Abstract:
A piezoelectric microelectromechanical acoustic transducer, having a semiconductor substrate with a frame portion and a through cavity defined internally by the frame portion; an active membrane, suspended above the through cavity and anchored, at a peripheral portion thereof, to the frame portion of the substrate by an anchorage structure, a plurality of piezoelectric sensing elements carried by a front surface of the active membrane so as to detect mechanical stresses of the active membrane; a passive membrane, suspended above the through cavity, underneath the active membrane, interposed between the through cavity and a rear surface of the active membrane; and a pillar element, which fixedly couples, and is centrally interposed between, the active membrane and the passive membrane. A ventilation hole passes through the entire active membrane, the passive membrane and the pillar element to set the through cavity in fluidic communication with the front surface of the active membrane.
Abstract:
A method for manufacturing a filtering module comprising the steps of: forming a multilayer body comprising a filter layer of semiconductor material and having a thickness of less than 10 μm, a first structural layer coupled to a first side of the filter layer, and a second structural layer coupled to a second side, opposite to the first side, of the filter layer; forming a recess in the first structural layer, which extends throughout its thickness; removing selective portions, exposed through the recess, of the filter layer to form a plurality of openings, which extend throughout the thickness of the filter layer; and completely removing the second structural layer to connect fluidically the first and second sides of the filter layer, thus forming a filtering membrane designed to inhibit passage of contaminating particles.
Abstract:
A piezoelectric MEMS transducer formed in a body of semiconductor material, which has a central axis and a peripheral area and comprises a plurality of beams, transverse to the central axis and having a first end, coupled to the peripheral area of the body, and a second end, facing the central axis; a membrane, transverse to the central axis and arranged underneath the plurality of beams; and a pillar, parallel to the central axis and rigid with the second end of the beams and to the membrane. The MEMS transducer further comprises a plurality of piezoelectric sensing elements arranged on the plurality of beams.
Abstract:
A semiconductor integrated device, comprising: a package defining an internal space and having an acoustic-access opening in acoustic communication with an environment external to the package; a MEMS acoustic transducer, housed in the internal space and provided with an acoustic chamber facing the acoustic-access opening; and a filtering module, which is designed to inhibit passage of contaminating particles having dimensions larger than a filtering dimension and is set between the MEMS acoustic transducer and the acoustic-access opening. The filtering module defines at least one direct acoustic path between the acoustic-access opening and the acoustic chamber.