U.S. Philips Corporation

Peter A Janiel

Georg Friedrich Gartner

Hans-Jurgen Lydtin

Hans Rau

A method of manufacturing a hot-cathode element which consists of a rare-earth-oxide-doped refractory metal, notably thoriated tungsten, and which also contains carbon components, first a plurality of layers of the hot-cathode element being successively deposited on a substrate member (2) by means of a CVD process, after which notably the hot-cathode element is separated from the substrate member (2). The strength required for further working of the hot-cathode element is improved in that in the course of the CVD process decarburizing intermediate treatments are performed, the hot-cathode element being carburized during an aftertreatment.

Method of manufacturing a hot-cathode element

Electrically conductive multicomponent material is deposited on a tubular substrate (3) by means of a PCVD method. A plasma (9) is produced between an inner electrode (13) and an outer electrode, one of which is tubular and serves as a substrate. In order to obtain multicomponent material of the desired composition, the composition of the gas phase is changed as a function of time and/or place. In particular when metalorganic starting compounds are used, PCVD of many single layers together with an intermittent, for example, Ar/O.sub.2 plasma intermediate treatment yields an efficient removal of undesired carbon or fluorine from the deposited multicomponent material already during its manufacture.

Method for the plasma-activated reactive deposition of electrically

An arrangement for producing a gas flow which is enriched with the vapor of a low-volatile material. The arrangement comprises a vessel (1) having an interior space (12) for holding a powder bed (13), which consists of a low-volatile material and an additional solid inert component. The vessel is arranged in a thermostatically controlled bath (2). A gas flow (4, 16) consisting of an inert gas flows through the arrangement, preferably in the direction of the gravitational force. The gas flow passes, in this sequence, through a thick gas inlet plate (10), the powder bed (13) and a thin gas outlet plate (14). By proper dimensioning the component parts of the arrangement and providing a low pressure in the arrangement a high mass flow of the low-volatile material with a flow constant of a long duration is achieved. The enriched gas flow is conducted, for example, to a low-pressure CVD reactor.

Arrangement for producing a gas flow which is enriched with the vapor of

Process for glow-discharge-activated reactive deposition of metal from a

An enriching device consisting of a container which comprises a removable tightly fitting metal body the sparingly volatile material being present in a coiled groove. During operation of this device transverse flows and shortcuts, respectively, of the carrier gas flow occur. To assure that the carrier gas flows through the material without having an escape possibility, the groove (5) is made either in an outer wall of the metal body (8) or in the bottom (4) of the container (1), and the parts (6) present between the individual turns of the groove have a cutting edge, i.e. a cross-sectional profile in the form of a wedge, the tip of which is in contact either with the smooth inner wall of the container (1) or with the smooth lower side of the metal body (8). The device is suitable for adjusting a defined mass flow of sparingly volatile materials which are used as starting compounds for chemical deposition from the gaseous phase.

Device for enriching a carrier gas with the vapor of a sparingly

For the reactive deposition of tubular bodies of electrically conductive material from a flowing gas phase on a tubular substrate, a glow discharge 11 is produced between an inner electrode 6 and an outer electrode 2, one of which is constructed so as to be tubular and serves as a substrate. It is ensured that the electrodes 2, 6 are not short-circuited by growing conductive surface layers so that the glow discharge 11 extinguishes. Furthermore, the electrically conductive coating on the electrode 6 which does not function as the substrate electrode is interrupted in an insulating manner to locally limit the glow discharge 11. For example, by a gas barrier the deposit of an electrically conducting material on the insulation can be avoided. The glow discharge 11 is reciprocated during the deposition process.

Method for the glow-discharge-activated reactive deposition of

In the reactive deposition from a gaseous phase containing tungsten hexafluoride and hydrogen on a substrate at an overall pressure of 10 to 100 hPa (low-pressure CVD method) an inert carrier gas is enriched with a rare earth metal acetyl acetonate hydrate and is conducted across the substrate and the growing tungsten layer together with the reactive gases tungsten hexafluoride and hydrogen.

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Wurselen, Germany

Peter A Janiel