The physical quantity sensor includes a substrate having several areas, a movable body, and a detection electrode. The detection electrode straddles the several areas. When setting a first imaginary straight line which is the smallest in an angle formed with an X-axis direction of imaginary straight lines connecting two of end parts on respective areas of the detection electrode, and a second imaginary straight line extending along a principal surface of the movable body in a maximum displacement state around the oscillation axis, the first and second imaginary straight lines fail to cross each other in an area between a first normal line which passes the end part of the first one of the several areas and a second normal line which passes the end part of the last one of the several areas.

A micro-electromechanical-system (MEMS) device may be formed to include an anti-stiction polysilicon layer on one or more moveable MEMS structures of a device wafer of the MEMS device to reduce, minimize, and/or eliminate stiction between the moveable MEMS structures and other components or structures of the MEMS device. The anti-stiction polysilicon layer may be formed such that a surface roughness of the anti-stiction polysilicon layer is greater than the surface roughness of a bonding polysilicon layer on the surfaces of the device wafer that are to be bonded to a circuitry wafer of the MEMS device. The higher surface roughness of the anti-stiction polysilicon layer may reduce the surface area of the bottom of the moveable MEMS structures, which may reduce the likelihood that the one or more moveable MEMS structures will become stuck to the other components or structures.

A microelectromechanical system (MEMS) device includes a substrate and a movable element at least partially suspended above the substrate and having at least one degree of freedom. The MEMS device further includes a protrusion extending from the substrate and configured to contact the movable element when the movable element moves in the at least one degree of freedom, wherein the protrusion comprises a surface having a water contact angle of higher than about 15° measured in air.

A modification to rough polysilicon using ion implantation and silicide is provided herein. A method can comprise depositing a hard mask on a single crystal silicon, patterning the hard mask, and depositing metal on the single crystal silicon. The method also can comprise forming silicide based on causing the metal to react with exposed silicon of the single crystal silicon. Further, the method can comprise removing unreacted metal and stripping the hard mask from the single crystal silicon. Another method can comprise forming a MEMS layer based on fusion bonding a handle MEMS with a device layer. The method also can comprise implanting rough polysilicon on the device layer. Implanting the rough polysilicon can comprise performing ion implantation of the rough polysilicon. Further, the method can comprise performing high temperature annealing. The high temperature can comprise a temperature in a range between around 700 and 1100 degrees Celsius.

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.

A micro-electromechanical-system (MEMS) device may be formed to include an anti-stiction polysilicon layer on one or more moveable MEMS structures of a device wafer of the MEMS device to reduce, minimize, and/or eliminate stiction between the moveable MEMS structures and other components or structures of the MEMS device. The anti-stiction polysilicon layer may be formed such that a surface roughness of the anti-stiction polysilicon layer is greater than the surface roughness of a bonding polysilicon layer on the surfaces of the device wafer that are to be bonded to a circuitry wafer of the MEMS device. The higher surface roughness of the anti-stiction polysilicon layer may reduce the surface area of the bottom of the moveable MEMS structures, which may reduce the likelihood that the one or more moveable MEMS structures will become stuck to the other components or structures.

Angular accelerometers are described, as are systems employing such accelerometers. The angular accelerometers may include a proof mass and rotational acceleration detection beams directed toward the center of the proof mass. The angular accelerometers may include sensing capabilities for angular acceleration about three orthogonal axes. The sensing regions for angular acceleration about one of the three axes may be positioned radially closer to the center of the proof mass than the sensing regions for angular acceleration about the other two axes. The proof mass may be connected to the substrate though one or more anchors.

A manufacturing method of microelectromechanical system (MEMS) device includes providing a first, a second and a third substrates, wherein the first substrate includes a first and a second circuit, the second substrate includes second and third connection areas, and the third substrate includes first connection areas. Second grooves and a dividing groove are formed on the fourth surface of the third substrate. The second and third substrates are bonded to make the first and the second connection areas correspondingly connect with each other. The second substrate is divided to form electrically isolating first and second movable elements. The first movable element is spatial separated from the third substrate and corresponding to the second groove. The second movable element is connected to the third substrate. The first and the second substrates are bonded to make the fourth and the third connection areas connect correspondingly. The third substrate is thinned, divided into a first and a second cap from the dividing groove, and formed a first groove from the fifth surface. The first cap is corresponding to the first movable element and the first circuit. Air tight space to sense a pressure variation of exterior environment is formed between the first substrate and the second cap. The second movable element is movable with the second cap by the pressure variation of the exterior environment. Accordingly, the pressure sensor and the MEMS structure for sensing other physical quantity can be integrated in the foregoing MEMS device by a single process.

Various embodiments of the present disclosure are directed towards a method to roughen a crystalline layer. A crystalline layer is deposited over a substrate. A mask material is diffused into the crystalline layer along grain boundaries of the crystalline layer. The crystalline layer and the mask material may, for example, respectively be or comprise polysilicon and silicon oxide. Other suitable materials are, however, amenable. An etch is performed into the crystalline layer with an etchant having a high selectivity for the crystalline layer relative to the mask material. The mask material defines micro masks embedded in the crystalline layer along the grain boundaries. The micro masks protect underlying portions of the crystalline layer during the etch, such that the etch forms trenches in the crystalline layer where unmasked by the micro masks.

A structure of micro-electro-mechanical-system (MEMS) microphone includes a substrate, having a first opening. A dielectric layer is disposed on the substrate, wherein the dielectric layer has a second opening aligned to the first opening. A membrane is disposed within the second opening of the dielectric layer. A peripheral region of the membrane is embedded into the dielectric layer at sidewall of the second opening. A backplate layer is disposed on the dielectric layer. The backplate layer includes a protection layer, having a peripheral region disposed on the dielectric layer and a central region with venting holes over the second opening. The central region of the protection layer further has anti-sticky structures at a side of the protection layer toward the membrane. An electrode layer is disposed on the side of the protection layer, surrounding the anti-sticky structures.