Patents Examined by Felisa Garrett
  • Patent number: 5788768
    Abstract: A silicon carbide feedstock charge for growing silicon carbide boules in a physical vapor transport system. The feedstock charge includes silicon carbide particles, as well as any dopant material, if required, in a structure which is rigid and self supportable. An elongated feedstock charge may be moved toward the seed crystal as the feedstock is depleted during boule growth. The feedstock charge may be tailored to provide a non-uniform flux for growing more planar boule faces.
    Type: Grant
    Filed: May 8, 1997
    Date of Patent: August 4, 1998
    Assignee: Northrop Grumman Corporation
    Inventors: Donovan L. Barrett, Richard H. Hopkins
  • Patent number: 5788718
    Abstract: An apparatus for growing a single crystal which comprises a quartz crucible in a chamber for containing a semiconductor melt from which a semiconductor single crystal rod is pulled, wherein there further comprises a cylinder concentrically surrounding the single crystal rod to be pulled whose top is connected to the edge of the opening at the center of the ceiling of the chamber in an airtight fashion and whose bottom hangs down toward the semiconductor melt, and a collar which spreads open upward and outward and whose outer circumferential part extends above the top end of the quartz crucible wherein the outer circumferential part is situated such that it does not touch the top end of the quartz crucible when said quartz crucible is at its highest position.
    Type: Grant
    Filed: December 20, 1996
    Date of Patent: August 4, 1998
    Assignee: Shin-Etsu Handotai Co., Ltd.
    Inventors: Hirotoshi Yamagishi, Kiyotaka Takano, Eiichi Iino, Masanori Kimura
  • Patent number: 5788763
    Abstract: In a heat history initializing step, a heat treatment in performed in an atmosphere including at least one of hydrogen, helium, and argon while the temperature is increased in a range of 700.degree. C. to 1,000.degree. C. at a rate of 15.degree.-1,000.degree. C./min. In a controlled nuclei growing step, a heat treatment is performed in the above atmosphere while the temperature is kept constant in a range of 850.degree. C. to 980.degree. C. for 0.5-60 minutes.
    Type: Grant
    Filed: March 7, 1996
    Date of Patent: August 4, 1998
    Assignee: Toshiba Ceramics Co., Ltd.
    Inventors: Kenro Hayashi, Ryuji Takeda, Katsuhiro Chaki, Ping Xin, Jun Yoshikawa, Hiroyuki Saito
  • 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: 5785755
    Abstract: Disclosed are methods of preparing multilayer structures with InGaAsP layers of different compositions by metal organic vapor phase epitaxy, which result in formation of sharp heterointerfaces. After an InGaAsP well layer has been grown, the process is kept on standby with a flow of AsH.sub.3 and PH.sub.3, which are sources comprising elements of group V, at the well's composition ratios, and then with a flow of a source comprising an element of group V, including TBP (TBP/standby step), and an InGaAsP barrier layer is grown which has a smaller arsenic content than the well layer. TBP has a decomposition temperature approximately 100.degree. C. lower than PH.sub.3, and thus provides a phosphorus pressure which is five times or more as high as that of PH.sub.3 at identical growth temperatures and at identical V/III ratios.
    Type: Grant
    Filed: March 15, 1996
    Date of Patent: July 28, 1998
    Assignee: NEC Corporation
    Inventors: Takahiro Nakamura, Satoshi Ae
  • Patent number: 5785752
    Abstract: 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: Grant
    Filed: December 12, 1995
    Date of Patent: July 28, 1998
    Assignee: Shin-Etsu Chemical Co., Ltd.
    Inventors: Masayuki Tanno, Toshihiko Ryuo
  • Patent number: 5785753
    Abstract: In a single-crystal manufacturing method, after a single crystal is grown, the crystal is separated from the molten melt and gradually cooled while suspended immediately above the surface of the melt. During this cooling, a measure, which produces solidification of the melt, is locally applied. As a result, the solidification of the melt is selectively forced so that at least the melt forms a crust and prevents the crystal, should it fall, from becoming immersed in molten melt. This measure also protects the crystal from any sudden release of heat such as tends to occur if the melt becomes supercooled prior to the onset of crystallization.
    Type: Grant
    Filed: November 9, 1995
    Date of Patent: July 28, 1998
    Assignee: Sony Corporation
    Inventors: Yasujiro Taguchi, Tsutomu Okamoto
  • Patent number: 5779792
    Abstract: The present invention provides an improved single crystal pulling apparatus for pulling a single crystal semiconductor such as silicon or gallium arsenide. The apparatus of the present invention comprises a gas tight container, a crucible which is disposed inside the container, a heater, and a pair of coils to apply a cusp magnetic field in the semiconductor melt. The crucible is separated into two regions by a cylindrical partition body, and an outside region is used to supply source material and to melt the source material and an inside region is used for pulling up the single crystal. The inside and outside regions are communicated with the communication passage provided at the bottom of the partition body. Electrical currents in opposing directions are applied to a pair of coils for generating in the melt a cusp magnetic field which includes a vertical portion and a horizontal portion relative to the crucible.
    Type: Grant
    Filed: January 10, 1997
    Date of Patent: July 14, 1998
    Assignees: Mitsubishi Materials Silicon Corporation, Mitsubishi Materials Corporation
    Inventors: Takashi Atami, Hisashi Furuya, Michio Kida
  • Patent number: 5779790
    Abstract: In a method of manufacturing a silicon monocrystal using the Czochralski method, a seed crystal is brought into contact with silicon melt and is then pulled such that after a neck portion is formed, a silicon monocrystal is grown below the neck portion. The crystal has a hollow portion which has an opening in a contact surface of the seed crystal to be brought into contact with the silicon melt. Alternatively, the seed crystal has a hollow portion which will have an opening in the contact surface of the seed crystal when the contact surface is brought into contact with the silicon melt. Use of such seed crystals makes it possible to increase the strength of the neck portion and to pull a heavy and long silicon monocrystal having a large diameter.
    Type: Grant
    Filed: March 10, 1997
    Date of Patent: July 14, 1998
    Assignee: Shin-Etsu Handotai Co., Ltd.
    Inventors: Toshinari Murai, Naoki Nagai
  • Patent number: 5779791
    Abstract: A Czochralski method of producing a single crystal silicon ingot having a uniform thermal history from a silicon melt contained in a crucible coaxial with the ingot. In the process the pulling rate of the end-cone of the ingot is maintained at a relatively constant rate which is comparable to the pulling rate for the second half of the main body of the ingot. During the pulling of the end-cone of the crystal at a constant rate, the process may be further refined by, either independently or in combination, increasing the heat supplied to the melt, reducing the crystal rotation rate and/or reducing the crucible rotation rate. The second half of the main body of a single crystal silicon ingot grown in accordance with this process exhibits a relatively uniform axial concentration of flow pattern defects and amount of oxygen precipitated.
    Type: Grant
    Filed: August 8, 1996
    Date of Patent: July 14, 1998
    Assignee: MEMC Electronic Materials, Inc.
    Inventors: Harold W. Korb, Sadasivam Chandrasekhar, Robert J. Falster, Joseph C. Holzer, Kyong-Min Kim, Steven L. Kimbel, Larry E. Drafall
  • Patent number: 5772761
    Abstract: The invention concerns a crystallization furnace for a material with low thermal conductivity arid/or low hardness.This furnace can obtain high quality single crystals.This furnace comprises a heating chamber (1), heating means (13) to create a temperature profile along the center line of said chamber and thus define at least one heating zone (3), and at least one cooling zone (5) and a crucible (9) filled with a solution of a solute to be crystallized in a solvent, said crucible (9) being fixed and placed in the heating chamber (1) in the heating zone (3), characterized in that the furnace also comprises:a crystallization device (27) comprising a temperature homogenizer (29A) and a heat sink (29B) separated by a thermally insulating spacer (31), said temperature homogenizer, heat sink and insulating spacer being rigidly attached to each other, andmeans (37) of displacing said crystallization device (27) along the center line of the chamber and around said crucible (9).
    Type: Grant
    Filed: November 8, 1996
    Date of Patent: June 30, 1998
    Assignee: Commissariat a l'Energie Atomique
    Inventor: Gerard Petroz
  • Patent number: 5769941
    Abstract: A seed (22) is formed to have a ?110! direction (24) that is at an angle (26) to the pull direction (23) used for growing a semiconductor ingot (36). Dislocations (34) in the ingot (36) terminate on the surface of the neck (37) of the ingot, and do not propagate into the body (38) of the ingot (36).
    Type: Grant
    Filed: May 1, 1996
    Date of Patent: June 23, 1998
    Assignee: Motorola, Inc.
    Inventor: Herng-Der Chiou
  • Patent number: 5769944
    Abstract: An improved vertical gradient freeze and vertical Bridgman compound semiconductor crystal growth apparatus capable of applying an axial magnetic field of about 1600G in the crystal growth axis direction using an electrical resistance type electromagnet which has a simple structure and can be installed easily, which includes a high temperature electric furnace arranged at an upper portion of the apparatus, a crystal growth reaction tube disposed within a low temperature electric furnace arranged below the high temperature electric furnace and having a reaction container disposed therein, and an electromagnet surrounding the intermediate portion of the high temperature electric furnace.
    Type: Grant
    Filed: August 29, 1996
    Date of Patent: June 23, 1998
    Assignee: Korea Institute of Science and Technology
    Inventors: Young Ju Park, Suk-Ki Min
  • Patent number: 5769951
    Abstract: A platen supports a wafer during the deposition of tungsten, metal nitrides, other metals, and silicides in a chemical vapor deposition reactor. A deposition control gas that includes a suitable inert gas such as argon or a mixture of inert and reactant gases such as argon and hydrogen is introduced through a restrictive opening into an ambient in the reactor. An exclusion guard aligned with the platen has an extension extending over a frontside peripheral region of the wafer. Deposition control gas is introduced under the exclusion guard extension and exits through a restrictive opening between the exclusion guard extension and a wafer frontside peripheral region. The restrictive opening provides a uniform pressure of deposition control gas at the edge and frontside of the wafer to prevent deposition on the wafer edge and backside.
    Type: Grant
    Filed: January 17, 1996
    Date of Patent: June 23, 1998
    Inventors: Everhardus P. van de Ven, Eliot K. Broadbent, Jeffrey C. Benzing, Barry L. Chin, Christopher W. Burkhart, Lawrence C. Lane
  • Patent number: 5769943
    Abstract: Transition metals of Group VIII (Co, Rh and Ir) have been prepared as semiconductor compounds with the general formula TSb.sub.3. The skutterudite-type crystal lattice structure of these semiconductor compounds and their enhanced thermoelectric properties results in semiconductor materials which may be used in the fabrication of thermoelectric elements to substantially improve the efficiency of the resulting thermoelectric device. Semiconductor materials having the desired skutterudite-type crystal lattice structure may be prepared in accordance with the present invention by using vertical gradient freezing techniques and/or liquid phase sintering techniques. Measurements of electrical and thermal transport properties of selected semiconductor materials prepared in accordance with the present invention, demonstrated high Hall mobilities (up to 1200 cm.sup.2.V.sup.-1.s.sup.-1) and good Seebeck coefficients (up to 150 .mu.VK.sup.-1 between 300.degree. C. and 700.degree. C.).
    Type: Grant
    Filed: August 3, 1993
    Date of Patent: June 23, 1998
    Assignee: California Institute of Technology
    Inventors: Jean-Pierre Fleurial, Thierry F. Caillat, Alexander Borshchevsky
  • Patent number: 5766344
    Abstract: A preparing method of a semiconductor, particularly a preparing method of a polycrystal semiconductor film which has a good electrical property is disclosed. In order to obtain a non-crystalline silicon film containing a lot of combination of hydrogen and silicon, a forming process of a non-crystalline silicon film by a low temperature gas phase chemical reaction, a process of a heat annealing to produce a lot of dangling bonds of silicon, so as to draw out hydrogen from said non-crystalline silicon film, and a process of applying a laser irradiation to said non-crystal silicon film having a lot of dangling bond of silicon are conducted.
    Type: Grant
    Filed: May 26, 1995
    Date of Patent: June 16, 1998
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Honyong Zhang, Naoto Kusumoto
  • Patent number: 5766347
    Abstract: An apparatus for fabricating a semiconductor single crystal, which make it possible to reduce the oxygen concentration of a pulling single crystal, to steadily dissolve the polysilicon material received in a crucible, and to minimize the cost and installation space, is provided.The hollow cylindrical resistance heater of the apparatus, which co-axially surrounds a crucible, is provided with a ring-shaped slit excluding the location where at least two electrodes are formed, in a direction substantially perpendicular to the axial direction so as to divide the heater into an upper heating portion and a lower heating portion, and is provided with a plurality of vertical slits formed on the upper heating portion and the lower heating portion respectively, in a direction substantially parallel to the axial direction, wherein each vertical slit formed on the upper heating portion does not align with each vertical slit formed on the lower heating portion.
    Type: Grant
    Filed: February 24, 1997
    Date of Patent: June 16, 1998
    Assignee: Komatsu Electronic Metals Co., Ltd.
    Inventors: Koichi Shimomura, Yoshinobu Hiraishi, Mitsunori Kawabata
  • 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
  • Patent number: 5766341
    Abstract: Apparatus and methods for pulling a semiconductor crystal according to a Czochralski method are disclosed. The apparatus includes a crucible containing a melt, a crystal pulling mechanism which pulls the semiconductor crystal from the melt, a motor coupled to the crucible, and a control circuit for energizing the motor to rotate the crucible at a variable speed. The control circuit may energize the motor to rotate the crucible at a continuously varying acceleration and continuously varying rotational speed while the crystal pulling mechanism is pulling at least a portion of the semiconductor crystal from the melt in the crucible. The control circuit may also energize the motor to rotate the crucible at a rotational speed which monotonically increases and decreases.
    Type: Grant
    Filed: October 4, 1996
    Date of Patent: June 16, 1998
    Assignee: MEMC Electric Materials, Inc.
    Inventors: Steven L. Kimbel, Harold W. Korb, Cynthia F. Hall