Using A Magnetic Field Patents (Class 117/32)
-
Patent number: 6086671Abstract: A method for melting a silicon starting material can suppress silica (SiO2) from melting out from a quartz crucible wherein the silicon starting material is melted and can provide a high-quality silicon single crystal in a high yield. The growth method comprises melting the silicon starting material charged in the crucible while applying thereto a static magnetic field, contacting a seed crystal to a surface of the silicon melt, and pulling the seed crystal upwardly to solidify the contacted melt. The silicon starting material charged in the crucible, which is under melting, is applied with a static magnetic field such as a Cusp magnetic field, a horizontal magnetic field and/or a vertical magnetic field. The application can control heat convection occurring in the crucible during the course of the melting of the starting material, thereby obtaining a silicon single crystal having a reduced number of dislocation defects.Type: GrantFiled: September 1, 1998Date of Patent: July 11, 2000Assignee: Sumitomo Sitix CorporationInventors: Souroku Kawanishi, Youichi Yamamoto
-
Patent number: 6080237Abstract: This invention is directed to a method for the production of a dislocation-free silicon single crystal by the Czochralski method. This method attains growth of the main body part of the dislocation-free silicon single crystal by immersing a seed crystal in a melt of silicon and then pulling the seed crystal without recourse to the necking. The seed crystal thus used is a dislocation-free silicon single crystal. The horizontal maximum length of the part of the seed crystal being immersed in the melt at the time of completing the immersion of the seed crystal in the melt is not less than 5 mm. The immersing rate of the seed crystal in the melt is not more than 2.8 mm/min and the part of the seed crystal to be immersed in the melt is a crystal as grown.Type: GrantFiled: June 8, 1998Date of Patent: June 27, 2000Assignees: Nippon Steel Corporation, NSC Electron CorporationInventors: Toshio Iwasaki, Shin-ichi Fujimoto, Hiroshi Isomura, Takayoshi Ishida, Michiharu Tamura, Atsushi Ikari
-
Patent number: 6077346Abstract: In the growth of a semiconductor single crystal according to the Czochralski method, a magnetic field is generated in a semiconductor melt and a current is supplied in the semiconductor melt in a direction perpendicular to the magnetic field. This makes it possible to cause the semiconductor melt to rotate spontaneously without rotating the crucible, thereby to grow a single crystal of semiconductor without striation even when growing a single crystal of semiconductor having a large diameter. Also it is made possible to exactly control the rotation rate of the semiconductor melt by changing the intensity of the magnetic field and the magnitude of the current independently. Further, the distribution of the rotation rates in the semiconductor melt can also be varied by changing the position of electrodes or electrode protecting tubes for immersing in the semiconductor melt.Type: GrantFiled: December 11, 1998Date of Patent: June 20, 2000Assignee: NEC CorporationInventors: Masahito Watanabe, Minoru Eguchi
-
Patent number: 6060971Abstract: The present invention provides a superconducting magnet device for a crystal pulling device comprising a pair of ring-like superconducting coils facing with each other, with the crystal pulling device disposed therebetween, a radiation shield surrounding the superconducting coils, and a vessel surrounding the radiation shield, wherein the vessel on the side facing to the crystal pulling device is made from a nonmagnetic substance, and the vessel on the other side is made from a magnetic substance.Type: GrantFiled: February 16, 1999Date of Patent: May 9, 2000Assignee: Kabushiki Kaisha ToshibaInventors: Takashi Sasaki, Masanori Arata
-
Patent number: 6019837Abstract: 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: GrantFiled: November 25, 1997Date of Patent: February 1, 2000Assignees: 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: 6001170Abstract: 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: GrantFiled: August 9, 1996Date of Patent: December 14, 1999Assignee: Wacker Siltronik Gesellschaft fur Halbleitermaterialien AGInventors: Erich Tomzig, Werner Zulehner, Wilfried Von Ammon, Yu M Gelfgat, Leonid Gorbunov
-
Patent number: 5997641Abstract: The hold member has a small-diameter portion and a large-diameter portion. An inner cylinder and an outer cylinder are disposed around the hold member in a concentric manner. The upper end of the hold member is affixed to a wire and suspended therefrom. A clearance is formed between the small-diameter portion and the inner cylinder. Clearances are created between the outer peripheral surface of the inner cylinder and the inner peripheral surface of the outer cylinder.Type: GrantFiled: December 8, 1997Date of Patent: December 7, 1999Assignee: Komatsu Electronic Metals Co., Ltd.Inventors: Mitsunori Kawabata, Yoshinobu Hiraishi, Mitsuo Usukubo, Ayumi Suda
-
Patent number: 5980630Abstract: In a single crystal manufacturing method by a horizontal magnetic field applied CZ method wherein coils are disposed interposing a crucible coaxially with each other, the coils constituting superconductive electromagnets of a magnetic field application apparatus and the silicon crystal is pulled from melt in the crucible while applying a horizontal magnetic field to the melt; an elavation apparatus capable of finely adjusting relative positions of the superconductive electromagnets and the crcucible in a vertical direction is disposed. The descent of a central portion Cm in a depth direction of the melt is canceled by elevating the crucible with the elevating apparatus, the descent being accompanied with proceeding of process of pulling the single crystal, thereby a coil central axis Cc of the superconductive electromagnets always passes through the central portion Cm or below this portion.Type: GrantFiled: May 20, 1998Date of Patent: November 9, 1999Assignee: Shin-Etsu Handotai, Co., Ltd.Inventors: Eiichi Iino, Kiyotaka Takano, Masanori Kimura, Hirotoshi Yamagishi
-
Patent number: 5976246Abstract: A MCZ method in which the single crystal is pulled while being rotated under the conditions where the crystal growth rate V.sub.1 (mm/min) and the crystal circumference velocity V.sub.2 (mm/min) satisfy the following relationships:0.4.ltoreq.V.sub.10.628.times.10.sup.4 .ltoreq.V.sub.2 .ltoreq.1.0.times.10.sup.4andV.sub.2 .ltoreq.-3.72.times.10.sup.4 V.sub.1 +4.35.times.10.sup.4It is possible to manufacture a silicon single crystal with a large diameter with the MCZ method without causing distortion.Type: GrantFiled: November 19, 1997Date of Patent: November 2, 1999Assignee: Shin-Etsu Handotai Co., Ltd.Inventors: Eiichi Iino, Masanori Kimura, Shozo Muraoka
-
Patent number: 5968264Abstract: In method for manufacturing a silicon single crystal in accordance with a Czochralski method, during the growth of the silicon single crystal, pulling is performed such that a solid-liquid interface in the crystal, excluding a peripheral 5 mm-width portion, exists within a range of an average vertical position of the solid-liquid interface .+-.5 mm. There is also disclosed a method for manufacturing a silicon single crystal in accordance with the Czochralski method, wherein during the growth of a silicon single crystal, a furnace temperature is controlled such that a temperature gradient difference .DELTA.G (=Ge-Gc) is not greater than 5.degree. C./cm, where Ge is a temperature gradient (.degree.C./cm) at a peripheral portion of the crystal, and Gc is a temperature gradient (.degree.C./cm) at a central portion of the crystal, both in an in-crystal descending temperature zone between 1420.degree. C. and 1350.degree. C. or between a melting point of silicon and 1400.degree. C.Type: GrantFiled: July 2, 1998Date of Patent: October 19, 1999Assignee: Shin-etsu Handotai Co., Ltd.Inventors: Makoto Iida, Eiichi Iino, Masanori Kimura, Shozo Muraoka, Hideki Yamanaka
-
Patent number: 5968266Abstract: An apparatus for manufacturing a single crystal of silicon includes a crucible, a heater, electrodes, and a magnet. In addition to a plurality of heat generating portions and two main electrode portions, the heater has two or more auxiliary electrode portions. Two or more heater support members having an insulating property are further provided so as to support the heater through the auxiliary electrode portions. The number of heat generating portions which may be present between a heater support member and an electrode and between heater support members if adjacent to each other is equal to or less than 4. Each generating portion of the heater has a thickness of 25 mm or more. This structure makes it possible to produce a single crystal of silicon without causing breakage of a heater, even if a large electric current flows through the heater, even if a magnetic field of a high intensity is applied to a silicon melt in the crucible, and even if the heater has a large diameter.Type: GrantFiled: March 20, 1997Date of Patent: October 19, 1999Assignee: Shin-Etsu Handotai Co., Ltd.Inventors: Eiichi Iino, Masanori Kimura, Shozo Muraoka
-
Patent number: 5938836Abstract: This invention provides an apparatus and a method for manufacturing semiconductor single crystals, which enable a steady process of pulling up high-quality single silicon crystals to be easily performed during the growing of silicon single crystals by the CZ method aided by applying a Cusp magnetic field. Three facing homopolar magnets (hereinafter referred to as magnet) 1, 2, and 3 arc disposed outside the single-crystal pulling up chamber. The magnet 3 is located at the same height as the free surface of the melt 6 stored in a quartz crucible as the free surface of the melt 6 stored in a quartz crucible 5. Furthermore, the strength of the magnets 3 is set to be weaker than that of the magnets 1 and 2. The flux lines of the magnets 3 substantially pass through the quartz crucible 5 in the horizontal direction. However, the flux lines of the magnet 3 do not reach the silicon single crystal 7 being pulled up.Type: GrantFiled: October 23, 1997Date of Patent: August 17, 1999Assignee: Komatsu Electronic Metals Co., Ltd.Inventors: Junsuke Tomioka, Hiroshi Inagaki, Katsura Yamamoto
-
Patent number: 5938841Abstract: 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: GrantFiled: November 21, 1996Date of Patent: August 17, 1999Assignee: Shin-Etsu Handotai Co., Ltd.Inventors: Kouji Kitagawa, Kouji Mizuishi, Masahiko Urano, Kenji Araki, Eiichi Iino, Izumi Fusegawa
-
Patent number: 5935327Abstract: An apparatus for producing silicon crystals (24) having highly uniform characteristics from a silicon melt (22) comprising a furnace (12), a crucible (14) disposed within the furnace (12) for containing the silicon melt (22), a heater (20) disposed around the crucible (14) for heating the silicon melt (22) and a pair of cusp magnets (28, 30) disposed around the furnace (12) and spaced a distance apart from one another such that the distance between the cusp magnets (28, 30) is variable.Type: GrantFiled: May 9, 1997Date of Patent: August 10, 1999Assignee: Texas Instruments IncorporatedInventors: Farouk A. Hariri, Michael D. Dangel, H. Michael Grimes
-
Patent number: 5925185Abstract: 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: GrantFiled: June 19, 1997Date of Patent: July 20, 1999Assignee: Komatsu Electronic Metals Co., Ltd.Inventors: Shigeki Kawashima, Hiroshi Inagaki, Hirotaka Nakajima
-
Patent number: 5911823Abstract: A method for pulling a <110> single-crystal silicon aims at preventing the crystal from being cut in diameter-reducing and suppress the increase in cost due to the cut prevention to the minimum. In the step for forming a diameter-reduced portion performed prior to the step for growing a <110> single-crystal silicon by the Czochralski method, a magnetic field having a strength of 500 gauss or more is applied and while suppressing a melt surface vibration and temperature variation, the crystal diameter is reduced to 2.00 mm or smaller.Type: GrantFiled: December 10, 1996Date of Patent: June 15, 1999Assignee: Komatsu Electronics Metals Co., Ltd.Inventors: Kouji Sonoda, Toshio Mimura
-
Patent number: 5882398Abstract: A single crystal of silicon is manufactured in accordance with the Czochralski method. A magnetic field is applied to a quartz crucible filled with silicon melt. Subsequently, a single crystal of silicon is pulled in a state in which no magnetic field is applied to the crucible, so as to obtain a single crystal of silicon. Therefore, the inner surface of a quartz crucible becomes very unlikely to deteriorate, and when the inner surface deteriorates, the deteriorated inner surface is restored. Accordingly, it is possible to manufacture a single crystal of silicon having a large diameter without generating a dislocation in the crystal. Moreover, even when a single crystal of silicon having a large diameter is manufactured, a larger number of single crystals of silicon can be manufactured from a single quartz crucible, and the pulling apparatus can be operated over a longer period of time using a single quartz crucible, thereby making it possible to manufacture a longer single crystal.Type: GrantFiled: January 23, 1997Date of Patent: March 16, 1999Assignee: Shin-Etsu Handotai Co., Ltd.Inventors: Susumu Sonokawa, Toshiro Hayashi, Atsushi Iwasaki, Tomohiko Ohta
-
Patent number: 5871578Abstract: Oscillation of a growing crystal is suppressed in a Czochralski method when part of the growing crystal is mechanically held. Methods for holding and pulling a single crystal in a Czochralski method, wherein a seed crystal is pulled while rotating after the seed crystal is contacted with a raw material melt, part of the growing single crystal is mechanically held during pulling and the single crystal of heavy weight can be pulled regardless of mechanical strengths of the seed crystal or a neck portion thereof, wherein the raw material melt is under application of a magnetic field thereto when the growing crystal is mechanically held.Type: GrantFiled: August 20, 1997Date of Patent: February 16, 1999Assignee: Shin-Etsu Handotai Co., Ltd.Inventors: Eiichi Iino, Makoto Iida, Masanori Kimura, Shozo Muraoka
-
Patent number: 5868832Abstract: 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: GrantFiled: March 31, 1997Date of Patent: February 9, 1999Assignee: Tesla Engineering LimitedInventor: Michael Colin Begg
-
Patent number: 5858084Abstract: A method of growing crystals from solution is described which includes growing crystals from a solution comprising ions under the combined effect of gravity and an applied magnetic field, in which the magnetic field in the range of about 1 to 10 times the strength of the Earth's magnetic field.Type: GrantFiled: February 28, 1997Date of Patent: January 12, 1999Assignee: Massachusetts Institute of TechnologyInventors: Min-Chang Lee, Caroline H. Lee
-
Patent number: 5851283Abstract: A single crystal production apparatus based on an HMCZ method for production a large-diametered single crystal having a uniform microscopic oxygen concentration distribution in its crystal growth direction to thereby provide a wafer having a high in-plane uniformity of oxygen concentration distribution. In the single crystal production apparatus based on the HMCZ method, when B denotes a vertical position of the bottom surface of a melt within a crucible and L denotes the depth of the melt at the time of starting crystal pulling operation, a vertical position of the coil central axis Cc of superconducting electromagnets 12 and 15 is controlled to be a proper value included in a range from a position below the position B by {(1/3).times.L} to a position above the position B by {(1/3).times.L} to pull the single crystal.Type: GrantFiled: December 20, 1996Date of Patent: December 22, 1998Assignee: Shin-Etsu Handotai Co. Ltd.Inventors: Ryouji Hoshi, Masashi Sonokawa, Izumi Fusegawa, Tomohiko Ohta
-
Patent number: 5827366Abstract: In a Czochralski monocrystalline silicon growing apparatus for growing a silicon monocrystalline by pulling up a crystal seed by a wire in a growing furnace, a magnetic ring is mounted on the silicon monocrystal, and an electromagnet is fixed to the growing furnace for pulling up the magnetic ring.Type: GrantFiled: November 22, 1996Date of Patent: October 27, 1998Assignee: NEC CorporationInventor: Masahito Watanabe
-
Patent number: 5797990Abstract: 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: GrantFiled: February 26, 1996Date of Patent: August 25, 1998Assignee: Ferrofluidics CorporationInventor: Zhixin Li
-
Patent number: 5792255Abstract: In a single crystal manufacturing method by a horizontal magnetic field applied CZ method wherein coils are disposed interposing a crucible coaxially with each other, the coils constituting superconductive electromagnets of a magnetic field application apparatus and the silicon crystal is pulled from melt in the crucible while applying a horizontal magnetic field to the melt; an elavation apparatus capable of finely adjusting relative positions of the superconductive electromagnets and the crcucible in a vertical direction is disposed. The descent of a central portion Cm in a depth direction of the melt is canceled by elevating the crucible with the elevating apparatus, the descent being accompanied with proceeding of process of pulling the single crystal, thereby a coil central axis Cc of the superconductive electromagnets always passes through the central portion Cm or below this portion.Type: GrantFiled: May 30, 1996Date of Patent: August 11, 1998Assignee: Shin-Etsu Handotai Co., Ltd.Inventors: Eiichi Iino, Kiyotaka Takano, Masanori Kimura, Hirotoshi Yamagishi
-
Patent number: 5785752Abstract: Proposed is an improvement in the method for the preparation of a chip of an oxide garnet film epitaxially having a specific chemical composition as grown on the surface of a GGG substrate wafer having a crystallographic plane orientation of (111), which is useful as a working element in a magnetostatic wave device such as high-frequency filters, signal noise enhancers, isolators and the like with decreased temperature dependence of the properties. The epitaxially grown single crystal film is adjusted to have such dimensions that the thickness h and the smallest dimension L within the plane of the film satisfy the relationship that the ratio h/L is in the range from 0.001 to 0.25.Type: GrantFiled: December 12, 1995Date of Patent: July 28, 1998Assignee: Shin-Etsu Chemical Co., Ltd.Inventors: Masayuki Tanno, Toshihiko Ryuo
-
Patent number: 5647904Abstract: A method and an apparatus for fabricating single crystals of superconducting ceramics are described. A powdered row oxide mixture is placed and molten in a melting pot. The surface of the molten mixture is approximately at the freezing point of the mixture. From the surface, a single crystal is pulled in accordance with the known pulling crystal technique. The pulled mixture is subjected to a magnetic field normal to the pulling direction. By virtue of the magnetic field, single crystal superconducing oxide ceramics can be obtained without twin crystals.Type: GrantFiled: May 23, 1995Date of Patent: July 15, 1997Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventor: Shunpei Yamazaki
-
Patent number: 5571320Abstract: The invention defines an apparatus for controlling oxygen content in Czochralski silicon crystal pullers in which silicon is melted in a quartz crucible. The apparatus includes a susceptor 10, a quartz crucible 12 in said susceptor, a cable 16 for lowering a seed crystal 14 into silicon melted in said crucible, and a combination spiral heater/magnetic coil 25 for heating and melting silicon in said crucible, and for producing a magnetic field around the crucible.Type: GrantFiled: June 7, 1995Date of Patent: November 5, 1996Assignee: Texas Instruments IncorporatedInventors: H. Michael Grimes, Farouk A. Hariri
-
Patent number: 5349921Abstract: Semiconductor crystalline materials, e.g. silicon, GaAs, are grown from a melt, e.g. using the Czochralski technique where a seed crystal is dipped into the melt then slowly withdrawn. Rotation of the growing crystal (6) is partly responsible for convective flows within the melt (5). Convective flows are reduced while radial uniformity is improved by subjecting the crystal/melt interface to a shaped magnetic field. This magnetic field is rotationally symmetrical about the axis of crystal rotation, with a component of field parallel to this axis that is less than 500 gauss, preferably less than 200 gauss, with a value above 500 gauss at other parts of the melt. The field may be produced by two superconducting magnet coils (21, 22) spaced apart and arranged co-axially with the axis of crystal rotation.Type: GrantFiled: October 12, 1990Date of Patent: September 27, 1994Assignee: Her Majesty the Queen in right of Canada, as represented by The Secretary of State for Defence in Her Britannic Majesty's Government of the United Kingdom of Great Britain and Northern IrelandInventors: Keith G. Barraclough, Robert W. Series