Including A Sectioned Crucible (e.g., Double Crucible, Baffle) Patents (Class 117/213)
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Patent number: 6740160Abstract: In a high rate pulling with a cooler 10 surrounding a single crystal 8, steam explosion by leakage from the cooler 10 is prevented. Flow rates La, Lb of cooling water are measured by flowmeters 14a, 14b on a cooling water inflow side and cooling water outflow side of the cooler 10. When flow rate difference &Dgr;L (La−Lb) determined from the flow rates La, Lb exceeds 20 cc/minute, open/close valves 15a, 15b, 15c are operated to stop water supply to the cooler 10 and drain outward the cooing water in the cooler 10.Type: GrantFiled: March 26, 2002Date of Patent: May 25, 2004Assignee: Sumitomo Mitsubishi Silicon CorporationInventors: Takayuki Kubo, Hiroshi Asano, Fumio Kawahigashi, Akira Tsujino
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Patent number: 6733585Abstract: In a Czochralski (CZ) single crystal puller equipped with a cooler and a thermal insulation member, which are to be disposed in a CZ furnace, smooth recharge and additional charge of material are made possible. Further, elimination of dislocations from a silicon seed crystal by use of the Dash's neck method can be performed smoothly. To these ends, there is provided a CZ single crystal puller, wherein a cooler and a thermal insulation member are immediately moved upward away from a melt surface during recharge or additional charge of material or during elimination of dislocations from a silicon seed crystal by use of the Dash's neck method.Type: GrantFiled: February 1, 2001Date of Patent: May 11, 2004Assignee: Komatsu Denshi Kinzoku Kabushiki KaishaInventors: Hiroshi Inagaki, Shigeki Kawashima, Makoto Kamogawa, Tadashi Hata
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Publication number: 20040069214Abstract: A silicon single crystal growing apparatus supplemented with a low melting point dopant feeding instrument and a low melting point dopant feeding method thereof for producing a heavily doped silicon single crystal with a dopant of low melting point. The apparatus includes a quartz crucible containing molten silicon liquid, a heating unit supplying the quartz crucible with a radiant heat, a crystal pulling lifter pulling up a silicon single crystal from a molten silicon liquid contained in the quartz crucible, and a low melting point dopant feeding instrument. The low melting point dopant feeding instrument includes a sidewall portion, an upper portion, and an open bottom portion with net-like structure having many holes, the sidewall and upper portions being vacuum-tight sealed and a low melting point dopant being loaded inside the low melting point dopant feeding instrument.Type: ApplicationFiled: December 13, 2002Publication date: April 15, 2004Inventors: Ill Soo Choi, Hyun Kyo Choi
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Patent number: 6689213Abstract: To impart flexibility suitable for recovery of a quartz crucible to a divided type graphite crucible and avoid damage to the quartz crucible due to the flexibility. A graphite crucible 10 is divided into two or more parts by radial dividing lines 14. An opening 11a is provided in a center of a bottom of the graphite crucible 10. A protrusion 21 fitting into the opening 11a is provided on a crucible placing surface of a crucible tray 20. An inner diameter d2 of the opening 11a is 0.04 to 0.9 times an inner diameter d1 of a straight body portion of the graphite crucible 10. An outer diameter D2 of the crucible tray 20 is 0.5 or more times an outer diameter D1 of the straight body portion of the graphite crucible 10. Minimum thickness of the crucible tray 20 is 15 mm or more.Type: GrantFiled: March 13, 2002Date of Patent: February 10, 2004Assignee: Sumitomo Mitsubishi Silicon CorporationInventors: Takayuki Kubo, Katsuhito Makiyama, Tatsuya Yabusame
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Patent number: 6676753Abstract: A silicon wafer is provided having controlled distribution of defects, in which denuded zones having a sufficient depth inward from the surface of the wafer are combined with a high gettering effect in a bulk region of the wafer. In the silicon wafer, oxygen precipitates, which act as intrinsic gettering sites, show vertical distribution. The oxygen precipitate concentration profile from the top to the bottom surfaces of the wafer includes first and second peaks at first and second predetermined depths from the top and bottom surfaces of the wafer, denuded zones between the top and bottom surfaces of the wafer and each of the first and second peaks, and a concave region between the first and second peaks, which corresponds to a bulk region of the wafer. For such an oxygen precipitate concentration profile, the wafer is exposed to a rapid thermal annealing process in a gas mixture atmosphere comprising ammonia (NH3) and argon (Ar) at temperatures below about 1200° C.Type: GrantFiled: September 4, 2002Date of Patent: January 13, 2004Assignee: Samsung Electronics Co., Ltd.Inventor: Jea-gun Park
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Publication number: 20030183163Abstract: In a high rate pulling with a cooler 10 surrounding a single crystal 8, steam explosion by leakage from the cooler 10 is prevented. Flow rates La, Lb of cooling water are measured by flowmeters 14a, 14b on a cooling water inflow side and cooling water outflow side of the cooler 10. When flow rate difference &Dgr;L (La−Lb) determined from the flow rates La, Lb exceeds 20 cc/minute, open/close valves 15a, 15b, 15c are operated to stop water supply to the cooler 10 and drain outward the cooing water in the cooler 10.Type: ApplicationFiled: March 26, 2002Publication date: October 2, 2003Inventors: Takayuki Kubo, Hiroshi Asano, Fumio Kawahigashi, Akira Tsujino
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Patent number: 6616756Abstract: Prior to housing the crucible in the bowl, a consumable buffer ply is applied over at least a portion of the inside face of the bowl, the ply being constituted essentially by a non-rigid carbon fiber fabric for protecting the bowl from both physical and chemical interactions with the crucible. The buffer ply is essentially constituted by a flexible fabric selected from: a woven cloth, a knit, a multidirectional sheet, and a thin felt. Prior to putting the ply into place in the bowl, it is possible to form a thin deposit of pyrolytic carbon on the fibers of the fabric.Type: GrantFiled: December 26, 2001Date of Patent: September 9, 2003Assignee: Snecma MoteursInventors: Jacques Thebault, Jean Michel Georges, Dominique Coupe
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Patent number: 6605152Abstract: The present invention provides a catch pan for melt leakage provided under a crucible at a bottom portion of a chamber in a single crystal pulling apparatus based on the CZ method, wherein the catch pan for melt leakage comprises at least a bottom portion and a barrel portion, and the bottom portion and the barrel portion are connected by screw-fitting or by using a tap bolt. There is provided a catch pan for melt leakage provided in a single crystal pulling apparatus, which can, even if a melt flows out of the crucible by a certain possible cause in a CZ method single crystal pulling apparatus, prevent the melt flowed out from reaching lower mechanisms including metal parts, piping and so forth, and thereby prevent bad influences on operators and peripheral equipments.Type: GrantFiled: October 31, 2001Date of Patent: August 12, 2003Assignee: Shin-Etsu Handotai Co., Ltd.Inventors: Koji Mizuishi, Tomohiko Ohta
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Patent number: 6579363Abstract: By using a semiconductor single crystal pulling apparatus for growing single crystals by the Czochralski method while rotating the melt by a magnetic field and electric current, namely by the EMCZ method, which comprises a main pulling means for pulling a single crystal, a holding mechanism for gripping an engaging stepped portion formed on the single crystal through engaging members and a sub pulling means for moving the holding mechanism up and down and in which an electric current is passed through the main pulling means and through the sub pulling means, it is possible to prevent heavy single crystals from undergoing a falling accident and, at the same time, effectively reduce the power consumption. In this pulling apparatus, it is effective to feed an electric current to the sub pulling means alone and it is desirable to dispose two or more electrodes whether the pulling means is of a shaft type or wire type.Type: GrantFiled: October 17, 2001Date of Patent: June 17, 2003Assignees: Sumitomo Metal Industries, Ltd., NEC CorporationInventors: Souroku Kawanishi, Masahito Watanabe, Minoru Eguchi
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Patent number: 6579362Abstract: A heat shield assembly for use in a crystal puller has an outer reflector interposed between the ingot and the crucible as the ingot is pulled from the molten source material. A cooling shield is interposed between the ingot and the outer reflector whereby the cooling shield is exposed to heat radiated from the ingot for increasing the rate at which the ingot is cooled, thereby increasing the axial temperature gradient of the ingot. In a further embodiment, an inner shield panel is disposed generally intermediate the cooling shield and the ingot in radially spaced relationship with the cooling shield and is constructed of a material substantially transparent to radiant heat from the ingot.Type: GrantFiled: March 23, 2001Date of Patent: June 17, 2003Assignee: MEMC Electronic Materials, Inc.Inventors: Lee W. Ferry, Richard G. Schrenker, Mohsen Banan
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Publication number: 20030084840Abstract: A crystal-pulling apparatus for pulling and growing a monocrystalline silicon ingot comprises a quartz crucible placed in a chamber and containing a silicon melt from which a monocrystalline silicon ingot will be pulled, a graphite crucible container to support the quartz crucible by surrounding the outer circumferential surface and external base surface of crucible, and a heater provided around the outer circumferential surface of the crucible container to heat the silicon melt. This apparatus further comprises a spacer having a top surface whose area is smaller than the base area of the quartz crucible and having a melting point higher than that of silicon, is inserted between the base of the quartz crucible and the base of the crucible container while the monocrystalline silicon ingot is pulled.Type: ApplicationFiled: November 20, 2001Publication date: May 8, 2003Inventors: Volker R. Todt, Rocky Oakley, Peter Wildes, Fritz Kirscht, Haresh Siriwardane, Joel Kearns
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Publication number: 20030070612Abstract: A susceptor for use in a Czochralski crystal growing apparatus is disclosed wherein erosion of the susceptor is minimized. The susceptor contains ventilation holes that allow process gases found between the susceptor and crucible to escape. The crucible may incorporate the use of a protective coating over part or all of the susceptor, such as a silicon carbide coating. The ventilation holes are placed at various heights along the susceptor wall to allow ventilation near the area of plastic deformation of the crucible.Type: ApplicationFiled: October 12, 2001Publication date: April 17, 2003Inventor: Kennard K. Addis
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Publication number: 20030024473Abstract: A crystal puller for growing monocrystalline silicon ingots includes first and second electrical resistance heaters in the crystal puller in longitudinal, closely spaced relationship with each other to radiate heat toward the ingot as the ingot is pulled upward within the housing. An adapter mounting the heaters may also be provided for adapting existing crystal pullers to incorporate the heaters.Type: ApplicationFiled: September 25, 2002Publication date: February 6, 2003Applicant: MEMC Electronic Materials, Inc.Inventors: Zheng Lu, Mohsen Banan, Ying Tao, Lee Ferry, Carl F. Cherko
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Publication number: 20020185061Abstract: A crucible 1 made of a C/C composite material for use in single crystal pulling, the crucible 1 having a lateral cylindrical portion 11 and a bottom portion 12 integrally formed as multiple layers wound by a filament winding method, in which the first layer 2 as the innermost crucible layer, among the multiple layers, is wound such that carbon fibers form tracks passing the polar point O at the bottom 12, the second layer 3 wound on the outer surface of the first layer 2 is wound along tracks to form a first outer circular bottom 8 that extends outwardly from about a middle part of a raised portion 6 where the carbon fibers of the first layer 2 are localized to the polar point O, and the third layer 4 and the succeeding layers wound on the outer surface of the second layer 3 are wound respectively along tracks to form outer circular bottoms that extend stepwise outwardly from about the middle parts of the outer surfaces of layers situated inside the respective layers, and the top for the raised portion of theType: ApplicationFiled: May 2, 2002Publication date: December 12, 2002Applicant: Toyo Tanso Co., Ltd.Inventors: Masatoshi Yamaji, Hisanori Nishi, Yuji Tomita, Shingo Bito, Toshiyuki Miyatani
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Publication number: 20020157602Abstract: The present invention provides a catch pan for melt leakage provided under a crucible at a bottom portion of a chamber in a single crystal pulling apparatus based on the CZ method, wherein the catch pan for melt leakage comprises at least a bottom portion and a barrel portion, and the bottom portion and the barrel portion are connected by screw-fitting or by using a tap bolt. There is provided a catch pan for melt leakage provided in a single crystal pulling apparatus, which can, even if a melt flows out of the crucible by a certain possible cause in a CZ method single crystal pulling apparatus, prevent the melt flowed out from reaching lower mechanisms including metal parts, piping and so forth, and thereby prevent bad influences on operators and peripheral equipments.Type: ApplicationFiled: October 31, 2001Publication date: October 31, 2002Applicant: SHIN-ETSU HANDOTAI CO.Inventors: Koji Mizuishi, TOMOHIKO OHTA
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Publication number: 20020139298Abstract: An apparatus is provided which is to be used in producing single crystals for silicon wafers useful as semiconductor materials and which can stably produce large-diameter, long-length and high-quality single crystals from which wafers limited in the number of grown-in defects can be taken. This silicon single crystal production apparatus comprises a cooling member surrounding the single crystal to be pulled up and having an internal surface coaxial with the pulling axis and thermal insulating members disposed outside the outer surface and below the bottom surface of the cooling member, the cooling member having an internal surface diameter of 1.20D to 2.50D (D being the diameter of the single crystal to be pulled up) and a length of not less than 0.25D, the distance from the melt surface to the bottom surface of the cooling member being 0.30D to 0.Type: ApplicationFiled: November 20, 2001Publication date: October 3, 2002Inventors: Masahiko Okui, Manabu Nishimoto, Takayuki Kubo, Fumio Kawahigashi, Hiroshi Asano
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Publication number: 20020134302Abstract: A heat shield assembly for use in a crystal puller has an outer reflector interposed between the ingot and the crucible as the ingot is pulled from the molten source material. A cooling shield is interposed between the ingot and the outer reflector whereby the cooling shield is exposed to heat radiated from the ingot for increasing the rate at which the ingot is cooled, thereby increasing the axial temperature gradient of the ingot. In a further embodiment, an inner shield panel is disposed generally intermediate the cooling shield and the ingot in radially spaced relationship with the cooling shield and is constructed of a material substantially transparent to radiant heat from the ingot.Type: ApplicationFiled: March 23, 2001Publication date: September 26, 2002Inventors: Lee W. Ferry, Richard G. Schrenker, Mohsen Banan
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Publication number: 20020124795Abstract: The invention relates to a method and to a device for supporting a crystal ingot while pulling a single crystal, in particular such a crystal composed of silicon, according to the Czochralski method. To this end, a crystal support is provided which engages with a specialized bead, which is formed on the neck of the single crystal ingot and which has the shape of a bicone, by means of bearings in a housing. A support of the crystal ingot is thus achieved which may be disengaged at any time, and which has no disruptive effects on crystal growth and which acts independently of the length of the grown crystal. The bearings are moved into the support position on the bicone by a central pulling element which can be independently displaced relative to a second pulling element.Type: ApplicationFiled: March 11, 2002Publication date: September 12, 2002Inventors: Winfried Schulmann, Helmut Kaiser
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Patent number: 6447602Abstract: Crystal growth apparatus comprising a crucible for containing a supply of molten material from which the crystal may be grown and first reflection means for receiving radiation directed along an input path and reflecting radiation towards second reflection means, whereby the second reflection means reflect output radiation along an output path. The first and second reflection means are arranged at or in close proximity with the surface of the molten material such that during crystal growth they maintain a substantially constant position relative to the surface of the molten material. The apparatus may comprise support means for supporting the first and second reflection means, whereby the support means are arranged to float on the molten material. The apparatus may be a single crucible apparatus or a double crucible apparatus.Type: GrantFiled: November 6, 2000Date of Patent: September 10, 2002Assignee: Qinetiq LimitedInventor: John A Beswick
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Publication number: 20020020339Abstract: A process for controlling the amount of insoluble gas trapped by a silicon melt is disclosed. After a crucible is charged with polycrystalline silicon, a gas comprising at least about 10% of a gas having a high solubility in silicon is used as the purging gas for a period of time during melting. After the polycrystalline silicon charge has completely melted, the purge gas may be switched to a conventional argon purge. Utilizing a purge gas highly soluble in silicon for a period of time during the melting process reduces the amount of insoluble gases trapped in the charge and, hence, the amount of insoluble gases grown into the crystal that form defects on sliced wafers.Type: ApplicationFiled: August 30, 2001Publication date: February 21, 2002Inventor: John D. Holder
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Patent number: 6261364Abstract: 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: September 1, 1998Date of Patent: July 17, 2001Assignees: Mitsubishi Materials Corporation, Mitsubishi Materials Silicon CorporationInventors: Yoshiaki Arai, Keisei Abe, Norihisa Machida
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Patent number: 6251184Abstract: Heat shields for Czochralski pullers include a ring-shaped heat shield housing comprising inner and outer heat shield housing walls and an oblique heat shield housing floor and a heat shield housing roof that extend between the inner and outer heat shield housing walls. The heat shield housing contains insulating material therein. A support member is configured to support the heat shield housing within the crucible in a Czochralski puller. In one embodiment, the support member includes at least one support arm that extends to the ring-shaped heat shield housing. The at least one support arm may be hollow and may contain insulating material therein. In another embodiment, the support member is a ring-shaped support member. The ring-shaped support member may include inner and outer support member walls containing insulating material therebetween. The ring-shaped support member may also include at least one window therein. The ring-shaped member may be oblique.Type: GrantFiled: May 26, 1999Date of Patent: June 26, 2001Assignee: Samsung Electronics Co., Ltd.Inventor: Jae-gun Park
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Patent number: 6231669Abstract: A crystal pulling unit for the production of a crystal block has a recharging tube (7), via which granulate (17) is introduced into a crucible (2) with a melt (3), located inside a container (1). A fine-dust separator (8) is located in the recharging tube (7) outside the container (1); the separator works like an air classifier and, by means of a protective gas cushion, removes fine dusts from the granulate (17). This counters the danger of clogging of the recharging tube (7) by the caking of the recharging material.Type: GrantFiled: March 22, 1999Date of Patent: May 15, 2001Assignee: Leybold Systems GmbHInventors: Burkhard Altekrüger, Joachim Aufreiter
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Patent number: 5993902Abstract: An apparatus and a method for preventing buildup of silicon oxides and silicon carbides on the inner surface of exhaust sleeves utilized in Czochralski (Cz) silicon crystal pullers are provided. The apparatus and the method include the provision of a vapor impervious layer coated on the inner surface of an exhaust sleeve, and forming a barrier to silicon oxides and silicon carbides deposition on the inner surface, to prevent the buildup of silicon oxides and silicon carbides on the surface of exhaust sleeves, thereby allowing more uniform laminar flow of process gases in the Cz chamber and the exhaust sleeve, and extending the useful lifetime of exhaust sleeves.Type: GrantFiled: April 9, 1997Date of Patent: November 30, 1999Assignee: SEH America, Inc.Inventor: Gary Randolph Heid
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Patent number: 5976247Abstract: A crucible in which a semiconductor material is melted and held during a crystal growing process. The crucible includes a body of vitreous silica having a bottom wall and a sidewall formation extending up from the bottom wall and defining a cavity for holding the molten semiconductor material. The sidewall formation has an inner and an outer surface. A first devitrification promoter on the inner surface of the sidewall formation is distributed such that a first layer of substantially devitrified silica is formed on the inner surface of the crucible which is in contact with the molten semiconductor material when the semiconductor material is melted in the crucible during the crystal growing process. A second devitrification promoter on the outer surface of the sidewall formation is distributed such that a second layer of substantially devitrified silica is formed on the outer surface of the crucible when the semiconductor material is melted in the crucible during the crystal growing process.Type: GrantFiled: June 14, 1995Date of Patent: November 2, 1999Assignee: MEMC Electronic Materials, Inc.Inventors: Richard L. Hansen, Larry E. Drafall, Robert M. McCutchan, John D. Holder, Leon A. Allen, Robert D. Shelley
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Patent number: 5932007Abstract: A puller apparatus for a Czochralski crystal puller system is provided which includes a primary puller chuck and a secondary puller chuck. The primary puller chuck is attached to a seed crystal. The secondary puller chuck is shaped to enclose and retain a portion of a growing crystal so that the growing crystal can be pulled by the secondary puller chuck.Type: GrantFiled: June 3, 1997Date of Patent: August 3, 1999Assignee: General Signal Technology CorporationInventor: Zhixin Li
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Patent number: 5932008Abstract: In this invention, three equally spaced and "L" shaped hooks 6B are rotatably supported on the upper peripheral wall of the body 6A of the seed holder 6 at pivots 6E. A radiation screen 7 is hung at the front ends of the hooks 6B via three engaging fixtures 6C affixed on its upper rim. The radiation screen 7 shaped like a hollow trancated cone, is used to surround the lower end of the single-crystal being lifted from the quartz crucible 3 which is disposed within the main chamber 1. According to the apparatus for manufacturing a single-crystal which can perform the descending or ascending movements of the radiation screen, the setting operation, and the lifting operation consecutively and automatically. Therefor the apparatus can enhance the productivity and avoid any problems with process automation, furthermore, it is compatible with conventional equipment.Type: GrantFiled: June 13, 1997Date of Patent: August 3, 1999Assignee: Komatsu Electronic Metals Co., Ltd.Inventors: Yoshinobu Hiraishi, Koichi Shimomura
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Patent number: 5925147Abstract: A process 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. The process of producing single crystals in accordance with this invention is characterized by confluence of the inert gas flows (33 and 32) once divided into outside and inside a heat resistant and heat insulative component (7).Type: GrantFiled: December 19, 1996Date of Patent: July 20, 1999Assignee: Sumitomo Sitix CorporationInventor: Makoto Ito
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Patent number: 5919306Abstract: A silicon melting crucible having a double structure, in which a quartz crucible is inserted inside of a carbon crucible, is provided with devices for preventing deformation, such as turning-down, buckling and bending at an upper portion of the quartz crucible, or invasion of an SiO gas into a space between the quartz crucible and the carbon crucible during pulling up of a silicon single crystal. According to one form of the invention an upper portion of the quartz crucible has a frusto-conical inclined portion with an angle of inclination desirably of from 5.degree. to 40.degree.. According to another form of the invention a carbon ring having a cross section of either L-shape or U-shape is applied to the upper portion of the quartz crucible and the carbon crucible.Type: GrantFiled: November 3, 1997Date of Patent: July 6, 1999Assignee: Sumitomo Sitix CorporationInventor: Kaoru Takemura
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Patent number: 5917103Abstract: Quartz powder is fed into a rotating mold to form a crucible-like quartz powder layer body with the help of centrifugal force in the mold. The layer is melted by heating through the inner surface with an arc discharge to manufacture an outer crucible member. A hollow cylindrical inner crucible member having a beveled lower edge is welded to the outer crucible member while a temperature of the inner surface portion of the outer crucible member remains at 1400.degree. C. or higher by a remaining heat.Type: GrantFiled: May 24, 1996Date of Patent: June 29, 1999Assignees: Heraeus Quarzglas GmbH, Shin-Etsu Quartz Products Co., Ltd.Inventors: Hiroyuki Watanabe, Tatsuhiro Sato, Hiroshi Matsui
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Patent number: 5913975Abstract: A quartz crucible for use in the preparation of silicon crystals substantially free from crystal void defects and a process for its preparation are disclosed. The crucible is prepared by introducing quartz powder into a rotating mould in an atmosphere containing less than about 0.5% insoluble gases such as argon. The quartz powder accumulates along the inner surface of the mould, and is subsequently heated to fuse the quartz powder to produce the crucible. The gases contained in the bubbles in the resulting crucible are comprised of less than about 0.5% insoluble gases.Type: GrantFiled: February 3, 1998Date of Patent: June 22, 1999Assignee: MEMC Electronic Materials, Inc.Inventor: John Davis Holder
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Patent number: 5902394Abstract: A method is provided for stabilizing Czochralski (CZ) silicon melt by controlled oscillation of the crucible rotation during the stabilization period of the silicon melt to reduce the gas bubbles and unmelted polysilicon particles contained therein and thereby increase the yield and productivity of CZ silicon crystal production. The crucible rotation is controlled to follow an Oscillating Crucible Rotation (OCR) pattern or a saw tooth rotation pattern, which include rapid oscillations between a high rate of rotation and a low rate of rotation of the crucible during a period prior to the growth of the CZ crystal ingot.Type: GrantFiled: March 31, 1997Date of Patent: May 11, 1999Assignee: SEH America, Inc.Inventors: Charles Curtis Burkhart, Bruce Laurence Colburn
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Patent number: 5900055Abstract: A silicon monocrystal is manufactured according to the continuously charged Czochralski method in which a double crucible is used which includes an outer crucible and an inner crucible which communicate with each other through pores. A dopant is charged to the silicon melt stored in the double crucible before commencing pulling of a silicon monocrystal such that the ratio of the dopant concentration of the silicon melt stored in the outer crucible to the dopant concentration of the silicon melt stored in the inner crucible becomes greater than an effective segregation coefficient of the dopant. The silicon monocrystal is then pulled while silicon material is charged to the silicon melt within the outer crucible, during which the dopant concentration ratio becomes equal to the effective segregation coefficient and then becomes smaller than the effective segregation coefficient.Type: GrantFiled: March 25, 1997Date of Patent: May 4, 1999Assignee: Shin-Etsu Handotai Co., Ltd.Inventors: Naoki Nagai, Koji Mizuishi, Michiaki Oda
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Patent number: 5897706Abstract: An improvement in the safety, ease and speed with which the operation of attaching a crucible 1 to a support base 10 of a single crystal pulling apparatus can be completed is provided. With the method of attaching the crucible 1 to the support base 10, the support base 10 is divided into a support base bottom portion 11 and a support base drum portion 12 which is fitted to the bottom portion 11, and the crucible 1 is mounted on the support base bottom portion 11. The support base 10 is then assembled by fitting the support base drum portion 12 to the support base bottom portion 11.Type: GrantFiled: April 15, 1997Date of Patent: April 27, 1999Assignees: Mitsubishi Materials Silicon Corporation, Mitsubishi Materials CorporationInventors: Masakazu Yamazaki, Michio Yanaba, Hiroaki Taguchi, Takashi Atami, Hisashi Furuya
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Patent number: 5891245Abstract: A single crystal pulling method employing; a gas tight container, a double crucible for storing a semiconductor melt inside the gas tight container comprising an inter-connected outer crucible and inner crucible, and a source material supply tube suspended from an upper portion of the gas tight container and positioned so that a granulated or powdered source material can be added from a lower end opening thereof to the semiconductor melt inside the outer crucible, with the source material being injected into the source material supply tube together with an inert gas flowing towards the enclosed container, characterized in that said source material is injected under conditions where the flow rate N (1/min.multidot.cm.sup.2) of the inert gas is within the range 0.0048P+0.0264<N<0.07P, where P (Torr) is the internal pressure inside said gas tight container.Type: GrantFiled: January 10, 1997Date of Patent: April 6, 1999Assignees: Mitsubishi Materials Sillcon Corporation, Mitsubishi Materials CorporationInventors: Takashi Atami, Hiroaki Taguchi, Hisashi Furuya, Michio Kida
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Patent number: 5879449Abstract: Homogeneous crystals are grown from a multicomponent melt double crucible assembly with an injector which affords improved flow of melt from the outer to the inner crucible. Guide rods are provided external to the outer crucible and locate the inner crucible with reduced probability of sticking. Means are also provided for withdrawing the inner crucible after crystal growth is complete as is a method of removing trapped gas from the apparatus prior to crystal growth.Type: GrantFiled: December 20, 1996Date of Patent: March 9, 1999Assignee: The Secretary of State for Defence in Her Britannic Majesty's Government of the United Kingdom of Great Britain and Northern IrelandInventor: John Alfred Beswick
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Patent number: 5873938Abstract: A single crystal pulling apparatus wherein a semiconductor melt is stored in an outer crucible, and a cylindrical inner crucible which acts as a partition body, is mounted inside the outer crucible to thus form a double crucible, and a single crystal of semiconductor is pulled from the semiconductor melt inside the inner crucible. The inner crucible contains a communicating portion, which is formed when the double crucible is formed, for allowing flow of the semiconductor melt into the inner crucible, and the communicating portion incorporates an arrangement for removal of gas bubbles which have adhered to the communicating portion.Type: GrantFiled: December 26, 1996Date of Patent: February 23, 1999Assignees: Mitsubishi Materials Silicon Corporation, Mitsubishi Materials CorporationInventors: Takashi Atami, Hisashi Furuya, Michio Kida
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Patent number: 5871582Abstract: This invention provides a melt receiver for a semiconductor single-crystal manufacturing device, which is capable of protecting the main chamber from being damaged by the outflow of the melt or dropping of the debris of the broken crucibles and therefore preventing steam explosion. The melt receiver 1 is consisted of an adiabatic member 3 made of carbon fibers; a cover 2 made of high strength C/C material which shelters the surface of the adiabatic member 3; and a bottom plate 4. A groove 2a is formed on the upper surface of the cover 2. The groove 2a has a size capable of accommodating all of the melt stored in the quartz crucible 7. The melt flown out or articles dropped down due to damage of the crucible are received by the melt receiver 1, and the melt flown out can not reach the bottom of the main chamber 9. The melt receiver can also be consisted of a melt absorption layer made of adiabatic material, and a melt isolation layer made of graphite or high strength C/C material.Type: GrantFiled: October 23, 1997Date of Patent: February 16, 1999Assignee: Komatsu Electronic Metals Co., Ltd.Inventor: Shigeki Kawashima
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Patent number: 5871581Abstract: A single crystal pulling apparatus comprising: a gas tight container, a double crucible for storing a semiconductor melt inside the gas tight container comprising an outer crucible and an inner crucible which are connected at a lower edge, and source material supply means for adding source material to the semiconductor melt at a position between the outer crucible and the inner crucible, characterized in that a flow restriction member is provided inside the semiconductor melt region between the outer crucible and the inner crucible for restricting the flow of the semiconductor melt.Type: GrantFiled: January 10, 1997Date of Patent: February 16, 1999Assignees: Mitsubishi Materials Silicon Corporation, Mitsubishi Materials CorporationInventors: Takashi Atami, Hiroaki Taguchi, Hisashi Furuya, Michio Kida
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Patent number: 5858087Abstract: The principal construction of a single crystal pulling apparatus involves a chamber (gas tight chamber) inside of which is a double crucible 3 for storing a semiconductor melt 21, comprising an outer crucible 11 and an inner crucible 12 communicated with each other, and a source material supply tube 5 suspended from an upper portion of the chamber, and positioned so that granular source material 8 can be introduced from a lower end opening 5a thereof into the semiconductor melt 21 between the outer crucible 11 and the inner crucible 12. An incline portion 13 is provided at a lower end of the source material supply tube 5 on the inner crucible 12 side, for introducing source material 8 discharging from the lower end opening 5a to the semiconductor melt 21 in the vicinity of the side wall of the outer crucible 11.Type: GrantFiled: December 26, 1996Date of Patent: January 12, 1999Assignees: Mitsubishi Materials Silicon Corp., Mitsubishi Materials Corp.Inventors: Hiroaki Taguchi, Takashi Atami, Hisashi Furuya, Michio Kida
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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: 5820649Abstract: A liquid material such as molten silicon is stored in a crucible. A liquid material, which is identical to and held in the same conditions as the liquid material in the crucible, is continuously supplied from an auxiliary crucible to the crucible to keep constant the surface level of the liquid material in the crucible. The liquid material is continuously pulled up from the crucible at a predetermined speed while the liquid material is being solidified into a solid material such as a ribbon-like thin web of single-crystal silicon.Type: GrantFiled: April 14, 1997Date of Patent: October 13, 1998Assignee: Ebara CorporationInventors: Naoaki Ogure, Kazuyoshi Terashima
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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: 5720809Abstract: A double-wall crucible is disclosed which is constructed by coaxially disposing a cylindrical partition wall in an outer crucible for holding a molten mass of silicon as a raw material and operated by heating the outer crucible and meanwhile supplying the raw material silicon to the gap between the outer crucible and the cylindrical partition wall and introducing the consequently produced molten mass of silicon to the interior of the cylindrical partition wall through a passage below the level of the molten mass of silicon interconnecting the outer crucible and the inner side of the cylindrical partition wall and meanwhile pulling a single crystal bar from the molten mass of silicon in the cylindrical partition wall. In this double-wall crucible, at least the cylindrical partition wall is formed of quartz glass having a hydroxyl group (OH group) content of not more than 30 ppm.Type: GrantFiled: August 2, 1995Date of Patent: February 24, 1998Assignee: Shin-Etsu Handotai Co., Ltd.Inventors: Eiichi Iino, Kiyotaka Takano, Izumi Fusegawa, Hirotoshi Yamagishi
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Patent number: 5580171Abstract: There is disclosed a static mixer for intimate mixing of granular solids, a solids flow controller and a solids transfer tube which are useful to mix polycrystalline material with dopant solids, and to feed the resultant mixture continuously and accurately into a modified Czochralski-type furnace for growing single crystal material. The static mixer is a series of conical funnel plates interspaced by thieving divider plates that are formed by a plurality of triangular V-shaped, radial sectors. Contiguous to the static mixer is a storage hopper which has sufficient storage capacity for all the polycrystalline feed material required in a single run of the furnace. Located beneath the hopper is a solids flow controller that is a V-shaped trough which is vibrated along its longitudinal axis. At one end, the trough has a transverse baffle located with a gap between its bottom edge and the bottom of the trough that controls the rate of flow of the solids.Type: GrantFiled: July 24, 1995Date of Patent: December 3, 1996Inventors: John C. Lim, William A. Koch, Mohan Chandra
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Patent number: 5524571Abstract: Herein disclosed are apparatuses for manufacturing compound semiconductor polycrystals comprising a pressure vessel, an upper shaft, a container for a first component fixed to the upper shaft, a heater around the container, a lower shaft, a susceptor and a crucible for charging a second component, a heater for the crucible and a communicating pipe for spatially connecting the container and the crucible optionally provided with a porous member at the lower extremity and/or a cylindrical member for confining a space over a part of the melt surface contained in the crucible from the remaining inner space of the vessel, the apparatuses permitting the substantial reduction of the reaction time and an improvement of the yield of the polycrystals due to the presence of the porous member and/or the cylindrical member separating the inner space of the vessel into two portions.Type: GrantFiled: February 9, 1990Date of Patent: June 11, 1996Assignee: Sumitomo Electric Industries, Ltd.Inventors: Akihisa Kawasaki, Toshihiro Kotani
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Patent number: 5515810Abstract: To manufacture a low-carbon concentration GaAs wafer required for devices such as hall sensors, FETs, HEMTs etc. at a high production yield without deteriorating the semi-insulation characteristics thereof, a method of manufacturing a semi-insulation GaAs monocrystal by controlling carbon concentration during crystal growth by a simple method is disclosed. The method of manufacturing a semi-insulation GaAs monocrystal in accordance with liquid encapsulated Czochralski method, comprises the steps of: preparing a crucible (5) formed with a crucible body (6) and a small chamber (8) communicating with a lower part of the crucible body and a carbon heater (4) processed to reduce surface blow holes thereof; putting a melted GaAs liquid and a sealing compound B.sub.2 O.sub.3 in the crucible housed in an airtight vessel in such a way that the sealing compound B.sub.2 O.sub.Type: GrantFiled: March 22, 1995Date of Patent: May 14, 1996Assignee: Kabushiki Kaisha ToshibaInventor: Youji Yamashita
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Patent number: 5487354Abstract: A method for pulling a silicon single crystal has the single crystal being pulled at a speed defined as maximum pulling speed in the vertical direction with respect to a silicon melt held in a crucible. The value of the maximum pulling speed is approximately proportional to the axial temperature gradient in the growing single crystal.Type: GrantFiled: December 5, 1994Date of Patent: January 30, 1996Assignee: Wacker-Chemitronic Gesellschaft fuer Eletronik-Grundstoffe mbHInventors: Wilfried von Ammon, Erich Dornberger, Hans Oelkrug, Peter Gerlach, Franz Segieth
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Patent number: 5474022Abstract: There is provided a double crucible for growing a silicon single crystal in which the partition wall 17 in the shape of ring is concentric with the main crucible 6 in the shape of bottomed cylinder and the lower end of the partition wall 17 is fixed on the inner bottom of the main crucible, and thus the outer crucible 18 and the inner crucible 19 are formed inside the main crucible. The partition wall 17 is uniform in thickness and has introducing holes 20 in its lower part which link the outer crucible with the inner crucible. The partition wall is made so that the inner diameter of its lower part may be smaller than the inner diameter of its upper part. Supposing that A is the diameter of the partition wall at a level of molten silicon, h is a depth from the surface of the molten silicon to the introducing holes, V(out) is an amount of molten silicon stored in the outer crucible, and V(in) is an amount of molten stored in the inner crucible, the relation of D/A=1.5 to 3, 2h/A>1, and V(out)/V(in)=0.Type: GrantFiled: April 11, 1995Date of Patent: December 12, 1995Assignees: Mitsubishi Materials Corporation, Mitsubishi Materials Silicon CorporationInventors: Keisei Abe, Hisashi Furuya, Norihisa Machida, Yoshiaki Arai