Bell Telephone Laboratories

Larry F Thompson

Eugene D Feit

Murrae J Bowden

Cletus W Wilkins, Jr

Edwin Arthur Chandross

Louis Thomas Manzione

Daniel L Flamm

Robert L Barns

Silicon tetrachloride is processed to ultrahigh purity by subjecting it to a specific succession of purification steps. These steps include the photochlorination of the SiCl.sub.4 using a reactor that allows a long residence time for the SiCl.sub.4. After photochlorination, highly volatile products such as HCl are removed and the remaining impurities are then separated by a distillation technique.

Purification process for compounds useful in optical fiber manufacture

A phase compatibile polymer blend serves as a radiation sensitive lithographic resist in the fabrication of circuits and circuit elements. Radiation sensitivity is due to inclusion of a 'modifier'. Resist properties, notably stability to agents and ambients to be masked are attributed largely to a second component, the 'matrix polymer'. In an exemplary embodiment in which the blend is positive acting, fabrication including dry processing is dependent upon use of a resist blend of a vapor developing polysulfone and a novolac. The novolac, inherently soluble in alkaline media is rendered insoluble in the blend. Radiation initiated depolymerization results in volatilization of the modifier to render the irradiated portions of the resist soluble in alkaline developers. Modifier may function in other manner; for example, it may undergo radiation initiated polymerization so as to insolubilize the blend in irradiated regions, so resulting in a negative acting resist. Effective isolation of lithographic from masking functions permits design of blends with high lithographic sensitivity, as well as good processing stability. The latter is sufficient to permit use in many dry processing procedures as practiced in direct writing, as well as in mask fabrication of large scale integrated silicon circuits.

Fabrication based on radiation sensitive resists and related products

Radiation sensitive negative resists with requisite stability for dry processing of integrated circuits are polymerized from aromatic moieties containing halogen atoms. Halogen-aryl bridging, generally carbonaceous, increases sensitivity to radiation. Exemplary materials, copolymers prepared from aromatic and glycidyl methacrylate (GMA) comonomers, are suitable for direct processing of large-scale integrated circuits. While electron beam patterning is contemplated both for direct processing and mask making, radiation such as X-ray and deep u.v. may be used.

Fabrication based on radiation sensitive resists of halo-alkyl styrene

The disclosed device fabrication method makes use of a multicomponent polymer material comprising a mixture of radiation curable material and thermally curable material. The multicomponent polymer is dispensed onto a substrate and irradiated with actinic radiation. A heat cure is then performed. This method provides an initial gelling of the multicomponent polymer material so that the desired shape of the dispensed material may be retained while the heat cure is performed. This method has been applied successfully to a class of opto-electronic devices known as opto-isolators or optically coupled isolators.

Method for the fabrication of devices including polymeric materials

Negative resist compositions are based on carbonaceous polymers with substituent branches containing epoxy groupings. Exemplary materials which include, for example, a copolymer of glycidyl methacrylate and ethyl acrylate in which epoxy groupings are unesterified show high sensitivity, for example, to electron radiation and to X-rays. Resolution is sufficient to permit expedient fabrication of detailed resist patterns for integrated circuits. High adherence permits use of acid or base reagents and thermal stability permits use of ion milling for circuit fabrication.

Process using radiation curable epoxy containing resist and resultant

Iron oxide films are produced on substrates by oxidative decomposition of polyvinyl ferrocene. The polymer may be applied to the substrate in the form of a solution by spinning. Resultant films may be relatively soluble or relatively insoluble in acidic media depending upon processing conditions. Soluble films are of interest for hard copy masks designed for use in the fabrication of printed circuits. Such masks may be pattern-delineated by photoresist techniques or by selective insolubilization. Alternatively, patterns may result from selective deposition or removal of the polymer prior to decomposition.

Fabrication of an iron oxide film

Patterned iron oxide films are produced on substrates by oxidative decomposition of polyvinyl ferrocene. The polymer may be applied to the substrate in the form of a solution by spinning. Resultant films may be relatively soluble or relatively insoluble in acidic media depending upon processing conditions. Soluble films are of interest for hard copy masks designed for use in the fabrication of printed circuits. Such masks may be pattern-delineated by photoresist techniques or by selective insolubilization. Alternatively, patterns may result from selective deposition or removal of the polymer prior to decomposition.

Fabrication of iron oxide pattern

Several materials have been proposed as protective coatings for magnetic sensing heads in magnetic tape readers. Some of these, known for hardness, are not very wear resistant. Others that seem to wear well tend to spall. The invention is a polymer coating that wears exceptionally well, can be formed conveniently to encapsulate the magnetic sensing elements, can be photocured and therefore photopatterned, and is inexpensive. The polymer is composed of a mixture of urethane-modified acrylates and methacrylates.

Growing community of inventors

Gillette, NJ, United States of America

Larry F Thompson