A manufacturing method of miniature fluid actuator is disclosed and includes the following steps. A flow-channel main body manufactured by a CMOS process is provided, and an actuating unit is formed by a deposition process, a photolithography process and an etching process. Then, at least one flow channel is formed by etching, and a vibration layer and a central through hole are formed by a photolithography process and an etching process. After that, an orifice layer is provided to form at least one outflow opening by an etching process, and then a chamber is formed by rolling a dry film material on the orifice layer. Finally, the orifice layer and the flow-channel main body are flip-chip aligned and hot-pressed, and then the miniature fluid actuator is obtained by a flip-chip alignment process and a hot pressing process.

In an embodiment a sensor device includes a substrate with a first membrane and a first cover layer, the first membrane and the first cover layer being monolithically integrated into the substrate and a first pellistor element including a heater element and a temperature sensor element, the heater element and/or the temperature sensor element being arranged in or on the first membrane, wherein the first cover layer is arranged over or under the first membrane, and wherein the first membrane, the first cover layer and a part of the substrate surround a first cavity.

The present invention provides a MEMS pressure sensor and a manufacturing method. The pressure is formed by a top cap wafer, a MEMS wafer and a bottom cap wafer. The MEMS wafer comprises a frame and a membrane, the frame defining a cavity. The membrane is suspended by the frame over the cavity. The bottom cap wafer closes the cavity. The top cap wafer has a recess defining with the membrane a capacitance gap. The top cap wafer comprises a top cap electrode located over the membrane and forming, together with the membrane, a capacitor to detect a deflection of the membrane. Electrical contacts on the top cap wafer are connected to the top cap electrode. A vent extends from outside of the sensor into the cavity or the capacitance gap. The pressure sensor can include two cavities and two capacitance gaps to form a differential pressure sensor.

In an embodiment a MEMS microphone includes a substrate, a shield layer, a central insulation layer and a membrane, wherein the substrate has an upper surface with a first opening therein, wherein the shield layer is arranged between the upper surface of the substrate and the membrane, the shield layer having a second opening, wherein the central insulation layer is arranged between the shield layer and the membrane, the shield layer comprising a dielectric bulk material having a third opening and an etch stopper forming an edge of the central insulation layer towards the third opening such that the dielectric bulk material of the central insulation layer is completely enclosed between the shield layer, the etch stopper and the membrane, and wherein all openings are arranged one above another to form a common sound channel to the membrane.

A semiconductor wafer has formed within it a plurality of piston tops of equal area. Each of the piston tops includes a thin flat region from which a majority of the thickness of the original semiconductor wafer may have been removed. A first one of the piston tops has a lower thickness than a second one of the piston tops. The second piston top has at least one hole in it, the volume of the hole corresponding to the difference in thickness between the first and second piston tops, such that the masses of the first and second piston tops differ by less than the variation in thickness between them.

A MEMS device formed using the materials of the BEOL of a CMOS process where a post-processing of vHF and post backing was applied to form the MEMS device and where a total size of the MEMS device is between 50 um and 150 um. The MEMS device may be implemented as an inertial sensor among other applications.

A valve module includes a semiconductor body, cavities in the semiconductor body separated from each other by a distance, a cantilever structure suspended over each cavity to enable at least partial closing of the cavity, and a piezoelectric actuator for each cantilever structure. The piezoelectric actuator is configured for use to cause a positive bending of the respective cantilever structure and so modulate a rate of air flow through the valve module.

A process for manufacturing a microelectromechanical device envisages: providing a wafer of semiconductor material; forming a buried cavity, completely contained within the wafer, and a structural layer formed by a surface portion of the wafer and suspended over the buried cavity; forming first trenches through the structural layer as far as the buried cavity, which define the suspended structure in the structural layer; filling the first trenches and the buried cavity with sacrificial material; forming a closing structure above the structural layer; removing the sacrificial material from the first trenches and from the buried cavity to release the suspended structure, the suspended structure being isolated and buried within the wafer in a buried environment formed by the first trenches and by the buried cavity.

A method for sealing an access opening to a cavity comprises the following steps: providing a layer arrangement having a first layer structure and a cavity arranged adjacent to the first layer structure, wherein the first layer structure has an access opening to the cavity, performing a CVD layer deposition for forming a first covering layer having a layer thickness on the first layer structure having the access opening, and performing an HDP layer deposition with a first and second substep for forming a second covering layer on the first covering layer, wherein the first substep comprises depositing a liner material layer on the first covering layer, wherein the second substep comprises partly backsputtering the liner material layer and furthermore the first covering layer in the region of the access opening, and wherein the first and second substeps are carried out alternately and repeatedly a number of times.

In accordance with an embodiment, a microelectromechanical transducer includes a displaceable membrane having an undulated section comprising at least one undulation trough and at least one undulation peak and a plurality of piezoelectric unit cells. At least one piezoelectric unit cell is provided in each case in at least one undulation trough and at least one undulation peak, where each piezoelectric unit cell has a piezoelectric layer and at least one electrode in electrical contact with the piezoelectric layer. The membrane may be formed as a planar component having a substantially larger extent in a first and a second spatial direction, which are orthogonal to one another, than in a third spatial direction, which is orthogonal to the first and the second spatial direction and defines an axial direction of the membrane.