There is provided a piezoelectric microelectromechanical systems microphone comprising a sensor including at least one piezoelectric layer, at least one constraint in contact with the sensor at a position, such that the sensor is supported by the at least one constraint, and such that the sensor that the sensor has a membrane region to one side of the at least one constraint and a cantilevered region to the other side of the at least one constraint and a cavity defined at least partially by the at least one constraint. There is also provided a method of manufacturing the microphone.

A MEMS microphone includes a diaphragm having conductivity, first and second variable capacitors respectively including first and second fixed electrodes, a first voltage output section that outputs a first voltage changed according to a change in a capacitance of the first variable capacitor, and a second voltage output section that outputs a second voltage changed according to a change in a capacitance of the second variable capacitor. The first and second fixed electrodes face the diaphragm. The capacitances of the first and second variable capacitors are changed in accordance with a vibration of the diaphragm. A first bias voltage is applied to the first fixed electrode. A reference voltage is applied to the second fixed electrode. A second bias voltage is applied to the diaphragm. A difference between the second bias voltage and the reference voltage is half of a difference between the first bias voltage and the reference voltage.

Proposed is a MEMS device comprising a layer stack having at least one second layer formed between a first layer and a third layer. A cavity is formed in the second layer. The MEMS device further comprises two laterally deflectable elements arranged laterally spaced apart in the cavity. Each of the two laterally deflectable elements comprises a respective end connected to a side wall of the cavity. Additionally, the MEMS device comprises a connecting element connected to the two laterally deflectable elements to couple the movement of the two laterally deflectable elements. A plurality of first fingers are arranged discretely spaced between the two laterally deflectable elements on the side wall of the cavity. Further, a plurality of second fingers are arranged discretely spaced between the two laterally deflectable elements on the connecting element. The plurality of second fingers interdigitate with the plurality of first fingers. Further, the plurality of second fingers are laterally displaceable relative to the plurality of first fingers upon deformation of the two laterally deflectable elements such that the plurality of first fingers and the plurality of second fingers define a plurality of volume variable sub-cavities within the cavity. Each of the plurality of sub-cavities is in contact with an ambient fluid of the MEMS device via a respective opening. In case of adjacent sub-cavities of the plurality of sub-cavities, the respective opening of one sub-cavity of the adjacent sub-cavities is formed in a different layer of the first layer, the second layer and the third layer than the opening of the other sub-cavity of the adjacent sub-cavities.

A method of forming an ultrasonic transducer device includes forming a patterned metal electrode layer over a substrate, the patterned metal electrode layer comprising a lower layer and an upper layer formed on the lower layer; forming an insulation layer over the patterned metal electrode layer; and planarizing the insulation layer to the upper layer of the patterned metal electrode layer, wherein the upper layer comprises a electrically conductive material that serves as a chemical mechanical polishing (CMP) stop layer that has CMP selectivity with respect to the insulation layer and the lower layer, and wherein the upper layer has a CMP removal rate slower than that of the insulation layer.

A micro-electro-mechanical system (MEMS) device includes a supporting substrate, a cavity disposed in the supporting substrate, a stopper, and a MEMS structure. The stopper is disposed between the supporting substrate and the cavity, and an inner sidewall of the stopper is in contact with the cavity. The stopper includes a filling material surrounding a periphery of the cavity, and a liner wrapping around the filling material. The MEMS structure is disposed over the cavity and attached on the stopper and the supporting substrate.

A MEMS includes a substrate having a cavity, and a moveable element arranged in the cavity, the moveable element including a first electrode, a second electrode and a third electrode that is arranged between the first electrode and the second electrode and is fixed in an electrically insulated manner from the same at discrete areas. The moveable element is configured to perform a movement along a movement direction in a substrate plan in response to an electric potential between the first electrode and the third electrode or in response to an electric potential between the second electrode and the third electrode. A dimension of the third electrode perpendicular to the substrate plane is lower than a dimension of the first electrode and a dimension of the second electrode perpendicular to the substrate plane.

A microelectromechanical system (MEMS) device contains a movable MEMS structure, a first support structure in which an edge of the MEMS structure is attached, a cavity which is bounded by the MEMS structure and the first support structure, and a second support structure which is attached in the cavity and at the edge of the MEMS structure and is configured so as to support the edge of the MEMS structure mechanically.

A piezoelectric micromachined ultrasonic transducer (PMUT) includes a substrate, a stopper, and a membrane, where the substrate and the stopper are composed of same single-crystalline material. The substrate has a cavity penetrating the substrate, and the stopper protrudes from a top surface of the substrate and surrounds the edge of the cavity. The membrane is disposed over the cavity and attached to the stopper.

A microelectromechanical system (MEMS) device may include a MEMS structure over a first substrate. The MEMS structure comprises a movable element. Depositing a first conductive material over the first substrate and etching trenches in a second substrate. Filling the trenches with a second conductive material and depositing a third conductive material over the second conductive material and the second substrate. Bonding the first substrate and the second substrate and thinning a backside of the second substrate which exposes the second conductive material in the trenches.

An embodiment as described herein includes a microelectromechanical system (MEMS) with a first MEMS transducer element, a second MEMS transducer element, and a semiconductor substrate. The first and second MEMS transducer elements are disposed at a top surface of the semiconductor substrate and the semiconductor substrate includes a shared cavity acoustically coupled to the first and second MEMS transducer elements.