The invention provides a MEMS acoustic sensor, including: a base with a back cavity; a capacitance system fixed to the base, including a diaphragm that reciprocates in a vibration direction, a back plate spaced from the diaphragm; a first capacitor and a second capacitor formed cooperatively by the diaphragm and the back plate; and a number of through holes in the back plate facing the back cavity. The diaphragm includes a main body part opposite to the back plate for forming the first capacitor, and a plurality of combining parts recessed from the main body part. A projection of the combining part along the vibration direction completely falls into the through hole. The combining part is spaced from an inner wall of the through hole for forming the second capacitor. Due to the configuration of the invention, the acoustic sensor has improved capacitor value.

A process for manufacturing a diaphragm unit of a MEMS transducer that includes multiple piezoelectric transducer units, each of the multiple piezoelectric transducer units including at least one electrode layer and at least one piezoelectric layer formed on a carrier includes the step of removing the transducer units from the carrier. At least one of the transducer units that has been removed from the carrier is arranged on a diaphragm and connected to the diaphragm. Moreover, a diaphragm unit made according to the process includes a diaphragm and multiple piezoelectric transducer units arranged on and connected to the diaphragm. Each of the multiple piezoelectric transducer units includes at least one electrode layer and at least one piezoelectric layer formed on a carrier.

A method for manufacturing a microelectromechanical systems microphone comprises depositing a membrane on a first sacrificial layer on a substrate, releasing the membrane by removing the first sacrificial layer, depositing a resist layer on the membrane, and patterning the resist layer to expose the membrane, such that at least one section of resist layer remains at at least one edge of the membrane to form an anchor. A microphone manufactured by this method is also provided. There is also provided a method for manufacturing a microelectromechanical systems microphone comprising depositing a membrane on a first sacrificial layer deposited on a substrate, releasing the membrane by removing at least the first sacrificial layer, depositing a resist layer on membrane, patterning the resist layer to expose an edge of the membrane, and forming an anchor at the exposed edge of the membrane. A microphone manufactured by this method is also provided.

A transducer includes a first piezoelectric layer; and a second piezoelectric layer that is above the first piezoelectric layer; wherein the second piezoelectric layer is a more compressive layer with an average stress that is less than or more compressive than an average stress of the first piezoelectric layer.

A method for manufacturing a microelectromechanical systems (MEMS) microphone comprises depositing a membrane on a first sacrificial layer, wherein the first sacrificial layer is deposited on a substrate, etching the substrate to define a cavity, releasing the membrane by removing at least the first sacrificial layer, and forming at least one anchor at the edge of the membrane.

A process for manufacturing electroacoustic modules including: forming an assembly with a redistribution structure and a plurality of dice arranged in a dielectric region; forming a wafer with a semiconductor body and a plurality of respective unit portions laterally staggered, each of which includes a respective supporting region, set in contact with the semiconductor body, and a number of actuators; reducing the thickness of the semiconductor body and then selectively removing portions of the semiconductor body so as to singulate, starting from the wafer, a plurality of transduction structures, each including a semiconductor substrate, which contacts a corresponding supporting region and is traversed by cavities delimited by portions of the supporting region that form membranes mechanically coupled to the actuators; and then coupling the transduction structures to the redistribution structure of the assembly.

A microelectromechanical systems (MEMS) diaphragm assembly comprises a first diaphragm and a second diaphragm. A plurality of pillars connects the first and second diaphragms, wherein the plurality of pillars has a higher distribution density at a geometric center of the MEMS diaphragm assembly than at an outer periphery thereof.

Various embodiments of the present disclosure are directed towards a microelectromechanical systems (MEMS) device in which a slit at a movable mass of the MEMS device has a top notch slit profile. The MEMS device may, for example, be a speaker, an actuator, or the like. The slit extends through the movable mass, from top to bottom, and has a width that is uniform, or substantially uniform, from the bottom of the movable mass to proximate the top of movable mass. Further, in accordance with the top notch slit profile, top corner portions of the MEMS substrate in the slit are notched, such that a width of the slit bulges at the top of the movable mass. The top notch slit profile may, for example, increase the process window for removing an adhesive from the slit while forming the MEMS device.

A MEMS microphone includes a substrate, a diaphragm disposed over the substrate to cover the cavity, the diaphragm defining an air gap together with the back plate, and the diaphragm being spaced apart from the substrate, a back plate disposed over the diaphragm and in the vibration area, an upper insulation layer to cover the back plate, a plurality of chamber portions provided in the supporting area, a lower insulation layer provided under the upper insulation layer and on the substrate, and an intermediate insulation layer provided between the lower insulation layer and the upper insulation layer and disposed further from the vibration area than the chamber portions.

In one embodiment, a method of manufacturing a semiconductor device includes oxidizing a substrate to form local oxide regions that extend above a top surface of the substrate. A membrane layer is formed over the local oxide regions and the top surface of the substrate. A portion of the substrate under the membrane layer is removed. The local oxide regions under the membrane layer are removed.