A process for fabricating a symmetrical MEMS accelerometer. A pair of half parts is fabricated by, for each half part: (i) forming a plurality of resilient beams, first connecting parts, second connecting parts, and a plurality of comb structures, by etching a plurality of holes on a bottom surface of a first silicon wafer; (ii) etching a plurality of hollowed parts on a top surface of a second silicon wafer; (iii) forming a silicon dioxide layer on the top and bottom surface of the second silicon wafer; (iv) bonding the bottom surface of the first silicon wafer with the top surface of the second silicon wafer; (v) depositing a layer of silicon nitride on the bottom surface of the second silicon wafer, and removing parts of the silicon nitride layer and silicon dioxide layer on the bottom surface of the second silicon wafer; (vii) deep etching the exposed parts of the bottom surface of the second silicon wafer to the silicon dioxide layer located on the top surface of the second silicon wafer, and reducing the thickness of the first silicon wafer; and (viii) removing the silicon nitride layer, and etching the silicon dioxide to form the mass. The two half parts are then bonded along their bottom surface. The device is deep etched to form a movable accelerometer. A bottom cap is fabricated by hollowing out the corresponding area, and depositing metal as electrodes. The accelerometer is bonded with the bottom cap. Metal is deposited on the first silicon wafer to form electrodes.

A method for manufacturing a microelectromechanical systems (MEMS) structure with sacrificial supports to prevent stiction is provided. A first etch is performed into an upper surface of a carrier substrate to form a sacrificial support in a cavity. A thermal oxidation process is performed to oxidize the sacrificial support, and to form an oxide layer lining the upper surface and including the oxidized sacrificial support. A MEMS substrate is bonded to the carrier substrate over the carrier substrate and through the oxide layer. A second etch is performed into the MEMS substrate to form a movable mass overlying the cavity and supported by the oxidized sacrificial support. A third etch is performed into the oxide layer to laterally etch the oxidized sacrificial support and to remove the oxidized sacrificial support. A MEMS structure with anti-stiction bumps is also provided.

In an embodiment a semiconductor transducer device includes a semiconductor body and a diaphragm having a first layer and a second layer, wherein a main extension plane of the diaphragm is arranged parallel to a surface of the semiconductor body, wherein the diaphragm is suspended at a distance from the semiconductor body in a direction perpendicular to the main extension plane of the diaphragm, wherein the second layer comprises titanium and/or titanium nitride, wherein the first layer comprises a material that is resistant to an etchant comprising fluorine or a fluorine compound, and wherein the second layer is arranged between the semiconductor body and the first layer.

A PMUT includes a substrate, a stopper, and a multi-layered structure, where the substrate includes a corner, and a cavity is disposed in the substrate. The stopper is in contact with the corner of the substrate and the cavity. The multi-layered structure is disposed over the cavity and attached to the stopper and the multi-layered structure includes at least one through hole in contact with the cavity.

In accordance with an embodiment, a MEMS structure is produced on a front side of a substrate. A decoupling structure which has recesses is produced in the substrate, which decoupling structure decouples a first region from a second region of the substrate in terms of stresses. In a rear side, situated opposite the front side, of the substrate, a first cavity is produced by means of a first etching process and a second cavity is produced by means of a second etching process. The first cavity and the second cavity are produced such that the second cavity encompasses the first cavity and such that the second cavity adjoins a base region of the MEMS structure and a base region of the decoupling structure.

Provided herein is a method for manufacturing a semiconductor device. A substrate including a MEMS region and a connection region thereon is provided; a dielectric layer disposed on the substrate in the connection region is provided; a poly-silicon layer disposed on the dielectric layer is provided, wherein the poly-silicon layer serves as an etch-stop layer; a connection pad disposed on the poly-silicon layer is provided; and a passivation layer covering the dielectric layer is provided, wherein the passivation layer includes an opening that exposes the connection pad and a transition region between the connection pad and the passivation layer, and a conductive layer conformally covering the connection pad and the poly-silicon layer in the transition region is provided.

An example microelectromechanical system (MEMS) force sensor is described herein. The MEMS force sensor can include a sensor die configured to receive an applied force. The sensor die can include a first substrate and a second substrate, where a cavity is formed in the first substrate, and where at least a portion of the second substrate defines a deformable membrane. The MEMS force sensor can also include an etch stop layer arranged between the first substrate and the second substrate, and a sensing element arranged on a surface of the second substrate. The sensing element can be configured to convert a strain on the surface of the membrane substrate to an analog electrical signal that is proportional to the strain.

Various embodiments may provide a method of fabricating a meta-lens structure. The method may include forming a first dielectric layer in contact with a silicon wafer. The method may also include forming a second dielectric layer in contact with the first dielectric layer. A refractive index of the second dielectric layer may be different from a refractive index of the first dielectric layer. The method may further include, in patterning the second dielectric layer. The method may additionally include removing at least a portion of the silicon wafer to expose the first dielectric layer.

A method for producing a microelectromechanical sensor. The microelectromechanical sensor is produced by connecting a cap wafer to a sensor wafer. The cap wafer has a bonding structure for connecting the cap wafer to the sensor wafer. The sensor wafer has a sensor core having a movable structure. The cap wafer has a stop structure for limiting an excursion of the movable structure. The method includes a first step and a second step following the first step, the stop surface of the stop structure being situated at the level of the original surface of the unprocessed cap wafer.

A method for processing a silicon substrate includes forming a structure having a bottom surface and a depth of 200 m or more or 300 m or more from a first surface of a silicon substrate, forming a protective film on an inner wall of the structure, and performing plasma etching so as to selectively remove the protective film disposed on the bottom surface of the structure with respect to the protective film disposed on the substantially perpendicular side wall of the structure, wherein the plasma etching is performed under the condition in which plasma with a sheath length at least 10 times the depth when the depth is 200 m or more, or at least 5 time the depth when the depth is 300 m or more, is generated and a mean free path of ions generated in the plasma is longer than the sheath length.