A method includes a step of forming a sacrificial layer on a first film, a step of forming a second film on the sacrificial layer, a step of forming an etching opening that extends through at least one of the first film and the second film so as to communicate with the sacrificial layer, and a step of forming a hollow portion by etching the sacrificial layer using a gas containing a fluorine-containing gas and hydrogen via the etching opening, wherein a composition ratio of silicon to nitrogen in a first region having a face in contact with the sacrificial layer is larger than a composition ratio of silicon to nitrogen in a second region not including the first region.

A sensor includes a membrane electrode, a counter-electrode, and at least one spring. The sensor can include a structure; a membrane electrode, which is deformable as a consequence of pressure and which is in contact with the structure; a counter-electrode mechanically connected to the structure and separated from the membrane electrode by a gap; and at least one spring mechanically connected to the membrane electrode and the counter-electrode, so as to exert an elastic force between the membrane electrode and the counter-electrode.

A diaphragm-based sensor includes a deflectable diaphragm, a base layer opposite the diaphragm, and a corrugated wall extending between the diaphragm and the base layer. The diaphragm is suspended over a cavity enclosed by the diaphragm, the base layer and the corrugated wall. The diaphragm includes a first electrode and the base layer includes a second electrode such that a capacitance between the first and second electrodes changes when the diaphragm is deflected relative to the cavity.

Various embodiments of the present disclosure are directed towards a semiconductor device. The semiconductor device includes an interconnect structure disposed over a semiconductor substrate. A dielectric structure is disposed over the interconnect structure. A plurality of cavities are disposed in the dielectric structure. A microelectromechanical system (MEMS) substrate is disposed over the dielectric structure, where the MEMS substrate comprises a plurality of movable membranes, and where the movable membranes overlie the cavities, respectively. A plurality of fluid communication channels are disposed in the dielectric structure, where each of the fluid communication channels extend laterally between two neighboring cavities of the cavities, such that each of the cavities are in fluid communication with one another.

A sound producing cell includes a membrane and an actuating layer. The membrane includes a first membrane subpart and a second membrane subpart, wherein the first membrane subpart and the second membrane subpart are opposite to each other. The actuating layer is disposed on the first membrane subpart and the second membrane subpart. The first membrane subpart includes a first anchored edge which is fully or partially anchored, and edges of the first membrane subpart other than the first anchored edge are non-anchored. The second membrane subpart includes a second anchored edge which is fully or partially anchored, and edges of the second membrane subpart other than the second anchored edge are non-anchored.

A method of manufacturing a plurality of resonators, each formed by a membrane sealing a cavity, includes forming a plurality of cavities starting from one face called the front face of a support substrate, the plurality of cavities comprising central cavities and peripheral cavities arranged around the assembly formed by the central cavities, and forming central membranes and peripheral membranes covering the central cavities and peripheral cavities, respectively, by the transfer of a coverage film on the front face of the support substrate. At least part of the peripheral membranes is removed.

Multiple degenerately-doped silicon layers are implemented within resonant structures to control multiple orders of temperature coefficients of frequency.

A method of forming an ultrasonic transducer device includes forming and patterning a film stack over a substrate, the film stack comprising a metal electrode layer and a chemical mechanical polishing (CMP) stop layer formed over the metal electrode layer; forming an insulation layer over the patterned film stack; planarizing the insulation layer to the CMP stop layer; measuring a remaining thickness of the CMP stop layer; and forming a membrane support layer over the patterned film stack, wherein the membrane support layer is formed at thickness dependent upon the measured remaining thickness of the CMP stop layer, such that a combined thickness of the CMP stop layer and the membrane support layer corresponds to a desired transducer cavity depth.

The invention provides a MEMS microphone. The MEMS microphone includes a substrate, having a first opening. A dielectric layer is disposed on the substrate, wherein the dielectric layer has a second opening aligned to the first opening. A diaphragm is disposed within the second opening of the dielectric layer, wherein a peripheral region of the diaphragm is embedded into the dielectric layer at sidewall of the second opening. A backplate layer is disposed on the dielectric layer and covering over the second opening. The backplate layer includes a plurality of acoustic holes arranged into a regular array pattern. The regular array pattern comprises a pattern unit, the pattern unit comprises one of the acoustic holes as a center hole, and peripheral holes of the acoustic holes surrounding the center hole with a same pitch to the center hole.

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.