In described examples, a system (e.g., a microelectromechanical system) includes a substrate, a support coupled to the substrate and a first and second element. The first element includes a contactor spring having a first portion coupled to the support and having a second portion including a cavity having a sloped surface. A clearance from the sloped surface to the substrate is widened as the sloped surface extends away from the first portion. The second portion includes a first contact surface adjacent to the sloped surface. The second element is coupled to the substrate and has a second contact surface adjacent to the first contact surface. One of the first element and the second element is adapted: in a first direction to urge the first contact surface and the second contact surface together; and in a second direction to urge the first contact surface and the second contact surface apart.

A microelectromechanical system device includes a substrate, a dielectric layer, an electrode, a surface modification layer and a membrane. The dielectric layer is formed on the substrate, and is formed with a cavity that is defined by a cavity-defining wall. The electrode is formed in the dielectric layer. The surface modification layer covers the cavity-defining wall, and has a plurality of hydrophobic end groups. The membrane is connected to the dielectric layer, and seals the cavity. The membrane is movable toward or away from the electrode. A method for making a microelectromechanical system device is also provided.

A semiconductor structure includes a substrate, a MEMS substrate, a dielectric structure between the substrate and the MEMS substrate, a cavity in the dielectric structure, an electrode over the substrate, and a protrusion disposed in the cavity. The MEMS substrate includes a movable membrane, and the cavity is sealed by the movable membrane. A height of the protrusion is less than a depth of the cavity.

PMUT acoustic transducer formed in a body of semiconductor material having a face and accommodating a plurality of first buried cavities, having an annular shape, arranged concentrically with each other and extending at a distance from the face of the body. The first buried cavities delimit from below a plurality of first membranes formed by the body so that each first membrane extends between a respective first buried cavity of the plurality of first buried cavities and the face of the body. A plurality of piezoelectric elements extend on the face of the body, each piezoelectric element extending above a respective first membrane of the plurality of first membranes. The first membranes have different widths, variable between a minimum value and a maximum value.

An example silicon MEMS resonator device includes a support structure, a resonator element with at least one associated eigenmode of vibration, at least one anchor coupling the resonator element to the support structure, at least one driving electrode, and at least one sense electrode. The resonator element is homogeneously doped with N-type or P-type dopants to a doping concentration that causes a closely temperature-compensated mode in which (i) an absolute value of a first order temperature coefficient of frequency of the resonator element is reduced to a first value below a threshold value and (ii) an absolute value of a second order temperature coefficient of frequency of the resonator element is reduced to about zero. Further, a geometry of the resonator element is chosen such that the absolute value of the first order temperature coefficient of frequency is further reduced to a second value smaller than the first value.

In described examples, apparatus includes a first substrate that delimits a surface of a cavity and a bondline structure arranged along a periphery of the cavity, where the bondline structure extends from the first substrate, and the bondline structure configured to bond with an interposer arranged on a second substrate. The apparatus also includes a diffusion barrier on the first substrate, the diffusion barrier configured to contact the interposer and impede a contaminant against migrating from the bondline structure and entering the cavity.

Electronic acoustic devices and methods of operating the same include a microphone having a frequency response including a resonance frequency, a reference microphone having a frequency response including a resonance frequency, the microphone and the reference microphone configured to substantially simultaneously receive a common acoustic signal to produce a transduced signal of the microphone and a transduced signal of the reference microphone, the resonance frequency of the reference microphone being different than the resonance frequency of the microphone, and an equalization module configured to equalize the frequency response of the microphone based on the transduced signal of the microphone and the transduced signal of the reference microphone.

Method for manufacturing a micro-electro-mechanical system, MEMS, integrating a first MEMS device and a second MEMS device. The first MEMS device is a capacitive pressure sensor and the second MEMS device is an inertial sensor. The steps of manufacturing the first and second MEMS devices are, at least partly, shared with each other, resulting in a high degree of integration on a single die, and allowing to implement a manufacturing process with high yield and controlled costs.

A microelectromechanical (MEMS) microphone with membrane trench reinforcements and method of fabrication is provided. The MEMS microphone includes a flexible plate and a rigid plate mechanically coupled to the flexible plate. The MEMS microphone includes a stoppage member affixed to the rigid plate and extending perpendicular relative to a surface of the rigid plate opposite the surface of the flexible plate. The stoppage member limits motion of the flexible plate. The rigid plate includes a reverse bending edge that includes a first lateral etch stop that includes a first corner radius and a second corner radius. The first corner radius is more than 100 nanometers and the second corner radius is more than 25 nanometers. Further, a lateral step width between the first corner radius and the second corner radius is less than around 4 micrometers.

A method is provided that includes forming a first metal layer of a seal structure over a micro-electromechanical system (MEMS) structure and over a channel formed through the MEMS structure to an integrated circuit of a semiconductor structure. The first metal layer is formed at a first temperature. The method includes forming a second metal layer over the first metal layer. The second metal layer is formed at a second temperature less than the first temperature. The method includes performing a first cooling process to cool the semiconductor structure.