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 first cavity and a second cavity are disposed in the dielectric structure. A microelectromechanical system (MEMS) substrate is disposed over the dielectric structure, where the MEMS substrate comprises a first movable membrane overlying the first cavity and a second movable membrane overlying the second cavity. A first functional structure overlies the first movable membrane, where the first functional structure comprises a first material having a first chemical composition. A second functional structure overlies the second movable membrane, where the second functional structure is laterally spaced from the first functional structure, and where the second functional structure comprises a second material having a second chemical composition different than the first chemical composition.

Microphones including a housing defining a cavity, a plurality of conductors positioned within the cavity, at least one dielectric bar positioned within the cavity, and a transducer diaphragm. The conductors are structured to move in response to pressure changes while the housing remains fixed. A first conductor generates first electrical signals responsive to the pressure changes resulting from changes in an atmospheric pressure. A second conductor generates second electrical signals responsive to the pressure changes resulting from acoustic activity. The dielectric bar is fixed with respect to the cavity and remains fixed under the pressure changes. The dielectric bar is adjacent to at least one of the conductors. In response to an applied pressure that is an atmospheric pressure and/or an acoustic pressure, the transducer diaphragm exerts a force on the housing and displaces at least a portion of conductors with respect to the dielectric bar.

An integrated structure of a MEMS microphone and an air pressure sensor, and a fabrication method for the integrated structure, the structure including a base substrate; a vibrating membrane, back electrode, upper electrode, and lower electrode formed on the base substrate, as well as a sacrificial layer formed between the vibrating membrane and the back electrode and between the upper electrode and the lower electrode; a first integrated circuit electrically connected to the vibrating membrane and the back electrode respectively; and a second integrated circuit electrically connected to the lower electrode and the upper electrode respectively, wherein a region of the base substrate corresponding to the vibrating membrane is provided with a back cavity; the sacrificial layer between the vibrating membrane and the back electrode is hollowed out to from a vibrating space that communicates with the exterior of the integrated structure, and the sacrificial layer between the upper electrode and the lower electrode is hollowed out to form a closed space; and the integrated circuits are formed on a chip, thereby reducing the interference of connection lines on the performance of a microphone, reducing the introduction of noise, reducing the size of a product and reducing power consumption.

Discharge circuits, devices and methods. In some embodiments, a MEMS device can include a substrate and an electromechanical assembly implemented on the substrate. The MEMS device can further include a discharge circuit implemented relative to the electromechanical assembly. The discharge circuit can be configured to provide a preferred arcing path during a discharge condition affecting the electromechanical assembly. The MEMS device can be, for example, a switching device, a capacitance device, a gyroscope sensor device, an accelerometer device, a surface acoustic wave (SAW) device, or a bulk acoustic wave (BAW) device. The discharge circuit can include a spark gap assembly having one or more spark gap elements configured to facilitate the preferred arcing path.

A low-profile packaging structure for a microelectromechanical-system (MEMS) resonator system includes an electrical lead having internal and external electrical contact surfaces at respective first and second heights within a cross-sectional profile of the packaging structure and a die-mounting surface at an intermediate height between the first and second heights. A resonator-control chip is mounted to the die-mounting surface of the electrical lead such that at least a portion of the resonator-control chip is disposed between the first and second heights and wire-bonded to the internal electrical contact surface of the electrical lead. A MEMS resonator chip is mounted to the resonator-control chip in a stacked die configuration and the MEMS resonator chip, resonator-control chip and internal electrical contact and die-mounting surfaces of the electrical lead are enclosed within a package enclosure that exposes the external electrical contact surface of the electrical lead at an external surface of the packaging structure.

Described examples include a micromechanical device including a substrate and a base formed on a surface of the substrate; and a first layer extending from the base to a plane separated from the base by a via. The first layer forms an outer layer of the via and has a portion lying in the plane and surrounding the via. A first fill is formed in a first portion of the via. A strut is in the via and on the first fill. A second fill is in a second portion of the via on the strut and extends from the strut to the plane. A second layer is over the second fill and at least a portion of the second layer is over the portion of the first layer lying in the plane.

Methods and systems for reducing stiction through roughening the surface and reducing the contact area in MEMS devices are disclosed. A method includes fabricating bumpstops on a surface of a MEMS device substrate to reduce stiction. Another method is directed to applying roughening etchant to a surface of a silicon substrate to enhance roughness after cavity etch and before removal of hardmask. Another embodiment described herein is directed to a method to reduce contact area between proof mass and UCAV (upper cavity) substrate surface with minimal impact on the cavity volume by introducing a shallow etch process step and maintaining high pressure in accelerometer cavity. Another method is described as to increasing the surface roughness of a UCAV substrate surface by depositing a rough layer (e.g. polysilicon) on the surface of the substrate and etching back the rough layer to transfer the roughness.

A low-profile packaging structure for a microelectromechanical-system (MEMS) resonator system includes an electrical lead having internal and external electrical contact surfaces at respective first and second heights within a cross-sectional profile of the packaging structure and a die-mounting surface at an intermediate height between the first and second heights. A resonator-control chip is mounted to the die-mounting surface of the electrical lead such that at least a portion of the resonator-control chip is disposed between the first and second heights and wire-bonded to the internal electrical contact surface of the electrical lead. A MEMS resonator chip is mounted to the resonator-control chip in a stacked die configuration and the MEMS resonator chip, resonator-control chip and internal electrical contact and die-mounting surfaces of the electrical lead are enclosed within a package enclosure that exposes the external electrical contact surface of the electrical lead at an external surface of the packaging structure.

A method for forming an MEMS inertial sensor is provided, comprising: providing a first substrate having a first surface and a second surface, wherein providing the first substrate comprises providing a first base substrate and forming at least one conductive layer; providing a second substrate having a third surface and a fourth surface; bonding the first surface of the first substrate and the third surface of the second substrate together to form a first bonding interface; thinning the first base substrate from the second surface of the first substrate to remove part of the first base substrate; and forming a movable element of the MEMS inertial sensor, wherein the at least one conductive layer comprises a shielding layer, and the shielding layer is located between the first base substrate and the first bonding interface.

Described examples include a micromechanical device including a substrate and a base formed on a surface of the substrate; and a first layer extending from the base to a plane separated from the base by a via. The first layer forms an outer layer of the via and has a portion lying in the plane and surrounding the via. A first fill is formed in a first portion of the via. A strut is in the via and on the first fill. A second fill is in a second portion of the via on the strut and extends from the strut to the plane. A second layer is over the second fill and at least a portion of the second layer is over the portion of the first layer lying in the plane.