Seed Pulling Patents (Class 117/208)
  • Patent number: 6051064
    Abstract: An apparatus for weighing single crystals during Czochralski crystal growing processes includes a pivotal elongated member such as a beam, a contact element and a load sensor. The load sensor can be mounted to at least one of the elongated member and a support surface of a crystal growing vessel. The beam is attached to a lift for pulling single crystals from a melt. During crystal growing, the weight of the grown crystal causes increased loading along the elongated member such that the contact element exerts an increasing force on the load sensor. The contact element and load sensor have respective contact surfaces which are shaped such that the force exerted on the load sensor corresponds substantially to the weight of grown single crystal. Typically, at least one of the contact surfaces is a rolling surface.
    Type: Grant
    Filed: August 20, 1998
    Date of Patent: April 18, 2000
    Assignee: SEH America, Inc.
    Inventor: Aaron L. Labrie
  • Patent number: 6039801
    Abstract: A continuous oxidation process and apparatus for using the same are disclosed. During growth of a semiconductor crystal an oxygen-containing gas is continuously injected into the crystal pulling apparatus in an exhaust tunnel downstream from the hot zone to continuously oxidize hypostoichiometric silicon dioxide, silicon vapor, and silicon monoxide produced in the hot zone during the crystal growth so as to minimize or eliminate the possibility of rapid over-pressurization of the apparatus upon exposure to the atmosphere.
    Type: Grant
    Filed: October 7, 1998
    Date of Patent: March 21, 2000
    Assignee: MEMC Electronic Materials, Inc.
    Inventors: John D. Holder, Bayard K. Johnson
  • Patent number: 6036775
    Abstract: A process is disclosed for continuously producing a single crystal by drawing downwardly a melt of a single crystal raw material, wherein a single crystal body grown from the melt is continuously pulled downwardly, and a plurality of single crystal products are continuously formed by intermittently cutting the single crystal body being downwardly moved.
    Type: Grant
    Filed: July 21, 1999
    Date of Patent: March 14, 2000
    Assignee: NGK Insulators, Ltd.
    Inventors: Minoru Imaeda, Akihiko Honda, Katsuhiro Imai, Yuichiro Imanishi, Nobuyuki Kokune, Shoji Sogo, Kazuaki Yamaguchi, Tetsuo Taniuchi
  • Patent number: 6033472
    Abstract: The object of the present invention is to achieve reliable and safe pulling operation of a single crystal having large diameter and heavy weight in a chamber with reduced pressure. The semiconductor manufacturing apparatus of the invention comprises a seed crystal lift mechanism for holding a seed crystal and for moving it up and down, and a single crystal gripping mechanism for gripping a constricted portion of a single crystal formed, whereby the apparatus comprises an accommodation container 10a for accommodating at least a driving unit 14 of the seed crystal lift mechanism and at least a driving unit 15 of the single crystal gripping mechanism, and further accommodation container lift mechanisms 3 and 4 for moving the accommodation container up and down. The accommodation container may be designed in heat-insulating structure, or a cooling means for cooling inside the accommodation container may be further provided.
    Type: Grant
    Filed: March 10, 1998
    Date of Patent: March 7, 2000
    Assignee: Super Silicon Crystal Research Institute Corp.
    Inventor: Yutaka Shiraishi
  • Patent number: 6019841
    Abstract: The invention is an improved method and apparatus for growing crystals that incorporates an isolation valve between the growth and injection chambers to allow the growth chamber to be maintained at operating temperature and pressure while decoupling the injector chamber in order to make changes necessary to restart or advance the process. Separate heating elements in the injector assembly or chamber provide related heating control. Upper and lower load cells and programmable signal amplifiers are configured to weigh and output the dynamic weight range of the loss or gain of process materials of the growth chamber crucible and the injector assembly, and are connected by electrical slip rings or wireless means to a computer control system.
    Type: Grant
    Filed: March 24, 1998
    Date of Patent: February 1, 2000
    Assignee: G.T. Equuipment Technologies Inc.
    Inventors: Ijaz H. Jafri, Mohan Chandra, Rick C. White, Kedar P. Gupta, Robert B. Farmer, Bernard D. Jones, David F. Bliss
  • Patent number: 6004393
    Abstract: A temperature sensor 42 is provided in a furnace 11, measuring temperature above a molten liquid 24 put in a crucible 12 to check proceedings of evaporation of oxygen vaporized from a free surface 44 of the molten liquid 24. From the data, and considering the relation with the oxygen dissolved into the crucible 12, the oxygen concentration in the molten liquid 24 can be found and the amount of oxygen taken into a single silicon crystal 40 pulled up from the molten liquid 24 can be figured out.
    Type: Grant
    Filed: January 22, 1999
    Date of Patent: December 21, 1999
    Assignees: Komatsu Electronic Metals Co., Ltd., Mitsubishi Materials Silicon Corporation, Kagaku Gijutsu Sinkou Jigyo Dan, Toshiba Ceramics Co., Ltd.
    Inventors: Susumu Maeda, Keisei Abe, Kazutaka Terashima, Hideo Nakanishi
  • Patent number: 6001170
    Abstract: A process for the growth of a single crystal from semiconductor material by the Czochralski method, in which the melt is subjected to the influence of a magnetic field during the crystal growth and the magnetic field is generated by superposing a static magnetic field and an alternating magnetic field. An apparatus for carrying out the process, has a magnetic means which comprises two coils which are arranged around a crucible, one coil generating a static magnetic field and the other coil generating an alternating magnetic field.
    Type: Grant
    Filed: August 9, 1996
    Date of Patent: December 14, 1999
    Assignee: Wacker Siltronik Gesellschaft fur Halbleitermaterialien AG
    Inventors: Erich Tomzig, Werner Zulehner, Wilfried Von Ammon, Yu M Gelfgat, Leonid Gorbunov
  • Patent number: 5997636
    Abstract: For growing crystals, either in ground testing or in space, a capillary tube is used, which contains the solution of the substance to be crystallized, a layer of absorbent and a layer of air or other gas separating the solution from the absorbent. Two absorbent layers may be used on opposite sides of the solution, each separated from the solution by a gaseous layer. To delay the onset of crystallization, the absorbent on each side may be separated from the solution by two gaseous layers, with a charge of absorbable liquid between them. An absorbent may be removed or modified by removing or perforating an end cap used to seal the absorbent within the capillary tube.
    Type: Grant
    Filed: May 1, 1998
    Date of Patent: December 7, 1999
    Assignee: Instrumentation Technology Associates, Inc.
    Inventors: Moisey Y. Gamarnik, Ulises R. Alvarado
  • Patent number: 5993545
    Abstract: A sintered rhenium crucible, highly suitable for growing single crystals from refractory metal oxides, for example by the Czochralski technique, is formed of fine rhenium powder, by sintering. A compact is formed by cold isostatic pressing and thereafter the compact is sintered at 500-2800.degree. C. to obtain a sintered crucible. Product density is limited to 88-95% of theroretical in order to maximize creep resistance.
    Type: Grant
    Filed: January 9, 1998
    Date of Patent: November 30, 1999
    Assignee: W.C. Heraeus GmbH & Co. KG
    Inventors: David Francis Lupton, Jorg Schielke, Manfred Weigelt, Klaus Petermann, Eric Mix, Livio Fornasiero
  • Patent number: 5993902
    Abstract: 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: Grant
    Filed: April 9, 1997
    Date of Patent: November 30, 1999
    Assignee: SEH America, Inc.
    Inventor: Gary Randolph Heid
  • Patent number: 5989341
    Abstract: A single crystal producing apparatus to be used for raising the single crystals by a CZ method. A cylindrical portion of a main chamber of the single crystal producing apparatus can be separated from the apparatus. Hot zone components can be retained within the cylindrical portion. After the pulling up operation, the cylindrical portion is separated from the apparatus with the hot zone components being engaged with within the cylindrical portion and is carried to another chamber. In another chamber, an overhauling, reproducing and assembling operations of the hot components can be conducted. In the single crystal producing apparatus, a cylindrical portion which goes through an assembling operation of the hot zone components in another chamber is engaged with the apparatus, and the next pulling up operation is conducted. Time required to the next pulling up operation is shortened. The dust amount within the pulling up chamber is reduced.
    Type: Grant
    Filed: October 7, 1997
    Date of Patent: November 23, 1999
    Assignee: Sumitomo Sitix Corporation
    Inventors: Munehiro Yasuda, Shinichi Sakurada
  • Patent number: 5968267
    Abstract: The uniformity of solid crystals grown by pulling a seed crystal from a molten charge material in a crucible is increased by eliminating vibration by supporting a housing for the solid crystal on a vibration isolator which rests on a supporting floor. Vibration isolators may also be placed between a crucible lift and rotation mechanism and the supporting floor. The crystal pull head for pulling the seed crystal also can be isolated from the remainder of the apparatus by vibration isolators.
    Type: Grant
    Filed: January 24, 1997
    Date of Patent: October 19, 1999
    Assignee: General Signal Technology Corporation
    Inventor: Zhixin Li
  • Patent number: 5964941
    Abstract: A method and an apparatus for pulling a single crystal are disclosed. A neck portion, a corrugated portion, and a single crystal are formed below a seed crystal held by a seed chuck. When the corrugated portion is raised to a predetermined position (where lifting jig can hold the corrugated portion) by the seed chuck, the rising speed Va of the seed chuck is reduced, and a slider that supports a seed chuck lifting mechanism is raised at a speed Vb in order to maintain a constant pulling speed of the single crystal. Eventually, the pulling by the seed chuck is switched to the pulling by the slider. Subsequently, the lifting jig provided on the slider is raised slightly by a moving mechanism so that the crystal holding portions of the lifting jig are brought into contact with the corrugated portion and 1-50% of the weight of the crystal is shifted to the lifting jig. This enables safe and accurate growth of a heavy single crystal in accordance with, for example, the CZ method.
    Type: Grant
    Filed: September 15, 1997
    Date of Patent: October 12, 1999
    Assignee: Shin-Etsu Handotai., Ltd.
    Inventors: Eiichi Iino, Makoto Iida, Masanori Kimura, Shozo Muraoka
  • Patent number: 5958133
    Abstract: A crystal-growing machine (10) includes a furnace chamber (12) and two loading chambers (14 and 16) that permit simultaneous processing operations. At least one of the two loading chambers (14 and 16) includes a lifting mechanism (36) for pulling a crystal (40) from a melt (20) in the furnace chamber (12). A positioning mechanism (60) disengages one of the loading chambers (14 and 16) from the furnace chamber (12) for cooling the crystal (40) in an evacuated environment and engages the other of the loading chambers (14 and 16) for simultaneously recharging the melt (20) or starting growth of another crystal.
    Type: Grant
    Filed: January 29, 1996
    Date of Patent: September 28, 1999
    Assignee: General Signal Corporation
    Inventor: Anatoli S. Boulaev
  • Patent number: 5951759
    Abstract: This invention provides a apparatus and a method of pulling up single crystals, which respond to the weight increase of semiconductor single crystal produced by the CZ method. The retaining wire wind-up mechanisms 11, 12; multiple pairs of guide pipes 4a, 4c capable of being moved upward or downward with respect to the seed holder 1; and a plurality of retaining wires 13, 15, each retaining wire passing through one pair of the guide pipes and having its central portion to be bent into a "U" shape are provided in the central portion of the lifting wire 5. The single crystal 17 can be retained by the retaining wire 13, 15, if the guide pipes 4a, 4c are driven to move downward and the "U" shaped portions of the retaining wires 13, 15 are driven to engage with the necked portion 17b so as to lift single crystal 17. The load is determined based on the detected value coming from the weight sensors installed on the means for winding up the retaining wires.
    Type: Grant
    Filed: October 15, 1997
    Date of Patent: September 14, 1999
    Assignee: Komatsu Electronic Metals Co., Ltd.
    Inventors: Hiroshi Inagaki, Fumitaka Ishikawa
  • Patent number: 5948163
    Abstract: A crystal manufacturing apparatus includes a crucible for containing a material, a heater for heating and melting the material, and a heat insulating cylinder arranged so as to surround the crucible and the heater. The crystal manufacturing apparatus is operated in accordance with the Czochralski method. The heat insulating cylinder is arranged to be vertically movable. When two or more crystals are pulled within a single batch, the vertical position of the heat insulating cylinder is changed between the manufacture of the crystals, so that the thermal histories of the crystals are made different from one another. Moreover, when a crystal is pulled in accordance with the Czochralski method, the heat insulating cylinder is moved vertically while the crystal is being pulled.
    Type: Grant
    Filed: February 10, 1997
    Date of Patent: September 7, 1999
    Assignee: Shin-Etsu Handotai Co., Ltd.
    Inventors: Masahiro Sakurada, Tomohiko Ohta
  • Patent number: 5944892
    Abstract: A crystal growing system has a plurality of crystal growing stations which are each comprised of a crucible, furnace, vacuum chambers and related equipment which is continuously used during the actual crystal growing process. A central process control console is connected to each crystal growing station so that growing parameters for all stations can be controlled from a single location. A common server unit services all crystal growing stations. The server unit is movable so that it can be positioned at each station both prior to initiating crystal formation and subsequent to completing crystal formation in order to service the station before and after the crystal growing operation. The server unit comprises a movable support structure which can be rolled along a set of tracks to be positioned sequentially adjacent to each station. The server unit includes a main hoist constructed to move a receiving chamber, either alone or together with a transition chamber.
    Type: Grant
    Filed: February 27, 1997
    Date of Patent: August 31, 1999
    Assignee: General Signal Technology Corporation
    Inventor: Zhixin Li
  • Patent number: 5942032
    Abstract: A heat shield assembly is used in a Czochralski crystal puller for selectively shielding a monocrystalline ingot of semiconductor material to control the type and number density of agglomerated defects in the crystal structure of the ingot. The heat shield assembly has an upper heat shield connected to a lower heat shield. The upper and lower heat shields are connected to each other and slidingly connected to an intermediate heat shield. The lower heat shield is able to telescope up into the intermediate heat shield to minimize the profile of the heat shield assembly located within a crystal growth chamber of the crystal puller. However when needed to control formation of the monocrystalline ingot, the lower heat shield may be extended from the intermediate heat shield and project downwardly into the crystal puller crucible in close proximity to an upper surface of molten semiconductor source material in the crucible. A method employing the heat shield assembly is also disclosed.
    Type: Grant
    Filed: August 1, 1997
    Date of Patent: August 24, 1999
    Assignee: MEMC Electronic Materials, Inc.
    Inventors: Kyong-Min Kim, William L. Luter, Lee W. Ferry, Robert J. Braun, Srdjan Ilic, Mauro Dioda, Paolo Tosi, Marco Gobbo, Umberto Martini
  • Patent number: 5938841
    Abstract: A novel device for producing a single crystal by the CZ or MCZ method is provided, which comprising a crucible for containing silicon melt therein, a wire reel and a wire for pulling a single crystal, a motor and a rotation shaft for rotating the crucible, a speed change device being inserted between the motor and the rotation shaft, and, if necessary, a magnetic field generator, by which the magnetic field is applied to the melt. According to the device for producing a single crystal, the rotation accuracy of a crucible can be improved, so that the concentrations of impurities in the pulled single crystal can be highly precisely controlled.
    Type: Grant
    Filed: November 21, 1996
    Date of Patent: August 17, 1999
    Assignee: Shin-Etsu Handotai Co., Ltd.
    Inventors: Kouji Kitagawa, Kouji Mizuishi, Masahiko Urano, Kenji Araki, Eiichi Iino, Izumi Fusegawa
  • Patent number: 5935329
    Abstract: In a lifting unit for a device for pulling monocrystals, a frame that extends in the horizontal direction and surrounds a pulling shaft and/or a crystal is provided with at least two bearings as well as two-armed grippers that are held in the aforementioned bearings and can be pivoted in vertical planes. The respective gripping arms are aligned with the rotational axis of the frame and have such a length that the end surfaces of the gripping arms which face one another tightly adjoin one another in the closed position and only allow a limited pivoting movement. The respective free ends of the two-armed grippers are coupled to tie rods that approximately extend in the vertical direction. The upper ends of the tie rods are connected in articulated fashion via a horizontally extending crossbeam, where the crossbeam with a spindle nut can be adjusted along the pulling shaft via a threaded spindle. The frame is suspended on cables that serve for pivoting the gripping arms.
    Type: Grant
    Filed: March 13, 1998
    Date of Patent: August 10, 1999
    Assignee: Leybold Systems GmbH
    Inventor: Winfried Schulmann
  • Patent number: 5935328
    Abstract: An apparatus for pulling a monocrystalline ingot from a semiconductor source material located within a growth chamber as the ingot is grown on a seed crystal according to the Czochralski method. The apparatus comprises a drum, a chuck constructed for holding the seed crystal and the ingot, and a cable having a first end connected to the drum, a second end connected to the chuck and a portion wound around the drum. The portion of the cable wound around the drum exerts a normal force on a circumferential surface of the drum corresponding to the tension in the cable. The drum and cable interact to produce a friction force resisting sliding movement of the cable relative to the drum in a direction lengthwise of the cable. The drum is capable of unwinding cable from the drum thereby to let out the cable and lower the chuck, and capable of winding the cable around the drum thereby to reel in the cable and draw the chuck upwardly.
    Type: Grant
    Filed: November 25, 1997
    Date of Patent: August 10, 1999
    Assignee: MEMC Electronic Materials, Inc.
    Inventors: Carl F. Cherko, Harold Korb, Richard G. Schrenker, Dick S. Williams
  • Patent number: 5935325
    Abstract: A weight control in diameter method by using a load cell is applied to a wire-single crystal silicon pulling mechanism, such that the weight of single crystal silicon can be correctly measured, thereby obtaining superior control in diameter and reducing the cost of manufacturing the single crystal silicon.
    Type: Grant
    Filed: June 13, 1997
    Date of Patent: August 10, 1999
    Assignee: Komatsu Electronic Metals, Co., Ltd.
    Inventors: Hideki Tsuji, Mitsunori Kawabata, Yoshinobu Hiraishi, Ryo Yamagishi
  • Patent number: 5932007
    Abstract: 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: Grant
    Filed: June 3, 1997
    Date of Patent: August 3, 1999
    Assignee: General Signal Technology Corporation
    Inventor: Zhixin Li
  • Patent number: 5925185
    Abstract: A method for fabricating a semiconductor single crystal by the MCZ method by which it is possible to pull large diameter and heavy semiconductor single crystals without breaking the contraction portion, is provided.In the contracting step, change the shape of the crystal growth interface by making the range of the temperature fluctuation caused by convection in the vicinity of the melt surface more than 5.degree. C. so as to eliminate the dislocation in the contracted portion. When a transverse magnetic field is applied by magnets 6,6, the magnetic field intensity is set below 2000 Gauss to properly change the shape of the crystal growth interface to form the contracted portion 10. Thus,even though the diameter of the contracted portion 10 is larger than normal, free dislocation is achieved. After the dislocation is eliminated, the magnetic field intensity is recovered and shoulder 11 is formed.
    Type: Grant
    Filed: June 19, 1997
    Date of Patent: July 20, 1999
    Assignee: Komatsu Electronic Metals Co., Ltd.
    Inventors: Shigeki Kawashima, Hiroshi Inagaki, Hirotaka Nakajima
  • Patent number: 5911821
    Abstract: There is disclosed a Czochralski method in which a seed crystal in contact with material melt is pulled, while being rotated, so as to grow a monocrystal, and a part of the crystal being grown is mechanically held during the pulling operation. The crystal is mechanically held in such a way that the weight W(kg) of the crystal satisfies the following Formula (1):W<12.5.times..pi.D.sup.2 /4 (1)where D designates the minimum diameter (mm) of a neck. This makes it possible to pull a heavy monocrystal safely and reliably.
    Type: Grant
    Filed: September 5, 1997
    Date of Patent: June 15, 1999
    Assignee: Shin-Etsu Handotai Co., Ltd.
    Inventors: Eiichi Iino, Makoto Iida, Masanori Kimura, Shozo Muraoka
  • Patent number: 5904768
    Abstract: A process and apparatus for regulating the concentration and distribution of oxygen in a single crystal silicon rod pulled from a silicon melt, optionally doped with antimony or arsenic, in accordance with the Czochralski method wherein an atmosphere is maintained over the melt. In batch embodiments of the process, the gas pressure of the atmosphere over the melt is progressively increased to a value in excess of 100 torr as the fraction of silicon melt solidified increases. In continuous embodiments of the process, the gas pressure of the atmosphere over the melt is maintained at or near a constant value in excess of 100 torr. The process and apparatus are further characterized in that a controlled flow of inert gas is used to remove vapors and particulate away from the surface of the rod and melt, resulting in the production of a single crystal silicon rod having zero dislocations.
    Type: Grant
    Filed: October 15, 1996
    Date of Patent: May 18, 1999
    Assignee: MEMC Electronic Materials, Inc.
    Inventor: John D. Holder
  • Patent number: 5900058
    Abstract: An apparatus for producing a single crystal by the Czochralski method is disclosed in which an exhaust system is provided with a water sealing bubbler. On the upstream side of the bubbler is provided a buffer or a vacuum breaker or a buffer and a vacuum breaker. The structure prevents the sealing water in the bubbler from flowing backward, so that danger of steam explosion can be avoided.
    Type: Grant
    Filed: December 5, 1996
    Date of Patent: May 4, 1999
    Assignee: Shin-Etsu Handotai Co., Ltd.
    Inventors: Kouji Mizuishi, Atsushi Iwasaki
  • Patent number: 5897706
    Abstract: 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: Grant
    Filed: April 15, 1997
    Date of Patent: April 27, 1999
    Assignees: Mitsubishi Materials Silicon Corporation, Mitsubishi Materials Corporation
    Inventors: Masakazu Yamazaki, Michio Yanaba, Hiroaki Taguchi, Takashi Atami, Hisashi Furuya
  • Patent number: 5882402
    Abstract: A method and system for determining a diameter of a silicon single crystal being pulled from a silicon melt contained in a heated crucible. The melt has a surface with a meniscus visible as a bright area adjacent the pulled crystal. A camera generates an image of the interior of the crucible including a portion of the bright area adjacent the crystal. Image processing circuitry defines a central window region of the image having an elliptical shape at a position corresponding to an approximate center of the crystal and processes the image as a function of its pixel values to detect edges within the central window region. The image processing circuitry further groups the detected edges to define an object in the image corresponding to the crystal, determines a dimension of the defined object and determines an approximate diameter of the crystal as a function of the determined dimension of the defined object.
    Type: Grant
    Filed: September 30, 1997
    Date of Patent: March 16, 1999
    Assignee: MEMC Electronic Materials, Inc.
    Inventor: Robert H. Fuerhoff
  • Patent number: 5879452
    Abstract: The pull head of a Czochralski crystal puller is mounted on a frame which is supported independently from the crystal puller receiving chamber. In particular, the pull head is mounted on a rigid frame which is supported by the same surface that supports the melt charge crucible. The pull head thereby can be aligned relative to the rigid frame, rather than to the receiving chamber, and can be accurately aligned with the crucible rotation axis and positioned in order to insure that its rotation axis is vertical. In one embodiment, the pull head is mounted on a plate which engages alignment pins attached to the rigid frame. The alignment pins insure proper alignment of the pull head relative to the frame. When the receiving chamber is raised to allow the crystal to be removed, the plate is engaged by the receiving chamber and lifted off the alignment pins so that the pull head moves with the receiving chamber.
    Type: Grant
    Filed: January 23, 1997
    Date of Patent: March 9, 1999
    Assignee: Ferrofluidics Corporation
    Inventor: Zhixin Li
  • Patent number: 5879448
    Abstract: A method and an apparatus for pulling a single crystal are disclosed. A first neck portion, a convex portion, and a second neck portion are formed in this order under a seed crystal held by a seed chuck, and subsequent to the second neck portion, a single crystal having a diameter-expanding portion and a straight cylindrical portion is formed. Lifting holders are brought around and in proximity to the second neck portion when the second neck portion rises to a predetermined position during the pulling by the seed chuck. The single crystal and the lifting holders are moved relative to each other in the vertical direction to thereby bring the convex portion into contact with the lifting holders in a resting manner, so that part of a load borne by the seed chuck is shifted to the lifting holders. Subsequently, the pulling operation is performed by the lifting holders. Accordingly, a single crystal having a larger weight can be pulled safely while maintaining high quality.
    Type: Grant
    Filed: June 26, 1997
    Date of Patent: March 9, 1999
    Assignee: Shin-Etsu Handotai Co., Ltd.
    Inventors: Masahiko Urano, Yasushi Nakamura, Seiichiro Otsuka, Eiichi Iino
  • Patent number: 5879451
    Abstract: An apparatus for measuring the weight of a crystal in a cable-type crystal pulling apparatus. A cable winding mechanism of the crystal pulling apparatus includes a guide pulley which is supported by a load plate and which changes the direction of the cable by 180 degrees, and a winding drum 8 which is disposed on a base plate and onto which the cable is wound. The load plate, on which a load due to pulling acts, is supported by a plurality of small-load load cells so that the load is equally distributed to the small-load load cells. Thus, the weight measuring apparatus can have a simple and low-cost structure, and the accuracy of measurement can be improved.
    Type: Grant
    Filed: December 11, 1996
    Date of Patent: March 9, 1999
    Assignee: Shin-Etsu Handotai Co., Ltd.
    Inventor: Kouji Mizuishi
  • Patent number: 5871582
    Abstract: 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: Grant
    Filed: October 23, 1997
    Date of Patent: February 16, 1999
    Assignee: Komatsu Electronic Metals Co., Ltd.
    Inventor: Shigeki Kawashima
  • Patent number: 5868832
    Abstract: Magnetic field generating apparatus comprises a pair of axially spaced coils which are so arranged that when energized, they produce a magnetic field which has a zero axial field or substantially zero axial field at an axial position midway between the coils. The annular space between the coils is filled with a material such as steel or steel with a layer of material magnetized in the radial direction, which enhances the radial field strength generated by the coils. The apparatus as application in the growth of single crystals of semiconductor material.
    Type: Grant
    Filed: March 31, 1997
    Date of Patent: February 9, 1999
    Assignee: Tesla Engineering Limited
    Inventor: Michael Colin Begg
  • Patent number: 5868836
    Abstract: 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: Grant
    Filed: January 21, 1997
    Date of Patent: February 9, 1999
    Assignee: Komatsu Electronic Metal Co., Ltd.
    Inventors: Shigeki Nakamura, Koichi Shimomura, Teruhiko Uchiyama
  • Patent number: 5853479
    Abstract: An image of the meniscus ring (21) between the crystal (20) and the melt (4) is formed by optical means (12, 24) on a sensor, the signals of which yield the actual value for the diameter of the crystal. Two optical measuring devices are provided, the optical paths of which are defined by base points on the meniscus ring (21) and two planes which are offset by 90.degree. to each other and which are parallel to the main axis of the crystal and in tangential contact with the meniscus ring (21). The two optical paths are preferably set up to intersect, their intersection being in the viewing window.
    Type: Grant
    Filed: December 3, 1996
    Date of Patent: December 29, 1998
    Assignee: Balzers und Leybold
    Inventors: Joachim Aufreiter, Dieter Bruss, Burkhard Altekruger
  • Patent number: 5851287
    Abstract: A seed crystal holder is used to grow a single crystal in an intended direction. In order to grow a single crystal in an intended direction by a crystal pulling method, a seed crystal is accurately cut out along a crystal orientation, and this seed crystal is accurately held in a predetermined attitude by the seed crystal holder. A seed crystal insertion bore having a rectangular cross-section is formed in the body of the seed crystal holder. A seed crystal having a taper surface at one edge is inserted into the seed crystal insertion bore. The inserted seed crystal is pressed at its taper surface by a taper surface of a block, so that two surfaces of the seed crystal are fixedly pressed against two inner surfaces of the seed crystal insertion bore. The other end of the block is covered with a block-retaining ring, so that the block does not come off the seed crystal holder.
    Type: Grant
    Filed: February 20, 1997
    Date of Patent: December 22, 1998
    Assignee: Shin-Etsu Handotai Co., Ltd.
    Inventor: Satoshi Soeta
  • Patent number: 5846322
    Abstract: A crucible is mounted on a crucible support bolt (11, 34) in a vacuum chamber (33) resting on a base stand (32) and can be heated by the thermal radiation of a heating element. A drawing element (35) is provided above the melt, by means of which the crystal can be drawn up from the surface of the melt into a transfer lock chamber (36), which can be pivoted laterally with respect to the base stand (32). A separating device is provided between the crystal and the drawing element (35) to separate the crystal from the drawing element (35). The base stand (32) is formed by a platform (38) supported by four posts (37) three additional legs (39) of equal length extend upward from three of the four corners of the rectangular platform (38) holding the vacuum chamber (33), these (39) being held together at their top ends by a horizontal frame (40), which forms a right triangle.
    Type: Grant
    Filed: March 18, 1997
    Date of Patent: December 8, 1998
    Assignee: Balzers UND Leybold Deutschland Holding AG
    Inventors: Winfried Schulmann, Helmut Kaiser, Franz Thimm
  • Patent number: 5846323
    Abstract: 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: Grant
    Filed: October 8, 1996
    Date of Patent: December 8, 1998
    Assignees: International Superconductivity Technology Center, the Juridical Foundation, Ishikawajima-Harima Heavy Industries Co. Ltd., Sumitomo Electric Industries, Ltd.
    Inventors: Masahiro Egami, Yuh Shiohara, Yasuo Namikawa
  • Patent number: 5846318
    Abstract: Method and system for use with a Czochralski crystal growing apparatus. The crystal growing apparatus has a heated crucible for melting solid silicon to form a melt from which the single crystal is pulled. The melt has an upper surface above which unmelted silicon is exposed until melted. A camera generates images of a portion of the interior of the crucible. Each image includes a plurality of pixels and each pixel has a value representative of an optical characteristic of the image. An image processor processes the images as a function of the pixel values to detect edges in the images and groups the detected edges as a function of their locations in the images to define objects in the images. The defined objects each include one or more pixels and at least one of the defined objects is representative of a portion of solid silicon which is visible on the melt surface.
    Type: Grant
    Filed: July 17, 1997
    Date of Patent: December 8, 1998
    Assignee: MEMC Electric Materials, Inc.
    Inventor: Massoud Javidi
  • Patent number: 5843229
    Abstract: In a crystal holding apparatus, a stepped engagement portion of a single crystal formed below a seed crystal is held by holding portions of a pair of lifting jigs so as to be pulled up. A lock mechanism consisting of a hook lever and an engagement pin is provided in order to prevent the closed lifting jigs from opening. Further, a portion of each holding portion to be contacted with a crystal is provided with a swing claw which is swingable about a horizontal pin. Accordingly, it becomes possible to reliably hold the crystal, to prevent generation of a defect in the crystal structure, and to prevent a material melt from being contaminated.
    Type: Grant
    Filed: December 11, 1996
    Date of Patent: December 1, 1998
    Assignee: Shin-Etsu Handotai Co., Ltd.
    Inventors: Masanori Kimura, Eiichi Iino, Hirotoshi Yamagishi, Kiyotaka Takano
  • Patent number: 5840120
    Abstract: 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: Grant
    Filed: January 22, 1996
    Date of Patent: November 24, 1998
    Assignee: MEMC Electronic Materials, Inc.
    Inventors: Kyong-Min Kim, Roger W. Shaw, Sadasivam Chandrasekhar, Richard G. Schrenker
  • Patent number: 5827367
    Abstract: 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: Grant
    Filed: September 13, 1996
    Date of Patent: October 27, 1998
    Assignee: SEH America
    Inventors: Witawat Wijaranakula, Akihiko Tamura
  • Patent number: 5824153
    Abstract: An apparatus for holding a single-crystal semiconductor ingot which is stored in a pulling chamber of a single-crystal semiconductor pulling apparatus is disclosed. The apparatus includes a spindle; a base installed on the spindle and movable along the spindle; a pair of arms for holding the single-crystal semiconductor ingot; means for driving the arms; a pair of sensors for detecting the distance between the ingot and the arms; and a controller for driving the arms to the ingot according to the sensors; when each of the arms is detected to have a predetermined distance from the ingot, the controller stopping the movement of the arm; when both the arms have the predetermined distance to the ingot, the controller driving simultaneously both the arms to the ingot surface, thereby holding the ingot.
    Type: Grant
    Filed: December 10, 1996
    Date of Patent: October 20, 1998
    Assignee: Komatsu Electronic Metals Co., Ltd
    Inventors: Ayumi Suda, Yoshinobu Hiraishi, Koichi Shimomura
  • Patent number: 5824152
    Abstract: 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: Grant
    Filed: July 9, 1996
    Date of Patent: October 20, 1998
    Assignee: Komatsu Electronic Metals Co., Ltd.
    Inventors: Toshimichi Kubota, Toshiro Kotooka, Toshiaki Saishoji, Tetsuhiro Iida
  • Patent number: 5800924
    Abstract: A Czochralski process furnace component is disclosed. The component comprises a high purity, semiconductor standard composite including a carbon fiber reinforced carbon matrix having a level of metal impurity below the detection limit of inductively coupled plasma spectroscopy. A process for producing the components includes heat treatment of the carbon fiber and the components.
    Type: Grant
    Filed: March 31, 1997
    Date of Patent: September 1, 1998
    Assignee: SGL Carbon Composites, Inc.
    Inventor: Robert Howard Metter
  • Patent number: 5797990
    Abstract: Orbital oscillations of the crystal ingot suspended in a cable in a Czochralski crystal puller are damped by mechanically connecting a high-temperature conductor to the ingot and generating a magnetic field in the vicinity of the conductor. The magnetic field induces an eddy current in the conductor when the ingot moves. The eddy current then interacts with the magnetic field to damp motion of the ingot. In one embodiment, the magnetic field generator is moved as the ingot grows to maintain the magnetic field in the vicinity of the conductor. In another embodiment, the strength of the magnetic field is adjusted dependent on the amplitude of the oscillations to conserve power.
    Type: Grant
    Filed: February 26, 1996
    Date of Patent: August 25, 1998
    Assignee: Ferrofluidics Corporation
    Inventor: Zhixin Li
  • Patent number: 5785757
    Abstract: 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: Grant
    Filed: December 13, 1996
    Date of Patent: July 28, 1998
    Assignee: Komatsu Electronic Metals Co., Ltd.
    Inventor: Yoshinobu Hiraishi
  • Patent number: 5785758
    Abstract: In a single crystal growing apparatus which pulls a semiconductor single crystal rod 14 from a semiconductor melt 13 contained in a quartz crucible 5 to grow the semiconductor single crystal, quartz crucible 5 is designed such that it can move up and down so as to maintain the level of semiconductor melt 13 constant and a main heater 7 which can move up and down and a subheater 10 which can move up and down are provided to heat semiconductor melt 13 so that the thermal environment of semiconductor melt 13 is maintained substantially constant.
    Type: Grant
    Filed: December 20, 1996
    Date of Patent: July 28, 1998
    Inventors: Hirotoshi Yamagishi, Kiyotaka Takano, Masanori Kimura
  • Patent number: 5766346
    Abstract: An apparatus for producing a silicon single crystal by the MCZ method is disclosed in which electrodes and magnets are arranged so as to make such a condition that a line of magnetic force passing through the central axis of the crucible and a horizontal electric current which results from the supply of a direct current to the heater forms a counterclockwise angle of more than 0.degree. and less than 180.degree. on the basis of the condition where the direction of the line of magnetic force coincides with the direction of the horizontal electric current.
    Type: Grant
    Filed: December 5, 1996
    Date of Patent: June 16, 1998
    Assignee: Shin-Etsu Handotai Co., Ltd.
    Inventors: Toshirou Hayashi, Ryouji Hoshi, Izumi Fusegawa, Tomohiko Ohta