A method for forming a microelectromechanical systems (MEMS) device may include performing a first silicon-on-nothing process to form a first cavity in a substrate. The method may include depositing an epitaxial layer on a surface of the substrate. The method may include performing a second silicon-on-nothing process to form a second cavity in the epitaxial layer. The method may include exposing the first cavity and the second cavity by removing a portion of the substrate and the epitaxial layer.

A method for manufacturing a semiconductor-device in which a semiconductor-substrate is provided, including a SOI-wafer having a carrier-layer (CL) defining a rear-side, a functional-layer (FL), an insulation-layer (IL) situated between the CL and FL, and a passivation-layer (PL) applied to the FL and defining a front-side. The FL includes a functional-area having functional-structures. The front-side of the semiconductor-substrate is masked, a first-mask opening being configured, which defines an interior-area containing the functional-area, and the PL and FL are removed by etching the front-side of the semiconductor-substrate. The rear-side of the semiconductor-substrate is masked, a second-mask opening being configured, and a circumferential-edge of the second-mask opening being spaced outwardly relative to an outer-circumferential-edge of the interior-area. The CL and the IL are removed at least in the area of the second-mask opening by etching the rear-side of the semiconductor-substrate to expose the interior-area. A semiconductor-device is also described.

A bottom semiconductor region is formed to include a main sub-region, extending through a bottom dielectric region that coats a semiconductor wafer, and a secondary sub-region which coats the bottom dielectric region and surrounds the main sub-region. First and second top cavities are formed through the wafer, delimiting a fixed body and a patterned structure that includes a central portion which contacts the main sub-region, and deformable portions in contact with the bottom dielectric region. A bottom cavity is formed through the bottom semiconductor region, as far as the bottom dielectric region, the bottom cavity laterally delimiting a stiffening region including the main sub-region and leaving exposed parts of the bottom dielectric region that contact the deformable portions and parts of the bottom dielectric region that delimit the first and second top cavities. The parts left exposed by the bottom cavity are selectively removed.

A method for producing thin MEMS chips on SOI substrate including: providing an SOI substrate having a silicon layer on a front side and having an oxide intermediate layer, producing a layer structure on the front side of the SOI substrate and producing a MEMS structure from this layer structure, capping the MEMS structure and producing a cavity, and etching a back side of the SOI substrate down to the oxide intermediate layer. Also described is a micromechanical component having a substrate, a MEMS layer structure having a MEMS structure in a cavity and a cap element, the MEMS structure and its cavity being enclosed by the substrate underneath and the cap element above, the substrate being made of polycrystalline silicon.

The invention relates to a miniature kinetic energy harvester for generating electrical energy, comprising a support, a first element having walls surrounding at least one cavity, at least one spring mounted between the first element and the support, the spring being arranged so that the first element may be brought into oscillation relative to the support according to at least one direction of oscillation, a transducer arranged between the first element and the support for converting oscillation of the first element relative to the support into an electrical signal, at least one second element housed within the cavity and mounted to freely move within the cavity relative to the first element so as to impact the walls of the cavity when the harvester is subjected to vibrations.

A process for manufacturing a MEMS pressure sensor having a micromechanical structure envisages: providing a wafer having a substrate of semiconductor material and a top surface; forming a buried cavity entirely contained within the substrate and separated from the top surface by a membrane suspended above the buried cavity; forming a fluidic-communication access for fluidic communication of the membrane with an external environment, set at a pressure the value of which has to be determined; forming, suspended above the membrane, a plate made of polysilicon, separated from the membrane by an empty space; and forming electrical-contact elements for electrical connection of the membrane and of the plate, which are designed to form the plates of a sensing capacitor, the value of capacitance of which is indicative of the value of pressure to be detected. A corresponding MEMS pressure sensor having the micromechanical structure is moreover described.

A method for forming a microelectromechanical device is shown. The method comprises forming a cavity in a semiconductor substrate material, wherein the semiconductor substrate material comprises an opening for providing access to the cavity through a main surface area of the semiconductor substrate material. In a further step, the method comprises forming a support structure having a support structure material different from the semiconductor substrate material to close the opening at least partially by mechanically connecting the main surface area of the semiconductor substrate material with the bottom of the cavity. Furthermore, the method comprises a step of forming a lamella structure in the main surface area above the cavity such that the lamella structure is held spaced apart from the bottom of the cavity by the support structure.

A microelectromechanical microphone includes a reference electrode, a first membrane arranged on a first side of the reference electrode and displaceable by sound to be detected, and a second membrane arranged on a second side of the reference electrode, said second side being situated opposite the first side of the reference electrode, and displaceable by sound to be detected. A region of one from the first and second membranes that is displaceable by sound relative to the reference electrode, independently of said region's position relative to the reference electrode, can comprise a planar section and also an undulatory section adjoining the planar section and arranged in a region of overlap one of the first membrane or the second membrane with the other one of the first membrane and or the second membrane.

Aspects of the disclosure provide a capacitive pressure sensor. The sensor can include a first substrate having a first surface and a second surface, a movable plate at a bottom of a first cavity recessed into the substrate from the first surface, and a second substrate bonded to the first substrate over the first surface. The second substrate includes a fixed plate disposed over the movable plate to form a capacitor. A second cavity is formed between the movable plate and the second surface.

There is provided a piezo-electric actuator comprising an assembly comprising a first electrode, a second electrode, and at least one piezoelectric layer located between said first electrode and said second electrode, wherein at least one of the first electrode and the second electrode is split into at least two different sub-electrodes, wherein at least part of the assembly is configured to move along an axis perpendicular to a surface of the assembly, in response to an electrical stimulus applied to at least one of said first and second electrodes.