Patents by Inventor Yasuo Kohsaka
Yasuo Kohsaka has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 9437486Abstract: A sputtering target contains high purity Nb of which Ta content is 3000 ppm or less and oxygen content is 200 ppm or less. Dispersion of the Ta content in all the sputtering target is within ±30% as a whole target. Dispersion of the oxygen content is within ±80% as a whole target. According to such sputtering target, an interconnection film of low resistivity can be realized. In addition, each grain of Nb in the sputtering target has a grain diameter in the range of 0.1 to 10 times an average grain diameter and ratios of grain sizes of adjacent grains are in the range of 0.1 to 10. According to such sputtering target, giant dust can be largely suppressed from occurring. The sputtering target is suitable for forming a Nb film as liner material of an Al interconnection.Type: GrantFiled: October 25, 2011Date of Patent: September 6, 2016Assignee: KABUSHIKI KAISHA TOSHIBAInventors: Koichi Watanabe, Yasuo Kohsaka, Takashi Watanabe, Takashi Ishigami, Yukinobu Suzuki, Naomi Fujioka
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Publication number: 20120038050Abstract: A sputtering target consists of high purity Nb of which Ta content is 3000 ppm or less and oxygen content is 200 ppm or less. Dispersion of the Ta content in all the sputtering target is within ±30% as a whole target. Dispersion of the oxygen content is within ±80% as a whole target. According to such sputtering target, an interconnection film of low resistivity can be realized. In addition, each grain of Nb in the sputtering target has a grain diameter in the range of 0.1 to 10 times an average grain diameter and ratios of grain sizes of adjacent grains are in the range of 0.1 to 10. According to such sputtering target, giant dust can be largely suppressed from occurring. The sputtering target is suitable for forming a Nb film as liner material of an Al interconnection.Type: ApplicationFiled: October 25, 2011Publication date: February 16, 2012Inventors: Koichi WATANABE, Yasuo Kohsaka, Takashi Watanabe, Takashi Ishigami, Yukinobu Suzuki, Naomi Fujioka
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Patent number: 7718117Abstract: A method of manufacturing a tungsten sputtering target includes pressing a high purity tungsten powder to form a pressed compact, first sintering the pressed compact at a temperature of 1450-1700° C. for one hour or longer after the pressed compact is heated at a heating-up rate of 2-5° C./min on the way to a maximum sintering temperature, second sintering the pressed compact to form a sintered body at a temperature of 1900° C. or higher for 5 hours or longer, working the sintered body to obtain a shape of a target, subjecting the target to a grinding work of at least one of rotary grinding and polishing, and subjecting the target to a finishing work of at least one of etching and reverse sputtering.Type: GrantFiled: September 3, 2001Date of Patent: May 18, 2010Assignee: Kabushiki Kaisha ToshibaInventors: Koichi Watanabe, Yoichiro Yabe, Takashi Ishigami, Takashi Watanabe, Hitoshi Aoyama, Yasuo Kohsaka, Yukinobu Suzuki
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Publication number: 20090134020Abstract: There are provided a sputtering target and a process for producing a sputtering target. The sputtering target includes a first layer located on its side to be sputter treated and a second layer located on its side not to be sputter treated. The first and second layers are bonded to each other through a bonding interface between the first layer and the second layer. The sputtering target satisfying the following requirements X and Y: requirement X: A/B?1.5 and requirement Y: A/C?1.5, wherein A represents an oxygen peak value for the bonding interface; B represents an oxygen peak value for the first layer; and C represents an oxygen peak value for the second layer. The sputtering target is advantageous in that a spent sputtering target can be recycled to utilize resources and can form a thin film while effectively preventing the occurrence of abnormal discharge and splash.Type: ApplicationFiled: November 2, 2006Publication date: May 28, 2009Applicants: Kabushiki Kaisha Toshiba, Toshiba Materials Co., Ltd.Inventors: Yukinobu Suzuki, Koichi Watanabe, Toshiya Sakamoto, Michio Sato, Yasuo Kohsaka
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Patent number: 7153589Abstract: A Mo—W material for the formation of wirings is discloses which, as viewed integrally, comprises 20 to 95% of tungsten and the balance of molybdenum and inevitable impurities by atomic percentage. The Mo—W material for wirings is a product obtained by compounding and integrating a Mo material and a W material as by the powder metallurgy technique or the smelting technique or a product obtained by arranging these materials in amounts calculated to account for the percentage composition mentioned above. The Mo—W material containing W in a proportion in the range of from 20 to 95% manifests low resistance and, at the same time, excels in workability and tolerance for etchants. The wiring thin film which is formed of the Mo—W alloy of this percentage composition is used as address wirings and others for liquid crystal display devices.Type: GrantFiled: October 6, 1998Date of Patent: December 26, 2006Assignee: Kabushiki Kaisha ToshibaInventors: Yasuo Kohsaka, Yoshiharu Fukasawa, Yoshiko Tsuji, Mitsushi Ikeda, Michio Sato, Toshihiro Maki
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Publication number: 20050029094Abstract: The tungsten sputtering target of the present invention is characterized in that a half band width of a peak corresponding to a crystal plane (110) of the target is 0.35 or less when a surface of the target to be sputtered is analyzed by X-ray diffraction. Further, the method of manufacturing the tungsten sputtering target of the present invention is characterized by comprising the steps of: pressing a high purity tungsten powder to form a pressed compact; sintering the pressed compact to form a sintered body; working the sintered body to obtain a shape of a target; subjecting the target to a grinding work of at least one of rotary grinding and polishing; and subjecting the target to a finishing work of at least one of etching and reverse sputtering.Type: ApplicationFiled: September 3, 2001Publication date: February 10, 2005Inventors: Koichi Watanabe, Yoichiro Yabe, Takashi Ishigami, Takashi Watanabe, Hitoshi Aoyama, Yasuo Kohsaka, Yukinobu Suzuki
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Patent number: 6750542Abstract: A sputter target is made of a Ti—Al alloy containing Al in the range of 1 to 30 atm %. In the Ti—Al alloy constituting the sputter target, Al exists in at least one of a solid solution state in Ti and a state in which Al forms an intermetallic compound with Ti, and variation in Al content in the entire target is limited within 10%. Furthermore, an average crystal grain diameter of the Ti—Al alloy is 500 &mgr;m or less, and variation in crystal grain diameter in the entire target is limited within 30%. A Ti—Al—N film as a barrier film is formed by using the sputter target made of the Ti—Al alloy as described above. An electronic component includes a barrier film formed on a semiconductor substrate.Type: GrantFiled: October 21, 2002Date of Patent: June 15, 2004Assignee: Kabushiki Kaisha ToshibaInventors: Yukinobu Suzuki, Takashi Ishigami, Yasuo Kohsaka, Naomi Fujioka, Takashi Watanabe, Koichi Watanabe, Kenya Sano
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Publication number: 20030116849Abstract: A sputter target is made of a Ti—Al alloy containing Al in the range of 1 to 30 atm %. In the Ti—Al alloy constituting the sputter target, Al exists in at least one of a solid solution state in Ti and a state in which Al forms an intermetallic compound with Ti, and variation in Al content in the entire target is limited within 10%. Furthermore, an average crystal grain diameter of the Ti—Al alloy is 500 &mgr;m or less, and variation in crystal grain diameter in the entire target is limited within 30%. A Ti—Al—N film as a barrier film is formed by using the sputter target made of the Ti—Al alloy as described above. An electronic component includes a barrier film formed on a semiconductor substrate.Type: ApplicationFiled: October 21, 2002Publication date: June 26, 2003Inventors: Yukinobu Suzuki, Takashi Ishigami, Yasuo Kohsaka, Naomi Fujioka, Takashi Watanabe, Koichi Watanabe, Kenya Sano
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Patent number: 6200694Abstract: A Mo—W material for the formation of wirings is discloses which, as viewed integrally, comprises 20 to 95% of tungsten and the balance of molybdenum and inevitable impurities by atomic percentage. The Mo—W material for wirings is a product obtained by compounding and integrating a Mo material and a W material as by the powder metallurgy technique or the smelting technique or a product obtained by arranging these materials in amounts calculated to account for the percentage composition mentioned above. The Mo—W material containing W in a proportion in the range of from 20 to 95% manifests low resistance and, at the same time, excels in workability and tolerance for etchants. The wiring thin film which is formed of the Mo—W alloy of this percentage composition is used as address wirings and others for liquid crystal display devices.Type: GrantFiled: December 1, 1998Date of Patent: March 13, 2001Assignee: Kabushiki Kaisha ToshibaInventors: Yasuo Kohsaka, Yoshiharu Fukasawa, Yoshiko Tsuji, Mitsushi Ikeda, Michio Sato, Toshihiro Maki
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Patent number: 5913100Abstract: A Mo-W material for the formation of wirings is discloses which, as viewed integrally, comprises 20 to 95% of tungsten and the balance of molybdenum and inevitable impurities by atomic percentage. The Mo-W material for wirings is a product obtained by compounding and integrating a Mo material and a W material as by the powder metallurgy technique or the smelting technique or a product obtained by arranging these materials in amounts calculated to account for the percentage composition mentioned above. The Mo-W material containing W in a proportion in the range of from 20 to 95% manifests low resistance and, at the same time, excels in workability and tolerance for etchants. The wiring thin film which is formed of the Mo-W alloy of this percentage composition is used as address wirings and others for liquid crystal display devices.Type: GrantFiled: September 6, 1996Date of Patent: June 15, 1999Assignee: Kabushiki Kaisha ToshibaInventors: Yasuo Kohsaka, Yoshiharu Fukasawa, Yoshiko Tsuji, Mitsushi Ikeda, Michio Sato, Toshihiro Maki
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Patent number: 4761074Abstract: A method and an apparatus for measuring an impurity concentration of a liquid comprises atomizing step for atomizing the objective liquid, e.g. pure water, having a predetermined droplet size distribution, and an evaporating step for evaporating to dryness the droplets so as to generate fine particles. Those particles are fed to a condensation nuclei counter, hereinafter referred to as CNC, which counts the number of fine particles and has a specified sensitivity characteristic curve. Then impurity concentration of the objective liquid can be measured, since the concentration is related to the counted number of the CNC, the distribution of droplet size of the atomizer, and the sensitivity characteristic of the CNC including the particle deposition loss.Type: GrantFiled: March 24, 1987Date of Patent: August 2, 1988Assignees: Nihon Kagaku Kogyo Co., Ltd., Nomura Micro Science Co., Ltd.Inventors: Yasuo Kohsaka, Tohru Niida, Hisao Sato, Hajime Kano
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Patent number: 4449816Abstract: A method and a system for measuring the number of hyperfine particles comprising the step in which an air aerosol containing fine particles is led into a saturated vapor chamber and a high temperature saturated vapor chamber, respectively, to produce saturated vapor aerosols, the step in which the two saturated vapor aerosols produced as aforenoted are led into a mixing chamber, so that the aforementioned vapor is condensed on the aerosol particles as the nuclei, thereby achieving growth of the aforementioned fine particles, and the step for measuring the number of the said fine particles grown in that way.Type: GrantFiled: May 11, 1981Date of Patent: May 22, 1984Assignee: Nitta Gelatin Kabushiki KaishaInventors: Yasuo Kohsaka, Yoshihiro Nonaka, Hideo Tachibana