In described examples, a bondline structure is arranged along a periphery of a cavity. The bondline structure extends from a first substrate and is configured to bond with an interposer arranged on a second substrate. A diffusion barrier is arranged on the first substrate for contacting the interposer. The diffusion barrier is arranged to impede a contaminant against migrating from the bondline structure and entering the cavity.

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.

A capacitive transducer or microphone includes a first substrate of one or more layers and which includes a first surface, a first cavity in the first surface, and a mesa diaphragm that spans the first cavity. The capacitive transducer or microphone includes a second substrate fixed to the first substrate. The second substrate has one or more layers which includes a second cavity having a nonplanar (e.g., contoured or structured or stepped) bottom surface that faces the mesa diaphragm. A shape or relief of the bottom surface of the cavity may advantageously be, to at least some degree, complementary to a deformed shape of the diaphragm. The second substrate may include one or more acoustic holes, non-uniformly distributed thereacross. One or more vents may vent the second 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 MEMS device includes a package for providing an inner volume, a MEMS microphone arranged in the inner volume, a sound port through the package to the inner volume, and a passive acoustic attenuation filter acoustically coupled to the sound port.

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.

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.

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 method produces a micromechanical sensor element having a first electrode and a second electrode, wherein electrode wall surfaces of the first and the second electrodes are situated opposite one another in a first direction and form a capacitance, wherein one of the first electrode or the second electrode is movable in a second direction, in response to a variable to be detected, and a second one of the first electrode and the second electrode is fixed. The method includes producing a cavity in a semiconductor substrate, the cavity being closed by a doped semiconductor layer; producing the first and the second electrodes in the semiconductor layer, including modifying the electrode wall surface of the first electrode in order to have a smaller extent in the second direction than the electrode wall surface of the second electrode.

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.