A method for forming a MEMS device may include performing a silicon-on-nothing process to form a cavity in a monocrystalline silicon substrate at a first depth relative to a top surface of the monocrystalline silicon substrate; forming, in an electrically conductive electrode region of the monocrystalline silicon substrate, an electrically insulated region extending to a second depth that is less than the first depth relative to the top surface of the monocrystalline silicon substrate; and etching the monocrystalline silicon substrate to expose a gap between a first electrode and a second electrode, wherein the second electrode is separated from the first electrode, within a first depth region, by a first distance defined by the electrically insulated region and the gap, and wherein the second electrode is separated from the first electrode, within a second depth region, by a second distance defined by the gap.

A microelectromechanical system (MEMS) device is provided that includes a substrate having a dielectric cavity formed therein and a movable electromechanical device suspended in the dielectric cavity. The dielectric cavity includes a substantially planar bottom surface and at least one sidewall surface extending substantially perpendicularly from the bottom surface. The movable electromechanical device is suspended in the dielectric cavity such that the movable electromechanical device is spaced apart from the bottom surface and the at least one sidewall surface of the dielectric cavity. The bottom surface of the cavity and each of the at least one sidewall surface of the cavity meet at a rectilinear corner.

A MEMS micromirror device includes a monolithic body of semiconductor material having a first main surface and a second main surface, with the monolithic body having an opening extending from the second main surface and including a suspended membrane of monocrystalline semiconductor material extending between the opening and the first main surface of the monolithic body. The suspended membrane includes a supporting frame and a mobile mass carried by the supporting frame and rotatable about an axis parallel to the first main surface, with the mobile mass having a width less than a width of the opening. A reflecting region extends over the mobile mass.

A method for manufacturing at least one membrane system for a micromechanical sensor for the calorimetric detection of gases. A wafer-shaped substrate is provided. At least one reference volume is introduced from a front side into the wafer-shaped substrate with the aid of a surface or volume micromechanical process while forming a reference membrane covering the reference volume at least in some areas. At least one measuring volume, which is adjacent to the at least one reference volume, is introduced into the substrate from a back side or the front side of the wafer-shaped substrate while forming a measuring membrane. A wafer-shaped cap substrate is applied onto the front side of the wafer-shaped substrate. A membrane system and a component are described.

A micromechanical sensor includes a base substrate, a cap substrate, and a MEMS substrate that is connected to each of the base and cap substrates by respective metallic bond connections and that includes a mechanical functional layer including movable MEMS elements, an electrode device for acquiring an indication of a movement of the MEMS elements and fashioned by layer deposition, and a sacrificial layer that is lower than the mechanical function layer, is fashioned by layer deposition, and is omitted in a region underneath the movable MEMS elements.

Suspended microelectromechanical systems (MEMS) devices including a stack of one or more materials over a cavity in a substrate are described. The suspended MEMS device may be formed by forming the stack, which may include one or more electrode layers and an active layer, over the substrate and removing part of the substrate underneath the stack to form the cavity. The resulting suspended MEMS device may include one or more channels that extend from a surface of the device to the cavity and the one or more channels have sidewalls with a spacer material. The cavity may have rounded corners and may extend beyond the one or more channels to form one or more undercut regions. The manner of fabrication may allow for forming the stack layers with a high degree of planarity.

A sensor element includes a membrane structure suspended on a frame structure, wherein the membrane structure includes a membrane element and an actuator. The membrane structure is deflectable in a first stable deflection state and in a second stable deflection state and is operable in a resonance mode in at least one of the first and the second stable deflection states. The actuator is configured to deflect the membrane structure in a first actuation state into one of the first and the second stable deflection states, and to operate the membrane structure in a second actuation state in a resonance mode having an associated resonance frequency.

An electrostatic-type transducer (1) includes: an insulator sheet (11) formed of an elastomer; a plurality of first electrode sheets (12, 13, 14) which is arranged on a front surface side of the insulator sheet (11), adhered to the insulator sheet (11) by fusion of the insulator sheet (11), and arranged with a distance from each other in the surface direction of the insulator sheet (11); and one second electrode sheet (15) which is disposed on the back surface side of the insulator sheet (11) and adhered to the insulator sheet (11) by fusion of the insulator sheet (11), and in which portions facing the plurality of first electrode sheets (12, 13, 14) and portions facing each region between the adjacent first electrode sheets (12, 13, 14) in the surface direction are formed integrally.

A dual-shell architecture and methods of fabrication of fused quartz resonators is disclosed. The architecture may include two encapsulated and concentric cavities using plasma-activated wafer bonding followed by the high-temperature glassblowing. The dual-shell architecture can provide a protective shield as well as a fixed-fixed anchor for the sensing element of the resonators. Structures can be instrumented to operate as a resonator, a gyroscope, or other vibratory sensor and for precision operation in a harsh environment. Methods for fabricating a dual-shell resonator structure can include pre-etching cavities on a cap wafer, pre-etching cavities on a device wafer, bonding the device wafer to a substrate wafer to form a substrate pair and aligning and bonding the cap wafer to the substrate pair to form a wafer stack with aligned cavities including a cap cavity and a device cavity. The wafer stack may be glassblown to form a dual-shell structure.

A method for manufacturing a structure comprising membranes overhanging cavities, comprises: a) forming cavities opening at a front face of a support substrate, the cavities having a depth and an area, and being spaced apart by a spacing; b) assembling, by way of direct bonding, a donor substrate on the support substrate to seal the cavities under vacuum, the direct bonding being hydrophilic and involving a given number of water monolayers at a contact interface between the substrates; and c) transferring a thin layer from the donor substrate onto the support substrate, the thin layer comprising the membranes.

A specific area is defined around each cavity in the plane of the contact interface and is expressed as a function of half of the spacing. The area, the depth of each cavity, and the specific area are defined in step a) to satisfy a particular relationship.