A microphone including a casing having a front wall, a back wall, and a side wall joining the front wall to the back wall, a transducer mounted to the front wall, the transducer including a substrate and a transducing element, the transducing element having a transducer acoustic compliance dependent on the transducing element dimensions, a back cavity cooperatively defined between the back wall, the side wall, and the transducer, the back cavity having a back cavity acoustic compliance. The transducing element is dimensioned such that the transducing element length matches a predetermined resonant frequency and the transducing element width, thickness, and elasticity produces a transducer acoustic compliance within a given range of the back cavity acoustic compliance.

The present disclosure discloses a MEMS chip which includes a substrate, a back plate fixed on the substrate, and a membrane fixed on the substrate and located above the back plate. A sealed space is formed between the membrane and the back plate. A support pillar is received in the sealed space. Two ends of the support pillar along a vibration direction of the membrane are separately fixed on the membrane and the back plate. As a result, when decreasing the volume of the back cavity, the resonance frequency of the MEMS chip has been effectively improved and the SNR is simultaneously high. Furthermore, the support pillar can effectively improve the reliability and crack resistance of the membrane.

The present disclosure discloses a MEMS chip including a capacitance system and a substrate with a back cavity. The capacitance system includes a back plate and a membrane; the substrate is located on one side of the membrane away from the back plate, including a first surface opposite to the membrane, a second surface opposite to the first surface, and an inner wall connecting the first surface and the second surface and enclosing the back cavity; the inner wall includes a first opening close to the membrane, having a first width along a first direction perpendicular with a vibration direction of the membrane, and a second opening away from the membrane, having a second width smaller than the first width along the first direction. The resonance frequency of the MEMS chip has been effectively improved and the SNR is simultaneously high.

A micro-electromechanical system (MEMS) device includes a moveable element within a cavity. The MEMS device also includes a first layer over the cavity, the first layer having a first hole and a second hole. The first hole has a first diameter. The second hole has a second diameter. The second diameter is larger than the first diameter, and the second hole is farther from the moveable element than the first hole. The first hole is sealed with a first dielectric material. The second hole is sealed with a second dielectric material. The cavity filled with a gas at a pressure of at least approximately 10 torr.

A piezoelectric microelectromechanical systems device can include a cavity bounded by walls and an asymmetrical bimorph structure at least partially spanning the cavity that includes at least a piezoelectric layer and two electrode layers. The electrode layers can have relative thicknesses configured to compensate for expected temperature stress in the bimorph structure. Thus, metals having different thicknesses can be positioned and configured to compensate deflection due to thermal stress of any or all of the piezoelectric layer, the first metal layer, and second metal layer and a substrate. A method for making the piezoelectric microelectromechanical systems device is also provided.

An interposer substrate, a MEMS device and a corresponding manufacturing method. The interposer substrate is equipped with a front side and a rear side, a cavity starting from the rear side, which extends up to a first depth, a through-opening and a sunken area situated between the cavity and the through-opening, which is sunken from the rear side up to a second depth in relation to the rear side, the first depth being greater than the second depth.

A piezoelectric microelectromechanical systems microphone is provided comprising a substrate including at least one wall defining a cavity, the at least one wall defining an anchor region around a perimeter, a piezoelectric film layer forming a membrane, the piezoelectric film layer being supported at the anchor region by a spring region, and an electrode disposed over the piezoelectric film layer. A method of manufacturing such a MEMS microphone is also provided.

Various implementations of MEMS sensors include an IC die having a cavity that forms at least part of the back volume of the sensor. This arrangement helps to address the problems of lateral velocity gradients and viscosity-induced losses. In some of the embodiments, the cavity is specially configured (e.g., with pillars, channels, and/or rings) to reduce the lateral movement of air. Other solutions (used in conjunction with such cavities) include ways to make a diaphragm move more like a piston (e.g., by adding a protrusion that gives it more “up-down” motion and less lateral motion) or to use a piston (e.g., a rigid piece of silicon such as an integrated circuit die) in place of a diaphragm

A semiconductor pressure sensor includes: a first silicon substrate including a first recessed part; and a second silicon substrate including a diaphragm covering a first space in the first recessed part, the second silicon substrate being configured to hermetically seal the first space. In cross-section, a plurality of second spaces are hermetically sealed in a state of being separated away from the first space between the first silicon substrate and the second silicon substrate, and are provided in one of or each of a first end side and a second end side of the first space.

Devices for ultrasonic transmission and/or reception having a piezoelectric micromachined ultrasonic transducer (pMUT). The device employs a material such as lithium niobate as a piezoelectric layer in a membrane suspended over a cavity. Two activation electrodes on an upper surface of the membrane can activate one or more flexural modes of mechanical vibration in the membrane, the flexural modes of vibration including a displacement in a cross-sectional plane of the membrane. The device can be used individually or in an array. The device can be configured for use in a liquid medium or in biological tissue. A method of operating an ultrasonic transducer is provided. A method of fabrication of an ultrasonic transducer is provided.