A pressure sensing element, including a substrate, a device layer coupled to the substrate, a diaphragm being part of the device layer, and a plurality of piezoresistors coupled to the diaphragm. A plurality of bond pads is disposed on the device layer, and an electrical field shield is bonded to the top of device layer and at least one of the bond pads. At least one stress adjustor is part of the electrical field shield, where the stress adjustor is a cut-out constructed and arranged to reduce thermal hysteresis of the pressure sensing element caused by stress relaxation of the electrical field shield during a cooling and heating cycle. The stress adjustor may be a thin film deposited on top of the electrical field shield, which may apply residual stress to the piezoresistors. The pressure sensing element may include a cavity integrally formed as part of the substrate.

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.

Measurement with satisfactory sensitivity in a low-pressure range, and accurate measurement in a wider pressure range, are realized by a pressure sensor that includes a diaphragm layer and a pressure receiving region formed on the diaphragm layer. The pressure sensor includes a first piezostrictive element, a second piezostrictive element, a third piezostrictive element, and a fourth piezostrictive element. In addition, the pressure sensor includes a first magnetostrictive element, a second magnetostrictive element, a third magnetostrictive element, and a fourth magnetostrictive element. A switching function unit outputs a pressure value calculated by a second calculation function unit until a pressure value calculated by a first calculation function unit exceeds a set threshold value, and outputs the pressure value calculated by the first calculation function unit when the pressure value calculated by the first calculation function unit exceeds the threshold value.

A pressure sensor includes a base, a membrane disposed at a distance from the base, a first fixed electrode provided on the base so as to be opposite to the membrane and including a dielectric layer, and a second fixed electrode provided on the base so as to be opposite to the membrane. When pressure that acts on the membrane increases to cause the membrane to sag toward the base, the membrane comes in contact with the dielectric layer of the first fixed electrode before a distance between the membrane and the second fixed electrode becomes constant.

Pressure sensor systems that include a pressure sensor die and other components in a small, space-efficient package, where the package allow gas or liquid to reach either or both sides of a membranes of the pressure sensor die. A package can include a substrate and a cap, where either or both the substrate and the cap divide the package internally into two chambers. The substrate can have a solid bottom layer, a middle layer having a slot or path running a portion of the length of the layer, and a top layer having two through-holes that provide access to the slot or path. The cap can have two ports. A first port can lead to a first chamber where a top side of a pressure sensor is in the first chamber. A second port can lead to a second chamber and the slot or path, where the slot or path leads to a bottom side of the pressure sensor.

Pressure sensors having ring-tensioned membranes are disclosed. A tensioning ring is bonded to a membrane in a manner that results in the tensioning ring applying a tensile force to the membrane, flattening the membrane and reducing or eliminating defects that may have occurred during production. The membrane is bonded to the sensor housing at a point outside the tensioning ring, preventing the process of bonding the membrane to the housing from introducing defects into the tensioned portion of the membrane. A dielectric may be introduced into the gap between the membrane and the counter electrode in a capacitive pressure sensor, resulting in an improved dynamic range.

A sensor unit includes a transducer element monitoring a measurand and generating an electrical output signal correlated with the measurand, a sensor substrate having a first surface and an opposite second surface, a recess extending from the first surface of the substrate through to the second surface of the substrate, and a circuit carrier. The transducer element and a first electrically conductive contact pad are arranged on the first surface and electrically connected. The circuit carrier has a second electrically conductive contact pad. The sensor substrate is mounted on the circuit carrier with the first surface facing the circuit carrier. The first electrically conductive contact pad and the second electrically conductive contact pad are interconnected by an electrically conductive material filled in from the second surface towards the first surface of the sensor substrate.

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.

Methods of manufacturing a pressure sensor from an SOI wafer are provided. In preferred embodiments, the methods comprise forming a cavity in a SOI wafer by removing a first portion of a bottom silicon layer on the bottom side of the SOI wafer to a depth of an insulator layer; depositing a layer of a second material over the cavity; removing both the silicon layer and the insulator layer from a top side of the SOI wafer in a first plurality of areas above the cavity to form a diaphragm from the layer of a second material, wherein at least one support structure that spans the diaphragm is formed from material above the cavity that was not removed; and forming at least one piezoresistor in the SOI wafer over an intersection of the support structure and SOI wafer at an outside edge of the diaphragm.

Aspects of the subject technology relate to an apparatus including a housing, one or more piezoresistive elements and a magnetic actuator. The housing includes a membrane, and the piezoresistive elements are disposed on the membrane to sense a displacement due to a deflection of the membrane. The magnetic actuator is disposed inside a cavity of the housing. The magnetic actuator exerts a repulsive force onto the membrane to reduce the deflection of the membrane.