A sensor device includes a substrate having a front surface and an opposing back surface. The back surface defines an indented region having an indented surface. The substrate defines a bottom port extending between the front surface and the indented surface. The sensor further includes a microelectromechanical systems (MEMS) transducer mounted on the front surface of the substrate over the bottom port. The sensor also includes a filtering material disposed on the indented surface and covering the bottom port. The filtering material provides resistance to ingression of solid particles or liquids into the sensor device. The filtering material is configured to provide high acoustic permittivity and have low impact on a signal-to-noise ratio of the sensor device.

MEMS based sensors, particularly capacitive sensors, potentially can address critical considerations for users including accuracy, repeatability, long-term stability, ease of calibration, resistance to chemical and physical contaminants, size, packaging, and cost effectiveness. Accordingly, it would be beneficial to exploit MEMS processes that allow for manufacturability and integration of resonator elements into cavities within the MEMS sensor that are at low pressure allowing high quality factor resonators and absolute pressure sensors to be implemented. Embodiments of the invention provide capacitive sensors and MEMS elements that can be implemented directly above silicon CMOS electronics.

A capacitive sensor includes a first electrode structure; a second electrode structure that is counter to the first electrode structure, wherein the second electrode structure is movable relative to the first electrode structure and is capacitively coupled to the first electrode structure to form a capacitor having a capacitance that changes with a change in a distance between the first electrode structure and second electrode structure; a signal generator configured to apply an electrical signal at an input or at an output of the capacitor to induce a voltage transient response at the output of capacitor; and a diagnostic circuit configured to detect a fault in the capacitive sensor by measuring a time constant of the first voltage transient response and detecting the fault based on the time constant and based on whether the first electrical signal is the pull-in signal or the non-pull-in signal.

A pressure sensor structure includes a sensor body including a diaphragm plate that functions as a sense electrode, a base electrode that faces the diaphragm plate, and a sidewall layer maintaining a gap between the diaphragm plate and the base electrode, and a conductive guard substrate to support the sensor body. The sidewall layer includes a guard electrode layer and upper and lower electrically insulating layers to electrically insulate the guard electrode layer. An electrically insulating layer is between the guard substrate and the sensor body to electrically insulate the guard substrate. The guard substrate is electrically connected to the guard electrode layer to function as a guard electrode together with the guard electrode layer.

A micro pressure sensor includes a body having a compartmentalized chamber provided by membranes anchored between opposing walls of the body and carrying electrodes disposed on surfaces of the membranes. The body has a first pair of opposing walls and a second pair of opposing walls orthogonal to the first pair that define a chamber, a plurality of membranes having a correspond electrode layer over a surface, the plurality of membranes disposed in the chamber, anchored between the first pair of opposing walls of the body to provide plural compartments, a first set of ports coupled to a first set of the plural compartments, the first set of ports disposed in corresponding portions of a first one of the first pair of opposing walls of the body, with a second one of the first pair of opposing walls of the body being a solid portion of the body; and a second set of ports coupled to a second different set of the plural compartments, the second set of ports disposed in corresponding portions of the second one of the first pair of opposing walls of the body, with the first one of the first pair of walls of the body being a solid portion of the body.

The present disclosure is directed to a monolithic MEMS (micro-electromechanical system) platform having a temperature sensor, a pressure sensor and a gas sensor, and an associated method of formation. In some embodiments, the MEMS platform includes a semiconductor substrate having one or more transistor devices and a temperature sensor. A dielectric layer is disposed over the semiconductor substrate. A cavity is disposed within an upper surface of the dielectric layer. A MEMS substrate is arranged onto the upper surface of the dielectric layer and has a first section and a second section. A pressure sensor has a first pressure sensor electrode that is vertically separated by the cavity from a second pressure sensor electrode within the first section of a MEMS substrate. A gas sensor has a polymer disposed between a first gas sensor electrode within the second section of a MEMS substrate and a second gas sensor electrode.

A semiconductor pressure sensor includes a fixed electrode placed at a principal surface of a semiconductor substrate, and a diaphragm movable through an air gap in a thickness direction of the semiconductor substrate at least in an area where the diaphragm is opposed to the fixed electrode. The diaphragm includes: a movable electrode; a first insulation film placed closer to the air gap with respect to the movable electrode; a second insulation film placed opposite to the air gap with respect to the movable electrode, the second insulation film being of a same film type as the first insulation film; and a shield film that sandwiches the second insulation film with the movable electrode.

A sensor arrangement includes a substrate having a through opening between a first and a second main surface region, a sound transducing portion at the first main surface region of the substrate and spanning the through opening in the substrate, and a pressure sensing portion at the first main surface region of the substrate and fluidically coupled to the through opening in the substrate. The sound transducing portion includes a deflectable membrane structure, and a counter electrode. The pressure sensing portion includes a first and second rigid electrode and a deflectable membrane structure. The deflectable membrane structure of the pressure sensing portion opposes the plane of the first main surface region of the substrate. The first and second rigid electrodes of the pressure sensor form a reference capacitor of the pressure sensor, and the second rigid electrode and the membrane structure form a sense capacitor of the pressure sensor.

An air pressure sensing system including a first sensing unit and a second sensing unit is provided. The first sensing unit includes a substrate, a diaphragm, and a supporting member. The substrate has a cavity connected with an exterior environment. The diaphragm is movably and deformably disposed at the substrate and suspended in the cavity. An electrostatic force is provided to the substrate and the diaphragm to move the diaphragm, such that a portion of the base, the supporting member and the diaphragm are contacted with each other and a closed space is formed therebetween in the cavity. The closed space and the exterior environment are divided by the diaphragm, and the diaphragm is deformed due to an air pressure difference between the closed space and the exterior environment. An air pressure sensing method is also provided.

A microelectromechanical system (MEMS) device includes a first movable element and a second movable element, wherein the second movable element is connected with a movable membrane for sensing pressure to make the second movable element move with the movable membrane to sense the pressure variation of the external environment, and other portion of the substrate forming the movable membrane can form a cap to protect the first movable element for sensing other physical quantity.

Accordingly, the pressure sensor and the MEMS structure for sensing other physical quantity can be integrated in the foregoing MEMS device by a single process.