Lucent Technologies Inc.

At+t Corp.

Other

At&t Bell Laboratories

Princeton University

American Telephone & Telegraph Co., At&t Bell Laboratories

At&t Ipm Corp.

Robert J Cava

James Joseph Krajewski

Bertram Josef Batlogg

Robert Bruce Van Dover

Gordon Albert Thomas

Jueinai Raynien Kwo

Julia Mae Phillips

Steven A Sunshine

Ali Yazdani

William Frederick Peck

N Phuan Ong

Donald Winslow Murphy

Roderick Kent Watts

Theo Siegrist

Chang-Beom Eom

Eric W Seelig

Shang Y Hou

Sue A Carter

An interconnect is disclosed with enhanced immunity of electrical conductivity to defects. The interconnect includes a material with charge carriers having topological surface states. Also disclosed is a method for fabricating such interconnects. Also disclosed is an integrated circuit including such interconnects. Also disclosed is a gated electronic device including a material with charge carriers having topological surface states.

Electronic interconnects and devices with topological surface states and methods for fabricating same

A class of superconductive materials containing copper-oxygen bonding and with mixed cation-occupancy designed with a view to size and valence consideration yield useful values of critical temperature and other properties. Uses entail all applications which involves superconducting materials such as magnets and transmission lines which require continuous superconductivity paths as well as detectors (e.g., which may rely on tunneling).

Method of making cuprate superconducting material

Devices and systems based on novel superconducting material

Superconducting copper oxides of the perovskite structure are modified to have mixed occupancy of a cation site, thereby resulting in increased limits in critical field and/or critical current. Mixed occupancy may be observed in terms of increased resistivity as the superconducting material reverts to a nonsuperconducting state. A significant advantage, at least for preferred compositions, derives from the fact that critical temperature is unaffected relative to the prototypical material.

A novel intermetallic superconductor with surprisingly high transition temperature is disclosed. The material comprises B and C, and can form a bulk superconductor. Exemplary of the novel superconductors is material of nominal composition YPd.sub.5 B.sub.3 C.sub.x, with x chosen such that the C:B ratio is in the range 0.05-2. An exemplary bulk sample of such composition has T, (onset) of 22.5 K, with more than 15 volume % of the sample being superconducting.

Article comprising an intermetallic superconductor material

Dielectric materials comprising Ca.sub.5 R.sub.2 XO.sub.12 in which R is either Nb or Ta and X is selected from Ti and Ti.sub.1-x Zr.sub.x, have high dielectric constants (Ks), relatively low dielectric losses (Q), and low TCKs. The dielectric properties are affected by processing conditions, which for the both the niobate and tantalate embodiments preferably involve sintering and re-firing dielectric pellets at temperatures of 1400.degree. C. and above. The dielectric materials are particularly useful for microwave communications applications.

Low temperature coefficient dielectric materials and devices comprising

A novel intermetallic superconductor with surprisingly high transition temperature is disclosed. The material comprises B and C, and can form a bulk superconductor. Exemplary of the novel superconductors is material of nominal composition YPd.sub.5 B.sub.3 C.sub.x, with x chosen such that the C:B ratio is in the range 0.05-2. An exemplary bulk sample of such composition has T.sub.c (onset) of 22.5 K, with more than 15 volume % of the sample being superconducting.

Article comprising an intermetalllic superconductor material

Dielectric materials comprising Ca.sub.2 Ta.sub.2-x Nb.sub.x O.sub.7 have high dielectric constants (Ks) and relatively low temperature coefficients of dielectric constants (TCKs). Preferably, in this composition 0.20.ltoreq.x.ltoreq.1.20 and more preferably 0.32.ltoreq.x.ltoreq.0.40, and particularly preferred is the composite where x is 0.36. With a preferred embodiment where x is about 0.36, the dielectric constant is near 30 and the TCK is about 2 ppm/.degree.C., and the Q of the polycrystalline ceramic at 1 MHz is approximately 5000. The dielectric materials are particularly useful in microwave communications applications

Low temperature coefficient dielectric material comprising binary

Thin films of isotropically conductive material are formed from Sr.sub.1-x Ca.sub.x RuO.sub.3. This material is easily deposited as a thin film by methods such as 90.degree. off-axis sputtering and laser ablation. The materials are epitaxially deposited on a wide variety of substrates and allow overlying epitaxial growth of an equally large number of significant oxides such as superconducting oxides, dielectric, and ferroelectric materials.

Conductive oxide films

The present applicants have discovered a method for making thin films comprising tantalum oxide that enhances the dielectric constant with or without TiO.sub.2 doping. Specifically, applicants have discovered sputtering Ta.sub.2 O.sub.5 in an oxygen-rich ambient at a temperature in excess of 450.degree. C. and preferably in excess of 550.degree. C., produces a new crystalline phase thin film having enhanced dielectric properties.

Method for making thin film tantalum oxide layers with enhanced

Applicant has discovered that the dielectric constant of Ta.sub.2 O.sub.5 can be significantly enhanced by the addition of small quantities of TiO.sub.2. Specifically, if Ta.sub.2 O.sub.5 is doped with more than about 3 mole percent of TiO.sub.2 the doped material will have a dielectric constant higher than the undoped material. For example, at a ratio of 0.92 Ta.sub.2 O.sub.5 :0.08TiO.sub.2, the dielectric constant is enhanced by a factor of more than three. Because both Ta and Ti are compatible with current microelectronics processing, the new dielectric can be used to make capacitors of reduced size with but minor modifications of conventional processes.

Dielectric material compressing Ta.sub.2 O.sub.5 doped with TiO.sub.2

Dielectric material of nominal composition (Al.sub.2 O.sub.3).sub.x (Ta.sub.2 O.sub.5).sub.1-x, with 0.03&lt;x&lt;0.15, unexpectedly can exhibit a relatively small temperature variation of the dielectric constant (e.g., &lt;50 ppm/.degree.C. at 1 MHz and 20.degree. C.) and a relatively large value of the dielectric constant. The dielectric according to the invention advantageously is used in capacitive elements, e.g., in MOS capacitors in integrated circuits for personal communication devices.

Article comprising a relatively temperature-insensitive Ta-oxide based

The temperature dependent dielectric constants in the vicinity of room temperature have been measured for bulk ceramics which are phase-mixtures of Pb.sub.2 (Nb,Mg,Ti).sub.2 O.sub.6+x pyrochlores and Pb(Nb,Mg,Ti)O.sub.3 perovskites. A band of compositions has been found in which the negative temperature coefficient of dielectric constant for the pyrochlore is very closely compensated by the positive temperature coefficient of dielectric constant of the perovskite. These compositions have dielectric constants near 200, with Q's near 200 at 1 MHz, making them an intermediate family of dielectrics between the much studied high dielectric constant low Q Barium-Strontium Titanates and low dielectric constant high Q Barium-Lanthanide Titanates.

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Bridgewater, NJ, United States of America

Robert J Cava