Abstract:
Acoustic resonator device (1) includes an active element (6) and a support provided with a membrane (5). The active element (6) is provided with at least one piezoelectric layer (10) and is surmounted by a multilayer stack (12). The multilayer stack (12) is provided with at least three layers, including at least one layer (15) of high acoustic impedance and at least one layer (13) of low acoustic impedance. An integrated circuit including at least one such acoustic resonator device is also disclosed.
Abstract:
Method for making an electromechanical component on a plane substrate and comprising at least one structure vibrating in the plane of the substrate and actuation electrodes. The method comprises at least the following steps in sequence: formation of the substrate comprising one silicon area partly covered by two insulating areas, formation of a sacrificial silicon and germanium alloy layer by selective epitaxy starting from the uncovered part of the silicon area, formation of a strongly doped silicon layer by epitaxy, comprising a monocrystalline area arranged on said sacrificial layer and two polycrystalline areas arranged on insulating areas, simultaneous formation of the vibrating structure and actuation electrodes, by etching of a predetermined pattern in the monocrystalline area designed to form spaces between the electrodes and the vibrating structure, elimination of said sacrificial silicon and germanium alloy layer by selective etching.
Abstract:
A coupled Lamb wave resonator filter includes first and second Lamb wave resonators. The first Lamb wave resonator includes a first resonant layer, and first and second electrodes on opposite sides of the first resonant layer. The second Lamb wave resonator includes a second resonant layer, and third and fourth electrodes on opposite sides of the second resonant layer. One of the sides of the first resonant layer belongs to a plane parallel to a plane corresponding to one of the sides of the second resonant layer. Both planes pass through the third and fourth electrodes of the second Lamb wave resonator. A periodic lattice acoustically couples the first and second resonant layers.
Abstract:
The resonator comprises a piezoelectric layer arranged between two electrodes. An electrical heating resistor is arranged in thermal contact with at least one of the electrodes. Temporary heating of the electrode enables the material constituting the electrode to be partially evaporated, so as to thin the electrode and thus adjust the resonance frequency. Measurement of the resonance frequency in the course of evaporation enables the heating to be interrupted when the required resonance frequency is obtained. One of the electrodes can be arranged on a substrate formed by an acoustic Bragg grating. The resonator can comprise a substrate comprising a cavity whereon one of the electrodes is at least partially arranged.
Abstract:
A process for manufacturing a resonator including the steps of: forming on an insulating substrate a first portion of a conductive material and a second portion of another material on the first portion; forming an insulating layer having its upper surface flush with the upper part of the second portion; forming by a succession of depositions and etchings a beam of a conductive material above the second portion, the beam ends being on the insulating layer on either side of the second portion, the upper surface of the second portion being exposed on either side of the beam, a third portion of a piezoelectric material on the beam and a fourth portion of a conductive material on the third portion above the beam portion located above the second portion; and removing the second portion.
Abstract:
A support 7 for an acoustic resonator 4 includes at least one bilayer assembly having a layer of high acoustic impedance material 11 and a layer of low acoustic impedance material 12 made of material having a low electrical permittivity.
Abstract:
The resonator comprises a piezoelectric layer arranged between two electrodes. An electrical heating resistor is arranged in thermal contact with at least one of the electrodes. Temporary heating of the electrode enables the material constituting the electrode to be partially evaporated, so as to thin the electrode and thus adjust the resonance frequency. Measurement of the resonance frequency in the course of evaporation enables the heating to be interrupted when the required resonance frequency is obtained. One of the electrodes can be arranged on a substrate formed by an acoustic Bragg grating. The resonator can comprise a substrate comprising a cavity whereon one of the electrodes is at least partially arranged.