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

Freescale Semiconductor,inc.

Commissariat a L'energie Atomique

Centre National De La Recherche Scientifique

Commissariar Á L'energie Atomique at Aux Energies Alternatives (cea)

Francois Perruchot

Emmanuel Defay

Lianjun Liu

Bernard Diem

Patrice Rey

Sergio P Pacheco

Laurent Clavelier

Alexandre Reinhardt

Vincent Larrey

Philippe Robert

Sylvain Ballandras

Gilles Delapierre

The invention provides a method of fabricating an electromechanical structure presenting a first substrate including a layer of monocrystalline material covered in a sacrificial layer that presents a free surface, the structure presenting a mechanical reinforcing pillar in the sacrificial layer, the method including etching a well region in the sacrificial layer to define a mechanical pillar; depositing a first functionalization layer of the first material to at least partially fill the well region and cover the free surface of the sacrificial layer around the well region; depositing a second material different from the first material for terminating the filling of the well region to thereby cover the first functionalization layer around the well region, planarizing the filler layer, the pillar being formed by the superposition of the first material and second material in the well region; and releasing the electromechanical structure by removing at least partially the sacrificial layer.

Method of fabricating an electromechanical structure including at least one mechanical reinforcing pillar

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 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.

Electromechanical transducer device and method of forming a electromechanical transducer device

A method of forming an electromechanical transducer device comprises forming on a fixed structure a movable structure and an actuating structure of the electromechanical transducer device, wherein the movable structure is arranged in operation of the electromechanical transducer device to be movable in relation to the fixed structure in response to actuation of the actuating structure. The method further comprises providing a stress trimming layer on at least part of the movable structure, after providing the stress trimming layer, releasing the movable structure from the fixed structure to provide a released electromechanical transducer device, and after releasing the movable structure changing stress in the stress trimming layer of the released electromechanical transducer device such that the movable structure is deflected a predetermined amount relative to the fixed structure when the electromechanical transducer device is in an off state.

Method of forming an electromechanical transducer device

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. The first and second compensation layers are arranged to compensate a thermal effect produced by the different first and second thermal response characteristics of the mechanical structure and the at least one layer of the actuating structure such that movement of the movable structure is substantially independent of variations in temperature and to adjust a stress effect produced by the different first and second stress response characteristics of the mechanical structure and the at least one layer of the actuating structure such that the movable structure is deflected a predetermined amount relative to the substrate when the electromechanical transducer device is in an inactive state.

A process for closure of at least one cavity intended to encapsulate or be part of a microelectronic device, comprising the following steps:

Cavity closure process for at least one microelectronic device

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.

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Grenoble, France

Francois Perruchot