Abstract: A drive system which makes it possible to drive a matrix of picture elements, each including a cathode made of a material with low electron affinity. Each of crossover-point circuits include a switching device associated with a cathode of a picture element and makes it possible, with the aid of memory circuits, to connect the cathode to a current source during a time necessary for the driving of all the rows of the matrix and to regulate the current conduction of the corresponding picture element. Such a drive system may find particular application to electron guns and display screens.

Abstract: The disclosure concerns the making of microcomponents belonging to the family of vacuum tubes of the diode, triode and electroluminescent component type. The goal thereof is notably to resolve problems of fabrication under vacuum, and of precise anode-cathode spacing. This goal is achieved by means of a microcomponent of the stacked structure type wherein the anode is made in the form of a metallic layer for the sealing of said cavity under vacuum containing the microcathode, and wherein at least one solid dielectric layer provides for the spacing between said anode and said microcathode.

Abstract: Electron source made notably in the form of a micropoint cathode electrode in which a microcathode is located in a cavity (CA) of a dielectric (3). A first gate electrode (VG1) surrounds the cavity (CA) and a second gate electrode (VG2) surrounds the first gate electrode (VG1). The different electrodes are carried to potentials such that the first gate electrode (VG1) acts as an extraction electrode and the second gate electrode acts as a focusing electrode.

Abstract: In an electrochemical sensor, a gas analyzing electrochemical cell is implanted directly on a substrate wafer. The entire wafer is coated with enamel layers except at the places needed for the electrical connections. A fixing part fixes the sensor in a housing in such a way that the electrochemical cell is inside the housing which contains the gas to be analyzed. This fixing part provides imperviousness and prevents the gases from reaching the electrical connections.

Abstract: The invention relates to the "hardening" (resistance to ionizing radiations) of MOS-type components. In order to avoid the effects of these radiations (creation of electron-hole pairs), there is deposited on a substrate (1) of monocrystalline Si a layer of YSZ (2), and then a thin layer of monocrystalline Si (3). The other steps of production of the components are the same as conventional.

Abstract: The disclosure relates to the field of monocrystalline thin layers deposited on a substrate having an identical or a different nature, from a vapor phase. On the substrate made of monocrystalline material A, a cavity is built, determined by one face of the substrate and one face of a layer made of a material D in such a way that there can be neither nucleation nor growth on the faces exposed to the vapor phase. The growth is done from a seed made of monocrystalline material B located between two faces of the substrate and of the layer. The seed made of monocrystalline material B may be of a nature different from that of the substrate (for example, substrate=silicon and material B=GaAs) and is made, for example, by MBE or MOCVD. The material C to be made to grow is different from the material B of the seed. The material C is, for example, InP and the growth is done by VPE.

Abstract: A method of growth according to which a layer of a material having apertures is made on the surface of a substrate. A material is deposited in each aperture. When this material is liquid, it can absorb the material to be grown. Then, the growth is done in vapor phase. The material of the layer is chosen in such a way that there is neither growth nor nucleation on its surface during the growth in vapor phase. The disclosed method can be applied to the making of crystal whiskers positioned with precision, and to the making of tip type microcathodes.

Abstract: The invention pertains to the field of fabrication, by vapor phase deposition, of the thin layers of monocrystalline, polycrystalline or amorphous material on a substrate having an identical or different nature. The aim is to provide a method, enabling this structure to be made, that includes a modulation of both the composition and the doping, in a direction that is not perpendicular to the surface of the substrate, notably in a lateral way to obtain a planar technology. According to the invention, this thin layer is made by conformal epitaxy, using a crystalline seed in gas phase, between two confinement layers made of a distinct material in such a way that there can be neither nucleation nor deposition of semiconductive material on the surfaces of said confinement layers and wherein the variation of the gaseous mixture of said gas phase is controlled to obtain said modulation of the composition and/or of the doping of said thin film.

Abstract: A power transistor comprises, on a layer of insulator, a layer of a semiconductor material comprising several zones with N+, N and N+ doping. The N doped zone corresponds to the gate zone. The N+ doped zones correspond to the drain and source zones. A method for the making of such a transistor is also disclosed. Application: the making of a field-effect transistor with improved heat dissipation.

Abstract: Disclosed is a method for the growing of heteroepitaxial layers of monocrystalline semiconductor materials. To this end, on a substrate made of a material of a first type, there is made a seed of a second type of material. This seed is between a face of the substrate and a confinement layer which defines a confinement space with the face of the substrate. A vapor phase epitaxy of a material of the second type is then effected in the confinement space. This material of the second type grows from the seed in the confinement space. The method can be applied to the manufacture of heterogeneous semiconductor structures and to the three-dimensional integration of semiconductor components.

Abstract: The disclosure concerns the making of microcomponents belonging to the family of vacuum tubes of the diode, triode and electroluminescent component type. The goal thereof is notably to resolve problems of fabrication under vacuum, and of precise anode-cathode spacing. This goal is achieved by constructing a microcomponent of the stacked structure type wherein the anode is made in the form of a metallic layer for sealing the cavity under vacuum containing the microcathode, and wherein at least one solid dielectric layer provides for the spacing between the anode and the microcathode.

Abstract: Disclosed is a method for the fabrication of field emission peaks using a monocrystalline substrate with a suitable orientation coated with an insulating layer where square-shaped elementary zones with a suitable orientation with respect to the substrate have been removed. Silicon is deposited by selective epitaxy in these zones. The epitaxial growth of silicon, at high speed parallel to the substrate and at low speed along faces of the substrate at 45.degree. to the substrate, enables the making of pyramidal peaks which, afater being coated with tungsten, form emitting peaks.

Abstract: A method for making a microcavity in an enamel layer is disclosed. For this purpose, a layer of a carbon-based material with the dimensions of the microcavity to be obtained is provided. This layer is coated with an enamel except in a limited zone. The unit is heated to high temperature so as to cause combustion of the carbon-based material. The combustion gases escape through the reduced zone.

Abstract: Disclosed is a device made of superconductive material wherein the superconducting layer is enclosed by at least one material which is a conductor of ions of one of the anionic constituent elements of the superconductive layer. This makes it possible to adjust the stoichiometry of the superconductive layer. The disclosure also concerns a method for adjusting the content of the constituent elements of the superconductive layer by electrolysis.

Abstract: Disclosed is an oxygen sensor of the resistive type for the measurement of relative fluid concentrations of fluid reactive species. The following are disposed on one and the same substrate:a sensitive element, the resistivity of which is sensitive to an excess of one of the reactive species;a thermistor mounted as a resistance bridge with the sensitive element;a heating resistor fixing the minimum temperature threshold of operation.Application: The disclosed device can be applied notably to oxygen sensors.

Abstract: In a method for the fabrication of a layer of a monocrystalline semiconducting layer on a layer of insulating material, an epitaxial growth is achieved in a cavity closed by layers of dielectric material, using a seed of monocrystalline semiconducting material of a substrate. The growth takes place first of all, vertically, perpendicularly to the seed, and then horizontally in the plane of the cavity. This method thus enables a three-dimensional integration of semiconductor components.

Abstract: The disclosed microcomponent has a surface oxidated type of Si substrate, at least one cathode with caesiated surface made of n type monocrystalline Si being formed on this substrate. It is surrounded by monocrystalline p tyep Si. A layer of SiO.sub.2, formed on the p type Si, has an aperture facing the cathode. This aperture is self-sealed by the anode material.

Abstract: A method for making a microcavity in an enamel layer is disclosed. For this purpose, a layer of a carbon-based material with the dimensions of the microcavity to be obtained is provided. This layer is coated with an enamel except in a limited zone. The unit is heated to high temperature so as to cause combustion of the carbon-based material. The combustion gases escape through the reduced zone.

Abstract: A method for making a layer of monocrystalline, semiconducting material on a layer of insulating material is disclosed. For this, epitaxial growth is achieved in a cavity closed by layers of dielectric materials, using seeds of monocrystalline, semiconducting material of a substrate. This method thus enables a 3D integration of semiconductor components.

Abstract: The invention provides a process comprising a step for depositing at least one intrinsic or doped monocrystalline silicon layer on a substrate, also monocrystalline, followed by a step for forming a thin silica layer at the level of the original substrate-silicon interface. The silica layer is obtained by oxidation through the substrate, followed by a heat treatment step during which the monocrystalline silicon is oxidized by the implanted oxygen ions. The first approach may take place according to two variants: thermal or plasma oxidation of the silicon-substrate interface. Oxidation takes place during the return to ambient temperature of the stack of layers after the deposit has been made.