, said fluorine-containing glass having a concentration ratio of F/Cl of 100 or more. Also disclosed is fluorine-containing glass which contains not more than 10 ppm of OH group, not more than 10 ppm of Cl and not less than 1000 ppm of F, and has a concentration ratio of F/Cl of 1000 or more.
Type: Application
Filed: August 3, 2001
Issued: March 28, 2002
Assignee: Sumitomo Electric Industries, Ltd.
Inventors: Yuichi Ohga, Tadashi Enomoto
Patent number: 6355587
Abstract: The application discloses a number of unique sintered quartz glass products together with new silica compositions and processes for making and using such products. Nitrided clear and opaque nitrided quartz products are disclosed having incredible physical properties resulting from the incorporation of very small, but effective, amounts (e.g., 25 ppm or more) of chemically bound nitrogen. Opaque quartz glass heat shields with remarkable resistance to transmission of infrared radiation are disclosed which can have a high bubble population density, such as 80 to 120 per mm2. These heat shields make possible remarkable improvement in the performance of tube furnaces and other reactors used in processing silicon wafers and other electronic components.
Type: Grant
Filed: August 18, 1997
Issued: March 12, 2002
Inventors: Ted A. Loxley, John F. Blackmer, Klaus-Markus Peters
Patent number: 6342460
Abstract: The invention relates to a glass excellent in infrared absorption capability and corrosion resistance, and its fabrication process. A compound of divalent copper and a compound of a metal species for a network modifier oxide are introduced in a wet gel. Then, the wet gel is dipped in a dipping solution having a low solubility with respect to the compound of divalent copper and the compound of a metal species for a network modifier oxide for the precipitation in the wet gel of the divalent-t copper compound and the compound of a metal species for a network modifier oxide, followed by drying and firing. Thus, an infrared absorbing glass comprising 70 to 98 mol % of SiO2, 1 to 12 mol % of CuO and 1 to 18 mol % of a network modifier oxide other than CuO is fabricated.
Type: Grant
Filed: June 21, 1999
Issued: January 29, 2002
Assignee: Olympus Optical Co., Ltd.
Inventors: Yoshinobu Akimoto, Hiroaki Kinoshita
Patent number: 6339033
Abstract: A silica glass is provided for use in an optical system processing an excimer laser beam. The silica glass has a molecular hydrogen concentration of about 5×1018 molecules/cm3 or less and is substantially free from defects which become precursors susceptible to an one-photon absorption process and a two-photon absorption process upon irradiation of the excimer laser beam to the silica glass.
Type: Grant
Filed: December 15, 2000
Issued: January 15, 2002
Assignee: Nikon Corporation
Inventors: Hiroki Jinbo, Norio Komine, Seishi Fujiwara, Akiko Yoshida
Patent number: 6333284
Abstract: There is disclosed a synthetic fused silica member used at a wavelength of 200 nm or less which has a hydroxyl group-content of 1 to 50 ppm and a fluorine-content of 100 to 1000 ppm, and contains no chlorine, and has a birefringence of the synthetic fused silica member of 2 nm/cm or less. The synthetic fused silica member can be used as a synthetic fused silica substrate for photomask, or in an optical system wherein a fluorine excimer laser is used as a light source. There can be provided a synthetic fused silica member which can efficiently transmit a light having a wavelength as 200 nm or less, especially fluorine excimer laser (157 nm), and does not suffer from lowering of transmittance due to damage.
Type: Grant
Filed: March 7, 2000
Issued: December 25, 2001
Assignee: Shin-Etsu Chemical Co., Ltd.
Inventors: Hisatoshi Otsuka, Kazuo Shirota, Kazuhiro Kumakura
Patent number: 6333283
Abstract: A process of manufacturing a silica glass article comprising the steps of: (1) irradiating a silica glass article with electromagnetic waves to generate defects therein; and (2) immersing the thus irradiated silica glass article in an atmosphere comprising a hydrogen gas, thereby providing the resulting silica glass article with a characteristic that is effective for preventing it substantially from increasing its absorption within an ultraviolet region due to ultraviolet ray irradiation. Also disclosed are a silica glass article or a glass fiber produced according to the manufacturing process.
Type: Grant
Filed: August 6, 1999
Issued: December 25, 2001
Assignee: Sumitomo Electric Industries, Ltd.
Inventors: Akira Urano, Toshio Danzuka, Tatsuhiko Saito, Yasuhiko Shishido, Masaharu Mogi, Michihisa Kyoto
Patent number: 6309991
Abstract: Fused silica stepper lens for photolithographic application are disclosed which are resistant to laser-induced damage, specifically, compaction or densification which can lead to an increase in the optical path length of the lens. The figure compares the phase front distortions of a standard fused silica with the phase front distortions observed in two inventive stepper lens fused silica.
Type: Grant
Filed: February 25, 1999
Issued: October 30, 2001
Assignee: Corning Incorporated
Inventors: Nicholas F. Borrelli, Thomas P. Seward, III, Charlene Smith
Patent number: 6291377
Abstract: A method is provided for manufacturing a silica glass that is substantially free of chlorine. The method includes the step of separately expelling a silicon tetrafluoride gas, a combustion gas, and a combustible gas from a burner made of silica glass, the flow velocity of the silicon tetrafluoride gas being within the range of about 9 slm/cm2 to about 20 slm/cm2. The method further includes the steps of producing minute silica glass particles by reacting the silicon tetrafluoride gas with water produced by a reaction of the combustion gas with the combustible gas, depositing the minute silica glass particles on a target, and producing the silica glass by fusing and vitrifying the minute silica glass particles deposited on the target.
Type: Grant
Filed: September 10, 1998
Issued: September 18, 2001
Assignee: Nikon Corporation
Inventors: Norio Komine, Seishi Fujiwara, Hiroki Jinbo
Application number: 20010014424
Abstract: High purity silicon oxyfluoride glass suitable for use as a photomask substrates for photolithography applications in the VUV wavelength region below 190 nm is disclosed. The inventive silicon oxyfluoride glass is transmissive at wavelengths around 157 nm, making it particularly useful as a photomask substrate at the 157 nm wavelength region. The inventive photomask substrate is a “dry,” silicon oxyfluoride glass which exhibits very high transmittance in the vacuum ultraviolet (VUV) wavelength region while maintaining the excellent thermal and physical properties generally associated with high purity fused silica. In addition to containing fluorine and having little or no OH content, the inventive silicon oxyfluoride glass suitable for use as a photomask substrate at 157 nm is also characterized by having less than 1×1017 molecules/cm3 of molecular hydrogen and low chlorine levels.
Type: Application
Filed: March 6, 2001
Issued: August 16, 2001
Inventors: Lisa A. Moore, Charlene Smith
Patent number: 6225245
Abstract: A synthetic quartz powder obtained by calcining a powder of silica gel, characterized in that white devitrification spots having sizes of larger than 20 &mgr;m in diameter formed in an ingot obtained by vacuum melting the synthetic quartz powder at a temperature of from 1780 to 1800° C. to form an ingot, followed by maintaining the ingot at a temperature of 1630° C. for 5 hours, are at most 10 spots/50 g.
Type: Grant
Filed: November 19, 1997
Issued: May 1, 2001
Assignee: Mitsubishi Chemical Corporation
Inventors: Akira Utsunomiya, Yoshio Katsuro, Akihiro Takazawa, Takashi Moriyama
Application number: 20010000508
Abstract: A silica glass is provided for use in an optical system processing an excimer laser beam. The silica glass has a molecular hydrogen concentration of about 5×1018 molecules/cm3 or less and is substantially free from defects which become precursors susceptible to an one-photon absorption process and a two-photon absorption process upon irradiation of the excimer laser beam to the silica glass.
Type: Application
Filed: December 15, 2000
Issued: April 26, 2001
Assignee: NIKON CORPORATION
Inventors: Hiroki Jinbo, Norio Komine, Seishi Fujiwara, Akiko Yoshida
Patent number: 6219137
Abstract: A probe for a surface-enhanced Raman scattering spectrometer is provided for injection into a cell in order to detect trace amounts of a compound within that cell. The probe has a spherical shape with a diameter less than one micrometer and preferably in the 10-500 nanometer range. The nanoprobes can have a receptor coating related to the specific compound to be detected by the probe. A process for producing, injecting and utilizing the nanoprobes are described.
Type: Grant
Filed: December 3, 1998
Issued: April 17, 2001
Assignee: Lockheed Martin Energy Research Corporation
Inventor: Tuan Vo-Dinh
Patent number: 6181469
Abstract: In a method for evaluating the homogeneity of the refractive index of an optical member, the refractive index distribution of the optical member is measured, the measured refractive index distribution is separated into a rotationally symmetric element and a non-rotationally symmetric element in the optical axis direction before or after correction of the power element, and the rotationally symmetric element is further subjected to 2nd/4th-order element correction. Upon execution of such comprehensive evaluation, a photolithography optical member, which can realize a fine, sharp exposure-transfer pattern (e.g., a line width of 0.3 &mgr;m or less) is provided.
Type: Grant
Filed: November 30, 1999
Issued: January 30, 2001
Assignee: Nikon Corporation
Inventors: Hiroyuki Hiraiwa, Issey Tanaka, Katsuya Miyoshi
Patent number: 6174830
Abstract: A silica glass is provided for use in an optical system processing an excimer laser beam. The silica glass has a molecular hydrogen concentration of about 5×1018 molecules/cm3 or less and is substantially free from defects which become precursors susceptible to an one-photon absorption process and a two-photon absorption process upon irradiation of the excimer laser beam to the silica glass.
Type: Grant
Filed: September 29, 1998
Issued: January 16, 2001
Assignee: Nikon Corporation
Inventors: Hiroki Jinbo, Norio Komine, Seishi Fujiwara, Akiko Yoshida
Patent number: 6153546
Abstract: This ultralow-loss glass is characterized in that high purity silica glass contains 1 to 500 wt.ppm of at least one network modifying oxide. It is assumed that the network modifying oxide appropriately loosens the tetrahedral network structure of silica and hence Rayleigh scattering is decreased. Examples of the network modifying oxide include Na.sub.2 O, K.sub.2 O, Li.sub.2 O, MgO, CaO, and PbO. Since Rayleigh scattering losses are minimal in comparison with those of high purity silica glass, this impurity-added silica glass is excellent as a base material of a glass fiber for a long-distance transmission.
Type: Grant
Filed: January 13, 1999
Issued: November 28, 2000
Assignees: Toyota Jidosha Kabushiki Kaisha, Toyota School Foundation
Inventors: Kazuya Saitoh, Akira Ikushima
Patent number: 6143676
Abstract: An object of the present invention is to provide a synthetic silica glass optical material which exhibits excellent transmittance as well as durability for high output power vacuum ultraviolet rays, being emitted from, for example, ArF excimer lasers and Xe.sub.2 excimer lamps, and to provide a method for producing the same. A synthetic silica glass optical material for high output power vacuum ultraviolet rays made from ultra high purity synthetic silica glass for use in the wavelength region of from 165 to 195 nm, containing OH groups at a concentration of from 5 to 300 wtppm with a fluctuation width in OH group concentration (.DELTA.OH/cm) of 10 wtppm or less, containing hydrogen molecules at a concentration of from 1.times.10.sup.17 to 1.times.10.sup.19 molecule/cm.sup.3 with a fluctuation width in hydrogen molecule concentration (.DELTA.H.sub.2 /cm) of 1.times.10.sup.17 molecule/cm.sup.3 or lower, and containing chlorine at a concentration of 50 wtppm or lower.
Type: Grant
Filed: January 14, 1999
Issued: November 7, 2000
Assignees: Heraeus Quarzglas GmbH, Shin-Etsu Quartz Products Co., Ltd.
Inventors: Norio Ohashi, Michiyo Kuriyama, Shigeru Yamagata, Shigemasa Sunada
Patent number: 6136736
Abstract: A metal halide or mercury lamp including an arc tube comprised of a glass composition consisting essentially of at least 90 weight percent SiO.sub.2 and including between about 10 and 1000 parts per million of a trivalent element slected from the group consisting of Pr, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Ac, Th, Pa, U, Np, Pu, Am, Cm, Bk, Cf, Es, Fm, Md, No, Lr, Unq, Unp, Ga, and mixtures thereof such that the viscosity of the glass composition is greater than 10.sup.14.5 poise at 1100.degree. C.
Type: Grant
Filed: May 19, 1997
Issued: October 24, 2000
Assignee: General Electric Company
Inventors: Mohan Rajaram, Curtis E. Scott
Patent number: 6133178
Abstract: A high-purity transparent silica glass containing Fe, Na and K impurities each in an amount of 0.01-0.3 ppm, and an OH group in an amount of 0-3 ppm; among the Fe impurities, the content of metallic Fe having a valency of +0 being not larger than 0.1 ppm. This transparent silica glass exhibits, even when it is maintained at 900-1,400.degree. C. for at least 20 hours, an extinction coefficient of not larger than 0.009 at a wavelength of 400 nm, and does not become colored as visually examined. The silica glass is made by a process wherein powdery silica filled in a mold cavity is melted at 1,700.degree. C. or higher, characterized in that the melting is conducted in a graphite mold having a porous high-purity graphite layer provided on the mold inner surface so that the filled silica is not contacted with the mold; said porous layer having a bulk density of 0.1-1.5 g/cm.sup.3, and the content of each of Fe, Na and K impurities in the porous layer being not larger than 1 ppm.
Type: Grant
Filed: December 3, 1998
Issued: October 17, 2000
Assignees: Tosoh Corporation, Nippon Silica Glass Co., Ltd.
Inventors: Nobusuke Yamada, Shinkichi Hashimoto, Koji Tsukuma, Tomoyuki Akiyama, Yoshikazu Kikuchi, Hideaki Segawa
Patent number: 6133174
Abstract: A method for producing a machinable feldspathic porcelain comprising leucite is presented. Machinability is imparted to feldspathic porcelains by achieving homogeneous distribution of fine crystalline constituent comprised of at least one of the following leucite phases: potassium tetragonal leucite, rubidium leucite, cesium stabilized cubic leucite, rubidium stabilized cubic leucite, and pollucite. The porcelains produced in accordance with the present invention are readily machinable by using available diamond tooling techniques. Furthermore, the porcelains are especially useful for the fabrication of dental restorations using CAD/CAM technology.
Type: Grant
Filed: October 9, 1998
Issued: October 17, 2000
Assignee: Jeneric/Pentron Incorporated
Inventors: Dmitri Brodkin, Carlino Panzera, Paul Panzera
Patent number: 6129899
Abstract: A process for producing a synthetic quartz powder, which comprises a step of heat-treating a silica gel powder while permitting it to flow in a rotary kiln.
Type: Grant
Filed: November 26, 1997
Issued: October 10, 2000
Assignee: Mitsubishi Chemical Corporation
Inventors: Yoshio Katsuro, Masaru Shimoyama, Hiroshi Maeda, Shoji Oishi
Patent number: 6110852
Abstract: A process for producing synthetic quartz powder which comprises calcining silica gel powder to produce a synthetic quartz glass powder, wherein dry air is used in the calcining process at least in the process of cooling from 800.degree. C. to 200.degree. C. This process enables efficient production of synthetic quartz glass powder on an industrial scale.
Type: Grant
Filed: November 4, 1997
Issued: August 29, 2000
Assignee: Mitsubishi Chemical Corporation
Inventors: Yoshio Katsuro, Hozumi Endo, Akira Utsunomiya, Hiroaki Nagai, Toshifumi Yoshikawa, Shoji Oishi, Takashi Yamaguchi
Patent number: 6093666
Abstract: A quartz glass which would not become a source for the contamination even if it contains metallic impurities. This quartz glass includes a region where a concentration of E' center as measured by means of an electron spin resonance analysis is 3.times.10.sup.19 cm.sup.-3 or more. This quartz glass can be manufactured by a method including the steps of forming an initial quartz glass by melting and quenching a raw material for quartz glass, and implanting therein an ion, which is capable of entering into an SiO.sub.2 network of the initial quartz glass and substantially incapable of externally diffusing, to increase a concentration of E' center in at least part of the initial quartz glass. This quartz glass can be manufactured by a method making use of a quartz glass raw material containing 0.01 to 0.1% by weight of silicon, by a method of irradiating ultraviolet ray to the initial quartz glass, or by a method of giving an abrasion damage to the surface of the initial quartz glass by means of sand blast.
Type: Grant
Filed: May 28, 1998
Issued: July 25, 2000
Assignees: Kabushiki Kaisha Toshiba, Toshiba Ceramics., Ltd.
Inventors: Hiroshi Tomita, Tsuneo Ishii, Chie Hongo
Patent number: 6087283
Abstract: A silica glass has a structure determination temperature of 1200 K or lower and an OH group concentration of at least 1,000 ppm. The silica glass is used for photolithography together with light in a wavelength region of 400 nm or shorter.
Type: Grant
Filed: January 3, 1996
Issued: July 11, 2000
Assignee: Nikon Corporation
Inventors: Hiroki Jinbo, Norio Komine, Hiroyuki Hiraiwa
Patent number: 6077799
Abstract: These glasses incorporate a combination of F and Al.sub.2 O.sub.3 to achieve even wider fluorescence and improved gain flatness. In addition, SPCVD incorporates large amounts of N into low-loss fiber whose high charge has an impact on rare earth behavior. The Surface Plasma Chemical Vapor Deposition (SPCVD) produces fiber preforms with high levels of F, Al.sub.2 O.sub.3, and N. These heavily fluorinated glasses provide much broader Er.sup.3+ emission than Type I or Type II silica for enhanced multichannel amplifiers. SPCVD successfully fluorinates silica with losses below 5 dB/km and increased Er.sup.3+ emission width.
Type: Grant
Filed: March 12, 1999
Issued: June 20, 2000
Assignee: Corning Inc.
Inventors: Matthew J. Dejneka, Rostislav Khrapko
Patent number: 6071838
Abstract: A synthetic quartz glass powder obtained by sol-gel method, wherein the number of black spot particles is at most 5 particles per 50 g, provides a high quality quartz glass shaped product with low bubble content when fused.
Type: Grant
Filed: November 4, 1997
Issued: June 6, 2000
Assignee: Mitsubishi Chemical Corporation
Inventors: Hozumi Endo, Yoshio Katsuro, Akira Utsunomiya, Masaru Shimoyama
Patent number: 6012304
Abstract: A number of unique processes are disclosed for manufacture of sintered high-purity quartz glass products in which a shaped silica body or preform is made from an aqueous slurry of micronized silica particles by gel casting, slip casting or electrophoretic deposition. The silica particles may comprise a major portion by weight of crystalline silica. In one embodiment of the invention the sintered quartz glass is transparent, substantially bubble-free and suitable for scientific or optical uses. In another embodiment the porous silica preform is fired in steam to increase the hydroxyl content and then nitrided in a nitrogen-hydrogen reducing atmosphere. A minute amount of chemically-combined nitrogen in the high-purity quartz glass is sufficient to provide a tremendous improvement in physical properties and an incredible increase in the resistance to devitrification.
Type: Grant
Filed: February 22, 1997
Issued: January 11, 2000
Inventors: Ted A. Loxley, John F. Blackmer, Klaus-Markus Peters
Patent number: 6008152
Abstract: The invention concerns a refractory material comprised essentially of vitreous or amorphous silica and presenting an improved resistance to corrosion by molten metals, principally aluminium. It contains at least 0.1% and no more than 10% by wt. of barium sulfate. It has a crystallized silica content of less than 10% and it is comprised of at least 75% vitreous or amorphous silica.
Type: Grant
Filed: May 14, 1998
Issued: December 28, 1999
Assignee: Vesuvius Crucible Company
Inventors: Philippe Guillo, Mike Hankin
Patent number: 5985779
Abstract: Disclosed is a quartz glass product of enhanced opacity manufactured by fusion of silica particles, the opacity being enhanced by the reaction of an organosilicon additive in the course of the fusion process. A method of enhancing the opacity of a quart glass product by fusing silica particles in the presence of an organosilicon additive is also disclosed.
Type: Grant
Filed: August 13, 1998
Issued: November 16, 1999
Assignee: TSL Group PLC
Inventors: Ian George Sayce, Peter John Wells
Patent number: 5979186
Abstract: A method is provided for the manufacture of SiO.sub.2 granular material. Silicic acid is dispersed in a liquid to form a dispersion. The dispersion is stirred in a stirring tank with formation of a homogeneous liquid phase. The homogeneous liquid phase is maintained by stirring at a substantially constant rate until the granular mass develops, when the solids content of the dispersion is within the range of 65 to 80 weight percent. Moisture is gradually extracted to form a granular mass which is dried and sintered.
Type: Grant
Filed: July 9, 1998
Issued: November 9, 1999
Assignee: Heraeus Quarzglas GmbH
Inventors: Rainer Koppler, Fritz-Ulrich Kreis, Klaus Arnold
Patent number: 5977000
Abstract: Opaque silica glass having a density of 2.0 to 2.18 g/cm.sup.3, sodium and potassium elements concentrations in the silica glass of each 0.5 ppm or less and an OH group concentration of 30 ppm or less, and containing bubbles which are independent bubbles having the following physical values: a bubble diameter of 300 .mu.m or less, and a bubble density of 100,000 to 1,000,000 bubbles/cm.sup.3, and a production process for opaque silica glass, including: filling quartz raw material grain having a particle size of 10 to 350 .mu.m in a heat resistant mold, heating it in a non-oxidizing atmosphere from a room temperature up to a temperature lower by 50 to 150.degree. C. than a temperature at which the above raw material grain is melted at a temperature-raising speed not exceeding 50.degree. C./minute, then, slowly heating it up to a temperature higher by 10 to 80.degree. C. than the temperature at which the quartz raw material grain is melted at the speed of 10.degree. C.
Type: Grant
Filed: November 25, 1997
Issued: November 2, 1999
Assignee: Shin-Etsu Quartz Products Co., Ltd.
Inventors: Tatsuhiro Sato, Akira Fujinoki, Kyoichi Inaki, Nobumasa Yoshida, Tohru Yokota
Patent number: 5968259
Abstract: Provided are high-purity quartz glass having a high purity, in particular, with little zirconium (Zr) and manufactured at low costs from natural quartz as the starting material and a method for the preparation thereof.
Type: Grant
Filed: August 27, 1997
Issued: October 19, 1999
Assignee: Shin-Etsu Quartz Products Co., Ltd.
Inventors: Katsuhiko Kemmochi, Hiroyuki Miyazawa, Hiroyuki Watanabe, Kiyotaka Maekawa, Chuzaemon Tsuji, Manabu Saitou