Methods for fabricating MEMS tuning fork gyroscope sensor system using silicon wafers. This provides the possibly to avoid glass. The sense plates can be formed in a device layer of a silicon on insulator (SOI) wafer or in a deposited polysilicon layer in a few examples.

A micromechanical component for a sensor device or microphone device. The micromechanical component includes a diaphragm with a diaphragm inner side to which an electrode structure is directly or indirectly connected; and a cavity that is formed at least in a volume that is exposed by at least one removed area of at least one sacrificial layer. At least one residual area made of at least one electrically insulating sacrificial layer material of the at least one sacrificial layer is also present at the micromechanical component, and including at least one insulation area made of at least one electrically insulating material that is not the same as the electrically insulating sacrificial layer material. The electrode structure is electrically insulated from the diaphragm, and/or the at least one residual area of the at least one sacrificial layer is delimited from the cavity, using the at least one insulation area.

A free-standing microstructure may be formed from an engineered substrate including a first silicon layer, a second silicon layer, and an intermediate layer. The second silicon layer may include a monocrystalline silicon film. The intermediate layer may be between the first silicon layer and the second silicon layer. The intermediate layer may include a silicon- or germanium-based material having a different lattice constant than the first silicon layer or the second silicon layer. The intermediate layer of the free-standing microstructure may further include one or more voids wherein at least a portion of the silicon- or germanium-based material is absent between the first silicon layer and the second silicon layer.

The disclosure relates to a method for manufacturing recessed micromechanical structures in a MEMS device wafer. First vertical trenches in the device wafer define the horizontal dimensions of both level and recessed structures. The horizontal face of the device wafer and the vertical sidewalls of the first vertical trenches are then covered with a self-supporting etching mask which is made of a self-supporting mask material, which is sufficiently rigid to remain standing vertically in the location where it was deposited even as the sidewall upon which it was deposited is etched away. Recess trenches are then etched under the protection of the self-supporting mask. The method allows a spike-preventing aggressive etch to be used for forming the recess trenches, without harming the sidewalls in the first vertical trenches.

A method of manufacturing a MEMS vibration element having a fixed electrode, a movable electrode, and an elastic supporting unit that elastically supports the movable electrode with respect to the fixed electrode includes: etching a base material having a first thickness to form the fixed electrode and the movable electrode; and etching the base material to form the elastic supporting unit having a second thickness, the second thickness being less than the first thickness.

There is provided a method of producing a microstructure that comprises employing a hydrogen fluoride (HF) vapour to etch a sacrificial layer of silicon dioxide (SiO.sub.2) and thereafter removing a residual layer formed when HF vapour etching the layer of silicon dioxide. The residual layer may comprise silicon, ammonium salt or carbon and various techniques are disclosed for removing such layers. These techniques may be applied concurrently, or sequentially, to the microstructure. The described methodologies therefore produce microstructures that exhibits reduced levels of residue when as compared to those techniques known in the art.

A method includes forming an etch stop layer over a first side of a device wafer. The method also includes forming a polysilicon layer over the etch stop layer. A handle wafer is fusion bonded to the first side of the device wafer. A eutectic bond layer is formed on a second side of the device wafer. A micro-electro-mechanical system (MEMS) features are etched into the second side of the device wafer to expose the etch stop layer. The exposed etch stop layer is removed to expose the polysilicon layer. The exposed polysilicon layer is removed to expose a cavity formed between the handle wafer and the device wafer.

The present invention relates to a free-standing single crystalline diamond part and a single crystalline diamond part production method. The method includes the steps of: —providing a single crystalline diamond substrate or layer; —providing a first adhesion layer on the substrate or layer; —providing a second adhesion layer on the first adhesion layer: —providing a mask layer on the second adhesion layer; —forming at least one indentation or a plurality of indentations through the mask layer and the first and second adhesion layers to expose a portion or portions of the single crystalline diamond substrate or layer; and—etching the exposed portion or portions of the single crystalline diamond substrate or layer and etching entirely through the single crystalline diamond substrate or layer.

An integrated structure of a MEMS microphone and an air pressure sensor, and a fabrication method for the integrated structure, the structure including a base substrate; a vibrating membrane, back electrode, upper electrode, and lower electrode formed on the base substrate, as well as a sacrificial layer formed between the vibrating membrane and the back electrode and between the upper electrode and the lower electrode; a first integrated circuit electrically connected to the vibrating membrane and the back electrode respectively; and a second integrated circuit electrically connected to the lower electrode and the upper electrode respectively, wherein a region of the base substrate corresponding to the vibrating membrane is provided with a back cavity; the sacrificial layer between the vibrating membrane and the back electrode is hollowed out to from a vibrating space that communicates with the exterior of the integrated structure, and the sacrificial layer between the upper electrode and the lower electrode is hollowed out to form a closed space; and the integrated circuits are formed on a chip, thereby reducing the interference of connection lines on the performance of a microphone, reducing the introduction of noise, reducing the size of a product and reducing power consumption.

Described examples include a micromechanical device having a substrate. The micromechanical device includes a MEMS element and a via between the MEMS element and the substrate, the via having a conductive layer extending from the substrate to the MEMS element and having a structural integrity layer on the conductive layer.