Patents by Inventor Carlos A. Paz de Araujo

Carlos A. Paz de Araujo has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5932295
    Abstract: A mist generator produces a mist from a liquid precursor. The mist is charged and accelerated by a pair of charged electrodes in an acceleration chamber. The mist passes through a conduit charged to the same polarity of the mist particles, to a deposition chamber where they are deposited on a substrate having the opposite polarity as the particles. Infrared lamps heat the mist particles in the acceleration chamber to a temperature below the temperature at which the compounds and solvent in the liquid precursor decompose. In one embodiment the deposition chamber is tubular and a plurality of substrates are held within the chamber in a position substantially perpendicular to the direction of mist flow in the chamber. A heater and an electrical field generator in the tube add sufficient energy to the mist as it passes through the tube to provide uniform deposition of the mist on the plurality of substrates.
    Type: Grant
    Filed: November 3, 1997
    Date of Patent: August 3, 1999
    Assignee: Symetrix Corporation
    Inventors: Larry D. McMillan, Carlos A. Paz de Araujo
  • Patent number: 5909042
    Abstract: A precursor solution formed of a liquid polyoxyalkylated metal complex in a solvent is applied to a substrate in the formation of a metal oxide thin film. The liquid thin film is baked in air to a temperature up to 500.degree. C. while UV radiation having a wavelength ranging from 180 nm to 300 nm is applied. The thin film can be twice-baked at increasing temperatures while UV radiation is applied at one or both bakings. The film is then annealed at temperature ranging from about 700.degree. C. to 850.degree. C. to produce a thin-film solid metal oxide product. Alternatively, the UV radiation may be applied to the liquid precursor, the thin film may be annealed with UV radiation, or combinations of such applications of UV radiation to the precursor, to the thin film before or after baking, and/or UV annealing may be used. The use of UV radiation significantly reduces the leakage current and carbon impurity content of the final metal oxide.
    Type: Grant
    Filed: May 8, 1996
    Date of Patent: June 1, 1999
    Assignees: Symetrix Corporation, Matsushita Electronics Corporation
    Inventors: Masamichi Azuma, Larry D. McMillan, Carlos A. Paz De Araujo, Michael C. Scott
  • Patent number: 5888585
    Abstract: A charge storage device, such as an integrated circuit memory, including a dielectric comprising a barium-strontium-niobium oxide. A liquid precursor including the metals barium, strontium, and niobium is prepared and applied to a platinum electrode. The precursor is baked and annealed to form a dielectric having the formula Ba.sub.x Sr.sub.y Nb.sub.z O.sub.30, where x=1.3 to 3.5, y=1.5 to 3.7, and z =10. A top platinum electrode is then formed to provide a memory cell capacitor. Optimum results to date have been obtained with Ba.sub.2 Sr.sub.3 Nb.sub.10 O.sub.30, which yields a memory cell dielectric with dielectric constant over 1000 and a leakage current of less than 10.sup.-5 amperes per square centimeter for voltages up to 5 volts.
    Type: Grant
    Filed: December 16, 1996
    Date of Patent: March 30, 1999
    Assignee: Symetrix Corporation
    Inventors: Joseph D. Cuchiaro, Vikram Joshi, Claudia P. DaCruz, John M. McNelis, Carlos A. Paz de Araujo
  • Patent number: 5888583
    Abstract: A method and apparatus are disclosed for forming thin films of chemical compounds utilized in integrated circuits. The method includes steps forming a precursor liquid comprising a chemical compound in a solvent, providing a substrate within a vacuum deposition chamber, producing a mist of the precursor liquid, and flowing the mist into the deposition chamber while maintaining the chamber at ambient temperature to deposit a layer of the precursor liquid on the substrate. The liquid is dried to form a thin film of a solid material on the substrate, then the integrated circuit is completed to include at least a portion of the film of solid material in a component of the integrated circuit.
    Type: Grant
    Filed: January 23, 1995
    Date of Patent: March 30, 1999
    Assignee: Symetrix Corporation
    Inventors: Larry D. McMillan, Carlos A. Paz de Araujo, Tommy L. Roberts
  • Patent number: 5883828
    Abstract: Thin film ferroelectric materials for use in integrated memory circuits, such as FERAMS and the like, contain strontium bismuth niobium tantalate having an empirical formula SrBi.sub.2+E (Nb.sub.X Ta.sub.2-X)O.sub.9+3E/2, wherein E is a number representing an excess amount of bismuth ranging from zero to 2; and X is a number representing an excess amount of niobium ranging from 0.01 to 0.9. The thin films demonstrate an exceptional resistance to polarization imprinting when challenged with unidirectional voltage pulses.
    Type: Grant
    Filed: February 6, 1998
    Date of Patent: March 16, 1999
    Assignee: Symetrix Corporation
    Inventors: Joseph D. Cuchiaro, Narayan Solayappan, Carlos A. Paz de Araujo, Larry D. McMillan
  • Patent number: 5871853
    Abstract: A precursor solution formed of a liquid polyoxyalkylated metal complex in a solvent is applied to a substrate in the formation of a metal oxide thin film. The liquid thin film is baked in air to a temperature up to 500.degree. C. while UV radiation having a wavelength ranging from 180 nm to 300 nm is applied. The thin film can be twice-baked at increasing temperatures while UV radiation is applied at one or both bakings. The film is then annealed at temperature ranging from about 700.degree. C. to 850.degree. C. to produce a thin-film solid metal oxide product. Alternatively, the UV radiation may be applied to the liquid precursor, the thin film may be annealed with UV radiation, or combinations of such applications of UV radiation to the precursor, to the thin film before or after baking, and/or UV annealing may be used. The use of UV radiation significantly reduces the leakage current and carbon impurity content of the final metal oxide.
    Type: Grant
    Filed: May 8, 1996
    Date of Patent: February 16, 1999
    Assignees: Symetrix Corporation, Matsushita Electronics Corporation
    Inventors: Masamichi Azuma, Larry D. McMillan, Carlos A. Paz De Araujo, Michael C. Scott
  • Patent number: 5853889
    Abstract: An electromagnetic wave absorption panel for use in building construction includes a protective tile layer, an absorber layer, a metal reflective layer, and a building support layer, such as concrete. The absorber layer utilizes novel materials including high dielectric constant materials, such as ABO.sub.3 type perovskites, layered superlattice materials, conducting oxides, and signet magnetics, ferroelectrics, such as ABO.sub.3 type perovskites and layered superlattice materials, garnets, a nickel-zinc ferrite, Ni.sub.0.4 Zn.sub.0.6 Fe.sub.2 O.sub.4, and polymer-ceramic composites of the above materials.
    Type: Grant
    Filed: January 13, 1997
    Date of Patent: December 29, 1998
    Assignees: Symetrix Corporation, Fujita Corporation
    Inventors: Vikram Joshi, Kenichi Kimura, Carlos A. Paz de Araujo, Hiroshi Kiyokawa
  • Patent number: 5853500
    Abstract: A liquid precursor containing barium, strontium, and titanium, is applied to a first electrode, dried in air at a first temperature of 160.degree. C. and then a second temperature of 400.degree. C., and annealed at a temperature of 800.degree. C. in nitrogen to form a thin film of barium strontium titanate. A second electrode is deposited and then the device is patterned to form a capacitor, and a second anneal is performed at a temperature of 800.degree. C. in nitrogen. In this manner, a high electronic quality thin film of barium strontium titanate is fabricated without a high-temperature oxygen anneal.
    Type: Grant
    Filed: July 18, 1997
    Date of Patent: December 29, 1998
    Assignee: Symetrix Corporation
    Inventors: Vikram Joshi, Carlos A. Paz de Araujo
  • Patent number: 5849071
    Abstract: A precursor liquid comprising several metal 2-ethylhexanoates, such as strontium, tantalum and bismuth 2-ethylhexanoates, in a solvent such as xylenes/methyl ethyl ketone and a small amount of hexamethyl-disilazane. The liquid is dried, baked, and annealed to form a thin film of a layered superlattice material, such as strontium bismuth tantalate, on the substrate.
    Type: Grant
    Filed: June 16, 1997
    Date of Patent: December 15, 1998
    Assignees: Symetrix Corporation, Matsushita Electronics Corporation
    Inventors: Gary F. Derbenwick, Larry D. McMillan, Narayan Solayappan, Michael C. Scott, Carlos A. Paz de Araujo, Shinichiro Hayashi
  • Patent number: 5846597
    Abstract: A precursor liquid comprising several metal 2-ethylhexanoates, such as strontium, tantalum and bismuth 2-ethylhexanoates, in a xylenes/methyl ethyl ketone solvent is prepared, a substrate is placed within a vacuum deposition chamber, a small amount of hexamethyl-disilazane is added to the precursor liquid is misted, and the mist is flowed into the deposition chamber while maintaining the chamber at ambient temperature to deposit a layer of the precursor liquid on the substrate. The liquid is dried, baked, and annealed to form a thin film of a layered superlattice material, such as strontium bismuth tantalate, on the substrate. Then an integrated circuit is completed to include at least a portion of the layered superlattice material film in a component of the integrated circuit.
    Type: Grant
    Filed: June 16, 1997
    Date of Patent: December 8, 1998
    Assignees: Symetrix Corporation, Matsushita Electronics Corporation
    Inventors: Gary F. Derbenwick, Larry D. McMillan, Narayan Solayappan, Michael C. Scott, Carlos A. Paz de Araujo, Shinichiro Hayashi
  • Patent number: 5843516
    Abstract: A precursor liquid comprising several metal 2-ethylhexanoates, such as strontium, tantalum and bismuth 2-ethylhexanoates, in a xylenes/methyl ethyl ketone solvent is prepared, a substrate is placed within a vacuum deposition chamber, a small amount of hexamethyl-disilazane is added to the precursor liquid is misted, and the mist is flowed into the deposition chamber while maintaining the chamber at ambient temperature to deposit a layer of the precursor liquid on the substrate. The liquid is dried, baked, and annealed to form a thin film of a layered superlattice material, such as strontium bismuth tantalate, on the substrate. Then an integrated circuit is completed to include at least a portion of the layered superlattice material film in a component of the integrated circuit.
    Type: Grant
    Filed: September 16, 1996
    Date of Patent: December 1, 1998
    Assignees: Symetrix Corporation, Matsushita Electronics Corporation
    Inventors: Gary F. Derbenwick, Larry D. McMillan, Narayan Solayappan, Michael C. Scott, Carlos A. Paz de Araujo, Shinichiro Hayashi
  • Patent number: 5840110
    Abstract: Metal alkoxycarboxylate-based liquid precursor solutions are used to form electronic devices (100) that include mixed layered superlattice materials of a type having discrete oxygen octahedral layers and collated with a superlattice-generator layer. The precursor solutions include a plurality of metal moieties in effective amounts for yielding the layered superlattice materials. These metal moieties are mixed to include an A/B portion capable of forming an A/B layer, a perovskite-like AB layer portion capable of forming a perovskite-like AB octahedral layer, and a superlattice-generator portion capable of forming the superlattice-generator layer. The precursors are deposited in liquid form upon a substrate and annealed to provide the layered superlattice materials.
    Type: Grant
    Filed: May 10, 1996
    Date of Patent: November 24, 1998
    Assignees: Symetrix Corporation, Matsushita Electronics Corporation
    Inventors: Masamichi Azuma, Carlos A. Paz De Araujo, Larry D. McMillan
  • Patent number: 5825057
    Abstract: A liquid precursor containing a metal is applied to a substrate, RTP baked, and annealed to form a layered superlattice material. Prebaking the substrate and oxygen in the RTP and anneal is essential, except for high bismuth content precursors. Excess bismuth between 110% and 140% of stoichiometry and RTP temperature of 725.degree. C. is optimum. The film is formed in two layers, the first of which uses a stoichiometric precursor and the second of which uses an excess bismuth precursor. The electronic properties are so regularly dependent on process parameters and material composition, and such a wide variety of materials are possible, that electronic devices can be designed by selecting from a continuous record of the values of one or more electronic properties as a continuous function of the process parameters and material composition, and utilizing the selected process and material composition to make a device.
    Type: Grant
    Filed: December 5, 1994
    Date of Patent: October 20, 1998
    Assignees: Symetrix Corporation, Olympus Optical Co., Ltd.
    Inventors: Hitoshi Watanabe, Carlos A. Paz De Araujo, Hiroyuki Yoshimori, Michael C. Scott, Takashi Mihara, Joseph D. Cuchiaro, Larry D. McMillan
  • Patent number: 5814849
    Abstract: A method for fabricating an integrated circuit capacitor having a dielectric layer comprising BST with excess B-site material, such as titanium, added. A polyoxyalkylated metal liquid precursor solution is prepared comprising a stock solution of BST of greater then 99.999% purity blended with excess B-site material such as titanium such that the titanium is in the range of 0-100 mol %. A xylene exchange is then performed to adjust the viscosity of the solution for spin-on application to a substrate. The precursor is spun on a first electrode, dried at 400.degree. C. for 2 minutes, then annealed at 650.degree. C. to 800.degree. C. for about an hour to form a layer of BST with excess titanium. A second electrode is deposited, patterned, and annealed at between 650.degree. C. to 800.degree. C. for about 30 minutes. The resultant capacitor exhibits an enlarged dielectric constant with only a small increase in leakage current.
    Type: Grant
    Filed: January 27, 1997
    Date of Patent: September 29, 1998
    Assignees: Symetrix Corporation, Matsushita Electronics Corporation
    Inventors: Masamichi Azuma, Carlos A. Paz De Araujo, Michael C. Scott
  • Patent number: 5811847
    Abstract: An integrated circuit memory, MMIC, or other device including a dielectric comprising lead-tin zirconium-titanium oxide (PSZT). The proportion of tin ranges from 30% to 50% of the total amount of tin, zirconium and titanium. The dielectric is formed by applying a first liquid precursor having 10% excess lead to a substrate and heating it to form a first PSZT thin film, applying a second liquid precursor having 5% excess lead to the first thin film and heating to form a second thin film, then applying the first liquid precursor and heating to form a third thin film, and annealing the three thin films together to form a PSZT dielectric layer.
    Type: Grant
    Filed: June 28, 1996
    Date of Patent: September 22, 1998
    Assignee: Symetrix Corporation
    Inventors: Vikram Joshi, Joseph D. Cuchiaro, Carlos A. Paz de Araujo, Larry D. McMillan
  • Patent number: 5803961
    Abstract: Metal alkoxycarboxylate-based liquid precursor solutions are used to form electronic devices (100) that include mixed layered superlattice materials (112) of a type having discrete oxygen octahedral layers (124) and (128) collated with a superlattice-generator layer (116). The precursor solutions include a plurality of metal moieties in effective amounts for yielding the layered superlattice materials. These metal moieties are mixed to include an A/B portion capable of forming an A/B layer (124), a perovskite-like AB layer portion capable of forming a perovskite-like AB octahedral layer (128), and a superlattice-generator portion capable of forming the superlattice-generator layer (116). The precursors are deposited in liquid form upon a substrate and annealed to provide the layered superlattice materials.
    Type: Grant
    Filed: May 10, 1996
    Date of Patent: September 8, 1998
    Assignees: Symetrix Corporation, Matsushita Electronics Corporation
    Inventors: Masamichi Azuma, Carlos A. Paz De Araujo, Larry D. McMillan
  • Patent number: 5792592
    Abstract: A photosensitive liquid solution is used to make thin films for use in integrated circuits. The photosensitive liquid solution contains a photo initiator, and solvent, and a mixture of metals bonded to free-radical-susceptible monomers. The metals are mixed in amounts corresponding to the desired stoichiometry of a metal oxide thin film that derives from the. The photosensitive liquid solution is applied to a substrate, soft baked, and exposed to ultraviolet radiation under a photo mask. The ultraviolet radiation patterns the soft-baked film through a free radical polymerization chain reaction. A solvent etch is used to remove the unpolymerized portion of the polymerized film. The remaining thin film pattern is annealed to provide a patterned metal oxide film.
    Type: Grant
    Filed: May 24, 1996
    Date of Patent: August 11, 1998
    Assignees: Symetrix Corporation, Mitsubishi Materials Corporation
    Inventors: Hiroto Uchida, Nobuyuki Soyama, Kensuke Kageyama, Katsumi Ogi, Michael C. Scott, Larry D. McMillan, Carlos A. Paz de Araujo
  • Patent number: 5788757
    Abstract: A metal organic liquid precursor solution includes metal organic complexes dispersed in an ester solvent. The ester solvent has medium length carbon chains to prevent the precipitation of strongly electropositive metals in solution. A liquid precursor solution is used to make thin film metal oxides of uniform thickness and consistent quality.
    Type: Grant
    Filed: December 23, 1996
    Date of Patent: August 4, 1998
    Assignees: Symetrix Corporation, Mitsubishi Materials Corporation
    Inventors: Hiroto Uchida, Nobuyuki Soyama, Kensuke Kageyama, Katsumi Ogi, Jeffrey W. Bacon, Michael C. Scott, Larry D. McMillan, Carlos A. Paz de Araujo
  • Patent number: 5784310
    Abstract: Thin film ferroelectric materials for use in integrated memory circuits, such as FERAMS and the like, contain strontium bismuth niobium tantalate having an empirical formula SrBi.sub.2+E (Nb.sub.X Ta.sub.2-X)O.sub.9+3E/2, wherein E is a number representing an excess amount of bismuth ranging from zero to 2; and X is a number representing an excess amount of niobium ranging from 0.01 to 0.9. The thin films demonstrate an exceptional resistance to polarization imprinting when challenged with unidirectional voltage pulses.
    Type: Grant
    Filed: March 3, 1997
    Date of Patent: July 21, 1998
    Assignee: Symetrix Corporation
    Inventors: Joseph D. Cuchiaro, Narayan Solayappan, Carlos A. Paz de Araujo, Larry D. McMillan
  • Patent number: 5759923
    Abstract: A precursor liquid comprising silicon in a xylenes solvent is prepared, a substrate is placed within a vacuum deposition chamber, the precursor liquid is misted, and the mist is flowed into the deposition chamber while maintaining the chamber at ambient temperature to deposit a layer of the precursor liquid on the substrate. The liquid is dried, baked, and annealed to form a thin film of silicon dioxide or silicon glass on the substrate. Then an integrated circuit is completed to include at least a portion of the silicon dioxide or silicon glass layer as an insulator for an electronic device in the integrated circuit.
    Type: Grant
    Filed: March 14, 1996
    Date of Patent: June 2, 1998
    Assignees: Symetrix Corporation, Matsushita Electronics Corporation
    Inventors: Larry D. McMillan, Michael C. Scott, Carlos A. Paz de Araujo, Tatsuo Otsuki, Shinichiro Hayashi