Commissariat &#xc0; L'&#xc9;nergie Atomique Et Aux &#xc9;nergies Alternatives

Centre National De La Recherche Scientifique

Soitec

Université De Franche Comte

Ecole Nationale Superieure De Mecanique Et Des Microtechniques

Energies Alternatives

Stmicroelectronics S.a.

Alexandre Reinhardt

Marie Gorisse

Emmanuel Defay

Jean-Baptiste David

Francois Perruchot

Marie Bousquet

Ghislain Despesse

Sylvain Ballandras

Laurent Clavelier

Lamine Benaissa

Chrystel Deguet

Bruno Reig

Jean-Sebastien Moulet

Alexis Drouin

Sébastien Boisseau

Yann Sinquin

Isabelle Huyet

Sebastien Boisseau

Pierre Perreau

Jean-Sébastien Moulet

François Perruchot

Julie Abergel

Frédéric Domingue

Issiaka Kone

Brice Ivira

Thu Trang Vo

Ausrine Bartasyte

Axel Sauvage

An electromechanical device includes a piezoelectric support delimited by a surface, or by two surfaces parallel to each other, and, on this support, a resonator for elastic waves propagating parallel to the surface or surfaces, the resonator including two reflectors that delimit the resonator and which are reflective for the waves, several interfacing transducers, to generate the waves from an electrical signal, and several transducers for controlling the resonance frequency, each transducer including a first electrode and a second electrode that are interdigitated, the transducers being arranged along the propagation path followed by the waves in the resonator, with, along the path, an alternation between interfacing transducer and tuning transducer.

Electromechanical device with adjustable resonance frequency

A process for fabricating a component includes an operation of transferring at least one layer of one or more piezoelectric or pyroelectric or ferroelectric materials forming part of a donor substrate to a final substrate, the process comprising a prior step of joining the layer to a temporary substrate via production of a fragile separating region between the donor substrate of single-crystal piezoelectric or pyroelectric or ferroelectric material and the temporary substrate, the region comprising at least two layers of different materials in order to ensure two compounds apt to generate an interdiffusion of one or more constituent elements of at least one of the two compounds make contact, the fragile region allowing the temporary substrate to be separated.

Method of fabricating layers of single-crystal material

A process for fabricating a micro-electro-mechanical system, includes the following steps: production of a stack on the surface of a temporary substrate so as to produce a first assembly, comprising: at least depositing a piezoelectric material or a ferroelectric material to produce a layer of piezoelectric material or of ferroelectric material; producing a first bonding layer; production of a second assembly comprising at least producing a second bonding layer on the surface of a host substrate; production of at least one acoustic isolation structure in at least one of the two assemblies; production of at least one electrode level containing one or more electrodes in at least one of the two assemblies; bonding the two assemblies via the two bonding layers, before or after the production of the at least one electrode level in at least one of the two assemblies; removing the temporary substrate.

Process for producing a micro-electro-mechanical system from a transferred piezoelectric or ferroelectric layer

A method for producing an adjustable bulk acoustic wave resonator comprising a transducer stack (E) and a tuning stack (E). According to the invention, transducer stack (E) includes two defined electrodes () and piezoelectric material (), and stack (E) includes a layer of piezoelectric material () and two defined electrodes (). The method includes: a) production of the transducer stack; b) formation of an electrically insulating layer on an electrode () of the transducer stack; c) formation of a defined electrode () of the tuning stack on the electrically insulting layer such that it is aligned with the electrodes of the transducer stack; d) assembly, on the electrode (), of a substrate of piezoelectric material; e) fracturing of the substrate of piezoelectric material; and f) formation of the other defined electrode () of the tuning stack, aligned with the defined electrode ().

Method for the production of a bulk acoustic wave resonator with a reduced parasitic capacitance

The invention relates to a SAW resonator () comprising at least: a substrate (); a layer () of piezoelectric material arranged on the substrate; a first attenuation layer () arranged between the substrate and the layer of piezoelectric material, and/or, when the substrate comprises at least two different layers (), a second attenuation layer () arranged between the two layers of the substrate; and in which the at least one attenuation layer is/are heterogeneous.

Saw resonator comprising layers for attenuating parasitic waves

A method for the batch production of acoustic wave filters comprises: synthesizing N theoretical filters, each filter defined by a set of j theoretical resonator(s) having a triplet C, &#x3c9;and &#x3c9;, these parameters grouped into subsets; determining a reference resonator structure for each subset, naturally having a resonant frequency &#x3c9;, where &#x3c9;&#x3c;&#x3c9;&#x3c;&#x3c9;; determining, for each theoretical resonator, an elementary building block comprising an intermediate resonator R', a parallel reactance Xpand/or a series reactance Xs, the intermediate resonator R&#x2032;having a triplet C, &#x3c9;and &#x3c9;, the parameters C, Xpij and/or Xsdefined so the elementary building block has a triplet: C, &#x3c9;and &#x3c9;; determining the geometrical dimensions of the actual resonators Rof the filters so they have a capacitance C; producing each actual resonator; associating series and/or parallel reactances with actual resonators in order to form the elementary building blocks.

Method for producing a batch of acoustic wave filters

A resonant circuit comprises an input terminal and an output terminal and at least: a group of N resonators, where N&#x2267;1, the resonators having the same resonance frequency and the same antiresonance frequency; a first and a second impedance matching element having a non-zero reactance, the first element being in series with the group of resonators, and the second element being in parallel with the group of resonators, the resonant circuit comprising: first means for controlling the group of resonators, enabling the static capacitance of the group to be fixed at a first value; second control means, enabling the impedance of the first impedance matching element and that of the second element to be fixed at second values; the first and second values being such that the triplet of values composed of the static capacitance of the group, the impedance of the first element, and the impedance of the second element can be used to determine the following triplet of parameters: the characteristic impedanceof the assembly formed by the group, the first impedance matching element and the second matching element; the resonance frequencyof the assembly; the antiresonance frequencyof the assembly, in order to stabilize the impedance of the circuit at a chosen characteristic impedance.

Resonant circuit with variable frequency and impedance

An acoustic wave bandpass filter comprises at least an input first acoustic wave resonator with an output surface, and an output second acoustic wave resonator with an input surface, said resonators being coupled to each other along a set direction, the input and output surfaces being substantially opposite, and at least one first phononic crystal structure between said input and output resonators and/or a second phonic crystal structure at the periphery of said resonators so as to guide the acoustic waves, generated by said input resonator, toward said output resonator along said set direction, the resonators ensuring an impedance conversion and/or a mode conversion.

Acoustic wave bandpass filter comprising integrated acoustic guiding

An acoustic structure, comprising at least one acoustic resonator exhibiting at least one resonant frequency in a band of operating frequencies and an integrated capacitor, further comprises: a stack of layers, comprising at least one active layer of piezoelectric material or of ferroelectric material; the resonator being frequency tunable and being produced by a first subset of layers of the stack comprising the at least one active layer and at least two electrodes; the integrated capacitor being produced by a second subset of layers comprising the active layer and at least two electrodes; the first and second subsets of layers being distinguished by a modification of layers so as to exhibit different resonant frequencies.

Acoustic structure comprising at least one resonator and at least one cointegrated capacitor in one and the same piezoelectric or ferroelectric layer

An acoustic wave bandpass filter comprises at least two bulk acoustic wave resonators, laterally coupled to each other acoustically, each resonator including a film of piezoelectric material and at least a first electrode and/or a second electrode, said bulk waves propagating in a direction perpendicular to the plane of the film of piezoelectric material, characterized in that: it further comprises at least a first phononic crystal structure between said resonators such that the transmission coefficient of the lateral acoustic waves can be decreased in a direction parallel to the plane of the piezoelectric film; and the first phononic crystal structure is formed in a matrix of dielectric material or with patterns made from dielectric material.

Laterally coupled BAW filter employing phononic crystals

An acoustic structure comprising comprises a layer of material having a first Young's modulus called the intrinsic modulus and a first density called the intrinsic density, characterized in that the layer comprises at least one first zone having said first Young's modulus and said first density and at least one second zone buried in the volume of said layer of material and having a second Young's modulus and/or a second density obtained by implanting and/or by diffusing atoms into the volume of said layer.

Heterogenous acoustic structure formed from a homogeneous material

An acoustic wave device comprising at least one surface acoustic wave filter and one bulk acoustic wave filter, the device including, on a substrate comprising a second piezoelectric material: a stack of layers including a first metal layer and a layer of a first monocrystalline piezoelectric material, wherein the stack of layers is partially etched so as to define a first area in which the first and second piezoelectric materials are present and a second area in which the first piezoelectric material is absent; a second metallization at the first area for defining the bulk acoustic wave filter integrating the first piezoelectric material, and a third metallization at the second area for defining the surface acoustic wave filter integrating the second piezoelectric material.

Acoustic wave device including a surface wave filter and a bulk wave filter, and method for making same

An HBAR resonator comprises, on a substrate, a piezoelectric transducer, said transducer comprising at least one piezoelectric layer, at least two series of electrodes and exhibiting resonance frequencies Fi corresponding to wavelengths &#x3bb;i, characterized in that it comprises an amplification structure comprising at least one resonant cavity arranged on the substrate between said transducer and said substrate or in said substrate, this amplification structure being suitable for mechanically resonating at least one of the resonance frequencies Fi of said transducer corresponding to said wavelength &#x3bb;i, so as to amplify the amplitude of the electrical resonance generated at said frequency.

HBAR resonator comprising a structure for amplifying the amplitude of at least one resonance of said resonator and methods for producing such a resonator

An electromechanical device having a resonator using acoustic waves propagating laterally within a piezoelectric plane resonant structure and electrodes on a face of said structure. The resonant structure comprises: a transduction region having a transduction length and generating acoustic waves; a free propagation region for the acoustic waves, adjacent to the transduction region and defined the plane of the transduction region; the resonant structure length being equal to an integer number of half-wavelengths, the resonance frequency of said resonator equaling the average propagation velocity of the wave within the structure divided by said wavelength, to adjust the quality factor of the resonator fixed by the length of the resonant structure and the coupling coefficient fixed by the ratio of the transduction length over the length of the resonant structure; the resonant structure defined by the assembly of the transduction region and the propagation region being laterally bounded by reflection regions.

Acoustic wave electromechanical device comprising a transduction region and an extended cavity

A power device comprises an output port and at least one first acoustic pathway and one second acoustic pathway, each acoustic pathway comprising at least one first input acoustic wave transducer connected to an input port, and an output acoustic wave transducer connected to the output port. Each acoustic pathway further comprises a floating acoustic wave transducer connected to a floating port; the input transducer and the output transducer being separated by a distance equal to (2m+1)&#x3bb;/4 with m an integer and &#x3bb; the propagation wavelength; the input transducer and the floating transducer being separated by a distance equal to (2n+1) &#x3bb;/2 with n an integer; each output transducer being connected to the output port, said power device being a combiner.

Growing community of inventors

Saint Martin d'Heres, France

Alexandre Reinhardt