Abstract: The invention relates to a method of fabricating an electromechanical device including an active element, wherein the method comprises the following steps: a) making a monocrystalline first stop layer on a monocrystalline layer of a first substrate; b) growing a monocrystalline mechanical layer epitaxially on said first stop layer out of at least one material that is different from that of the stop layer; c) making a sacrificial layer on said active layer out of a material that is suitable for being etched selectively relative to said mechanical layer; d) making a bonding layer on the sacrificial layer; e) bonding a second substrate on the bonding layer; and f) eliminating the first substrate and the stop layer to reveal the surface of the mechanical layer opposite from the sacrificial layer, the active element being made by at least a portion of the mechanical layer.

Abstract: A transducer for transducing time-related temperature variations into a difference in potentials includes an upper conductive electrode designed to be exposed to a time-related temperature variation to be measured, a lower conductive electrode, and at least one layer of pyroelectric material based on a III-V nitride directly interposed between the upper and lower conductive electrodes to generate, between the upper and lower conductive electrodes, a difference in potentials corresponding to the temperature variation even in the absence of external mechanical stress.

Abstract: A method is disclosed, for producing a layer of AlN having substantially vertical sides relative to the surface of a substrate, comprising: the formation of an AlN growth layer on a substrate, the deposition of the AlN layer, on at least said growth layer, the formation of a mask layer over the AlN layer, at least one edge of which is aligned with at least one edge or side of the growth layer, in a plane which is substantially perpendicular to a surface of the substrate or a surface of the growth layer, the etching of the AlN layer.

Abstract: Acoustic resonator comprising an electret, and method of producing said resonator, application to switchable coupled resonator filters. The resonator comprises: at least one piezoelectric layer (30); electrodes (24, 26) on either side of this layer; and at least one electret layer (32) between the electrodes, to apply a permanent electric field to the piezoelectric layer. The intensity of this electric field is determined to shift the resonance frequency of the resonator by a desired value. The piezoelectric layer may contain electrical charges to itself constitute the electret layer.

Abstract: A micro or nano electromechanical transducer device formed on a semiconductor substrate comprises a movable structure which is arranged to be movable in response to actuation of an actuating structure. The movable structure comprises a mechanical structure comprising at least one mechanical layer having a first thermal response characteristic and a first mechanical stress response characteristic, at least one layer of the actuating structure, the at least one layer having a second thermal response characteristic different to the first thermal response characteristic and a second mechanical stress response characteristic different to the first mechanical stress response characteristic, a first compensation layer having a third thermal response characteristic and a third mechanical stress characteristic, and a second compensation layer having a fourth thermal response characteristic and a fourth mechanical stress response characteristic.

Abstract: A micro or nano electromechanical transducer device formed on a semiconductor substrate comprises a movable structure which is arranged to be movable in response to actuation of an actuating structure. The movable structure comprises a mechanical structure having at least one mechanical layer having a first thermal response characteristic, at least one layer of the actuating structure having a second thermal response characteristic different to the first thermal response characteristic, and a thermal compensation structure having at least one thermal compensation layer. The thermal compensation layer is different to the at least one layer and is arranged to compensate a thermal effect produced by the mechanical layer and the at least one layer of the actuating structure such that the movement of the movable structure is substantially independent of variations in temperature.

Abstract: The invention relates to a piezoelectric actuation structure including at least one strain gauge and at least one actuator produced from a stack on the surface of a substrate of at least one layer of piezoelectric material arranged between a bottom electrode layer and a top electrode layer, at least a portion of the stack forming the actuator being arranged above a cavity produced in the substrate, characterized in that the strain gauge is a piezoresistive gauge located in the top electrode layer and/or the bottom electrode layer, the layer or layers including electrode discontinuities making it possible to produce said piezoresistive gauge. The invention also relates to a method for producing such a structure.

Abstract: The invention relates to a method of making a component from a heterogeneous substrate comprising first and second portions in at least one monocrystalline material, and a sacrificial layer constituted by at least one stack of at least one layer of monocrystalline Si situated between two layers of monocrystalline SiGe, the stack being disposed between said first and second portions of monocrystalline material, wherein the method consists in etching said stack by making: e) at least one opening in the first and/or second portion and the first and/or second layer of SiGe so as to reach the layer of Si; and f) eliminating all or part of the layer of Si.

Abstract: The invention relates to a piezoelectric actuation structure including at least one strain gauge and at least one actuator produced from a stack on the surface of a substrate of at least one layer of piezoelectric material arranged between a bottom electrode layer and a top electrode layer, at least a portion of the stack forming the actuator being arranged above a cavity produced in the substrate, characterized in that the strain gauge is a piezoresistive gauge located in the top electrode layer and/or the bottom electrode layer, the layer or layers including electrode discontinuities making it possible to produce said piezoresistive gauge. The invention also relates to a method for producing such a structure.

Abstract: The device for detecting elements in a fluidic medium comprises at least one acoustic resonator having a surface intended for fixing the elements. The resonator includes means for generating and measuring Lamb waves, favouring the generation of symmetrical Lamb waves. The device analyses the resonant frequency of the resonator in order to determine the variation in the resonant frequency of the symmetrical Lamb waves representative of the presence of the elements.

Abstract: In a process for fabricating a membrane, including, on a substrate, a thin-film multilayer including a film of piezoelectric material placed between a top electrode film and a bottom electrode film and an elastic film supporting said piezoelectric film, the process includes: determining at least one concavity/convexity curvature of said membrane along an axis parallel to the plane of the films so that at least one inflection point is defined, said point allowing a first region and a second region, corresponding to a concave part and a convex part or vice versa, to be isolated; depositing, on the surface of the substrate, a thin-film multilayer including at least one film of piezoelectric material, one bottom electrode film and one top electrode film; and structuring at least one of the electrode films to define at least said first membrane region, in which an electric field perpendicular to the plane of the films may be applied, and at least said second region, in which an electric field parallel to the plane

Abstract: The invention provides a method of fabricating and electromechanical device having an active element on at least one substrate, the method having the steps of: a) making a heterogeneous substrate having a first portion, an interface layer, and a second portion, the first portion including one or more buried zones sandwiched between first and second regions formed in a first monocrystalline material, the first region extending to the surface of the first portion, and the second region extending to the interface layer, at least one said buried zone being made at least in part out of a second monocrystalline material so as to make it selectively attackable relative to the first and second regions; b) making openings from the surface of the first portion and through the first region, which openings open out to at least one said buried zone; and c) etching at least part of at least one buried zone to form at least one cavity so as to define at least one active element that is at least a portion of the second regio

Abstract: The invention relates to a process for forming a lead-based ceramic oxide dielectric material comprising at least one pyrochlore crystalline phase, which process comprises the following steps: a) a step of depositing at least one amorphous layer of said lead-based ceramic oxide material on a substrate; and b) a crystallization annealing step carried out on said amorphous layer at a temperature not exceeding 550° C., by means of which a lead-based ceramic oxide dielectric material comprising at least one pyrochlore phase is obtained. Application to the fabrication of capacitors on integrated circuits.

Abstract: The invention relates to a method of fabricating and electromechanical device on at least one substrate, the device including at least one active element and wherein the method comprises: a) making a heterogeneous substrate comprising a first portion, an interface layer, and a second portion, the first portion including one or more buried zones sandwiched between first and second regions formed in a first monocrystalline material, the first region extending to the surface of the first portion, and the second region extending to the interface layer, at least one said buried zone being made at least in part out of a second monocrystalline material so as to make it selectively attackable relative to the first and second regions; b) making openings from the surface of the first portion and through the first region, which openings open out to at least one said buried zone; and c) etching at least part of at least one buried zone to form at least one cavity so as to define at least one active element that is at

Abstract: The dielectric of a capacitor is formed by superposition of at least two thin layers made from the same metal oxide, respectively in crystalline and amorphous form and respectively presenting quadratic voltage coefficients of capacitance of opposite signs.

Abstract: The invention relates to a method of making a component from a heterogeneous substrate comprising first and second portions in at least one monocrystalline material, and a sacrificial layer constituted by at least one stack of at least one layer of monocrystalline Si situated between two layers of monocrystalline SiGe, the stack being disposed between said first and second portions of monocrystalline material, wherein the method consists in etching said stack by making: e) at least one opening in the first and/or second portion and the first and/or second layer of SiGe so as to reach the layer of Si; and f) eliminating all or part of the layer of Si.

Abstract: The invention relates to a method of fabricating an electromechanical device including an active element, wherein the method comprises the following steps: a) making a monocrystalline first stop layer on a monocrystalline layer of a first substrate; b) growing a monocrystalline mechanical layer epitaxially on said first stop layer out of at least one material that is different from that of the stop layer; c) making a sacrificial layer on said active layer out of a material that is suitable for being etched selectively relative to said mechanical layer; d) making a bonding layer on the sacrificial layer; e) bonding a second substrate on the bonding layer; and f) eliminating the first substrate and the stop layer to reveal the surface of the mechanical layer opposite from the sacrificial layer, the active element being made by at least a portion of the mechanical layer.

Abstract: The capacitor is a thin-film capacitor comprising two metal electrodes separated by a dielectric. The dielectric is formed by superposition of at least two sub-layers of preferably perovskite-based dielectric material. Two adjacent superposed dielectric sub-layers are separated by an electrically insulated metal intermediate layer, for example made of platinum. Using very thin dielectric sub-layers, preferably with a thickness of less than 20 nm, separated from one another by metal intermediate layers enables the increase of the breakdown field and the reduction of the leakage currents linked to a reduction of the thickness of the dielectric to be transposed to the level of the capacitor, while preserving a reasonable working field.