Various embodiments of the present disclosure are directed towards a microelectromechanical system (MEMS) device. The MEMS device includes a first dielectric structure disposed over a first semiconductor substrate, where the first dielectric structure at least partially defines a cavity. A second semiconductor substrate is disposed over the first dielectric structure and includes a movable mass, where opposite sidewalls of the movable mass are disposed between opposite sidewall of the cavity. A first piezoelectric anti-stiction structure is disposed between the movable mass and the first dielectric structure, wherein the first piezoelectric anti-stiction structure includes a first piezoelectric structure and a first electrode disposed between the first piezoelectric structure and the first dielectric structure

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 MEMS sensor including a diaphragm, a base surface area of the diaphragm being delimited with the aid of a peripheral wall structure, and the base surface area including at least two subareas, of which at least one of the subareas is deflectably situated, and the at least two subareas being separated from one another with the aid of at least one separating structure or being delimited by the latter. The separating structure includes at least one fluid through-opening for the passage of fluid.

Micromachined ultrasonic transducers having a self-assembled monolayer formed on a surface of a sealed cavity are described. A micromachined ultrasonic transducer may include a flexible membrane configured to vibrate over a sealed cavity, and the self-assembled monolayer may coat some or all of the interior surfaces of the sealed cavity. During fabrication, the sealed cavity may be formed by bonding the membrane to a substrate such that the sealed cavity is between the membrane and the substrate. An access hole may be formed through the membrane to the sealed cavity and the self-assembled monolayer is formed on surface(s) of the sealed cavity by introducing precursors into the sealed cavity through the access hole.

Provided are a method for preparing a silicon wafer with a rough surface and a silicon wafer, for solving the problem that a viscous force is likely to be generated when a smooth surface of the silicon wafer approaches another film layer. The method includes: depositing a porous oxide film layer on a surface of the first silicon planar layer that has been subjected to planar planarization, and then etching the porous oxide film layer by XeF.sub.2 vapor etching, during which XeF.sub.2 gas passes through the porous oxide film layer to etch the first silicon planar layer in an irregular way. Therefore, the first silicon planar layer has a greater surface roughness. When the silicon wafer approaches to another film layer, the viscous force generated therebetween is reduced, improving the sensitivity of the MEMS device and reducing the probability of out-of-work MEMS devices.

Various embodiments of the present disclosure are directed towards a microelectromechanical system (MEMS) device. The MEMS device includes a first dielectric structure disposed over a first semiconductor substrate, where the first dielectric structure at least partially defines a cavity. A second semiconductor substrate is disposed over the first dielectric structure and includes a movable mass, where opposite sidewalls of the movable mass are disposed between opposite sidewall of the cavity. A first piezoelectric anti-stiction structure is disposed between the movable mass and the first dielectric structure, wherein the first piezoelectric anti-stiction structure includes a first piezoelectric structure and a first electrode disposed between the first piezoelectric structure and the first dielectric structure.

A method of manufacturing a semiconductor structure includes following operations. A first substrate is provided. A plate is formed over the first substrate. The plate includes a first tensile member, a second tensile member, a semiconductive member between the first tensile member and the second tensile member, and a plurality of apertures penetrating the first tensile member, the semiconductive member and the second tensile member. A membrane is formed over and separated from the plate. The membrane include a plurality of holes. A plurality of conductive plugs passing through the plate or membrane are formed. A plurality of semiconductive pads are formed over the plurality of conductive plugs. The plate is bonded to a second substrate. The second substrate includes a plurality of bond pads, and the semiconductive pads are in contact with the bond pads.

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 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.