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:
A process for fabricating an acoustic wave resonator comprising a suspended membrane comprising a piezoelectric material layer, comprises the following steps: production of a first stack comprising at least one layer of first piezoelectric material on the surface of a first substrate; production of a second stack comprising at least one second substrate; production of at least one non-bonding initiating zone by deposition or creation of particles of controlled sizes leaving the surface of one of said stacks endowed locally with projecting nanostructures before a subsequent bonding step; direct bonding of said two stacks creating a blister between the stacks, due to the presence of the non-bonding initiating zone; and, thinning of the first stack to eliminate at least the first substrate.
Abstract:
An electrical component comprises a lead-based perovskite crystal material layer between a lower electrode on the surface of a substrate and an upper electrode, characterized in that the lower electrode comprises a stabilizing first layer made of a first material and a seeding second layer made of a second material, the first and second materials having the same chemical composition but different structural parameters and/or densities. A process for fabricating a component is also provided, in which the material with a perovskite structure may be PZT with a (100) or (111) orientation.
Abstract:
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.
Abstract:
A method for producing a layer of AlN having substantially vertical sides relative to the surface of a substrate, including: 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, and the etching of the AlN layer.
Abstract:
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.
Abstract:
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.
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; andf) 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:
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.