Abstract: A transducer apparatus is disclosed herein, including a method thereof for forming the transducer apparatus. A metal diaphragm can be molecularly bonded to a ceramic material to form a ceramic surface thereof. A bridge circuit is connected to the ceramic surface of the metal diaphragm. An input pressure port for pressure sensing thereof can then be provided, wherein the input pressure port is connected to the metal diaphragm to thereby form a transducer apparatus comprising the metal diaphragm, the bridge circuit and the input pressure port. The metal diaphragm is preferably welded to the input pressure. The metal diaphragm and the ceramic surface thereof preferably operate over a temperature of range of at least 40° C. to 150° C., as does the transducer apparatus. The transducer apparatus functions as a pressure transducer that can be used in corrosive media and high temperature applications.

Abstract: A pressure sensor includes: a casing; a sensor chip with a gauge resistor; a boss disposed on the gauge resistor; a metallic diaphragm capable of distorting in accordance with a pressure; and a load transmission member disposed between the metallic diaphragm and the boss. The casing accommodates the sensor chip, the boss and the load transmission member. The casing is covered with the metallic diaphragm. The pressure applied to the diaphragm is detected such that the load corresponding to the pressure is applied to the gauge resistor through the metallic diaphragm, the load transmission member and the boss so that the pressure is measured on the basis of a resistance change of the gauge resistor. The gauge resistor is larger than the boss.

Abstract: A means to accurately measure the pressure distribution across a rigid or semi-rigid surface, or between two rigid or semi-rigid surfaces with high special resolution is disclosed. The present invention relates to measuring a pressure distribution. The present invention would be ideal for use in various types of manufacturing tooling and various in situ industrial machine controls. The present invention uses an array of commercial micro-machined silicon pressure sensing die attached to a substrate and encapsulated in an elastomer.

Abstract: A method for making a pressure sensor by providing a wafer including a base silicon layer, a buried sacrificial layer, and a top silicon layer. The top silicon layer is arranged over the buried sacrificial layer and the buried sacrificial layer is arranged over the base silicon layer. Etching vents through the top silicon layer to the buried sacrificial layer and removing a portion of the buried sacrificial layer. Depositing silicon to seal the vents and arranging a strain gauge or a capacitance contact on the wafer. A method for making a pressure sensor including providing a bulk wafer and depositing a sacrificial layer on the bulk wafer. Depositing silicon on the sacrificial layer and the bulk wafer to form an encapsulation layer. Etching vents through the encapsulation layer to the sacrificial layer and removing the sacrificial layer. Closing the vents with a silicon deposition and arranging a strain gauge or a capacitance contact on the encapsulation layer.

Abstract: A micro pressure sensor comprising a glass substrate or a bulk silicon wafer with a rampart protruding from the surface and a plurality of first contacting pads, a thin membrane having a plurality of piezo-resistors, circuit patterns, and a plurality of second contact pads, and conducting lines, wherein the plurality of contact pads are partially exposed to outside. The rampart on the substrate has a cavity formed on the center of the top surface of the rampart. The top surface of the rampart is tightly bonded to the surface of the thin membrane. The piezo-resistors are sealed in the cavity. Preferably, the micro sensor further comprises a plurality of thermo sensors, and a plurality of temperature-controlling elements all enclosed inside the cavity, and additional protective layers formed on the exposure regions of all contact pads.

Abstract: An acceleration sensor includes a deflectable pressure measuring diaphragm and a counter-structure, which is deflectable as against the pressure measuring diaphragm. The acceleration sensor includes a detection means for detecting a deflection of the pressure measuring diaphragm as against the counter-structure. Further, a test mass is connected to the pressure measuring diaphragm or the counter-structure in order to be deflected from an idle position depending on an acceleration applied. The deflection of the test mass results in a change of the distance between the pressure measuring diaphragm and the counter-structure, which is detectable by the detection means.

Abstract: A semiconductor pressure sensor comprises a non-single-crystal-silicon-based substrate, a movable insulating diaphragm, at least one piezoresistor positioned on the insulating diaphragm, an insulating supporter positioned on the non-single-crystal-silicon-based substrate for fixing two ends of the insulating diaphragm and forming a cavity between the insulating diaphragm and the non-single-crystal-silicon-based substrate, and a thin film transistor (TFT) control circuit positioned on the non-single-crystal-silicon-based substrate and electrically connected to the insulating diaphragm and the piezoresistor.

Abstract: By sealing a diaphragm with less processes and lower cost and reducing deformation due to remaining stress, a stable and highly reliable pressure sensor construction is proposed. The pressure sensor is low in measurement error and small in floating capacitance and leakage current and good in characteristic. As a means to attain the above object, a polycrystalline silicon diaphragm is sealed with a silicon oxide film deposited through a LPCVD method and then completely covered. The diaphragm is placed on a surface of a semiconductor substrate with a nearly constant gap of 0.15 to 1.3 ?m, and has difference-in-grade constructions of a deformation reducing means due to remaining stress.

Abstract: In a pressure sensor module according to the prior art, which is intended for detecting the pressure of a corrosive medium, the conventional sensor cell with a pressure sensor chip is modified in order to protect it from corrosion, which results in a large volume for a pressure-transmitting-fluid. This is disadvantageous for the calibration and for a high degree of measurement precision. In a pressure sensor module (1) according to the invention, a convention sensor cell (5) is used that has an adapter (21) connected to it, which has a very small volume for a pressure-transmitting medium.

Abstract: A sensor device includes a circuit chip, an adhesion film, and a sensor chip mounted on the circuit chip through the adhesion film. The sensor chip includes a substrate having foreside and backside surfaces, a concavity disposed on the backside surface of the substrate, and a membrane disposed on the foreside surface of the substrate so that the membrane covers the concavity. The adhesion film is disposed between the sensor chip and the circuit chip so as to form a passage for connecting between the concavity and an outside of the concavity.

Abstract: In a diaphragm (30) having a square shape comprising four sides of a pair of first sides (31, 32) extending along the <110> crystal axis direction and a pair of second sides (33, 34) extending along the <100> crystal axis direction, when an axis bisecting each of the first sides (31, 32) of the diaphragm (30) and passing through the center point of the diaphragm is set as a first axis K1 and an axis vertically-intersecting to the first axis K1 and passing through the center point of the diaphragm is set as a second axis K2, each of the side gages Rs1, Rs2 is located on a virtual line T1, T2, T3, T4 which extends from the center point of each of the center gages Rc1, Rc2 to the peripheral portion of the diaphragm (30) and intersects to the first axis K1 and the second axis K2 at 45°.

Abstract: It is an object of the present invention to provide a touch mode capacitive pressure sensor having higher pressure durability than conventional sensors. In this invention, a touch mode capacitive pressure sensor has a diaphragm made from boron-doped silicon, and the boron concentration at the top face of the diaphragm is equal to or greater than 1×1019 cm?3 and less than 9×1019 cm?3. Further, in this invention, a touch mode capacitive pressure sensor has a conductive diaphragm made by doping of an impurity and anisotropic etching, and the etch pit density on the top face of the diaphragm is equal to or less than five per ?m2, and preferably equal to or less than one per ?m2. As a result, the pressure durability of the diaphragm is greatly improved.

Abstract: A pressure sensor includes a pair of base films, a pair of electrodes, a layer of pressure-sensitive resistor, a spacer, and a projection. The electrodes are located between the base films. The layer of pressure-sensitive resistor is located between the base films to be distant from one of the electrodes by a predetermined gap. The spacer is located outside the layer of pressure-sensitive resistor between the base films and used for forming the gap. The projection is located on an outer surface of one of the base films in order to decrease the lowest pressure that can be detected by the pressure sensor. The contact state between the layer of pressure-sensitive resistor and one of the electrodes varies to vary the resistance between the electrodes when a pressure acts on the projection.

Abstract: A semiconductor pressure sensor comprises a non-single-crystal-silicon-based substrate, a movable insulating diaphragm, at least one piezoresistor positioned on the insulating diaphragm, an insulating supporter positioned on the non-single-crystal-silicon-based substrate for fixing two ends of the insulating diaphragm and forming a cavity between the insulating diaphragm and the non-single-crystal-silicon-based substrate, and a thin film transistor (TFT) control circuit positioned on the non-single-crystal-silicon-based substrate and electrically connected to the insulating diaphragm and the piezoresistor.

Abstract: A stop member is secured to a piezoresistive semiconductor bossed diaphragm at the peripheral area, and includes a first and second slotted apertures in communication with the central active area, the first and second slotted apertures correspond in location with opposing sides of a central boss. The stop member includes a stop cavity located between the first slotted aperture and the second slotted aperture, and the stop cavity overlies the central boss and is separated therefrom to enable the diaphragm to deflect when a force is applied and to enable the central boss to impinge on the surface of the stop cavity when an excessive force is applied. The first and second slotted apertures permit another force to be applied to the active region of the diaphragm in a direction opposite to the stopped direction. A second stop member is secured to the diaphragm to provide stopping in either direction.

Abstract: A diaphragm-type semiconductor device includes a semiconductor substrate, a surface of which is substantially flat, a diaphragm, which covers a circular pressure reference space located on the surface, and a circular electrode layer, a middle part of which is embedded in the diaphragm. The electrode layer is larger than the space and is coaxial with the space. Therefore, internal stress is balanced between inner and outer sides of the diaphragm, and a step formed at the outer edge of the top electrode layer is separated from the diaphragm. The device also includes a step adjuster around the space on the surface. Therefore, another step formed at the outer edge of the space disappears, and a new step is formed separately from the diaphragm at the outer edge of the step adjuster. With this structure, the diaphragm has a desired flatness.

Abstract: In ECU in which a sensor IC and various engine control devices are mounted on a board in a case, the sensor IC has a pressure sensor element covered with mold resin having a pressure introduction hole extending outward from the pressure sensor element so as to open to an outer surface thereof. A cylindrical resilient member is disposed and resiliently deformed between an inner wall of the case and the outer surface of the mold resin so as to allow a pressure introduction inlet formed in the case to communicate with the pressure introduction hole and not to communicate with places where the engine control devices are mounted. The case of ECU is fixed to a surge tank so that a pressure introduction outlet formed in the surge tank communicates directly with the pressure introduction inlet.

Abstract: In a diaphragm (30) having a square shape comprising four sides of a pair of first sides (31, 32) extending along the <110> crystal axis direction and a pair of second sides (33, 34) extending along the <100> crystal axis direction, when an axis bisecting each of the first sides (31, 32) of the diaphragm (30) and passing through the center point of the diaphragm is set as a first axis K1 and an axis vertically-intersecting to the first axis K1 and passing through the center point of the diaphragm is set as a second axis K2, each of the side gages Rs1, Rs2 is located on a virtual line T1, T2, T3, T4 which extends from the center point of each of the center gages Rc1, Rc2 to the peripheral portion of the diaphragm (30) and intersects to the first axis K1 and the second axis K2 at 45°.

Abstract: A diaphragm-type semiconductor pressure sensor includes a substantially rectangular (110) semiconductor substrate, which has four sides, an active surface of (110) crystallographic face orientation, and a back surface, which is opposite to the active surface, of (110) crystallographic face orientation. Each of the surfaces is surrounded by the four sides. Each of the four sides is at an angle of substantially 45 degrees with a crystallographic axis of <110> orientation that is substantially parallel to the active surface. The substrate includes a diaphragm in the active surface. The diaphragm has been formed by forming a recess in the back surface. The diaphragm includes a gauge resistor. A pressure is detected on the basis of the variation in the resistance of the gauge resistor.

Abstract: A semiconductor pressure sensor is presented. The pressure sensor includes a silicon substrate with a diaphragm that produces a distortion depending on the pressure. Strain gauges are provided on the main surface side of the silicon substrate with the diaphragm and are formed by conductive diffusion resistors different from the substrate. A getter is provided on the main surface side of the silicon substrate including the periphery of the strain gauges adjacent to the strain gauges. The getter includes the PN-junction area to which reverse bias is impressed so that the metal impurities of at least an Fe atom that are contained in the silicon substrate may be captured.

Abstract: A semiconductor pressure sensor includes a semiconductor substrate having a diaphragm for receiving pressure and a bridge circuit for detecting a distortion of the diaphragm corresponding to the pressure. The bridge circuit includes a pair of first gauge resistors and a pair of second gauge resistors. The first gauge resistors are disposed on a center of the diaphragm, and the second gauge resistors are disposed on a periphery of the diaphragm. Each first gauge resistor has a first resistance, which is larger than a second resistance of each second gauge resistor. The TNO property of the sensor is improved, so that the sensor has high detection accuracy.

Abstract: The invention concerns a pressure sensor (1), able to operate at high temperature and measure the pressure of a hostile medium, comprising: a sensing element (4) integrating a membrane (8) in monocrystalline silicon carbide, made by micro-machining a substrate in polycrystalline silicon carbide, a first surface of membrane (8) intended to contact said medium, a second surface of membrane (8) comprising membrane deformation detection means (9) connected to electric contacts (10) to connect electric connection means (11), the surfaces of sensing element (4) contacting said medium being chemically inert to this medium; a carrier (5) to support sensing element (4) so that said first surface of membrane (8) may be contacted with said medium and the second surface of membrane (8) may be shielded from said medium, carrier (5) being in polycrystalline silicon carbide; a seal strip (6), in material containing silicon carbide, brazed between carrier (5) and sensing element (4) to protect the second surface of membra

Abstract: A surface-micromachined high-pressure sensor, formed by forming a cavity using a sacrificial layer. The sacrificial layer can be reflowed to make the edges of the cavity more rounded. The material that is used for the diaphragm can be silicon nitride, or multiple layers including silicon nitride and other materials. The pressure sensor is intended to be used in high pressure applications, e.g. pressure is higher than 6000, 10,000 or 30,000 P.S.I.

Abstract: A micromechanical component, in particular a pressure sensor, including a substrate that has a membrane region, a surrounding region of the membrane region, at least one measuring resistance provided in the membrane region and modifiable by deformation of the membrane region, and a corresponding evaluation circuit provided in the surrounding region. An interference effect on the measuring resistance is producible by way of a deformation of parts, in particular conductor paths, of the evaluation circuit relative to the substrate. The invention also creates a corresponding equalization method on a test chip or as an individual final equalization.

Abstract: A method for making a pressure sensor by providing a wafer including a base silicon layer, a buried sacrificial layer, and a top silicon layer. The top silicon layer is arranged over the buried sacrificial layer and the buried sacrificial layer is arranged over the base silicon layer. Etching vents through the top silicon layer to the buried sacrificial layer and removing a portion of the buried sacrificial layer. Depositing silicon to seal the vents and arranging a strain gauge or a capacitance contact on the wafer. A method for making a pressure sensor including providing a bulk wafer and depositing a sacrificial layer on the bulk wafer. Depositing silicon on the sacrificial layer and the bulk wafer to form an encapsulation layer. Etching vents through the encapsulation layer to the sacrificial layer and removing the sacrificial layer. Closing the vents with a silicon deposition and arranging a strain gauge or a capacitance contact on the encapsulation layer.

Abstract: Pressure gauge preferably arranged to function on the outside of a measuring element (1), the measuring element having a central cavity (103) and being constituted by at least two parts (100A-B) which are tightly joined for creation of the cavity, and comprising sensor organs (11-14) for the mechanical state of stress of the measuring element during pressure influence. The two parts of the measuring element (100A-B) are manufactured in planar techniques, preferably by silicon or quarts with the cavity running in the longitudinal direction. The central cavity has a considerably greater height than width. The sensor organs (11-14) have form of piezo-resistive elements arranged near an outer (105) eventually inner surface of the measuring element.

Abstract: A microelectronic pressure sensor comprises a resonator (23) made on the basis of a crystalline material and secured to the inside of package (24) made use of a cap (27) and a baseplate (26) for assembling one to the other. The cap (27) and the baseplate (26) are made completely or almost completely out of the same material as the resonator (23), and the pressure (Pe) to be detected is applied all around the package.

Abstract: In a pressure sensor in which a frame shaped protruding potion is formed on a surface side of a substrate by means of an etching process, and a blocking plate is connected to an upper part of the protruding portion, to form a standard pressure chamber, a recess is formed on at least one of the substrate and the blocking plate that constitute the standard pressure chamber, to increase the height of the standard pressure chamber, thereby preventing the lowering of pressure detection accuracy due to foreign substances within the standard pressure chamber.

Abstract: A method for producing an isolated micro pressure sensor and the process for producing the same are disclosed. The method for manufacturing the isolated micro pressure sensor includes: (A) etching one surface of a substrate to form a rampart with an open cavity on the center of its top surface and with plate portions surrounding the rampart; (B) forming a plurality of first contact pads on said plate portions of the substrate outside said rampart; (C) forming a plurality of second contact pads, a plurality of piezo-resistors, thermo sensors, temperature-controlling elements and circuit patterns on a bulk silicon wafer; (D) forming a plurality of grooves on the periphery of the bulk silicon wafer; (E) bonding the bulk silicon wafer and the substrate; and (F) thinning said bulk silicon wafer until said bulk silicon wafer forming a thin membrane.

Abstract: A means to accurately measure the pressure distribution across a rigid or semi-rigid surface, or between two rigid or semi-rigid surfaces with high special resolution is disclosed. The present invention relates to measuring a pressure distribution. The present invention would be ideal for use in various types of manufacturing tooling and various in situ industrial machine controls. The present invention uses an array of commercial micro-machined silicon pressure sensing die attached to a substrate and encapsulated in an elastomer.

Abstract: The semiconductor pressure sensor includes a substrate (20). The sensor includes a diaphragm (26) implemented in the substrate (26) and being displaceable by a pressure medium acting on a side of the substrate (26). The sensor includes sensor circuitry (22, 23) implemented on the opposite side of the substrate in coincidence with the diaphragm (26) for detecting displacement of the diaphragm (26) for pressure.

Abstract: The invention relates to a pressure sensor with an MEM structure (micro electro mechanical structure), which has a hollow housing (8) in which a semiconductor chip (2) with a pressure-sensitive area (4) is arranged. In its interior (12) and with parts of the semiconductor chip (2), the housing is covered by a first plastic compound (15), which has a lower level of deformation than a second plastic compound (16), which partly covers the pressure-sensitive area (4) of the semiconductor chip (2).

Abstract: The invention relates to a pressure sensor with an MEM structure (micro electro mechanical structure), which has a hollow housing in which a semiconductor chip with a pressure-sensitive area is arranged. In its interior and with parts of the semiconductor chip, the housing is covered by a first plastic compound, which has a lower level of deformation than a second plastic compound, which partly covers the pressure-sensitive area of the semiconductor chip.

Abstract: A micromechanical differential pressure sensor device for measuring a pressure difference between two mutually separated spaces or media, in which two absolute pressure measuring devices are monolithically integrated on a single support substrate, in particular on a semiconductor chip. The absolute pressure measuring devices are preferably fabricated by surface micromachining.

Abstract: The full bridge circuit in a pressure sensor including semiconductor piezoelectric resistive elements in a pressure detection structure is connected to a filter. That is, first and second output terminals of the full bridge circuit is connected to a capacitor. One end of the capacitor is connected to the first output terminal through a first resistor. The other end of the capacitor is connected to the second output terminal through a second resistor. In an exhaust system of an engine, the pressure of the exhaust gas is detected to detect clogging in the black smoke removing unit. The filter removes the pulsate component in the detection signal derived from the pulsate component in the exhaust gas.

Abstract: A sensor chip has a piezo-resistive bridge, a first resistor network that can be used for biasing when connected to an external amplifier, a second resistor network that can be used to set gain when connected to the external amplifier, and a leadout resistor that connects an output of the bridge to a common summing point of the two resistor networks. The summing point is connected to the non-inverting input of the external amplifier. The leadout resistor has a predetermined number of squares. A portion of the squares has a light implant and the remaining portion of the squares has a heavy implant. The ratio of the heavy and light implant portions provides customized span compensation of the amplified output for specific operating temperature ranges.

Abstract: The invention relates to a fluid pressure sensor for a lead (18) or catheter preferably intended to be placed in a living organism, such as the heart of a human being, said sensor comprising a piezoelectric element (4, 10, 11, 14) delivering an electric signal when subjected to a pressure variation, said piezoelectric element (4, 10, 11, 14) being designed to exhibit circumferential sensitivity and being disposed on at least parts of the outer surface of a rigid annular or tubular supporting structure (2). The rigidity of said sensor is such that the signal from the sensor relating to the pressure transferred to the sensor through an ongrowth of for instance tissue on the sensor would be at least 90% of the signal from the sensor without the ongrowth.

Abstract: The invention is intended to provide a small and highly reliable pressure sensor, which has a smaller number of components and can be produced by using a mold for resin molding in common. A sensor unit (11) is molded with resin. and includes a semiconductor chip (1) for converting the change in pressure of a medium introduced through an introduction hole for measurement into an electric signal. A lead member (12) has one end exposed in a connector (23) and is electrically connected to the semiconductor chip (1) in the sensor unit (11) beforehand. Pressure is applied to the semiconductor chip (1) through a pipe (22). An outer case (21) is integrally formed of synthetic resin by insert molding of the sensor unit (11), the lead member (12) and the pipe (22).

Abstract: Surface micromachined structures having a relatively thick silicon nitride layer and a relatively thin conductive polysilicon layer bonded together. Preferably, the silicon nitride layer and conductive polysilicon layer are made in the same low pressure chemical vapor deposition (LPCVD) step. The polysilicon layer is thin enough compared to the silicon nitride layer so that the mechanical properties of the microstructure are primarily determined by the silicon nitride layer. This provides superior mechanical properties for many applications. The thin conductive polysilicon layer provides conductivity for the microstructure (silicon nitride is an electrical insulator). The polysilicon layer has a thickness less than ⅕ the thickness of the silicon nitride layer. Preferably, the polysilicon layer is much thinner than this. The polysilicon layer can be located on a top surface or bottom surface of the silicon nitride layer. Also, the polysilicon layer can be located within the silicon nitride layer.

Abstract: A pressure sensor 10 comprises an upper substrate 30 having a detection face 30A, a diaphragm 20 provided with a space from the detection substrate 30 and displaceable to and from the upper substrate 30, fixed electrodes 32, 33 provided on the detection face 30A of the upper substrate 30, and a first signal fetching section 22 electrically connected to the diaphragm 20, and the diaphragm 20 is formed by dry-etching single-crystal silicon with the specific resistance lowered to 1.0 &OHgr;·cm or below by mixing dopant lowering the resistance value.

Abstract: A method for fabricating a dielectrically isolated silicon carbide high temperature pressure transducer which is capable of operating at temperatures above 600° C. The method comprises applying a layer of beta silicon carbide of a first conductivity, on a first substrate of silicon. A layer of beta silicon carbide of a second conductivity is then applied on a second substrate. A layer of silicon is sputtered, evaporated or otherwise formed on the silicon carbide surfaces of each of the substrates of the beta silicon carbide. The sputtered silicon layer on each substrate is then completely oxidized forming a layer of SiO2 from the silicon. The first and second substrates are subsequently fusion bonded together along the oxide layers of the first and second substrate with the oxide layer providing dielectric isolation between the first and second wafers. This oxide layer, which is formed from the Si layer, has a much lower defect density than SiO2 formed directly from SiC.

Abstract: A stop member is secured to a piezoresistive semiconductor bossed diaphragm at the peripheral area, and includes a first and second slotted apertures in communication with the central active area, the first and second slotted apertures correspond in location with opposing sides of a central boss. The stop member includes a stop cavity located between the first slotted aperture and the second slotted aperture, and the stop cavity overlies the central boss and is separated therefrom to enable the diaphragm to deflect when a force is applied and to enable the central boss to impinge on the surface of the stop cavity when an excessive force is applied. The first and second slotted apertures permit another force to be applied to the active region of the diaphragm in a direction opposite to the stopped direction. A second stop member is secured to the diaphragm to provide stopping in either direction.

Abstract: An electronic pressure sensing device includes a pressure sensing/transmitter module including at least one pressure sensor having a pair of opposed sensing elements, and a pair of inlet port on the module to supply fluid under pressure to the sensing elements. A plurality of adapters, each having a pair of outlet ports for connection to the inlet ports on the module, whereby each adapter can be selectively coupled to the module. Each adapter is capable of being connected to a different configuration of pressurized fluid supply to feed the associated supply to at least one of the inlet ports on the module. The module further includes an electronic device for interpreting and transmitting the values of pressure sensed by the sensing elements.

Abstract: The present invention provides a small-sized electrostatic condenser type pressure sensor having high assembly accuracy but no dispersion in a detection accuracy, and a method for manufacturing the pressure sensor. An annular spacer is mounted on the confronting faces of substrates around flat electrodes, and a frit is mounted around the spacer and is made of a material having a lower softening or melting point than that of the spacer.

Abstract: A diaphragm-type semiconductor pressure sensor includes a substantially rectangular (110) semiconductor substrate, which has four sides, an active surface of (110) crystallographic face orientation, and a back surface, which is opposite to the active surface, of (110) crystallographic face orientation. Each of the surfaces is surrounded by the four sides. Each of the four sides is at an angle of substantially 45 degrees with a crystallographic axis of <110> orientation that is substantially parallel to the active surface. The substrate includes a diaphragm in the active surface. The diaphragm has been formed by forming a recess in the back surface. The diaphragm includes a gauge resistor. A pressure is detected on the basis of the variation in the resistance of the gauge resistor.

Abstract: A pressure sensor using two capacitors for measuring a pressure stimulus includes a substrate having a diaphragm positioned at a center portion thereof. The diaphragm has a reduced thickness so that the diaphragm displaces upward and downward in response to a pressure stimulus. A first capacitor is provided on the diaphragm and at least a second capacitor is provided on a bulk portion of the substrate so as to be adjacent to the first capacitor. The first and the second capacitor are connected to each other in series, wherein capacitance differs between the first and the second capacitor when the diaphragm moves up and down in response to the pressure stimulus.

Abstract: A semiconductor sensor chip includes a thin diaphragm and an electrical circuit formed on a front surface of the diaphragm. The diaphragm distorts according to a pressure difference between pressures applied on both surfaces of the diaphragm, and the diaphragm distortion is converted into an electrical signal. Both surfaces of the diaphragm are covered with protecting members to protect the sensor chip from dusts and moisture contained in the gas. Since the gas is introduced to the rear surface of the diaphragm through a small passage while the front surface receives pressure with a relatively large area, the protecting member covering the rear surface is made softer than that covering the front surface. Thus, the sensor chip is properly protected against dusts and moisture.

Abstract: An integrated microsensor includes a bowed micromachined membrane coupled to a substrate to define a microcavity therebetween. An integrated strain sensor is coupled to the micromachined membrane to generate a signal responsive to (deformation of the membrane and hence responsive to the pressure of the fluid in the microcavity. A frame is coupled to the peripheral edge of the membrane to assist in enlarging the microcavity. The membrane is composed of a nitride of B, Al, Ga, In, Tl or combinations thereof, or more particularly of p-type GaN where the frame is comprised of n-type GaN. The membrane and frame are fabricated using a photoelectrochemical etching technique. The fabrication of the integrated strain sensor creates stresses across the membrane. The strain sensor comprises an integrated circuit strain-FET. The strain-FET comprises an AlGaN/GaN heterostructure having an AlGaN/GaN interface where deformation of the membrane is coupled as strain to the AlGaN/GaN piezoelectric interface.

Abstract: In a pressure sensor in which a frame shaped protruding potion is formed on a surface side of a substrate by means of an etching process, and a blocking plate is connected to an upper part of the protruding portion, to form a standard pressure chamber, a recess is formed on at least one of the substrate and the blocking plate that constitute the standard pressure chamber, to increase the height of the standard pressure chamber, thereby preventing the lowering of pressure detection accuracy due to foreign substances within the standard pressure chamber.

Abstract: The invention relates to a pressure sensor consisting of a chip (11) which is mounted on a support wall (10) and which is provided with a resistance unit consisting of strip conductors and being arranged at the lower side (13) of a substrate (12). Said lower side faces the support wall (10). The resistance unit is located on a thin membrane (18). A recess (19) is located behind said membrane. The chip (11) is fixed on the support wall (10) by means of an elastic intermediate layer (26). The electrical components of the chip are protectively arranged between the substrate (12) and the support wall (10). The invention provides for an extremely flat sensor unit without additional sensor housing. Said sensor unit can even be used for measuring pressures in electrically conductive mediums.