Including Heating Or Cooling Details (e.g., Shield Configuration) Patents (Class 117/217)
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Patent number: 5871583Abstract: An apparatus for producing a silicon single crystal grown by the Czochralski method includes a main chamber having a round soulder interconnecting the upper end of a side wall and the lower end of a neck of the main chamber. The round shoulder has an inside surface so profiled as to form a portion of the periphery of an ellipse drawn about two foci which are composed of the upper end of a heater and a point of the longitudinal axis of a silicon single crystal being grown. The inside surface has a low emissivity. With the apparatus thus constructed, a silicon single crystal having a high dielectric breakdown strength of oxide film (SiO.sub.2) can be produced in a stable manner with high yield and productivity.Type: GrantFiled: December 26, 1996Date of Patent: February 16, 1999Assignee: Shin-Etsu Handotai Co., Ltd.Inventors: Kiyotaka Takano, Izumi Fusegawa, Hirotoshi Yamagishi
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Patent number: 5868836Abstract: A semiconductor single crystal lift device which comprises a crucible for melting materials for forming semiconductor single crystals and a radiation screen disposed at an upper portion of the crucible and formed of a reversed-cone-shaped adiabatic tube surrounding a lift zone, the apparatus being adopted for lifting up the semiconductor single crystal from a melt in the crucible, in which the radiation screen is divided into more than three adiabatic members, at least part of the adiabatic members being configured in a detachable fashion so that an adiabatic nature of the radiation screen can be partly altered.Type: GrantFiled: January 21, 1997Date of Patent: February 9, 1999Assignee: Komatsu Electronic Metal Co., Ltd.Inventors: Shigeki Nakamura, Koichi Shimomura, Teruhiko Uchiyama
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Patent number: 5865887Abstract: An apparatus and method for growing large diameter silicon crystals using the Czochralski (Cz) method, wherein the neck section of the crystal is significantly strengthened to eliminate the risk of breakage in the neck section, by providing a heat shield assembly which is located adjacent to the neck section and ascends in conjunction therewith to force the cooling gas directly onto the neck section of the silicon ingot.Type: GrantFiled: July 17, 1997Date of Patent: February 2, 1999Assignee: SEH America, Inc.Inventors: Witawat Wijaranakula, Akihiko Tamura
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Patent number: 5863326Abstract: The invention is directed to an apparatus, system and methods for growing high-purity crystals of substances that are peritectic at atmospheric pressure using the Czochralski technique. The apparatus includes a pressure vessel that contains a pressurized gas. The apparatus also includes a cooling unit that is situated in the pressure vessel. The cooling unit receives a coolant flow from outside of the vessel, and has cooled surfaces that define an enclosure that receives the charge material. The apparatus further includes an inductive heating element situated in the vessel, that is coupled to receive electric power externally to the vessel. The element heats the interior portion of the charge material to form a molten interior portion contained by a relatively cool, exterior solid-phase portion of the charge material that is closer relative to the molten interior, to the cooled surfaces of the cooling unit.Type: GrantFiled: March 14, 1997Date of Patent: January 26, 1999Assignee: Cermet, Inc.Inventors: Jeffrey E. Nause, D. Norman Hill, Stephen G. Pope
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Patent number: 5858085Abstract: A system for growing high-quality, low-carbon-concentration single crystals which have an excellent gas-flow guiding function near the melt, containing 1) an inverted conical, flow-guide cover placed above and coaxially with a double-walled crucible, with its lower end located immediately above the surface of the melt and in the space between the outer surface of the single crystal to be grown and the inner surface of the sidewall of the inner crucible; 2) a short passage comprising a hole passing through the sidewall of the inner crucible at a position higher than the level of the melt; and 3) a flow guide cylinder placed above and coaxially with the double-walled crucible, with its lower end located immediately above the surface of the melt and in the space between the outer surface of the sidewall of the inner crucible and the inner surface of the sidewall of the outer crucible, all arranged in a furnace.Type: GrantFiled: May 28, 1997Date of Patent: January 12, 1999Assignees: Mitsubishi Materials Corporation, Mitsubishi Materials Silicon CorporationInventors: Yoshiaki Arai, Keisei Abe, Norihisa Machida
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Patent number: 5853480Abstract: An apparatus and a method for fabricating a single-crystal semiconductor by means of a CZ method are provided for improving the quality through modification of the thermal cycle of a pulled single-crystal semiconductor. The apparatus includes a ring-shaped after heater which is capable of elevation. The method decreases the temperature gradient to smaller than 20.degree. C./cm, and preferably under 15.degree. C./cm, when the pulled single-crystal semiconductor is cooled from 1200.degree. C. to 1000.degree. C. The after heater therefore heats the single-crystal semiconductor where there is a temperature of 100.degree.-300.degree. C. lower than the range of 1200.degree.-1000.degree. C. A thermal baffle (or shield) is provided to retain a temperature gradient of larger than 20.degree. C./cm when the single-crystal semiconductor is within the temperature range between the melting point and 1250.degree. C.Type: GrantFiled: February 18, 1997Date of Patent: December 29, 1998Assignee: Komatsu Electronic Metals Co., Ltd.Inventors: Toshimichi Kubota, Toshiro Kotooka, Makoto Kamogawa
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Patent number: 5846323Abstract: A crystal pulling apparatus is designed to generate a thermal gradient across the melt surface to prevent nucleation of stray crystals and production of floating debris to produce a high quality crystal, and has special provisions for observing the growth behavior and crystal dimension measurements. The apparatus includes a cylindrical chamber, a crucible disposed centrally within the chamber, a cylindrical heater surrounding the crucible, an insulation member disposed on the top section of the crucible, a first transparent plate and a second transparent plate for closing the center hole in the insulation member, a pull rod passing through the center hole of the transparent plates, a crystal illumination mechanism, a crystal size determination mechanism and an ambient atmosphere flowing mechanism.Type: GrantFiled: October 8, 1996Date of Patent: December 8, 1998Assignees: International Superconductivity Technology Center, the Juridical Foundation, Ishikawajima-Harima Heavy Industries Co. Ltd., Sumitomo Electric Industries, Ltd.Inventors: Masahiro Egami, Yuh Shiohara, Yasuo Namikawa
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Patent number: 5840120Abstract: An apparatus for producing a silicon single crystal grown by the Czochralski process. The apparatus includes a hollow growth chamber, a quartz crucible disposed within the growth chamber, and a pulling member for pulling a growing silicon single crystal upward from a silicon melt retained in the crucible. A crystal chamber above the growth chamber receives the crystal as it is pulled. A joining member joins the growth chamber and the crystal chamber. A first heating member defining a passageway through which the crystal is pulled, for preventing formation of oxygen precipitate nucleation centers in the crystal until the crystal has been pulled through the passageway, is disposed at least partially within the growth chamber. A second heating member defining a passageway through which the crystal is pulled, for controlling the formation of the oxygen precipitate nucleation centers in the crystal, is disposed within the crystal chamber.Type: GrantFiled: January 22, 1996Date of Patent: November 24, 1998Assignee: MEMC Electronic Materials, Inc.Inventors: Kyong-Min Kim, Roger W. Shaw, Sadasivam Chandrasekhar, Richard G. Schrenker
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Patent number: 5827367Abstract: An apparatus and method for growing large diameter silicon crystals using the Czochralski (Cz) method, wherein the neck section of the crystal is significantly strengthened to eliminate the risk of breakage in the neck section, by providing a heat shield assembly which is located adjacent to the neck section and ascends in conjunction therewith to force the cooling gas directly onto the neck section of the silicon ingot.Type: GrantFiled: September 13, 1996Date of Patent: October 27, 1998Assignee: SEH AmericaInventors: Witawat Wijaranakula, Akihiko Tamura
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Patent number: 5824149Abstract: An enclosing structure extends into a transition zone of a crystal growing system through which the growing crystal is pulled. One or more independent temperature control devices are secured to the inside surface of the enclosing structure, which control devices sense crystal temperature and supply to, or extract heat from, the crystal so that a carefully-controlled thermal gradient can be established either radially or longitudinally in the crystal. The temperature control devices may include temperature sensors that provide temperature information to a central control device connected to each temperature control device. The enclosing structure may have a hollow wall structure through which a heat exchange fluid, such as water, is passed to extract heat from the transition chamber and crystal. The temperature control apparatus may also be segmented so that each segment can be controlled independently of the remaining segments thereby permitting independent control to be effected at different crystal areas.Type: GrantFiled: February 27, 1997Date of Patent: October 20, 1998Assignee: Ferrofluidics CorporationInventor: Zhixin Li
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Patent number: 5824152Abstract: In the manufacture of a single crystal using a semiconductor single-crystal pulling apparatus equipped with a radiation screen, the time of passage of the single crystal through the high-temperature region of 1050.degree. C. and above is made to be long and the time of passage of the single crystal through the temperature region of about 900.degree. C.-500.degree. C. is made to be short. The semiconductor single-crystal pulling apparatus is so constructed that a radiation screen comprises an upper screen of 3-layer construction consisting of a heat-insulating member made of graphite or ceramics fiber clad with outer members made of graphite and a lower screen 3 of single-layer construction made of graphite, quartz or fine ceramics. Radiant heat from the molten liquid heats the lower part of single crystal as it passes through lower screen, thereby prolonging its period of passage through the high-temperature region.Type: GrantFiled: July 9, 1996Date of Patent: October 20, 1998Assignee: Komatsu Electronic Metals Co., Ltd.Inventors: Toshimichi Kubota, Toshiro Kotooka, Toshiaki Saishoji, Tetsuhiro Iida
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Patent number: 5817171Abstract: A puller and method for crystal growth using the Czochralski technique in which a temperature profile and a history of thermal conditions of a growing crystal is controllable with ease and a good accuracy, which puller comprises a crucible containing raw material, heater for melting by heating the raw material and a heat insulating cylinder surrounding them, the heat insulating cylinder being cross-sectionally divided by an annular separation gap or gaps into parts and which method is applicable to growth of such a single crystal as of silicon, germanium, GaP, GaAs or InP in the puller. Methods for controlling a temperature profile and a history of thermal conditions of a growing crystal using the czochralski technique in the puller.Type: GrantFiled: May 31, 1996Date of Patent: October 6, 1998Assignee: Shin-Etsu Handotai Co., Ltd.Inventors: Masahiro Sakurada, Tomohiko Oota, Kiyotaka Takano, Masanori Kimura
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Patent number: 5795383Abstract: A method and a mechanism for lifting a gas flow-guide cylinder of a crystal pulling apparatus are disclosed. The crystal pulling apparatus includes a crucible for accommodating a crystalline material and for melting the crystalline material through heating, and a gas flow-guide cylinder capable of being moved upward/downward above the crucible. The crystal pulling apparatus is operated to grow a single crystal from the crystalline material by a pulling method. When a solid crystalline material is to be placed in the crucible, the gas flow-guide cylinder is moved upward to thereby separate the bottom end of the gas flow-guide cylinder away from the top portion of the crucible. This prevents the crystalline material from coming into contact with the gas flow-guide cylinder.Type: GrantFiled: December 5, 1996Date of Patent: August 18, 1998Assignee: Shin-Etsu Handotai Co., Ltd.Inventors: Hideo Okamoto, Toshiharu Uesugi, Atsushi Iwasaki, Tetsuhiro Oda
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Patent number: 5792255Abstract: In a single crystal manufacturing method by a horizontal magnetic field applied CZ method wherein coils are disposed interposing a crucible coaxially with each other, the coils constituting superconductive electromagnets of a magnetic field application apparatus and the silicon crystal is pulled from melt in the crucible while applying a horizontal magnetic field to the melt; an elavation apparatus capable of finely adjusting relative positions of the superconductive electromagnets and the crcucible in a vertical direction is disposed. The descent of a central portion Cm in a depth direction of the melt is canceled by elevating the crucible with the elevating apparatus, the descent being accompanied with proceeding of process of pulling the single crystal, thereby a coil central axis Cc of the superconductive electromagnets always passes through the central portion Cm or below this portion.Type: GrantFiled: May 30, 1996Date of Patent: August 11, 1998Assignee: Shin-Etsu Handotai Co., Ltd.Inventors: Eiichi Iino, Kiyotaka Takano, Masanori Kimura, Hirotoshi Yamagishi
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Patent number: 5785757Abstract: The present invention provides a method and an apparatus for fabricating a single-crystal semiconductor by means of the CZ method in which the oxygen concentration in the single-crystal semiconductor is controlled within an acceptable range. The apparatus comprises a regulating cylinder concentrically covering the single-crystal semiconductor which is pulled from a melt in a crucible; a main chamber for isolating the growing single-crystal semiconductor from external atmosphere; and a falling gas introducing means on top of the main chamber for introducing an inert gas into the main chamber. The apparatus is characterized in that a whirling gas introducing means on a circumferential portion of the main chamber introduces an whirling inert gas into the main chamber in a tangential direction to the side walls of the main chamber and the regulating cylinder.Type: GrantFiled: December 13, 1996Date of Patent: July 28, 1998Assignee: Komatsu Electronic Metals Co., Ltd.Inventor: Yoshinobu Hiraishi
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Patent number: 5766347Abstract: An apparatus for fabricating a semiconductor single crystal, which make it possible to reduce the oxygen concentration of a pulling single crystal, to steadily dissolve the polysilicon material received in a crucible, and to minimize the cost and installation space, is provided.The hollow cylindrical resistance heater of the apparatus, which co-axially surrounds a crucible, is provided with a ring-shaped slit excluding the location where at least two electrodes are formed, in a direction substantially perpendicular to the axial direction so as to divide the heater into an upper heating portion and a lower heating portion, and is provided with a plurality of vertical slits formed on the upper heating portion and the lower heating portion respectively, in a direction substantially parallel to the axial direction, wherein each vertical slit formed on the upper heating portion does not align with each vertical slit formed on the lower heating portion.Type: GrantFiled: February 24, 1997Date of Patent: June 16, 1998Assignee: Komatsu Electronic Metals Co., Ltd.Inventors: Koichi Shimomura, Yoshinobu Hiraishi, Mitsunori Kawabata
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Patent number: 5759261Abstract: A method and an apparatus for pulling a silicon monocrystal from a melt iudes the pulling of a conical portion in each case at the beginning and at the end of the monocrystal and the pulling of a cylindrical portion between the conical portions. In this method, the surface of the conical portion at the beginning of the monocrystal is shielded by a shielding means spaced apart from the monocrystal.Type: GrantFiled: November 6, 1996Date of Patent: June 2, 1998Assignee: Wacker Siltronic Gesellschaft fur Halbleitermaterialien AGInventors: Erich Dornberger, Wilfried Von Ammon
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Patent number: 5746828Abstract: A crystal-pulling apparatus incorporates a temperature sensor and an adjustable radiation shield. The temperature sensor measures temperatures of a melt surface adjacent to a solidification interface between a crystal and the melt. The radiation shield regulates radiational cooling of the melt. A control system adjusts the radiation shield in response to changes in the measured temperature of the melt for enhancing dislocation-free growth of the crystal.Type: GrantFiled: January 16, 1996Date of Patent: May 5, 1998Assignee: General Signal CorporationInventor: Anatoli S. Boulaev
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Patent number: 5735951Abstract: A single crystal pulling apparatus which eliminates trouble caused by an isolation valve heated to a high temperature uses a heat insulation plate provided below the isolation valve. The heat insulation plate is operated synchronously with the opening or closing of the isolation valve. The heat insulation plate prevents hot gases from coming from the lower chamber from coming into direct contact with the isolation valve. The prevention of overheating of the isolation valve provides for smooth operation and growth of a good quality single crystal.Type: GrantFiled: July 1, 1996Date of Patent: April 7, 1998Assignee: Shin-Etsu Handotai Co., Ltd.Inventors: Eiichi Iino, Kiyotaka Takano, Masanori Kimura, Koji Mizuishi, Hirotoshi Yamagishi
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Patent number: 5733368Abstract: In a method of manufacturing a silicon monocrystal using a continuous Czochralski method, a silicon monocrystal is pulled from a silicon melt in a crucible while a silicon material is fed to the crucible. Supply of the silicon material is suspended until the temperature distribution of the silicon melt becomes stable after initiation of a straight body forming process, and the supply of the silicon material is commenced when the temperature distribution of the silicon melt has become stable. The feed rate of the silicon material is gradually increased until the feed rate becomes equal to a solidification rate of the silicon melt after the supply of the silicon material has been commenced. This method prevents the silicon monocrystal from becoming a polycrystal during the manufacture thereof.Type: GrantFiled: February 20, 1997Date of Patent: March 31, 1998Assignee: Shin-Etsu Handotai Co., Ltd.Inventors: Naoki Nagai, Isamu Harada, Michiaki Oda
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Patent number: 5730799Abstract: A device for producing single crystals has been presented which enables the pulling up and growing of single crystals. Without loss of accurate control of the oxygen concentration in the crystal, and with excellent dielectric strength of subsequently produced gate oxide films. A heat resistant and heat insulating component (7) of cylindrical or cylinder-like form surrounding the pulling up zone of the single crystal is suspended from the ceiling (6a) or the upper part of the wall of the metallic vessel (6) with a gap (h.sub.1) from the ceiling to divide the inert gas (30) supplied from above into inert gas flows (33 and 32) outside and inside this component.Type: GrantFiled: November 27, 1995Date of Patent: March 24, 1998Assignee: Sumitomo Sitix CorporationInventor: Makoto Ito
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Patent number: 5720810Abstract: A system for growing high-quality, low-carbon-concentration single crystals which have an excellent gas-flow guiding function near the melt, containing 1) an inverted conical, flow-guide cover placed above and coaxially with a double-walled crucible, with its lower end located immediately above the surface of the melt and in the space between the outer surface of the single crystal to be grown and the inner surface of the sidewall of the inner crucible; 2) a short passage comprising a hole passing through the sidewall of the inner crucible at a position higher than the level of the melt; and 3) a flow guide cylinder placed above and coaxially with the double-walled crucible, with its lower end located immediately above the surface of the melt and in the space between the outer surface of the sidewall of the inner crucible and the inner surface of the sidewall of the outer crucible, all arranged in a furnace.Type: GrantFiled: August 22, 1995Date of Patent: February 24, 1998Assignees: Mitsubishi Materials Corporation, Mitsubishi Materials Silicon CorporationInventors: Yoshiaki Arai, Keisei Abe, Norihisa Machida
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Patent number: 5707447Abstract: A crystal pulling apparatus for producing a crystal boule (17) from a material melted in a crucible (4) has, in a tank (1), a heater (5) surrounding the crucible (4). The tank (1) has in the area of the crucible (4) an annular chamber (8) defined on the heater (5) side by an inner protective wall (6) and connected to the shielding gas outlet (14, 15), and on the outside by an outer protective wall (7) behind which the thermal insulation (10) of the tank (1) is located.Type: GrantFiled: September 26, 1996Date of Patent: January 13, 1998Assignee: Balzers und Leybold Deutschland Holding AGInventors: Winfried Schulmann, Johann Scholler
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Patent number: 5683505Abstract: A process for producing single crystals with little OSF generation and excellent dielectric strength of gate oxide films by adjusting the temperature gradient of the silicon single crystal in the direction of pulling. The process is carried out with an apparatus including a crucible which contains the melt of the single crystal material, a heating element which heats the melt, a pulling shaft to grow the single crystal, a protective gas inlet pipe, and a chamber which contains all above mentioned components. In addition, the apparatus is provided with a circular cylinder or a conical shaped heat resistant and heat insulating component below the protective gas inlet pipe.Type: GrantFiled: February 27, 1996Date of Patent: November 4, 1997Assignee: Sumitomo Sitix CorporationInventors: Kaoru Kuramochi, Setsuo Okamoto
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Patent number: 5667588Abstract: Arranged is a covering plate which closes and opens an entrance of a valve container between a lower chamber and an upper chamber, the lower chamber containing a crucible and the upper chamber containing a wire to pull a single crystal. The covering plate is contained in a circle-shaped space portion within a wall by closing and opening means. The covering plate closes the entrance so that an isolation valve is protected. Since at the time of opening the entrance the covering plate is contained within the wall without contacting with the wall, the fall of dusts produced by peeling off of a film deposited on the wall can be prevented. Furthermore, the covering plate is contained in a circle-shaped space portion without exposing the front and back surfaces thereof to the air.Type: GrantFiled: June 5, 1996Date of Patent: September 16, 1997Assignee: Shin-Etsu Handotai Co., Ltd.Inventors: Eiichi Iino, Kiyataka Takano, Masanori Kimura, Koji Mizuishi, Hirotoshi Yamagishi
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Patent number: 5611857Abstract: A process and apparatus for producing silicon single crystals with excellent dielectric strength of gate oxide films by adjusting the temperature gradient of the pulled-up silicon single crystal without loss of its rate of pulling. The process of producing silicon single crystals by pulling up the single crystal from a melt of material of the single crystal imposes a certain average temperature gradient on the grown single crystal while it is still at high temperature. The apparatus is provided with a heating element outside a crucible and pulling shaft with which a single crystal is pulled up from the melt of the material in the crucible. The ratio of length h of the heating element to the inside diameter .phi. of the crucible is adjusted so as to be between 0.2 and 0.8 whereby the temperature gradient can be maintained below 2.5.degree. C./mm.Type: GrantFiled: June 7, 1995Date of Patent: March 18, 1997Assignee: Sumitomo Sitix CorporationInventors: Yoshihiro Akashi, Kaoru Kuramochi, Setsuo Okamoto, Yasuji Tsujimoto, Makoto Ito
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Patent number: 5587016Abstract: A source (1) is equipped with a conveying device (4) for discharging the particles (2, 2a) at adjustable rates per unit time. A crystal (16), formed from doped particles, is withdrawn from the melting crucible (13) at a predetermined rate per unit time. So that the control process can be conducted smoothly over prolonged periods of time with precise doping, the particles (2, 2a) are fed single file to the melting crucible (13) and counted by at least one sensor (21, 22). The sequence of count pulses is sent to a counter (25) and compared there with a corresponding sequence of reference input pulses. The comparison signal formed from the count pulses and the reference input pulses is used, in accordance with its sign, as a control signal for adjusting the amount of particles being discharged per unit time from source (1) to correspond to the reference value.Type: GrantFiled: November 13, 1995Date of Patent: December 24, 1996Assignee: Leybold AktiengesellschaftInventors: Burkhard Altekruger, Joachim Aufreiter, Dieter Bruss, Klaus Kalkowski
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Patent number: 5575847Abstract: This invention relates to the apparatus and the process for producing single crystals with little OSF generation and excellent dielectric strength of gate oxide films by adjusting the temperature gradient of the silicon single crystal in the direction of pulling. The apparatus is provided with a crucible which contains the melt of the single crystal material, a heating element which heats the melt, a pulling shaft to grow the single crystal, a protective gas inlet pipe, and a chamber which contains all above mentioned components. In addition, the apparatus is provided with a circular cylinder or a cylindrical shaped heat resistant and heat insulating component below the protective gas inlet pipe noted above.Type: GrantFiled: November 8, 1994Date of Patent: November 19, 1996Assignee: Sumitomo Sitix CorporationInventors: Kaoru Kuramochi, Setsuo Okamoto
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Patent number: 5571320Abstract: The invention defines an apparatus for controlling oxygen content in Czochralski silicon crystal pullers in which silicon is melted in a quartz crucible. The apparatus includes a susceptor 10, a quartz crucible 12 in said susceptor, a cable 16 for lowering a seed crystal 14 into silicon melted in said crucible, and a combination spiral heater/magnetic coil 25 for heating and melting silicon in said crucible, and for producing a magnetic field around the crucible.Type: GrantFiled: June 7, 1995Date of Patent: November 5, 1996Assignee: Texas Instruments IncorporatedInventors: H. Michael Grimes, Farouk A. Hariri
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Patent number: 5567399Abstract: Apparatus for producing a single crystal of semiconductor material in accance with the Czochralski method, has a cooling means which cools the growing single crystal and is constructed in two parts, The first is an upper part duct system through which a liquid coolant flows. The second is a lower part which is a heat-conducting cooling body.Type: GrantFiled: January 26, 1996Date of Patent: October 22, 1996Assignee: Wacker Siltronic Gesellschaft fur Halbleitermaterialien AGInventors: Wilfried Von Ammon, Erich Dornberger, Herber Weidner, Alfred Pardubitzki
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Patent number: 5551978Abstract: An apparatus for producing a single crystal comprising a heater which is arranged on the outer periphery of a crucible and movable along the axis of growth of a single crystal. The heater is moved along the direction of growth of the single crystal in accordance with the surface position of the molten liquid layer in the crucible. The apparatus for producing a single crystal further comprising means for adjusting the speed at which the seed crystal is pulled. For example, the pulling speed of the seed crystal is adjusted in accordance with the position of the heater.Type: GrantFiled: April 14, 1995Date of Patent: September 3, 1996Assignee: Sumitomo Sitix CorporationInventors: Yoshihiro Akashi, Kaoru Takiuchi, Setsuo Okamoto
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Patent number: 5476065Abstract: A monocrystal pulling apparatus according to the Czochralski technique, provided with a flow controller which guides a carrier gas supplied from the top of a pulling chamber to the surface of a melt of a material forming the monocrystal and exhausts the silicon oxide vaporizing from the surface of the melt to the outside of the pulling chamber and which surrounds the pulled monocrystal near the surface of the melt and is provided partially inside a crucible, wherein the flow controller has a tubular portion which has an outer diameter smaller than the inner diameter of the crucible and extends substantially perpendicularly along the direction of downward flow of the carrier gas, a constricted diameter portion which constricts in diameter from the bottom end of the tubular portion and forms a bottom gap with the pulled monocrystal, and an engagement portion which projects out from the top of the tubular portion and forms a top gap at the outer circumference of the tubular portion of the flow controller by suppType: GrantFiled: January 28, 1994Date of Patent: December 19, 1995Assignees: Mitsubishi Materials Silicon Corp., Mitsubishi Materials Corp.Inventors: Kazuhiro Ikezawa, Hiroshi Yasuda, Akira Tanikawa, Hiroyuki Kojima, Koji Hosoda, Yoshifumi Kobayashi
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Patent number: 5462011Abstract: A method and apparatus for pulling single crystals from a melt of semicontor material, in which a monocrystalline seed crystal grows to form a single crystal, the seed crystal being dipped into the melt and raised in a controlled manner in the vertical direction with respect to the melt, while the melt forms a molten pool which is held on a support body only by the surface tension and by electromagnetic forces due to an induction coil. This method includes recharging the melt with semiconductor material in solid or liquid form during the growth of the single crystal.Type: GrantFiled: May 25, 1994Date of Patent: October 31, 1995Assignee: Wacker-Chemitronic Gesellschaft fur Elektronik-Grundstoffe mbHInventors: Erich Tomzig, Reinhard Wolf, Wolfgang Hensel
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Patent number: 5450814Abstract: A plurality of shield blades 31 for defining an opening 25 surrounding a single crystal 15 are provided between a melt 14 received in a crucible 10 and a screen 30. The shield blades 21 are carried by operation rods 23 so as to make the gap between the inner edges of the shield blades 23 and the surface of the single crystal 15 constant. Since crystal growth continues under the same condition from the beginning to the end, an obtained single crystal 15 is free from defects such as dislocations and excellent in homogenieity.Type: GrantFiled: October 14, 1993Date of Patent: September 19, 1995Assignees: Research Development Corporation of Japan, Yutaka Shiraishi, Kazutaka TerashimaInventors: Yutaka Shiraishi, Kazutaka Terashima
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Patent number: 5437242Abstract: A process and an apparatus for carrying out the process provides for the accurate and simple control of the melt level when pulling single crystals according to the Czochralski process. The process comprises disposing a mechanical reference mark above the melt in such a way that it causes a reflection from the melt surface. An image of the metal surface is then recorded, and with the aid of the recorded image the distance of the mechanical reference mark from the melt surface is determined. An actual signal proportional to this distance is then generated and is compared with a set point signal, and the melt level is changed as a function of any difference observed.Type: GrantFiled: August 18, 1993Date of Patent: August 1, 1995Assignee: Wacker-Chemitronic Gessellschaft fuer Elektronik-Grundstoffe mbHInventors: Christian Hofstetter, Walter Berger, Werner Bauer, Bernd Mittelbach
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Patent number: 5419277Abstract: An apparatus for producing a semiconductor single-crystal grown by the Czochralski method includes a reference reflector disposed at the lower end of a gas rectifying tube, first and second optical systems disposed above the reference reflector for changing the direction of propagation of light from the horizontal to the vertical, and vice versa, a first position sensor composed of a first light source for emitting a light beam in a horizontal direction toward the first optical system, and a first photosensitive member which receives a reflection light reflected from the melt surface in a crucible, a second position sensor composed of a second light source for emitting a light beam in a horizontal direction toward the second optical system, and a second photosensitive member which receives a reflection light reflected from the reference reflector.Type: GrantFiled: February 4, 1994Date of Patent: May 30, 1995Assignee: Shin-Etsu Handotai Co. Ltd.Inventors: Masahiko Urano, Michiaki Oda
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Patent number: 5408952Abstract: In the present invention a signal is caused to fall on the molten liquid surface of single crystal raw material which was put into a crucible, the position of the molten liquid surface is measured by detecting the reflected signal coming from the molten liquid surface and the crucible is lifted according to the discrepancy to the set value.Type: GrantFiled: December 28, 1992Date of Patent: April 25, 1995Assignees: Mitsubishi Materials Corporation, Mitsubishi Materials Silicon CorporationInventors: Daisuke Wakabayashi, Toshio Anbe, Masao Saitoh
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Patent number: 5394829Abstract: A device for pulling a silicon single crystal is constructed so as to preclude deposition of a SiO-derived substance on graphite parts inside the device and prevent the graphite parts from deterioration, elongate the duration of continuous use of the device in a great measure, and simplify the disassembly and reassembly of the device.This device pulls a silicon single crystal in an atmosphere of inert gas by the Czochralski method, which device is chracterized by comprising a crucible 1 for accommodating a molten silicon mass 2, a heater 3 disposed round the periphery of the crucible 1, an outer member 14 forming a pulling chamber 6 for accomodating the crucible 1, an inert gas inlet part 15 disposed in the upper part of the pulling chamber 6, and an inert gas outlet part 16 separated from the inert gas inlet part 15 in the same upper part of the pulling chamber 6.Type: GrantFiled: March 23, 1993Date of Patent: March 7, 1995Assignee: Shin-Etsu Handotai Co., Ltd.Inventors: Toshiharu Uesugi, Koji Mizuishi, Atsushi Iwasaki, Tadashi Niwayama, Tetsuhiro Oda
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Patent number: 5363796Abstract: An apparatus for growing a single crystal having a crucible, two heaters arranged at the outside of the crucible and along the vertical direction, a heat shield placed at the outside of the heaters, a radiation shield for shielding the single crystal from the radiation heat, and an upper heat shield for preventing the upward heat, transfer of the heaters. In the apparatus, a melted layer and solid layer of raw material are formed in the upper and lower portions of the crucible, respectively. While melting the solid layer, the single crystal is pulled up. The lower portion of the heat shield is thinner than the upper portion. The ratio of the height to the diameter of the crucible is 0.85 or more. The melting amount of the solid layer is controlled in the pulling process according to the non-segregation condition in the variable-thickness melted layer method.Type: GrantFiled: February 18, 1992Date of Patent: November 15, 1994Assignee: Sumitomo Metal Industries, Ltd.Inventors: Sumio Kobayashi, Shunji Miyahara, Toshiyuki Fujiwara, Takayuki Kubo, Hideki Fujiwara, Shuichi Inami
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Patent number: 5361721Abstract: A single crystal pulling apparatus of Czochralski technique type including (i) a cylindrical partition adapted to divide the surface portion of the melt into an inner part and an outer part, the former being where the single crystal is grown and the latter being where granular polycrystal material is supplied, (ii) a flat ring having heat reflecting and insulating property held horizontally above the melt, and (iii) a vertically shiftable purge tube suspended centrally into the heating chamber adapted to enter into the inner hole of the flat ring.Type: GrantFiled: February 2, 1993Date of Patent: November 8, 1994Assignee: Shin-Etsu Handotai Co., Ltd.Inventors: Kiyotaka Takano, Izumi Fusegawa, Hirotoshi Yamagishi
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Patent number: 5360599Abstract: The present invention relates to a crucible support heater for the control of a melt flow pattern within a crucible, and more specifically to controlling a temperature gradient or distribution during crystal growth by the Czochralski method through the use of a heater located in the crucible lift rod.Type: GrantFiled: June 21, 1993Date of Patent: November 1, 1994Assignee: General Electric CompanyInventors: Michael K. Cueman, Farzin H. Azad
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Patent number: 5330729Abstract: A single crystal pulling apparatus of the Czochralski method type wherein the cylindrical heater is supported not only by the two existing electrodes which are vertically shiftable but also by one or more vertical shafts, which may be electrodes or electrically insulated dummy electrodes; the vertical shafts are capable of shifting vertically in synchronism with the existing two electrodes, and are arranged in a manner such that the existing two electrodes and the vertical shafts are at regular intervals along the bottom circumference of the cylindrical heater.Type: GrantFiled: February 10, 1992Date of Patent: July 19, 1994Assignee: Shin-Etsu Handotai Co., Ltd.Inventors: Michiaki Oda, Koji Mizuishi
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Patent number: 5316742Abstract: A single crystal pulling apparatus using Czochralski method includes a first screen in the shape of a hollow round cylinder. One side of the first screen facing a quartz crucible is made of a heat absorbent material and another side of the first screen is made of a heat insulator material. The upper and lower ends of the first screen have an outwardly extending flange and an inwardly extending flange, respectively. The first screen surrounds a single crystal pulling zone such that its lower flange is positioned near a melt charged zone in the crucible. The apparatus also includes a second screen positioned inside the first screen. The vertical section of the second screen has the shape of a substantially parabola and the center of the bottom of the second screen is open and surrounds the single crystal pulling zone. The upper end of the second screen has an outwardly extending flange.Type: GrantFiled: October 8, 1991Date of Patent: May 31, 1994Assignee: Komatsu Electronic Metals Co., Ltd.Inventors: Junsuke Tomioka, Kazunori Nagai, Akihiro Matsuzaki
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Patent number: 5312600Abstract: An apparatus for making a silicon single crystal large in diameter dependently on the Czochralski process, wherein appropriate openings (11) are provided on the warmth keeping over (10) so as to prevent an undesirable influence caused by atmospheric gas. The major elements of the apparatus are that the sum of areas of the openings (11) is larger than the area of gap (18) formed between the lower end of the warmth keeping cover (10) and the level of silicon solution, and that the warmth keeping cover and the heat insulating member (12) are composed of sheet metal.Type: GrantFiled: April 20, 1993Date of Patent: May 17, 1994Assignee: Toshiba Ceramics Co.Inventors: Hiroshi Kamio, Kenji Araki, Yoshinobu Shima, Makoto Suzuki, Takeshi Kaneto, Yasumitsu Nakahama, Takeshi Suzuki, Akio Fujibayashi