Lucent Technologies Inc.

At+t Corp.

At&t Bell Laboratories

Jorge L Valdes

Gardy Cadet

James W Mitchell

Sanjay Patel

Ralph E Taylor-Smith

Christopher Alan White

You-Lung Chen

Mary E Fiorino

Melanie Carasso

Ronald A Holland

Michael J Cauda

Jorge Sanchez

Three-phase composite materials system having a low dielectric constant and physico-chemical properties suitable for IC fabrication conditions, and a method for making such materials, are disclosed. The three-phase composite material includes an organic phase, an inorganic phase and a void phase. The organic phase is in the form of an organic polymer matrix, the void phase is represented by microporosity present in the matrix, and the inorganic phase is implemented as inorganic particles that are coupled, via a coupling agent, to the organic matrix. The low dielectric constant of the composite is attributable to the microporous organic polymer matrix. The inorganic particles are responsible, at least in part, for providing thermal stability and other required physico-chemical properties to the composite.

Hybrid inorganic-organic composite for use as an interlayer dielectric

An aqueous dispersion of silica particles is mixed with a dialkyldialkoxysilane monomer, e.g., dimethyldiethoxysilane (DMDES), typically under basic conditions. Optionally, the monomer, or a portion thereof, is partially reacted prior to mixing, such that it is possible for a polydialkylsiloxane oligomer, e.g., polydimethylsiloxane (PDMS), to be added either with or instead of the monomer. The addition of the monomer (or oligomer) induces gelation of the silica. The contemplated mechanism is that the silanol groups on the growing polydialkylsiloxane chains are able to condense with silanol groups found on the silica particle surfaces, thereby anchoring the chains to the particles. These chains appear to have the ability to form bridges between particles and/or loops on individual particles. Such bridges appear to initiate formation of a silica particle network, and both the bridges and loops increase the silica particles' hydrophobicity. Both of these features contribute to gelation of the silica particles, substantially independent of the particles' surface charge.

Fabrication including sol-gel processing

The invention provides an improved process for determining the characteristics of dispersed particles. The process involves directing waves (acoustic or light) into a dispersion, and measuring the attenuation of the waves for particular frequencies to provide an attenuation spectrum. The measured attenuation spectrum is then compared to a set of theory-based calculated attenuation spectra to determine the particle size distribution corresponding to the measured attenuation spectrum. Unlike previous processes, the particle size distribution is capable of being accurately determined by a single inversion algorithm, thus eliminating burdensome steps of previous methods.

Process for determining characteristics of suspended particles

The invention provides an alternative to conventional sol-gel methods that utilize undesirably high amounts of a stabilizing agent such as TMAH and a gelling agent such as methyl formate. The method involves the steps of (a) providing a colloidal silica dispersion containing a stabilizing/gelling agent, where only a portion of the molecules of the agent ionize, and (b) subsequently adding to the silica dispersion a pH-reducing additive. The stabilizing/gelling agent has a dual function. The agent, e.g., an amine, initially acts as a stabilizer in the silica dispersion in that a portion of its molecules ionize, while an appreciable amount of the agent remains non-ionized. The agent later transforms in situ to a gelling agent upon addition of a pH-reducing additive. Specifically, as the pH-reducing additive lowers the pH to values at or around the pK.sub.a of the stabilizing/gelling agent, more of the agent's molecules are ionized, these cations contributing to charge neutralization, and thus gellation, of the colloidal silica particles.

The present invention provides an acoustic cell for determining the composition of gas mixtures. The acoustic gas composition analysis cell has transducers isolated from the cell body by a metal housing. A sound-absorbing sleeve around the body of the transducer increases the signal-to-noise ratio to at least 4:1. Additionally, the transducers employed in the acoustic cell operate in the kilohertz range, reducing attenuation in the gas mixture being analyzed. The cell body employs vacuum seals which permit the use of the cell in line with vacuum equipment.

Acoustic analysis of gas mixtures

The present invention is directed to a substrate with a coating of titanium suboxide thereon. The coating protects the substrate from corrosion. Typically, the substrate is a current collector for a lead acid battery. The present invention is also directed to a process for forming the coating of titanium suboxide coating on the substrate. A colloidal dispersion of titanium suboxide particles in water is formed. The pH of the colloidal dispersion is brought within the range of 3 or less. The substrate to be coated is then placed in the colloidal dispersion. A positive electrode is also placed in the colloidal dispersion. An electric field is then introduced into the colloidal dispersion to effect electrophoretic deposition of the titanium suboxide on the substrate.

Current collecting elements

The present invention provides improved processes and apparatus for fabrication of articles having silicon-containing regions. The process comprises generating silane by electrochemical reaction with a silicon-containing precursor material. An electrochemical cell generates H.sup.+ species which react with silicon from the precursor material to form a silane. The silane is used to deposit a silicon-containing article region. An apparatus for fabricating an article having a silicon-containing region is also provided. The fabrication system includes a reaction chamber having a gas supply line communicating with a silane-generating electrochemical cell. The electrochemical cell includes a first electrode for generating a supply of H.sup.+ ions, a silicon-containing precursor material in communication with the first electrode, a second electrode, and a receptacle for retaining an electrolyte. Advantageously, the present invention eliminates the need for long-term storage and transport of silane by generating silane at the site of device fabrication.

Electrochemical generation of silane

The present invention provides an acoustic cell for determining the composition of gas mixtures. The acoustic gas composition analysis cell has transducers acoustically isolated from the cell body through the use of an acoustic isolation material positioned at least between the transducers and the transducer housings to produce a signal-to-noise ratio of at least 4 to 1. Additionally, the transducers employed in the acoustic cell operate in the kilohertz range, reducing attenuation in the gas mixture being analyzed. The cell body employs vacuum seals which permit the use of the cell in line with vacuum equipment.

Many devices, such as those based on III-V semiconductor materials, are produced utilizing gases such as arsine that require careful handling of compressed gas cylinders. This care has engendered a search for alternate approaches. It has been found that the use of electrochemically generated gases such as arsine yields an efficient, pure source of such gases without necessitating the storage of large gas quantities. Thus, a device fabrication procedure including in situ electrochemical generation of gases such as arsine is particularly useful.

Process and apparatus for generating precursor gases used in the

Many devices, such as those based on III-V semiconductor materials, are produced utilizing gases such as arsine that require careful handling of compressed gas cylinders. This care has engendered a search for alternate approaches. It has been found that the use of electrochemically generated gases such as arsine yields an efficient, pure source of such gases without necessitating the storage of large gas quantifies. Thus, a device fabrication procedure including in situ electrochemical generation of gases such as arsine is particularly useful.

Process for the manufacture of devices

Process for coating articles with thin film of diamond, and related diamond-like materials, using an electrophoretic technique. Diamond particles are suspended in a liquid electrolyte and subjected to a directional field which causes migration and deposition on a selected substrate electrode.

Growing community of inventors

Bedminster, NJ, United States of America

Jorge L Valdes