A device includes a substrate comprising a first standoff, a second standoff, a third standoff, a first cavity, a second cavity, and a bonding material covering a portion of the first, the second, and the third standoff. The first cavity is positioned between the first and the second standoffs, and the second cavity is positioned between the second and the third standoffs. The first cavity comprises a first cavity region and a second cavity region separated by a portion of the substrate extruding thereto, and wherein a depth associated with the first cavity region is greater than a depth associated with the second cavity. A surface of the first cavity is covered with a getter material.

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.

A method for producing microelectromechanical structures. The method includes: providing a carrier substrate having a central layer, and an insulation layer which is disposed on one side of the central layer and is applied to the surface; applying a silicon layer to the insulation layer; structuring the silicon layer forming trenches through the silicon layer in places; passivating the silicon layer, wherein the trenches are filled and a passivation layer forms; structuring the passivation layer, sacrificial regions and functional regions being formed, the sacrificial regions being free of the passivation layer in places; removing part of the carrier substrate forming a new surface; forming a second insulation layer on the new surface; repeating the applying, structuring and passivating for a second silicon layer on the second insulation layer and structuring for a second passivation layer to form sacrificial regions and functional regions and removing all of the sacrificial regions.

A method for making a hollow structure in a substrate. The method includes creating a lattice structure with at least two mutually spaced trench structures, creating a cavity structure below the lattice structure with respect to a normal direction by forming a buried, contiguous cavity that spans at least the area of the two trench structures. A micromechanical sensor is also described.

A micromechanical hydrogen sensor switch creates a conducting channel between two electrical contacts in response to atmospheric H.sub.2 at or above a selected threshold. The switch uses 100 nW or less in standby mode, three orders of magnitude less than existing hydrogen sensors. The sensor converts mechanical stress caused by hydrogen absorption by palladium into movement of a cantilever structure. The switch provides automatic temperature and stress compensation, separate gates for providing bias to regulate H.sub.2 sensitivity, a heater-based reset mechanism, low contact adhesion, and reliable platinum-to-platinum metal contacts. The sensor detects hydrogen concentrations as low as 10 parts per million (ppm) in the atmosphere.