Patents Examined by Felisa Garrett
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Patent number: 6326334Abstract: A lanthanum aluminate (LaAlO3) substrate on which thin films of layered perovskite copper oxide superconductors are formed. Lanthanum aluminate, with a pseudo-cubic perovskite crystal structure, has a crystal structure and lattice constant that closely match the crystal structures and lattice constants of the layered perovskite superconductors. Therefore, it promotes epitaxial film growth of the superconductors, with the crystals being oriented in the proper direction for good superconductive electrical properties, such as a high critical current density. In addition, LaAlO3 has good high frequency properties, such as a low loss tangent and low dielectric constant at superconductive temperatures. Finally, lanthanum aluminate does not significantly interact with the superconductors. Lanthanum aluminate can also be used to form thin insulating films between the superconductor layers, which allows for the fabrication of a wide variety of superconductor circuit elements.Type: GrantFiled: November 21, 1994Date of Patent: December 4, 2001Assignee: TRW Inc.Inventors: Randy Wayne Simon, Christine Elizabeth Platt, Alfred Euinam Lee, Gregory Steven Lee
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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: 6217648Abstract: With relatively simple arrangement and at low cost, the present invention provides a single crystal pulling apparatus, by which it is possible to prevent a single crystal from being turned to polycrystal, to move the crystal itself smoothly and gently from a necking portion during pulling operation of the single crystal, and to reliably hold the single crystal even in case of trouble such as power suspension.Type: GrantFiled: April 21, 1999Date of Patent: April 17, 2001Assignee: Super Silicon Crystal Research Institute CorporationInventor: Yutaka Shiraishi
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Patent number: 6197699Abstract: The present invention provides a method for cleaning a contaminated chamber used in the manufacture of semiconductor devices. In one embodiment, the method comprises the steps of injecting, under pressure, a gas mixture of a fluorine-containing gas and an inert gas into the contaminated chamber, radiating the contaminated chamber with a radio frequency during the step of injecting, and removing volatile by-products or solid particulates from the contaminated chamber by performing pump-purge cycles within the contaminated chamber.Type: GrantFiled: January 20, 1998Date of Patent: March 6, 2001Assignee: Lucent Technologies Inc.Inventors: Larry B. Fritzinger, Cynthia C. Lee, Edward M. Middlebrook, John M. Sniegowski
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Patent number: 6176923Abstract: A crucible is held in a closed position when the crucible is at a certain temperature. A temperature sensitive member expands differently in response to heat than other portions of the crucible. When the temperature of the temperature sensitive member is increased, the temperature sensitive member expands an amount different than do other portions of the crucible and thereby causes the crucible to open.Type: GrantFiled: November 2, 1999Date of Patent: January 23, 2001Assignee: SEH America, Inc.Inventor: Gary R. Heid
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Patent number: 6176924Abstract: A crystal growth system, comprising: a furnace; a plurality of heating elements coupled to said furnace, each said plurality of heating elements defining a heat zone, each said heating element set to a desired temperature value; a plurality of thermocouples associated with respective heat zones to detect a temperature value; a translation system for passing an ampoule containing crystal growth material through said furnace into said heat zones and providing a positional location of said ampoule and; a multi-variable self-tuning temperature controller connected to said plurality of heating elements, said plurality of thermocouples and said translation system, said controller monitoring each said zone temperature value and upon considering the thermal interaction of heating zones and the moving thermal inertia of the ampoule, adjusting voltage input to said heat zones to obtain optimal crystal growth within said ampoule.Type: GrantFiled: May 18, 2000Date of Patent: January 23, 2001Assignees: The University of Akron and Nasa, The United States of AmericaInventors: Walter Duval, Celal Batur, Robert J. Bennett
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Patent number: 6171392Abstract: A method for producing a silicon single crystal by a Czochralski method comprises bringing a seed crystal into contact with a melt, performing a necking operation, and growing a single crystal ingot, wherein concentration of interstitial oxygen incorporated during the necking operation is 1 ppma (JEIDA) or more. The rate of success in making dislocation-free crystals is improved in a seeding method in which a necking operation is performed.Type: GrantFiled: March 31, 1999Date of Patent: January 9, 2001Assignee: Shin-Etsu Handotai Co., Ltd.Inventor: Eiichi Iino
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Patent number: 6165263Abstract: A method for growing a single crystal by allowing a seed crystal to contact a molten zone formed by melting a polycrystalline material, followed by moving the molten zone away from the seed, wherein the oxygen concentration in the atmosphere during growth of the single crystal is lower than about 10% by volume.Type: GrantFiled: March 5, 1999Date of Patent: December 26, 2000Assignee: Murata Manufacturing Co., Ltd.Inventors: Takenori Sekijima, Takashi Fujii, Kikuo Wakino, Masakatsu Okada
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Patent number: 6143071Abstract: There is disclosed a method for heat treatment of a silicon substrate produced by the CZ method by utilizing a rapid thermal annealer, wherein the heat treatment is performed under an atmosphere composed of 100% nitrogen, or 100% oxygen, or a mixed atmosphere of oxygen and nitrogen by heating the silicon substrate to a maximum holding temperature within a range of from 1125.degree. C. to the melting point of silicon, and holding the substrate at that maximum holding temperature for a holding time of 5 seconds or more, and then the substrate is rapidly cooled at a cooling rate of 8.degree. C./second or more from the maximum holding temperature. In the method, the amount of oxygen precipitation nuclei in the substrate can be controlled by changing the maximum holding temperature and the holding time.Type: GrantFiled: June 30, 1999Date of Patent: November 7, 2000Assignee: Shin-Etsu Handotai Co., Ltd.Inventors: Ken Aihara, Hiroshi Takeno
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Patent number: 6139630Abstract: A suspender for suspending polycrystalline rods steadfastly and easily in a furnace for single-crystal fabrication by the recharge or additionally charged method is disclosed. The suspender includes a plate which is made of molybdenum or SiC-coated graphite and a stick perpendicularly connected to the center of the plate. Both sides of the openings are arms for supporting the polycrystalline rods, thereby suspending the polycrystalline rods vertically in the opening. Means for preventing the polycrystalline rods from slipping out of the suspender are provided at ends of the arms. Therefore, the polycrystalline rods will not slip from the opening even though the plate is inclined. The suspender is suspended in the furnace by a stick. The polycrystalline rods require few tasks to form grooves and install on the suspender, thus decreasing the process time and manufacturing cost.Type: GrantFiled: May 16, 1996Date of Patent: October 31, 2000Assignee: Komatsu Electronic Metals Co., Ltd.Inventors: Tatsuhiro Fujiyama, Hiroshi Inagaki, Teruhiko Uchiyama, Hidetoshi Kurogi
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Patent number: 6139625Abstract: There is disclosed a method of producing a silicon single crystal wafer wherein a silicon single crystal ingot in which nitrogen is doped is grown by Czochralski method, the single crystal ingot is sliced to yield a silicon single crystal wafer, and then the silicon single crystal wafer is subjected to heat treatment with a rapid heating/rapid cooling apparatus, and the silicon single crystal wafer produced by the method. There can be provided a method for producing a silicon single crystal wherein growth of crystal defects (grown-in defects) in silicon single crystal produced by CZ method are suppressed, particularly growth of crystal defects are prevented in the surface layer of the wafer, and crystal defect can be surely removed by a short time heat treatment even if small crystal defects are generated.Type: GrantFiled: March 8, 1999Date of Patent: October 31, 2000Assignee: Shin-Etsu Handotai Co., Ltd.Inventors: Masaro Tamatsuka, Norihiro Kobayashi, Satoshi Oka
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Patent number: 6136092Abstract: A crucible with 22 inches or more in inner diameter, which has a small deformation of the body under exposure to abundant heat radiation during pulling a single crystal, and which has no practical problem, and a method of producing the same are disclosed.Type: GrantFiled: August 19, 1999Date of Patent: October 24, 2000Assignee: Shin Etsu Quartz Products Co., Ltd.Inventors: Tatsuhiro Sato, Shigeo Mizuno, Mitsuo Matsumura, Hiroyuki Watanabe
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Patent number: 6132508Abstract: A multi-shelled melt container is disclosed for liquefying and crystallizing substances which comprises at least an inner shell and a bearing shell. While the inner shell--which has a thin wall in comparison to the wall of the bearing shell--consists of an inert material with respect to the melt, the bearing shell serves exclusively to fixate and support the inner shell and is correspondingly constructed in a mechanically stable fashion. The device can also comprise means to pump the melt over into a collection vessel.Type: GrantFiled: October 4, 1999Date of Patent: October 17, 2000Assignee: Siemens AktiengesellschaftInventors: Thomas Berthold, Hermann Boedinger
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Patent number: 6120599Abstract: In a method for producing a silicon single crystal wafer, a silicon single crystal is grown in accordance with the Czochralski method such that the F/G value becomes 0.112-0.142 mm.sup.2 /.degree. C..multidot.min at the center of the crystal, where F is a pulling rate (mm/min) of the single crystal, and G is an average intra-crystal temperature gradient (.degree. C./mm) along the pulling direction within a temperature range of the melting point of silicon to 1400.degree. C. Additionally, the single crystal is pulled such that the interstitial oxygen concentration becomes less than 24 ppma, or the time required to pass through a temperature zone of 1050-850.degree. C. within the crystal is controlled to become 140 minutes or less. The method allows production of silicon single crystal wafers in which neither FPDs nor L/D defects exist on the wafer surface, which therefore has an extremely low defect density, and whose entire surface is usable.Type: GrantFiled: December 6, 1999Date of Patent: September 19, 2000Assignee: Shin-Etsu Handotai Co., Ltd.Inventors: Makoto Iida, Eiichi Iino, Masanori Kimura, Shozo Muraoka
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Patent number: 6117233Abstract: Thin, single-crystal SiC films are obtained by means of a pyrolysis process, the substrate to be coated being covered with a carbonaceous polysilane, the adhering layer being pyrolyzed in an inert atmosphere and the amorphous layer of SiC obtained in this way being crystallized by maintaining it at a temperature of over 700.degree. C. Using a special variation of the process, it is easy to form doped SiC films. To this end the dopant is added in the form of a silane compound.Type: GrantFiled: August 6, 1997Date of Patent: September 12, 2000Assignee: Max-Planck-Gesellschaft zur Forderung DEInventors: Joachim Bill, Frederick F. Lange, Thomas Wagner, Fritz Aldinger, Detlef Heimann
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Patent number: 6113691Abstract: Semiconductor compounds and a method for producing the same are provided wherein a method for growing at least one epitaxial layer of a II-VI semiconductor compound using MOVPE is used, the method including the steps of subjecting a substrate to organometallic and hydride precursor compounds in a MOVPE reactor at ultra low pressure, i.e. a pressure in the range of about 10 to 1 mTorr, whereby the organometallic and hydride precursor compounds react at a substrate surface without substantial reaction in the gas phase. The epitaxial layers and semiconductor compounds are useful in blue laser devices.Type: GrantFiled: May 26, 1995Date of Patent: September 5, 2000Assignee: Philips Electronics North America CorporationInventors: Nikhil R. Taskar, Donald R. Dorman, Dennis Gallagher
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Patent number: 6110275Abstract: There is disclosed a method of producing, in large volume and at low cost, titanium carbide, nitride and carbonitride whiskers, with preferably submicron diameters, to be used as reinforcing material. The whiskers are suitable for use as a reinforcement material in a wide range of materials, including metals, intermetallics, plastics, ceramics and metallic bonded hard material. Titanium oxide, hydroxide or alkali compounds thereof are mixed with a carbon source with a volatile part which volatiles at temperatures exceeding 500.degree. C. and in an amount to satisfy the stoichiometric requirements of the carbide or nitride. A halogenide salt is used as a volatilization agent for titanium as well as a catalyst able to dissolve Ti plus C and/or N, such as Ni or Co. The reactant powders are blended in some typical manner, e.g., by using a high speed blender so as to intimately mix them.Type: GrantFiled: December 20, 1996Date of Patent: August 29, 2000Assignee: Sandvik ABInventors: Mats Nygren, Mats Johnsson, Niklas Ahlen, Magnus Ekelund
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Patent number: 6110272Abstract: A method of loading a crucible, comprises loading at least one polycrystalline silicon rod into the crucible. Lump and/or granular polycrystalline silicon may also be loaded into the crucible. Especially when loaded into the crucible in a close-packed pyramidal configuration, a high loading density is achieved.Type: GrantFiled: September 29, 1998Date of Patent: August 29, 2000Assignee: Sumitomo Sitix CorporationInventors: Katsunori Aikawa, Kuniharu Inoue
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Patent number: 6106612Abstract: A level detector detects the level of an approximately flat surface of a substance in a container. The level detector illuminates a portion of the surface, and detects the location of the illuminated portion on the surface. Based on detecting the location of the illuminated portion, the level detector generates a signal related to the level of the surface, which can represent the level of the surface in a direction perpendicular to the surface. A method for determining a level of a surface of a substance in a container includes illuminating a portion of the surface, detecting a location of the illuminated portion on the surface, and generating a signal related to the level of the surface based on the result of detecting the location of the illuminated portion.Type: GrantFiled: June 4, 1998Date of Patent: August 22, 2000Assignee: SEH America Inc.Inventor: Barton V. White
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Patent number: 6100201Abstract: A method of forming a capacitor by forming a dielectric layer over a bottom electrode layer, forming a top electrode layer over the dielectric layer to form laminations of the bottom electrode layer, the dielectric layer and the top electrode layer, and selectively etching the laminations to form a capacitor, the dielectric layer being etched by a reactive ion etching so that the dielectric layer of the capacitor receives no substantive damage in the etching process.Type: GrantFiled: March 3, 1998Date of Patent: August 8, 2000Assignee: NEC CorporationInventors: Yukihiko Maejima, Jun Kawahara, Shinobu Saitoh, Yoshihiro Hayashi