Abstract: Circuits, methods, and apparatus for testing pressure sensors and other integrated circuits and devices while applying a well-controlled pressure are provided. A fluid may be received by a flow controller. The flow controller may provide the fluid to a first branch of a Y-shaped nozzle. The fluid may be directed at a device-under-test by a second branch of the Y-shaped nozzle. A resulting backpressure may be measured by a pressure sensor at a third branch of the Y-shaped nozzle. A height controller may vary a height of the Y-shaped nozzle relative to the device-under-test based on the measured backpressure. Once a target backpressure is reached, the pressure sensor die or other integrated circuit may be tested. The device-under-test may be tested at zero pressure, at one or more different pressures, or combination thereof.

Abstract: Circuits, methods, and apparatus that provide pressure sensing devices having a pressure sensor including a diaphragm supported by a frame. The pressure sensor may be mounted on an application-specific integrated circuit. A passage may extend through the application-specific integrated circuit from its underside to its topside where it may terminate in a cavity formed under the diaphragm. Circuit components may be formed in the second wafer portion and located in areas that are not under the first wafer portion. Circuit components may be formed in the second wafer in areas under the first wafer portion, such as under the frame or under the diaphragm. Circuit components may be formed in the second wafer such that they are partially under the first wafer portion, or partially under the frame or partially under the diaphragm.

Abstract: The micro-electromechanical device has a substrate. Integrated into the substrate is a micromechanical component that has a bending element which can be bent reversibly and which has a first end connected to the substrate and extends from the first end over a free space. The bending element has at least one web having two side edges, the course of which is defined by depressions introduced into the bending element and adjacent to the side edges. In order to form a homogenization region located within the web, in which mechanical stresses occurring during bending of the bending element are substantially equal, the mutual spacing of the side edges of the web decreases, as viewed from the first end of the bending element. The device further comprises at least one microelectronic component that is sensitive to mechanical stresses and embedded in the web in the homogenization region of the latter.

Abstract: Pressure sensors that may be used in harsh or corrosive environments. One example may provide a pressure sensor having membrane with a top surface that may be free of components or electrical connections. Instead, components and electrical connections may be located under the membrane. By providing a top surface free of components and electrical connections, the top surface of the pressure sensor may be placed in harsh or corrosive environments, while components and electrical connections under the membrane may remain protected.

Abstract: Circuits, methods, and apparatus that provide pressure sensor devices where pressure sensors may be reliably attached to surfaces in device packages, and where the coefficients of expansion of the pressure sensor and the surface are at least approximately equal. Examples may provide pressure sensor devices where pressure sensors may be reliably attached to surfaces in device packages by providing interposers formed to prevent adhesives used to attach the pressure sensors to surfaces from blocking or encroaching into pressure sensor openings or cavities. These same features may be used to accurately locate a pressure sensor relative to the interposer. Embodiments of the present invention may provide pressure sensor devices where the coefficients of expansion of the pressure sensor and the surface are at least approximately equal by proving interposers that are formed of the same or similar material as the pressure sensors, such as silicon.

Abstract: Pressure sensors having components with reduced variations due to stresses caused by various layers and components that are included in the manufacturing process. In one example, a first stress in a first direction causes a variation in a component. A second stress in a second direction is applied, thereby reducing the variation in the component. The first and second stresses may be caused by a polysilicon layer, while the component may be a resistor in a Wheatstone bridge.

Abstract: Pressure sensors that may be used in harsh or corrosive environments. One example may provide a pressure sensor having membrane with a top surface that may be free of components or electrical connections. Instead, components and electrical connections may be located under the membrane. By providing a top surface free of components and electrical connections, the top surface of the pressure sensor may be placed in harsh or corrosive environments, while components and electrical connections under the membrane may remain protected.

Abstract: Pressure sensors having components with reduced variations due to stresses caused by various layers and components that are included in the manufacturing process. In one example, a first stress in a first direction causes a variation in a component. A second stress in a second direction is applied, thereby reducing the variation in the component. The first and second stresses may be caused by a polysilicon layer, while the component may be a resistor in a Wheatstone bridge.

Abstract: The microelectromechanical component has a semiconductor substrate (1), which has a cavity (2a) formed in the semiconductor substrate. The cavity is covered by a reversibly deformable membrane (2). A sensor (17) for detecting a deformation of the membrane (2) is formed within the region of the membrane (2). A test actuator (28, 29, 30) for deforming the membrane (2) for testing purposes is also arranged within the region of the membrane (2). Finally, the microelectromechanical component has an evaluation and activation unit (41) connected to the sensor (17) and the test actuator (28, 29, 30) for activating the test actuator (28, 29, 30) in order to deform the membrane (2) as a test and for evaluating a measurement signal of the sensor (17) as a sensor detection of a deformation of the membrane (2) as a result of the activation of the test actuator (28, 29, 30).

Abstract: The micro-electromechanical device has a substrate. Integrated into the substrate is a micromechanical component that has a bending element which can be bent reversibly and which has a first end connected to the substrate and extends from the first end over a free space. The bending element has at least one web having two side edges, the course of which is defined by depressions introduced into the bending element and adjacent to the side edges. In order to form a homogenization region located within the web, in which mechanical stresses occurring during bending of the bending element are substantially equal, the mutual spacing of the side edges of the web decreases, as viewed from the first end of the bending element. The device further comprises at least one microelectronic component that is sensitive to mechanical stresses and embedded in the web in the homogenization region of the latter.

Abstract: Pressure sensors having components with reduced variations due to stresses caused by various layers and components that are included in the manufacturing process. In one example, a first stress in a first direction causes a variation in a component. A second stress in a second direction is applied, thereby reducing the variation in the component. The first and second stresses may be caused by a polysilicon layer, while the component may be a resistor in a Wheatstone bridge.

Abstract: Pressure sensors having a topside boss and a cavity formed using deep reactive-ion etching (DRIE) or plasma etching. Since the boss is formed on the topside, the boss is aligned to other features on the topside of the pressure sensor, such as a Wheatstone bridge or other circuit elements. Also, since the boss is formed as part of the diaphragm, the boss has a reduced mass and is less susceptible to the effects of gravity and acceleration. These pressure sensors may also have a cavity formed using a DRIE or plasma etch. Use of these etches result in a cavity having edges that are substantially orthogonal to the diaphragm, such that pressure sensor die area is reduced. The use of these etches also permits the use of p-doped wafers, which are compatible with conventional CMOS technologies.

Abstract: Circuits, methods, and systems to compensate pressure sensor readings for changes in temperature. An example measures temperature in a field-effect-transistor-based pressure sensor or micro-electromechanical system by measuring the device's threshold voltage. This threshold voltage is linearly dependent on the temperature but shows negligible sensitivity to mechanical stress. This allows the pressure sensor's temperature to be determined in an environment of changing pressure. Once the temperature is known, the pressure sensor's pressure readings can be adjusted. The threshold voltage can be extracted by measuring the turn-on transistor characteristic of the device and using device models. Alternately, the threshold voltage can be extracted using threshold voltage extraction circuits.

Abstract: Pressure sensors having components with reduced variations due to stresses caused by various layers and components that are included in the manufacturing process. In one example, a first stress in a first direction causes a variation in a component. A second stress in a second direction is applied, thereby reducing the variation in the component. The first and second stresses may be caused by a polysilicon layer, while the component may be a resistor in a Wheatstone bridge.

Abstract: Circuits, methods, and systems that calibrate or account for packaging and related stress components in a pressure sensor. Further examples provide an improved sensor element or device. One example provides one or more sensing elements on the diaphragm and near the diaphragm-bulk boundary. Sensors near the diaphragm-bulk are used to estimate package-induced stress. This estimation can then be used in calibrating package stress from pressure measurements.

Abstract: Circuits, methods, and systems to compensate pressure sensor readings for changes in temperature. An example measures temperature in a field-effect-transistor-based pressure sensor or micro-electromechanical system by measuring the device's threshold voltage. This threshold voltage is linearly dependent on the temperature but shows negligible sensitivity to mechanical stress. This allows the pressure sensor's temperature to be determined in an environment of changing pressure. Once the temperature is known, the pressure sensor's pressure readings can be adjusted. The threshold voltage can be extracted by measuring the turn-on transistor characteristic of the device and using device models. Alternately, the threshold voltage can be extracted using threshold voltage extraction circuits.

Abstract: Pressure sensors having a topside boss and a cavity formed using deep reactive-ion etching (DRIE) or plasma etching. Since the boss is formed on the topside, the boss is aligned to other features on the topside of the pressure sensor, such as a Wheatstone bridge or other circuit elements. Also, since the boss is formed as part of the diaphragm, the boss has a reduced mass and is less susceptible to the effects of gravity and acceleration. These pressure sensors may also have a cavity formed using a DRIE or plasma etch. Use of these etches result in a cavity having edges that are substantially orthogonal to the diaphragm, such that pressure sensor die area is reduced. The use of these etches also permits the use of p-doped wafers, which are compatible with conventional CMOS technologies.

Abstract: Methods and apparatus for an absolute or gauge pressure sensor having a backside cavity with a substantially vertical interior sidewall. The backside cavity is formed using a DRIE etch or other MEMS micro-machining technique. The backside cavity has an opening that is cross shaped, where the dimensions of the cross may be varied to adjust pressure sensor sensitivity. The cross may have one or more rounded corners to reduce peak stress, for example, the interior corners may be rounded. A sensing conductor may be routed over one or more corners including the interior corners to detect breakage.

Abstract: Methods and apparatus for an absolute or gauge pressure sensor having a backside cavity with a substantially vertical interior sidewall. The backside cavity is formed using a DRIE etch or other MEMS micro-machining technique. One embodiment provides for a diaphragm having a boss manufactured using a two step process that results in a boss thickness that is independent of the thickness of the starting material. Another provides for various shapes to the backside cavity that reduces the likelihood of crystalline fractures while focusing stress on piezoresistive sensing elements. Another provides for a sensitivity adjustment by thinning the insulating and silicon layers that form the sensor diaphragm. A pressure sensor according to the present invention may incorporate one or more of these, or may incorporate other elements discussed herein.

Abstract: Glass with metal deposited on it in a pattern which is slightly larger than the cavity area of the corresponding silicon wafer. The metal layer has a thickness such that the glass can deform sufficiently to allow bonding of the glass to the silicon. The metal is then compressively bonded to the silicon in a rim area around the edge of the cavity. The metal provides a barrier to helium which can leak through the glass, but is stopped by the metal barrier.