Patents by Inventor Shoei Kurosaka
Shoei Kurosaka 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: 7329317Abstract: The present invention is to produce a silicon crystal wherein the boron concentration in the silicon crystal and the growth condition V/G are controlled so that the boron concentration in the silicon crystal is no less than 1×1018 atoms/cm3 and the growth condition V/G falls within the epitaxial defect-free region ?2 whose lower limit line LN1 is the line indicating that the growth rate V gradually drops as the boron concentration increases. A silicon wafer is also produced wherein the boron concentration in the silicon crystal and the growth condition V/G are controlled so as to include at least the epitaxial defect region ?1, and both the heat treatment condition and the oxygen concentration of the silicon crystal are controlled so that no OSF nuclei grow to OSFs.Type: GrantFiled: October 31, 2003Date of Patent: February 12, 2008Assignee: Komatsu Denshi Kinzoku Kabushiki KaishaInventors: Susumu Maeda, Hiroshi Inagaki, Shigeki Kawashima, Shoei Kurosaka, Kozo Nakamura
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Patent number: 7235128Abstract: A process for producing a single-crystal semiconductor and an apparatus therefor. A single-crystal semiconductor of large diameter and large weight can be lifted with the use of existing equipment not having any substantial change thereto while not influencing the oxygen concentration of single-crystal semiconductor and the temperature of melt and while not unduly raising the temperature of seed crystal. In particular, the relationship (L1, L2, L3) between the allowable temperature difference (?T) and the diameter (D) of seed crystal (14) is preset so that the temperature difference between the seed crystal (14) at the time the seed crystal (14) is immersed in the melt and the melt (5) falls within the allowable temperature difference (?T) at which dislocations are not introduced into the seed crystal (14). In accordance with the relationship (L1, L2, L3), the allowable temperature difference (?T) corresponding to the diameter (D) of seed crystal (14) to be immersed in the melt is determined.Type: GrantFiled: December 6, 2004Date of Patent: June 26, 2007Assignee: Komatsu Denshi Kinzoku Kabushiki KaishaInventors: Susumu Maeda, Hiroshi Inagaki, Shigeki Kawashima, Shoei Kurosaka, Kozo Nakamura
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Publication number: 20060005762Abstract: The present invention is to produce a silicon crystal wherein the boron concentration in the silicon crystal and the growth condition V/G are controlled so that the boron concentration in the silicon crystal is no less than 1×1018 atoms/cm3 and the growth condition V/G falls within the epitaxial defect-free region ?2 whose lower limit line LN1 is the line indicating that the growth rate V gradually drops as the boron concentration increases. Further, the present invention is to produce a silicon wafer wherein the boron concentration in the silicon crystal and the growth condition V/G are controlled so as to include at least the epitaxial defect region ?1, and the heat treatment condition of the silicon crystal and the oxygen concentration in the silicon crystal are controlled so that no OSF nuclei grow to OSFs.Type: ApplicationFiled: October 31, 2003Publication date: January 12, 2006Inventors: Susumu Maeda, Hiroshi Inagaki, Shigeki Kawashima, Shoei Kurosaka, Kozo Nakamura
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Publication number: 20050139149Abstract: A process for producing a single-crystal semiconductor and an apparatus therefor. A single-crystal semiconductor of large diameter and large weight can be lifted with the use of existing equipment not having any substantial change thereto while not influencing the oxygen concentration of single-crystal semiconductor and the temperature of melt and while not unduly raising the temperature of seed crystal. In particular, the relationship (L1, L2, L3) between the allowable temperature difference (?T) and the diameter (D) of seed crystal (14) is preset so that the temperature difference between the seed crystal (14) at the time the seed crystal (14) is immersed in the melt and the melt (5) falls within the allowable temperature difference (?T) at which dislocations are not introduced into the seed crystal (14). In accordance with the relationship (L1, L2, L3), the allowable temperature difference (?T) corresponding to the diameter (D) of seed crystal (14) to be immersed in the melt is determined.Type: ApplicationFiled: December 6, 2004Publication date: June 30, 2005Applicant: Komatsu Denshi Kinzoku Kabushiki KaishaInventors: Susumu Maeda, Hiroshi Inagaki, Shigeki Kawashima, Shoei Kurosaka, Kozo Nakamura
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Patent number: 6315827Abstract: There is described an apparatus for producing a single crystal ingot capable of stably manufacturing a single crystal ingot by means of the Czochralski method, without being affected by influence of variation in extension of wires or an offset in points clamped by a clamping member. The clamping member is engaged with an engagement step formed in a single crystal which is being pulled by the CZ method, and the single crystal is pulled. The single crystal ingot manufacturing apparatus is provided with a flexible mechanism for absorbing variation in extension of the wires, in intermediate portions of the wires. Variation in extension of the wires is eliminated by means of the flexible mechanism, thereby retaining the single crystal in an upright position. Further, a sacrifice member which deforms so as to conform to the circumference of the engagement step is interposed between the clamping member and the engagement step, thereby preventing occurrence of cracking or deformation in the single crystal.Type: GrantFiled: September 30, 1999Date of Patent: November 13, 2001Assignee: Komatsu Electronics Metals Co., Ltd.Inventors: Shoei Kurosaka, Junsuke Tomioka, Masakazu Kobayashi, Kazuhiro Mimura, Kenji Okamura, Hiroshi Monden, Naritoshi Ohtsukasa, Hiroshi Yoshinada
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Patent number: 6270575Abstract: A value of electric current flowing a neck to a melt is detected, and it is judged that a breaking of the neck occurs when the detected value has been zero, and then a seed is lowered to dip a broken part on the melt. After that the seed is lifted again to restart a pulling operation.Type: GrantFiled: June 21, 1999Date of Patent: August 7, 2001Assignee: Komatsu Electronic Metals Co., Ltd.Inventors: Shoei Kurosaka, Makoto Kamogawa, Nobuyuki Hukuda, Junsuke Tomioka
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Patent number: 6171393Abstract: A seed crystal 1 for manufacturing a single crystal incorporating an unconformity portion B formed at a predetermined position apart from a leading end thereof and structured to conduct the heat of melt and interrupt propagation of dislocation caused from thermal stress produced when dipping in the melt has been performed.Type: GrantFiled: February 17, 1999Date of Patent: January 9, 2001Assignee: Komatsu Electronic Metals Co., Ltd.Inventors: Shoei Kurosaka, Junsuke Tomioka, Masakazu Kobayashi, Shuji Onoue, Tsuyoshi Sadamatsu
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Patent number: 6099642Abstract: An object of the invention is to provide a single crystal clamping device and a single crystal supporting method. The single crystal clamping device does not become inclined and does not vibrate, and the center of the single crystal clamping device is congruous to the center of the growing single crystal.Type: GrantFiled: June 2, 1998Date of Patent: August 8, 2000Assignee: Komatsu Electronic Metals Co., Ltd.Inventors: Shoei Kurosaka, Hiroshi Inagaki, Shigeki Kawashima, Junsuke Tomioka
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Patent number: 6042644Abstract: A single crystal pulling method includes the steps of: immersing seed crystal in a melt; growing single crystal around the seed crystal and reducing its diameter to remove dislocation in the single crystal; prior to forming a straight waist product portion of single crystal having a prescribed diameter, forming a straight waist holding portion having a diameter smaller than the prescribed diameter; holding the straight waist holding portion by using a single crystal holding device; and pulling the straight waist product portion while the straight waist holding portion is held. Preferably the step of forming the straight waist holding portion includes a step of varying a pulling speed to make unevenness in the surface thereof.Type: GrantFiled: July 24, 1998Date of Patent: March 28, 2000Assignee: Komatsu Electronic Metals Co., Ltd.Inventors: Shoei Kurosaka, Hiroshi Inagaki, Shigeki Kawashima, Junsuke Tomioka
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Patent number: 5942033Abstract: A crystal-clamping fixture 30 is suspended by a pulling up mechanism 1 through the use of wires. The crystal-clamping fixture 30 includes a box 31 and a plurality of holding rods 32. The box 31 has two openings formed on its top and bottom sides. The reduced portion 2a, the enlarged portion 2b and the necked portion 2c formed beneath the seed crystal 5 are allowed to penetrate through the two openings during the pulling up operation. A plurality of "S" shaped slots 31a, 31b are formed on the lateral sides of the box 31. The holding rods 32 capable of rotating along the path of the "S" shaped slots 31a, 31b are horizontally disposed within the box 31 by inserting their two end portions through the "S" shaped slots 31a, 31b. The holding rods kept restrained at the upper ends of the "S" shaped slots are pushed out by the conic surface formed at the upper part of the enlarged portion 2b and rotate and descend to reach the lower ends of the "S" shaped slots.Type: GrantFiled: March 26, 1998Date of Patent: August 24, 1999Assignee: Komatsu Electronic Metals Co., Ltd.Inventors: Shoei Kurosaka, Hiroshi Inagaki, Shigeki Kawashima, Junsuke Tomioka
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Patent number: 5938843Abstract: This invention provides a apparatus for pulling up crystal bodies, which is capable of firmly clamping and safely pulling up large-diameter crystal bodies regardless of the location of the necked portions formed on the top of the crystal bodies. A large-diameter portion 52 and a necked portion 51 are formed on the top of the crystal body 5. The swaying members 12 of the necked-portion clamp 1 are capable of swaying upward and downward without restraint. The stopper 14 restrains the swaying members 12 to sway below the horizontal plane on which the swaying members 12a are located. The large-diameter portion 52 can pass through the clamp body 11 by lowering the necked-portion clamp 1 to sway the swaying members 12 upward. The swaying members 12 close to clamp the necked portion 51 when the necked-portion clamp 1 reaches a location near the necked portion 51. The distance between the necked-portion clamp 1 and the seed-crystal 3 is adjustable.Type: GrantFiled: March 27, 1998Date of Patent: August 17, 1999Assignee: Komatsu Electronic Metals Co.,Ltd.Inventors: Yoshinobu Hiraishi, Mitsunori Kawabata, Shoei Kurosaka, Hiroshi Inagaki
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Patent number: 5488923Abstract: The present invention employs the construction wherein a resistor heater is disposed inside a protective cylinder whose tip is open to a molten liquid packing zone of a crucible inside a pulling apparatus so that the resistor heater is above the tip of a lower portion and temperature setting can be made so as to be capable of fusing a starting material. Since the tip of the protective cylinder is positioned inside the molten liquid at the time of pulling of a single crystal, the gaseous phase portion inside the protective cylinder and the gaseous phase portion inside the pulling apparatus are separated apart by the molten liquid and are independent of each other and a starting material polycrystal rod loaded into the protective cylinder can be supplied to the molten liquid surface inside the crucible while being molten at the lower part of the protective cylinder by the resistor heater.Type: GrantFiled: March 7, 1995Date of Patent: February 6, 1996Assignee: Komatsu Electronic Metals Co., Ltd.Inventors: Masato Imai, Hiroyuki Noda, Yutaka Shiraishi, Keishi Niikura, Shoei Kurosaka
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Patent number: 5427056Abstract: The present invention employs the construction wherein a resistor heater is disposed inside a protective cylinder whose tip is open to a molten liquid packing zone of a crucible inside a pulling apparatus so that the resistor heater is above the tip of a lower portion and temperature setting can be made so as to be capable of fusing a starting material. Since the tip of the protective cylinder is positioned inside the molten liquid at the time of pulling of a single crystal, the gaseous phase portion inside the protective cylinder and the gaseous phase portion inside the pulling apparatus are separated apart by the molten liquid and are independent of each other and a starting material polycrystal rod loaded into the protective cylinder can be supplied to the molten liquid surface inside the crucible while being molten at the lower part of the protective cylinder by the resistor heater.Type: GrantFiled: April 6, 1993Date of Patent: June 27, 1995Assignee: Komatsu Electronic Metals Co., Ltd.Inventors: Masato Imai, Hiroyuki Noda, Yutaka Shiraishi, Keishi Niikura, Shoei Kurosaka