A method includes fusion bonding a handle wafer to a first side of a device wafer. The method further includes depositing a first mask on a second side of the device wafer, wherein the second side is planar. A plurality of dimple features is formed on an exposed portion on the second side of the device wafer. The first mask is removed from the second side of the device wafer. A second mask is deposited on the second side of the device wafer that corresponds to a standoff. An exposed portion on the second side of the device wafer is etched to form the standoff. The second mask is removed. A rough polysilicon layer is deposited on the second side of the device wafer. A eutectic bond layer is deposited on the standoff. In some embodiments, a micro-electro-mechanical system (MEMS) device pattern is etched into the device wafer.

A microelectromechanical systems (MEMS) die includes a substrate, a back plate, and a diaphragm. The back plate is coupled to the substrate and includes a dielectric layer and an electrode. The electrode is coupled to the dielectric layer and defines an opening that exposes a central portion of the dielectric layer. The diaphragm is oriented parallel to the back plate and is spaced apart from the back plate. In one implementation, a diameter of the opening is greater than or equal to 1/10 of the diameter of the diaphragm.

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.

Structures and formation methods of a semiconductor device structure are provided. The method includes forming a first dielectric layer over a substrate and forming a first recess in the first dielectric layer. The method also includes conformally forming a first movable membrane over the first dielectric layer. In addition, the first movable membrane has a first corrugated portion in the first recess. The method further includes forming a second dielectric layer over the first movable membrane and partially removing the substrate, the first dielectric layer, and the second dielectric layer to form a cavity. In addition, the first corrugated portion of the first movable membrane is partially sandwiched between the first dielectric layer and the second dielectric layer.

Provided are a method for preparing a silicon wafer with a rough surface and a silicon wafer, which solves the problem in the prior art that viscous force is likely to be generated. The method includes: depositing a first film layer having a large surface roughness on a surface of a silicon wafer that has been subjected to planar planarization, and then blanket etching the first film layer to remove the first film layer. Then, the surface of the first silicon layer facing away from the substrate is further etched to form grooves and protrusions, which provide roughness, thereby forming a silicon wafer with a rough surface. When the silicon wafer approaches to another film layer, the viscous force generated therebetween is reduced, and thus the sensitivity of the MEMS device is improved and the probability of out-of-work MEMS device is reduced.

A micromechanical structure including a substrate, a moveable seismic mass, a detection structure, and a main spring. The seismic mass is connected to the substrate using the main spring. A first direction and a second direction perpendicular thereto define a main extension plane of the substrate. The detection structure detects a deflection of the seismic mass and includes first electrodes mounted at the seismic mass and second electrodes mounted at the substrate. The first electrodes and second electrodes have a two-dimensional extension in the first and second directions. The micromechanical structure has a graduated stop structure including a first spring stop, a second spring stop, and a fixed stop.

A micro-electro mechanical system (MEMS) device includes a MEMS substrate, at least one movable element laterally confined within a matrix layer that overlies the MEMS substrate, and a cap substrate bonded to the matrix layer through bonding material portions. A first movable element selected from the at least one movable element is located inside a first chamber that is laterally bounded by the matrix layer and vertically bounded by a first capping surface that overlies the first movable element. The first capping surface includes an array of downward-protruding bumps including respective portions of a dielectric material layer. Each of the downward-protruding bumps has a vertical cross-sectional profile of an inverted hillock. The MEMS device can include, for example, an accelerometer.

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.

Provided are a method for preparing a silicon wafer with a rough surface and a silicon wafer, which solves the problem in the prior art that viscous force is likely to be generated. The method includes: depositing a first film layer having a large surface roughness on a surface of a silicon wafer that has been subjected to planar planarization, and then blanket etching the first film layer to remove the first film layer. Then, the surface of the first silicon layer facing away from the substrate is further etched to form grooves and protrusions, which provide roughness, thereby forming a silicon wafer with a rough surface. When the silicon wafer approaches to another film layer, the viscous force generated therebetween is reduced, and thus the sensitivity of the MEMS device is improved and the probability of out-of-work MEMS device is reduced.

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 comprises forming a MEMS layer, wherein the forming comprises fusion bonding a handle layer 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.