Patents by Inventor Larry D. McMillan

Larry D. McMillan 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).

  • Publication number: 20040089920
    Abstract: A nonconductive hydrogen barrier layer completely covers the surface area over a memory capacitor and a MOSFET switch of an integrated circuit memory cell. The nonconductive hydrogen barrier layer and a conductive diffusion barrier beneath the capacitor together provide a continuous diffusion barrier between the capacitor and a switch. Also, the nonconductive hydrogen barrier layer and the conductive diffusion barrier continuously envelop the capacitor, in particular a ferroelectric thin film in the capacitor. Preferably, a nonconductive “buried” diffusion barrier layer is disposed over an extended area, providing a continuous diffusion barrier between the capacitor and the switch. A preferred fabrication method comprises forming a thin stack-electrode layer on a capacitor dielectric layer, and then etching the substrate to form self-aligning capacitor stacks.
    Type: Application
    Filed: October 28, 2003
    Publication date: May 13, 2004
    Applicant: Symetrix Corporation
    Inventors: Vikram Joshi, Narayan Solayappan, Carlos A. Paz de Araujo, Larry D. McMillan
  • Publication number: 20040051129
    Abstract: Integrated circuit capacitors in which the capacitor dielectric is a thin film of BST having a grain size smaller than 200 nanometers formed above a silicon germanium substrate. Typical grain sizes are 40 nm and less. The BST is formed by deposition of a liquid precursor by a spin-on process. The original liquid precursor includes an alkoxycarboxylate dissolved in 2-methoxyethanol and a xylene exchange is performed just prior to spinning. The precursor is dried in air at a temperature of about 400° C. and then furnace annealed in oxygen at a temperature of between 600° C. and 850° C.
    Type: Application
    Filed: August 28, 2003
    Publication date: March 18, 2004
    Applicants: Symetrix Corporation, Matsushita Electric Industrial Co., Ltd.
    Inventors: Carlos A. Paz de Araujo, Masamichi Azuma, Larry D. McMillan, Koji Arita
  • Publication number: 20040046198
    Abstract: A nonconductive hydrogen barrier layer is deposited on a substrate and completely covers the surface area over a memory capacitor and a MOSFET switch of an integrated circuit memory cell. A portion of an insulator layer adjacent to the bottom electrode of a memory capacitor is removed by etching to form a moat region. A nonconductive oxygen barrier layer is deposited to cover the sidewall and bottom of the moat. The nonconductive oxygen barrier layer and a conductive diffusion barrier beneath the capacitor together provide a substantially continuous diffusion barrier between the capacitor and a switch. Also, the nonconductive hydrogen barrier layer, the nonconductive oxygen barrier, and the conductive diffusion barrier substantially completely envelop the capacitor, in particular a ferroelectric thin film in the capacitor.
    Type: Application
    Filed: September 19, 2003
    Publication date: March 11, 2004
    Applicant: Symetrix Corporation
    Inventors: Vikram Joshi, Narayan Solayappan, Carlos A. Paz de Araujo, Larry D. McMillan
  • Publication number: 20040047174
    Abstract: A ferroelectric memory 636 includes a group of memory cells (645, 12, 201, 301, 401, 501), each cell having a ferroelectric memory element (44, 218, etc.), a drive line (122, 322, 422, 522 etc.) on which a voltage for writing information to the group of memory cells is placed, a bit line (25, 49, 125, 325, 425, 525, etc.) on which information to be read out of the group of memory cells is placed, a preamplifier (20, 42, 120, 320, 420, etc.) between the memory cells and the bit line, a set switch (14, 114, 314, 414, 514, etc.) connected between the drive line and the memory cells, and a reset switch (16, 116, 316, 416, 516, etc.) connected to the memory cells in parallel with the preamplifier. The memory is read by placing a voltage less than the coercive voltage of the ferroelectric memory element across a memory element. Prior to reading, noise from the group of cells is discharged by grounding both electrodes of the ferroelectric memory element.
    Type: Application
    Filed: October 9, 2003
    Publication date: March 11, 2004
    Inventors: Zheng Chen, Vikram Joshi, Myoungho Lim, Carlos A. Paz de Araujo, Larry D. McMillan, Yoshihisa Kato, Tatsuo Otsuki, Yasuhiro Shimada
  • Patent number: 6686489
    Abstract: A liquid precursor for forming a transparent metal oxide thin film comprises a first organic precursor compound. In one embodiment, the liquid precursor is for making a conductive thin film. In this embodiment, the liquid precursor contains a first metal from the group including tin, antimony, and indium dissolved in an organic solvent. The liquid precursor preferably comprises a second organic precursor compound containing a second metal from the same group. Also, the liquid precursor preferably comprises an organic dopant precursor compound containing a metal selected from the group including niobium, tantalum, bismuth, cerium, yttrium, titanium, zirconium, hafnium, silicon, aluminum, zinc and magnesium. Liquid precursors containing a plurality of metals have a longer shelf life. The addition of an organic dopant precursor compound containing a metal, such as niobium, tantalum or bismuth, to the liquid precursor enhances control of the conductivity of the resulting transparent conductor.
    Type: Grant
    Filed: November 9, 2001
    Date of Patent: February 3, 2004
    Assignee: Symetrix Corporation
    Inventors: Jolanta Celinska, Carlos A. Paz de Araujo, Joseph D. Cuchiaro, Jeffrey W. Bacon, Larry D. McMillan
  • Patent number: 6639262
    Abstract: Integrated circuit capacitors in which the capacitor dielectric is a thin film of BST having a grain size smaller than 200 nanometers formed above a silicon germanium substrate. Typical grain sizes are 40 nm and less. The BST is formed by deposition of a liquid precursor by a spin-on process. The original liquid precursor includes an alkoxycarboxylate dissolved in 2-methoxyethanol and a xylene exchange is performed just prior to spinning. The precursor is dried in air at a temperature of about 400° C. and then furnace annealed in oxygen at a temperature of between 600° C. and 850° C.
    Type: Grant
    Filed: July 16, 2001
    Date of Patent: October 28, 2003
    Assignees: Symetrix Corporation, Matsushita Electric Industrial Co., Ltd.
    Inventors: Carlos A. Paz de Araujo, Masamichi Azuma, Larry D. McMillan, Koji Arita
  • Publication number: 20030152813
    Abstract: An integrated circuit includes a layered superlattice material including one or more of the elements cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium. These elements may either be A-site elements or superlattice generator elements in the layered superlattice material. In one embodiment, one or more of these elements substitute for bismuth in a bismuth layered material. They also are preferably used in combination with one or more of the following elements: strontium, calcium, barium, bismuth, cadmium, lead, titanium, tantalum, hafnium, tungsten, niobium, zirconium, bismuth, scandium, yttrium, lanthanum, antimony, chromium, thallium, oxygen, chlorine, and fluorine. Some of these materials are ferroelectrics that crystallize at relatively low temperatures and are applied in ferroelectric non-volatile memories.
    Type: Application
    Filed: November 29, 2001
    Publication date: August 14, 2003
    Applicant: Symetrix Corporation
    Inventors: Carlos A. Paz de Araujo, Larry D. McMillan, Narayan Solayappan
  • Publication number: 20030132470
    Abstract: A nonconductive hydrogen barrier layer is deposited on a substrate and completely covers the surface area over a memory capacitor and a MOSFET switch of an integrated circuit memory cell. A portion of an insulator layer adjacent to the bottom electrode of a memory capacitor is removed by etching to form a moat region. A nonconductive oxygen barrier layer is deposited to cover the sidewall and bottom of the moat. The nonconductive oxygen barrier layer and a conductive diffusion barrier beneath the capacitor together provide a substantially continuous diffusion barrier between the capacitor and a switch. Also, the nonconductive hydrogen barrier layer, the nonconductive oxygen barrier, and the conductive diffusion barrier substantially completely envelop the capacitor, in particular a ferroelectric thin film in the capacitor.
    Type: Application
    Filed: January 22, 2003
    Publication date: July 17, 2003
    Applicant: Symetrix Corporation
    Inventors: Vikram Joshi, Narayan Solayappan, Carlos A. Paz de Araujo, Larry D. McMillan
  • Publication number: 20030116091
    Abstract: A Chemical Vapor Deposition (CVD) vaporizer comprising: a liquid supply assembly having an environment supporting a liquid state for a plurality of precursor components of a liquid precursor blend; a venturi operative to atomize said liquid precursor blend; a vaporization chamber, located proximate to said liquid supply assembly and said venturi, having an environment supporting a vapor state for said plurality of precursor components; and a thermal barrier located between said liquid supply assembly and said vaporization chamber enabling preservation of a large temperature disparity between said liquid supply assembly and said proximately located vaporization chamber.
    Type: Application
    Filed: December 4, 2002
    Publication date: June 26, 2003
    Applicant: Primaxx, Inc.
    Inventors: Robert W. Grant, Larry D. McMillan
  • Patent number: 6582972
    Abstract: A thin film of precursor for forming a layered superlattice material is applied to an integrated circuit substrate, then a strong oxidizing agent is applied at low temperature in a range of from 100° C. to 300° C. to the precursor thin film, thereby forming a metal oxide thin film. The strong oxidizing agent may be liquid or gaseous. An example of a liquid strong oxidizing agent is hydrogen peroxide. An example of a gaseous strong oxidizing agent is ozone. The metal oxide thin film is crystallized by annealing at elevated temperature in a range of from 500° C. to 700° C., preferably not exceeding 650° C., for a time period in a range of from 30 minutes to two hours. Annealing is conducted in an oxygen-containing atmosphere, preferably including water vapor. Treatment by ultraviolet (UV) radiation may precede annealing. RTP in a range of from 500° C. to 700° C. may precede annealing.
    Type: Grant
    Filed: April 7, 2000
    Date of Patent: June 24, 2003
    Assignees: Symetrix Corporation, Matsushita Electronics Corporation
    Inventors: Vikram Joshi, Jolanta Celinska, Narayan Solayappan, Larry D. McMillan, Carlos A. Paz de Araujo, Koji Arita
  • Publication number: 20030102531
    Abstract: A nonconductive hydrogen barrier layer completely covers the surface area over a memory capacitor and a MOSFET switch of an integrated circuit memory cell. The nonconductive hydrogen barrier layer and a conductive diffusion barrier beneath the capacitor together provide a continuous diffusion barrier between the capacitor and a switch. Also, the nonconductive hydrogen barrier layer and the conductive diffusion barrier continuously envelop the capacitor, in particular a ferroelectric thin film in the capacitor. Preferably, a nonconductive “buried” diffusion barrier layer is disposed over an extended area, providing a continuous diffusion barrier between the capacitor and the switch. A preferred fabrication method comprises forming a thin stack-electrode layer on a capacitor dielectric layer, and then etching the substrate to form self-aligning capacitor stacks.
    Type: Application
    Filed: November 22, 2002
    Publication date: June 5, 2003
    Applicant: Symetrix Corporation
    Inventors: Vikram Joshi, Narayan Solayappan, Carlos A. Paz de Araujo, Larry D. McMillan
  • Publication number: 20030098497
    Abstract: A hydrogen diffusion barrier in an integrated circuit is located to inhibit diffusion of hydrogen to a thin film of a metal oxide, such as a ferroelectric layered superlattice material, in an integrated circuit. The hydrogen diffusion barrier comprises at least one of the following chemical compounds: strontium tantalate, bismuth tantalate, tantalum oxide, titanium oxide, zirconium oxide and aluminum oxide. The hydrogen barrier layer is amorphous and is made by a MOCVD process at a temperature of 450° C. or less. A supplemental hydrogen barrier layer comprising a material selected from the group consisting of silicon nitride and a crystalline form of one of said hydrogen barrier layer materials is formed adjacent to said hydrogen diffusion barrier.
    Type: Application
    Filed: November 29, 2001
    Publication date: May 29, 2003
    Applicant: Symetrix Corporation
    Inventors: Narayan Solayappan, Jolanta Celinska, Vikram Joshi, Carlos A. Paz de Araujo, Larry D. McMillan
  • Patent number: 6559469
    Abstract: An integrated circuit includes a layered superlattice material having the formula A1w1+a1A2w2+a2 . . . Ajwj+ajS1x1+s1S2x2+s2 . . . Skxk+skB1y1+b1B2y2+b2 . . . Blyl+blQz−q, where A1, A2 . . . Aj represent A-site elements in a perovskite-like structure, S1, S2 . . . Sk represent superlattice generator elements, B1, B2 . . . B1 represent B-site elements in a perovskite-like structure, Q represents an anion, the superscripts indicate the valences of the respective elements, the subscripts indicate the number of atoms of the element in the unit cell, and at least w1 and y1 are non-zero. Some of these materials are extremely low fatigue ferroelectrics and are applied in ferroelectric FETs in non-volatile memories. Others are high dielectric constant materials that do not degrade or break down over long periods of use and are applied as the gate insulator in volatile memories.
    Type: Grant
    Filed: October 11, 2000
    Date of Patent: May 6, 2003
    Assignee: Symetrix Corporation
    Inventors: Carlos A. Paz de Araujo, Larry D. McMillan, Vikram Joshi, Narayan Solayappan, Joseph D. Cuchiaro
  • Patent number: 6537830
    Abstract: A nondestructive read-out, nonvolatile ferroelectric field effect transistor (“FET”) memory in an integrated circuit, containing a thin film of polycrystalline crystallographically oriented ferroelectric material. Preferably, the material is polycrystalline c-axis oriented layered superlattice material. More preferably, it is c-axis oriented strontium bismuth tantalate or strontium bismuth tantalum niobate.
    Type: Grant
    Filed: March 23, 2000
    Date of Patent: March 25, 2003
    Assignees: Symetrix Corporation, Matsushita Electric Industrial Co., Ltd.
    Inventors: Koji Arita, Carlos A. Paz de Araujo, Larry D. McMillan, Masamichi Azuma
  • Patent number: 6511718
    Abstract: A venturi mist generator creates a mist comprising droplets having a mean diameter less than one micron from liquid precursors containing multi-metal polyalkoxide compounds. The mist is mixed and then passed into a gasifier where the mist droplets are gasified at a temperature of between 100° C. and 250° C., which is lower than the temperature at which the precursor compounds decompose. The gasified precursor compounds are transported by carrier gas through insulated tubing at ambient temperature to prevent both condensation and premature decomposition. The gasified precursors are mixed with oxidant gas, and the gaseous reactant mixture is injected through a showerhead inlet into a deposition reactor in which a substrate is heated at a temperature of from 300° C. to 600 ° C. The gasified precursors decompose at the substrate and form a thin film of solid material on the substrate. The thin film is treated at elevated temperatures of from 500° C. to 900° C.
    Type: Grant
    Filed: December 17, 1999
    Date of Patent: January 28, 2003
    Assignee: Symetrix Corporation
    Inventors: Carlos A. Paz de Araujo, Larry D. McMillan, Narayan Solayappan, Jeffrey W. Bacon
  • Publication number: 20020168785
    Abstract: A ferroelectric memory includes a plurality of memory cells each containing a ferroelectric thin film including a microscopically composite material having a ferroelectric material component and a fluxor material component, the fluxor material being a different chemical compound than the ferroelectric material. The fluxor is a material having a higher crystallization velocity than the ferroelectric material. The addition of the fluxor permits a ferroelectric thin film to be crystalized at a temperature of between 400° C. and 550° C.
    Type: Application
    Filed: May 10, 2001
    Publication date: November 14, 2002
    Applicant: Symetrix Corporation
    Inventors: Carlos A. Paz de Araujo, Vikram Joshi, Narayan Solayappan, Jolanta Celinska, Larry D. McMillan
  • Publication number: 20020125573
    Abstract: A hydrogen diffusion barrier in an integrated circuit is located to inhibit diffusion of hydrogen to a thin film of metal oxide material in an integrated circuit. The hydrogen diffusion barrier comprises at least one of the following nitrides: aluminum titanium nitride (Al2Ti3N6), aluminum silicon nitride (Al2Si3N6), aluminum niobium nitride (AlNb3N6), aluminum tantalum nitride (AlTa3N6), aluminum copper nitride (Al2Cu3N4), tungsten nitride (WN), and copper nitride (Cu3N2). The thin film of metal oxide is ferroelectric or high-dielectric, nonferroelectric material. Preferably, the metal oxide comprises ferroelectric layered superlattice material. Preferably, the hydrogen barrier layer is located directly over the thin film of metal oxide.
    Type: Application
    Filed: November 9, 2001
    Publication date: September 12, 2002
    Applicant: Symetrix Corporation
    Inventors: Joseph D. Cuchiaro, Carlos A. Paz de Araujo, Larry D. McMillan
  • Patent number: 6448190
    Abstract: A thin film of solid material is selectively formed during fabrication of an integrated circuit by applying a liquid precursor to a substrate having a first surface and a second surface and treating the liquid precursor. The first surface has different physical properties than the second surface such that a solid thin film forms on the first surface but does not form on the second surface. The substrate is washed after formation of said solid thin film to remove any residues of said liquid from the second substrate surface.
    Type: Grant
    Filed: May 21, 1999
    Date of Patent: September 10, 2002
    Assignees: Symetrix Corporation, Matsushita Electric Industrial Co., Ltd.
    Inventors: Shinichiro Hayashi, Larry D. McMillan, Carlos A. Paz de Araujo
  • Patent number: 6441414
    Abstract: A ferroelectric non-volatile memory in which each memory cell consists of a single electronic element, a ferroelectric FET. The FET includes a source, drain, gate and substrate. The fact that the drain to source current, lds, is always negative if a substrate to drain bias, Vss, of 0.8 volts or more is applied, permits the creation of a read and write truth table. A gate voltage equal to one truth table logic value is applied via a column decoder and a substrate bias equal to another truth table logic value is applied via a row decoder to write to the memory a resultant lds logic state, which can be read whenever a voltage is placed across the source and drain.
    Type: Grant
    Filed: October 13, 1998
    Date of Patent: August 27, 2002
    Assignee: Symetrix Corporation
    Inventors: Myoungho Lim, Vikram Joshi, Jeffrey W. Bacon, Joseph D. Cuchiaro, Larry D. McMillan, Carlos A. Paz de Araujo
  • Patent number: 6437380
    Abstract: An integrated circuit device includes a thin film of bismuth-containing layered superlattice material having a thickness not exceeding 100 nm, a capping layer thin film of bismuth tantalate, and an electrode. The capping layer has a thickness in a range of from 3 nm to 30 nm and is deposited between the thin film of layered superlattice material and the electrode to increase dielectric breakdown voltage. Preferably the capping layer contains an excess amount of bismuth relative to the stoichiometrically balanced amount represented by the balanced stoichiometric formula BiTaO4. Preferably, the layered superlattice material is ferroelectric SBT or SBTN. Preferably, the integrated circuit device is a nonvolatile ferroelectric memory. Heating treatments for fabrication of the integrated circuit device containing the bismuth tantalate capping layerare conducted at temperatures not exceeding 700° C., preferably in a range of from 650° C. to 700° C.
    Type: Grant
    Filed: March 28, 2001
    Date of Patent: August 20, 2002
    Assignee: Symetrix Corporation
    Inventors: Myoungho Lim, Vikram Joshi, Narayan Solayappan, Larry D. McMillan, Carlos A. Paz de Araujo