Abstract: A semiconductor sensor chip mounted on a thin diaphragm of a cylindrical metallic stem via an insulation layer is hermetically contained in a housing of a pressure sensor. The sensor chip includes a strain gage for outputting an electrical signal according to distortion of the diaphragm caused by pressure to be measured. A shield layer is interposed between the insulation layer and the sensor chip, and the shield layer is grounded. Influence of outside noises on the sensor outputs is eliminated or suppressed by the grounded shield layer even if the outside noises are in a high frequency region.

Abstract: A semiconductor device possessing a semiconductor substrate consisting of a single element semiconductor; directly formed on the semiconductor substrate, a buffer layer consisting of a compound semiconductor possessing a lattice constant differing from the lattice constant of the single element semiconductor; laminated on the buffer layer, an active layer consisting of the same compound semiconductor as the buffer layer, which functions as a semiconductor element; and, disposed between the buffer layer and the active layer, a barrier layer forming a voltage barrier against the active layer so as to control the flow of current from the active layer to the semiconductor substrate: and in the case where this is utilized as a Hall element, a semiconductor device is obtained which maintains good carrier mobility as a Hall element, and also, the leakage current to the substrate can be controlled, and therefore sufficient Hall electromotive force can be obtained.

Abstract: A pressure sensor has two sensor elements respectively disposed in different pressure spaces A and B. Each of the sensor elements has a semiconductor substrate having a pressure reference chamber therein, a diaphragm formed as a wall defining the pressure reference chamber, and gauges for converting deformation of the diaphragm into an electric signal. The two sensor elements overlap with each other at sides opposite to the respective diaphragms, and close a hole formed in a partition member partitioning the two pressure spaces A and B. A differential pressure between the pressure spaces A and B is detected as a relative pressure by a difference between outputs from the two sensor elements.

Abstract: A gas sensor includes a semiconductor substrate and a sensing membrane. The sensing membrane is located at the bottom of a recess, which is formed by etching the substrate, and includes a heater, heater extension electrodes, a gas sensitive film, and gas-sensitive-film extension electrodes. A first end of each heater extension electrode is in contact with the heater, and a second end of each heater extension electrode extends outward from the sensing membrane. A first end of each gas-sensitive-film extension electrode is in contact with the gas sensitive film, and a second end of each gas-sensitive-film extension electrode extends outward from the sensing membrane. All of the heater, the heater extension electrodes, and the gas-sensitive-film extension electrodes are made of polycrystalline silicon.

Abstract: A semiconductor strain sensor in which a sensor element for detecting a strain signal is mounted in a resin package member, which can restrain a creep stress of the package member from affecting to the sensor element. A semiconductor strain sensor is provided with a lead frame integrally molded with a resin package member, and a sensor chip made of silicon. The sensor chip is mounted on one surface of an element mounting portion of the lead frame, and is capable of externally outputting electric signal via a wire in accordance with strain when pressure is applied. An opening portion is provided in the package member, so that the entire area of another surface of the lead frame, where positions beneath the sensor chip, is non-contacted with the package member.

Abstract: On a substrate, first and second capacitive portions are formed to have movable diaphragms having different areas for pressure measurement and diagnostic, wherein a communication structure is provided between the cavity spaces of the first and second capacitive portions to equalize the pressure in the first capacitive space to that of the second capacitive space. The different sizes provide different sensitivity for efficient diagnostic. The first and second capacitive portions can be made in one diaphragm, wherein the second capacitive portion is formed around the first capacitive portion. The cavity spaces of the first and second capacitive portions are connected. Moreover, between the first and second capacitive spaces, an insulation portion may be formed in a ring shape to support the diaphragm portion of the first capacitive portion and the diaphragm portion the second capacitive portion with communication portions.

Abstract: First and second predetermined charging voltages are applied between the movable and fixed electrodes of a capacitive type of sensor to measure first and second capacitances between the movable and fixed electrodes, respectively. The first and second electrostatic capacitances are compared to obtain a characteristic of the sensor from a result of comparison. In measuring the first and second capacitances, first and second charging voltages are generated of which magnitudes are determined in accordance with the first and second capacitances, respectively. Equalization is made between the first output voltage when the first charging voltage is applied between the movable and fixed electrodes in a predetermined normal condition of the movable electrode and the second output voltage outputted when the second charging voltage is applied between the movable and fixed electrodes in the predetermined normal condition.

Abstract: In a capacitive sensor apparatus, a capacitive sensor includes a plurality of physical-quantity-detection capacitors each having a movable electrode and a fixed electrode. A conversion device operates for converting an output signal of the capacitive sensor into an apparatus output signal. Each of the physical-quantity-detection capacitors is selectively connected and disconnected to and from the conversion device. A determination is made as to whether or not each of the physical-quantity-detection capacitors fails in response to the sensor output signal. When it is determined that first one of the physical-quantity-detection capacitors fails, the first one is disconnected from the conversion device and second one of the physical-quantity-detection capacitors is connected to the conversion device.

Abstract: An electrical capacitance pressure sensor has a lower electrode, a movable electrode, and an upper electrode. A first cavity portion is formed between the lower electrode and the movable electrode. A second cavity portion is formed between the upper electrode and the movable electrode. The substrate has an opening portion that penetrates the substrate from the first surface to the second surface thereof. The lower electrode has at least one first window portion that penetrates the lower electrode from the side of the substrate to the side of the first cavity portion and communicates the cavity portion to the opening portion of the substrate. The upper electrode has at least one second window portion that penetrates the upper electrode from the side of the cavity portion to the outside thereof to communicate the cavity portion with the outside.

Abstract: A photo sensor has a first silicon chip and a second silicon chip mounted on the first silicon chip. Photodiodes are formed in an upper surface portion of the second silicon chip to transform light into electric signals, and circuit elements such as a transistor are formed in an upper surface portion of the first silicon chip to form a signal processing circuit, which manipulates the electric signals from the photodiodes. A metallic thin film is provided on the lower surface of the second silicon chip to cover the circuit element as a shielding film.

Abstract: In a method for manufacturing a semiconductor pressure sensor, after a reference pressure chamber is formed inside a semiconductor substrate and a diaphragm is formed from a part of the semiconductor substrate, a heat treatment is performed to form an insulation film, an element, or the like on the semiconductor substrate. At that time, a heat treatment temperature is controlled to be lower than (−430P0+1430)° C. where P0 is an internal pressure (atm) of the reference pressure chamber at a room temperature. Accordingly, crystal defects can be prevented from being produced in the diaphragm.

Abstract: Magnetoresistive devices are formed on the insulating surface of a substrate made of silicon. The devices are connected in series through an insulating film using a wiring layer formed on the surface of the substrate. An insulating film for passivation is formed to cover the devices and the wiring layer. A magnetic shield layer of Ni—Fe alloy is formed on the passivation insulating film through an organic film for relieving thermal stress to cover one of the devices. After removal of the sensor chip containing the magnetoresistive devices and other components from the wafer, the chip is bonded to a lead frame through an Ag paste layer by heat treatment. Preferably, the magnetic shield layer is made of a Ni—Fe alloy having a Ni content of 69% or less.

Abstract: In a thermo pile infrared ray sensor, an opening portion is formed by etching a substrate from a second surface after an n-type poly-Si layer and a thin aluminium layer are formed so that first and second connection portions are formed by parts thereof. An infrared ray absorbent layer is formed on the substrate to cover the first connection portion with a screen print after the opening portion is formed.

Abstract: A capacitive physical load sensor includes a substrate, which has fixed electrodes, and a diaphragm, which has movable electrodes. The diaphragm is located across a gap from the substrate, and retaining parts for the diaphragm are formed around the diaphragm. Protruding parts extend into the gap from the diaphragm or from the substrate. The protruding parts support the diaphragm at different levels of deformation to alter the characteristics of the diaphragm and extend its range.

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 a pressure sensor made by bonding a sensor chip and a metal stem together with a resin adhesive, fluctuation of the sensor output caused by temperature changes are maximally reduced. The resin adhesive for bonding together the sensor element and the metal stem has a creep characteristic defined as CR=A×&sgr;B between its creep rate CR and stress &sgr; upon it with A and B being constants. The resin adhesive is selected to satisfy that the constant B is not greater than 3.5.

Abstract: A bridge circuit includes four gage resistors. Each gage resistor is divided into two division gage resistors. A couple of division gage resistors. The junction points between division gage resistors outputting the same potential when no pressure is applied are used for diagnostic. Four gage resistors out of the eight gage resistors are arrange near the center of diaphragm 14, and the other four division resistor s are arranged near the peripheral edge portion of the diaphragm 14 to make the stress distribution even.

Abstract: A reference voltage generating circuit is constituted by resistors RE and RF each having a resistance not influenced by an application of pressure. The reference voltage generating circuit is connected between one and the other ends of a bridge circuit. A failure judgement of the bridge circuit is performed based on a comparison of a voltage difference VBC between two midpoints B and C of the bridge circuit and voltage differences VCE and VBE between a reference voltage level of the reference voltage generating circuit and the voltage levels of two midpoints B and C.

Abstract: A plurality of sensor chips, each having strain gauges and a thin diaphragm, are formed on a semiconductor wafer having an upper layer and a lower layer forming a P-N junction plane therebetween. The sensor chips are separated into individual pieces by dicing along column and row interstices dividing the sensor chips. Conductor lines for supplying an electrical voltage for electrochemically etching the diaphragms are formed on and along the interstices. All of the conductor lines are removed by a dicing blade having a wider width than the conductor lines to avoid electrical leakage due to particles of conductor lines leftover on side surfaces of the diced out sensor chips.

Abstract: A semiconductor sensor chip mounted on a thin diaphragm of a cylindrical metallic stem via an insulation layer is hermetically contained in a housing of a pressure sensor. The sensor chip includes a strain gage for outputting an electrical signal according to distortion of the diaphragm caused by pressure to be measured. A shield layer is interposed between the insulation layer and the sensor chip, and the shield layer is grounded. Influence of outside noises on the sensor outputs is eliminated or suppressed by the grounded shield layer even if the outside noises are in a high frequency region.