Symetrix Corporation

Other

Olympus Optical Company, Ltd.

Nec Corporation

Mitsubishi Materials Corporation

Matsushita Electronics Corporation

Matsushita Electric Industrial Co., Ltd.

Joseph D Cuchiaro

Carlos Alberto Paz De Araujo

Larry D McMillan

Michael C Scott

Vikram Joshi

Akira Furuya

Shinichiro Hayashi

Yoichi Miyasaka

Narayan Solayappan

Masamichi Azuma

Jeffrey W Bacon

Hitoshi Watanabe

Koji Arita

Jolanta Bozena Celinska

Takashi Mihara

Hiroyuki Yoshimori

Nobuyuki Soyama

Akihiro Matsuda

Katsumi Ogi

Hiroto Uchida

Gota Kano

Myoungho Lim

Claudia P DaCruz

John M McNelis

Yasuhiro Shimada

Eiji Fujii

Hideo Nagai

Yasuhiro Uemoto

Tatsuo Morita

Toru Nasu

Tatsuo Otsuki

Kensuke Kageyama

Carlos A De Araujo

Yoshihiro Shimada

Yoshio Yamaguchi

Gary F Derbenuick

A high dielectric constant insulator including a thin film of a metal oxide selected from the group consisting of tungsten-bronze-type oxides, pyrochlore-type oxides, and combinations of BiOwith an oxide selected from the group consisting of perovskites and pyrochlore-type oxides. An embodiment contains metal oxides represented by the general stoichiometric formulas ABO, ABOand ABiBO, wherein A represents A-site atoms selected from the group of metals consisting of Ba, Bi, Sr, Pb, Ca, K, Na and La; and B represents B-site atoms selected from the group of metals consisting of Ti, Zr, Ta, Hf, Mo, W and Nb. Preferably, the metal oxides are (BaSr)(TaNb)O, where 0&#x2266;y&#x2266;1.0 and 0&#x2266;y&#x2266;1.0; (BaSr)(TaNb)O, where 0&#x2266;x&#x2266;1.0 and 0&#x2266;y&#x2266;1.0; and (BaSr)Bi(TaNb)O, where 0&#x2266;x&#x2266;1.0 and 0&#x2266;y&#x2266;1.0. Thin films according to the invention have a relative dielectric constant &#x2267;40, and preferably about 100. The value of Vcc in the metal oxides of the invention is close to zero. The value of Tcc is &#x3c;1000 ppm, preferably &#x3c;100.

Interlayer oxide containing thin films for high dielectric constant application of the formula AB2O6 or AB2O7

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. In a second embodiment, a liquid precursor for forming a transparent metal oxide nonconductive thin film comprises an organic precursor compound containing a metal from the group including cerium, yttrium, titanium, zirconium, hafnium, silicon, aluminum, niobium, tantalum, and bismuth. Liquid precursors of the invention preferably comprise a metal organic precursor compound, such as an ethylhexanoate, an octanoate, or a neodecanoate, dissolved in a solvent, such as xylenes, n-octane and n-butyl acetate.

Metal organic precursors for transparent metal oxide thin films and method of making same

A hydrogen barrier layer is formed above a ferroelectric thin film in an integrated circuit. The hydrogen barrier layer is directly over a protected segment of the ferroelectric thin film, while a sacrificial segment of the ferroelectric thin film extends laterally beyond the edges of the hydrogen barrier layer. The sacrificial segment absorbs hydrogen so that it cannot diffuse laterally into the protected segment of the ferroelectric thin film. After it absorbs hydrogen, the sacrificial segment is etched away to allow electrical connection to circuit layers below it. The ferroelectric thin film preferably comprises a layered superlattice compound. Excess bismuth or niobium added to the standard precursor solution of a strontium bismuth tantalum niobate compound helps to reduce hydrogen degradation of the ferroelectric properties.

Ferroelectric integrated circuit having low sensitivity to hydrogen exposure and method for fabricating same

An integrated circuit includes a layered superlattice material having the formula A A . . . Aj S S . . . Sk B B . . . Bl Q , where A , A . . . Aj represent A-site elements in a perovskite-like structure, S , S . . . Sk represent superlattice generator elements, B , B . . . B 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 w and y 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.

Ferroelectric and high dielectric constant transistors

A high dielectric constant insulator including a thin film of a metal oxide selected from the group consisting of tungsten-bronze-type oxides, pyrochlore-type oxides, and combinations of Bi O with an oxide selected from the group consisting of perovskites and pyrochlore-type oxides. An embodiment contains metal oxides represented by the general stoichiometric formulas AB O , A B O and A Bi B O , wherein A represents A-site atoms selected from the group of metals consisting of Ba, Bi, Sr, Pb, Ca, K, Na and La; and B represents B-site atoms selected from the group of metals consisting of Ti, Zr, Ta, Hf, Mo, W and Nb. Preferably, the metal oxides are (Ba Sr )(Ta Nb ) O , where 0&lE;x&lE;1.0 and 0&lE;y&lE;1.0; (Ba Sr ) (Ta Nb ) O , where 0&lE;x&lE;1.0 and 0&lE;y&lE;1.0; and (Ba Sr ) Bi (Ta Nb ) O , where 0&lE;x&lE;1.0 and 0&lE;y&lE;1.0. Thin films according to the invention have a relative dielectric constant &gE;40, and preferably about 100. The value of Vcc in the metal oxides of the invention is close to zero. The value of Tcc is <1000 ppm, preferably <100.

Method for forming an integrated circuit

In an integrated circuit, a stack of thin film layers comprising respectively a bottom electrode, a thin film of metal oxide, a top electrode, a lower barrier-adhesion layer, a hydrogen barrier layer, and an upper barrier-adhesion layer are patterned to form a memory capacitor capped with a self-aligned hydrogen barrier layer. Preferably, the top and bottom electrodes comprise platinum, the metal oxide material comprises ferroelectric layered superlattice material, the upper and lower barrier-adhesion layers comprise titanium, and the hydrogen barrier layer comprises titanium nitride. The hydrogen barrier layer inhibits diffusion of hydrogen, thereby preventing hydrogen degradation of the metal oxides. Part of the upper barrier-adhesion layer is removed in order to increase the electrical conductivity in the layer. Preferably, the memory capacitor is a ferroelectric nonvolatile memory. Preferably, the layered superlattice material includes strontium bismuth tantalate or strontium bismuth tantalum niobate.

Integrated circuit having self-aligned hydrogen barrier layer and method for fabricating same

Interlayer oxide containing thin films for high dielectric constant application

A Ti/TiN adhesion/barrier layer is formed on a substrate and annealed. The anneal step is performed at a temperature within a good morphology range of 100&deg; C. above a base barrier anneal temperature that depends on the thickness of said barrier layer. The base barrier anneal temperature is about 700&deg; C. for a barrier thickness of about 1000 &angst; and about 800&deg; C. for a barrier thickness of about 3000 &angst;. The barrier layer is 800 &angst; thick or thicker. A first electrode is formed, followed by a BST dielectric layer and a second electrode. A bottom electrode structure in which a barrier layer of TiN is sandwiched between two layers of platinum is also disclosed. The process and structures also produce good results with other capacitor dielectrics, including ferroelectrics such as strontium bismuth tantalate.

Integrated circuit capacitors with barrier layer and process for making the same

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.

Ferroelectric field effect transistor, memory utilizing same, and method of operating same

Integrated circuit capacitors in which the capacitor dielectric is a thin film of BST having a grain size smaller than 2000 &angst;. Typical gain sizes are 40 nanometers 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 an xylene exchange is preformed just prior to spinning. The precursor is dried in air at a temperature of about 400&deg; C. and then furnace annealed in oxygen at a temperature of between 675&deg; C. and 850&deg; C.

Barium strontium titanate integrated circuit capacitors and process for making the same

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 (Al Ti N ), aluminum silicon nitride (Al Si N ), aluminum niobium nitride (AlNb N ), aluminum tantalum nitride (AlTa N ), aluminum copper nitride (Al Cu N ), tungsten nitride (WN), and copper nitride (Cu N ). 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.

Ferroelectric integrated circuit having hydrogen barrier layer

A liquid precursor for forming a thin film of ferroelectric metal oxide in an integrated circuit contains metal oxides in excess of the stoichiometrically balanced amount. When the precursor comprises strontium, bismuth, tantalum and niobium for forming strontium bismuth tantalum niobate, the precursor contains excess amounts of at least one of tantalum and niobium. Capacitors containing thin films of layered superlattice material made from a precursor containing excess tantalum and niobium show good polarizability and low percentage imprint after 10 negative polarization switching pulses at 75&deg; C., and after 10 negative polarization switching pulses at 125&deg; C.

Low imprint ferroelectric material for long retention memory and method of making the same

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. A cell is selected for writing or reading by application of bias voltages to the source, drain, gate or substrate. A gate voltage equal to one truth table logic value and a drain voltage equal to another truth table logic value are applied via a row decoder, and a substrate bias equal to a third truth table logic value is applied via a column decoder to write to the memory a resultant Ids logic state, which can be non-destructively read by placing a voltage across the source and drain.

Growing community of inventors

Colorado Springs, CO, United States of America

Joseph D Cuchiaro