Patents Assigned to Osaka Titanium Co., Ltd.
-
Patent number: 5392729Abstract: A method of producing a silicon single crystal, in which a cylindrical partition is immersed in a molten pure silicon liquid or molten silicon liquid containing a Sb dopant within a crucible and the molten liquid inside the partition is pulled up from the crucible to produce the silicon single crystal, wherein an interval between a lower end of the partition and a crucible bottom is changed to control an oxygen concentration in the pulling-up silicon single crystal. The interval is reduced in the case where the oxygen concentration in the pulling-up silicon single crystal is to be increased while the interval is increased in the case where the oxygen concentration is to be reduced.Type: GrantFiled: September 26, 1990Date of Patent: February 28, 1995Assignees: Osaka Titanium Co., Ltd., Kyushu Electronic Metal Co., Ltd.Inventors: Kaoru Kuramochi, Makoto Ito, Kiichiro Kitaura
-
Patent number: 5260037Abstract: An apparatus and a method for producing a silicon single crystal by Czochralski method, whereby the silicon single crystal is pulled up from a crucible while the crucible is heated by a side heater in the lateral periphery of the crucible and a bottom heater facing the bottom of the crucible. The outputs of the side heater and bottom heater are controlled independently each other so that an oxygen concentration in the pull-up direction of the pulled-up silicon single crystal is rendered uniform. In addition to the output control of the heaters, a magnetic field is applied to a molten liquid in the crucible, so that, a dopant concentration in a radial direction of the pulled-up silicon single crystal is rendered uniform.Type: GrantFiled: June 26, 1992Date of Patent: November 9, 1993Assignees: Osaka Titanium Co., Ltd., Kyushu Electronic Metal Co., Ltd.Inventors: Kiichiro Kitaura, Makoto Ito, Kaoru Kuramochi
-
Patent number: 5225235Abstract: A semiconductor wafer on which silicon or the like is epitaxially grown and p-type or n-type impurities are doped and which has at the rear surface except for the peripheral edge portion thereof a blocking film for preventing jumping out of impurities therefrom which causes auto-doping, thereby preventing silicon particles from being produced at the peripheral surface and preventing the semiconductor wafer from being contaminated by the silicon particles during the manufacturing a semiconductor device.Type: GrantFiled: August 5, 1991Date of Patent: July 6, 1993Assignees: Osaka Titanium Co., Ltd., Kyushu Electronic Metal Co., Ltd.Inventors: Tetsujiro Yoshiharu, Haruo Kamise
-
Patent number: 5223077Abstract: A single crystal silicon is prepared by providing a silicon melt reservoir formed of an induction coil coated on its internal surfaces with a high melting insulating material which is subjected to an electromagnetic field which heats silicon placed in said melt reservoir, melting silicon in the melt reservoir by the application of the electromagnetic field and simultaneously depositing a scull layer of silicon on the inner surface of said reservoir, and pulling up a single crystal silicon rod from the silicon melt in the melt reservoir.Type: GrantFiled: April 12, 1991Date of Patent: June 29, 1993Assignee: Osaka Titanium Co., Ltd.Inventors: Kyojiro Kaneko, Hideyuki Mizumoto
-
Patent number: 5211802Abstract: A method of producing single-crystal silicon is disclosed. Polycrystalline silicon rod is formed from polycrystalline silicon granules, lumps or a mixture thereof by continuous casting through electromagnetic induction. Then, silicon single cyrstal is grown from the polycrystalline silicon rod by the FZ method.Type: GrantFiled: April 1, 1991Date of Patent: May 18, 1993Assignee: Osaka Titanium Co., Ltd.Inventors: Kyojiro Kaneko, Hideyuki Mizumoto, Teruoki Misawa
-
Patent number: 5204031Abstract: A powder of oxide which is a material for dielectric ceramics including perovskite-type double oxide containing lead, and a process for producing dielectric ceramics using the powder. In the process of this invention, perovskite-type double oxide containing lead are initially produced by means of hydrothermal reaction, and the powder is heat-treated at 500.degree. to 1000.degree. C. Consequently, the specific surface area of the powder becomes 20 m.sup.2 /g or less. The powder is mixed with binder and compressed, molded and debinded, and consequently, the compact attains 50% or more of theoretical density. Thereafter, the compact is sintered. As a result, the process of manufacture according to the present invention is capable of producing dielectric ceramics, wherein deformation and cracks do not occur.Type: GrantFiled: January 30, 1992Date of Patent: April 20, 1993Assignee: Osaka Titanium Co., Ltd.Inventors: Munetoshi Watanabe, Yasuhiro Shimizu, Hiroyuki Hata
-
Patent number: 5152867Abstract: An apparatus and a method for producing a silicon single crystal by the Czochralski method, whereby the silicon single crystal is pulled up from a crucible while the crucible is heated by a side heater in the lateral periphery of the crucible and a bottom heater facing the bottom of the crucible. The outputs of the side heater and bottom heater are controlled independently of each other so that an oxygen concentration in the pull-up direction of the pulled-up silicon single crystal is rendered uniform. In addition to the output control of the heaters, a magnetic field is applied to a molten liquid in the crucible, so that, a dopant concentration in a radial direction of the pulled-up silicon single crystal is rendered uniform.Type: GrantFiled: July 19, 1990Date of Patent: October 6, 1992Assignees: Osaka Titanium Co., Ltd., Kyushu Electronic Metal Co., Ltd.Inventors: Kiichiro Kitaura, Makoto Ito, Kaoru Kuramochi
-
Patent number: 5108490Abstract: A method of refining high purity titanium, which comprises reacting crude titanium with titanium tetraiodide in a reactor, thereby forming lower valent titanium iodides, and thermally decomposing the formed lower valent titanium iodides, and depositing high purity titanium.Type: GrantFiled: January 22, 1991Date of Patent: April 28, 1992Assignee: Osaka Titanium Co., Ltd.Inventor: Yasunori Yoshimura
-
Patent number: 5077028Abstract: A method of manufacturing high-purity silicon crystals, which comprises depositing silicon on the surface of high-purity silicon particles, while feeding into a fluidized bed reactor at a high temperature a material gas consisting of high purity chlorosilane and a diluting gas, said method having a silicon deposition rate in excess of about 0.4 .mu.m/min.Type: GrantFiled: March 6, 1990Date of Patent: December 31, 1991Assignee: Osaka Titanium Co., Ltd.Inventor: Shuichi Age
-
Patent number: 5051375Abstract: Disclosed is a method of producing a semiconductor wafer through gettering by means of sand blasting in a semiconductor wafer fabrication process. The method includes blasting abrasives each having a configuration at least similar to a sphere against a back surface of the semiconductor wafer, causing shear stress having a maximum point in the interior of the wafer to be generated, whereby damage is produced mainly in the interior of the wafer.Type: GrantFiled: July 10, 1989Date of Patent: September 24, 1991Assignees: Kyushu Electronic Metal Co., Ltd., Osaka Titanium Co., Ltd.Inventors: Sueo Sakata, Yasunori Oka, Toshio Naritomi
-
Patent number: 5041308Abstract: An apparatus for heating polycrystalline silicon, in which polycrystalline silicon of semiconductor grade placed in the reaction vessel is directly heated by means of a heater outside of the reaction vessel where the inner surface of the reaction vessel is formed of graphite coated with highly pure silicon and having a thickness of 100 microns or more.Type: GrantFiled: December 13, 1989Date of Patent: August 20, 1991Assignee: Osaka Titanium Co., Ltd.Inventor: Makoto Kuramoto
-
Patent number: 5037503Abstract: A method for growing silicon single crystal uses as materials, silicon granules prepared by the silane process and having a residual hydrogen concentration of 7.5 wtppm or less, silicon granules prepared by the trichlorosilane process and having a residual chlorine concentration of 15 wtppm or less. In the case where such silicon granules are used, a bursting phenomenon does not occur when the silicon granules are melted. As a result, there is no scattered matter due to the bursting phenomenon, whereby the growth condition of the single crystal is not disturbed.Type: GrantFiled: May 26, 1989Date of Patent: August 6, 1991Assignees: Osaka Titanium Co., Ltd., Kyushu Electronic MetalInventors: Tsutomu Kajimoto, Daizou Horie, Shin-ichi Sakurada
-
Patent number: 4986215Abstract: A susceptor for use in a vertical vapor-phase growth system designed to heat substrates by means of heat transferred and radiated from a susceptor heated to cause vapor-phase growth on the substrates. The susceptor has a large number of spot-faced portions for receiving substrates, respectively. Each spot-faced portion has a concentrical circular ridge to define a pair of inner and outer spaces at the inner and outer sides, respectively, of the ridge, each of the inner and outer spaces having a concave bottom having a circular radial section, so that a substrate is supported by the circular ridge. Thus, the substrate is uniformly heated by means of the RF induction heat from the susceptor, so that generation of a thermal stress exceeding the critical strength of the substrate is suppressed and substantially no slip occurs.Type: GrantFiled: September 1, 1989Date of Patent: January 22, 1991Assignees: Kyushu Electronic Metal Co., Ltd., Osaka Titanium Co., Ltd.Inventors: Takayuki Yamada, Takeshi Kii
-
Patent number: 4959603Abstract: A solar battery system characterized by at least one solar cell for converting light energy to electrical energy which is stored in the system is provided. The solar cell is formed of a semiconductor selected from the group consisting of single crystal, polycrystalline and amorphous substrates and is coupled in parallel to an energy-storage capacitor, which capacitor is also connected in parallel with a loading circuit. The capacitor is formed of compressed particles of activated carbon which stores electrical energy charged to it by the solar cell at a selected voltage level. A diode is coupled in series to an output terminal of said solar cell to prevent the flow of a reverse current to the solar cell during discharge of the capacitor to the loading circuit.Type: GrantFiled: October 25, 1988Date of Patent: September 25, 1990Assignee: Osaka Titanium Co., Ltd.Inventors: Shigeo Yamamoto, Toshio Noda
-
Patent number: 4925809Abstract: A semiconductor wafer on which silicon or the like is epitaxially grown and p-type or n-type impurities are doped and which has at the rear surface except for the peripheral edge portion thereof a blocking film for preventing jumping out of impurities therefrom which causes auto-doping, thereby preventing silicon particles from being produced at the peripheral surface and preventing the semiconductor wafer from being contaminated by the silicon particles during the manufacturing of a semiconductor device.Type: GrantFiled: July 1, 1988Date of Patent: May 15, 1990Assignees: Osaka Titanium Co., Ltd., Kyushu Electronic Metal Co., Ltd.Inventors: Tetsujiro Yoshiharu, Haruo Kamise
-
Patent number: 4915723Abstract: For the continuous casting of silicon, an electrically conductive bottomless crucible is circumferentially divided by axial slits and is positioned within an electrical induction coil. The slits form circumferential gaps of between 0.3 mm and 1.0 mm and the inner wall of the crucible is inclined by between 0.4.degree. and 2.0.degree., so that the crucible expands in the downstream direction of movement of the silicon. In order to reduce the temperature gradient of the solidified silicon to between 20.degree. C./cm and 100.degree. C./cm, an additional heating element is disposed downstream of the boundary surface between the molten and solidified silicon. The crucible may be cooled by forming the crucible as a double walled cylinder and flowing a coolant therethrough.Type: GrantFiled: June 30, 1989Date of Patent: April 10, 1990Assignee: Osaka Titanium Co., Ltd.Inventors: Kyojiro Kaneko, Jun-Ya Masuda
-
Patent number: 4613489Abstract: The process of disproportionation of chlorosilanes in the presence of a dried catalyst which is dried by heating up to 200.degree. C. under vacuum starting from a water-containing anion exchange cross-linked resin matrix containing as a functional group and said resin matrix stable at temperatures up to about 200.degree. C. without separation of the functional group from the resin matrix to produce the disproportionated product of high purity, semiconductor grade, without any contamination from the catalyst.Type: GrantFiled: September 10, 1985Date of Patent: September 23, 1986Assignee: Osaka Titanium Co., Ltd.Inventor: Shiro Morimoto
-
Patent number: 4562338Abstract: A heating power supply apparatus for polycrystalline semiconductor rods, including a power transformer and anti-parallel thyristor unit groups connected to respective portions of the secondary of the power transformer, balance transformer groups connected to the anti-parallel thyristor groups and combined to make constant a secondary current of each of the balance transformers, and semiconductor rod connecting terminals connected to the secondaries of the balance transformer groups, respectively. The balance transformer groups are divided into a group of plural balance transformers of small current and high voltage for exclusive use during the starting and a group of plural balance transformers for taking over operation from the group of balance transformers of small current and high voltage and continuing subsequent operations.Type: GrantFiled: July 15, 1983Date of Patent: December 31, 1985Assignee: Osaka Titanium Co., Ltd.Inventor: Seiichi Okami