Abstract: A semiconductor pressure sensor includes a SOI substrate composed of first and second silicon substrates. A diaphragm portion is formed by the first silicon substrate as a bottom of a recess portion formed in the second silicon substrate. Strain gauges are formed on the diaphragm portion, and a circuit portion is formed on the first silicon substrate at a region other than the diaphragm portion. A LOCOS film for isolating the strain gauges from the circuit portion is formed on the first silicon substrate outside the outermost peripheral portion of the diaphragm portion.

Abstract: Metal wiring segments, which are located at peripheral positions of a diaphragm, are formed on a main surface of a thick portion of a semiconductor substrate. A ratio S/d is larger than 100, where an area of the diaphragm is S &mgr;m2 and a thickness thereof is d &mgr;m. Further, a total area of the metal wiring segments arranged on first sides of the substrate is larger than total area of the metal wiring segments arranged on second sides of the substrate, where the first sides indicate the sides in parallel with <110> crystalline axis and the second sides indicate the sides in parallel with <100> crystalline axis.

Abstract: A humidity sensor has two detection electrodes located on a semiconductor substrate and a humidity sensitive film. The capacitance of the film changes in response to humidity. The sensor includes a reference capacitor and a feedback capacitor. An electrode of each capacitor is located beneath one of the detection electrodes to limit the size of the device.

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: A capacitive moisture sensor includes a semiconductor substrate, which has a hole. A silicon oxide film is located to close the hole. A pair of electrodes is located on the silicon oxide film. Each electrode is in the shape of a comb, and the electrodes mesh with each other. A silicon nitride film is located on the electrodes to cover and protect the electrodes and on the silicon oxide film between the electrodes. A moisture-sensitive film, the dielectric constant of which varies in response to ambient moisture, is located on the silicon nitride film. The thickness of the substrate is substantially zero under the electrodes to eliminate the parasitic capacitance between each electrode and the substrate.

Abstract: A capacitance type humidity sensor is composed of a substrate, two electrodes, a passivation layer, and a humidity-sensitive layer. The two electrodes are disposed on the substrate and on the same plane, and face each other with spacing therebetween. The passivation layer covers the two electrodes. The humidity-sensitive layer is disposed on the spacing or between the spacing, and the dielectric constant of the humidity-sensitive layer is changed corresponding to humidity. As the spacing is broadened, the hysteresis in the humidity sensor is reduced. Especially, when the spacing is twice or more larger than the film thickness of the passivation layer, the hysteresis is reduced to be less than 10 % RH in relative humidity.

Abstract: A diaphragm that distorts according to pressure applied thereon and a signal processor circuit are formed on a semiconductor substrate having an (110)-surface-orientation. Stain gauges converting the diaphragm distortion into an electric signal and forming a bridge circuit are formed on the diaphragm. The electric signal from the bridge circuit is processed by the signal processor circuit. A pair of transistors constituting an input circuit of an amplifier in the signal processor circuit are positioned on the substrate to equalize their source-drain current directions. Thermal stress influence on the sensor outputs is minimized since sensor components are formed on the substrate having the (110)-surface orientation, and thereby the pressure applied to the diaphragm is accurately detected.

Abstract: A semiconductor magnetic sensor includes a semiconductor substrate, a source, a drain, a gate, and a carrier condensing means. The source and the drain are located in a surface of the substrate. One of the source and the drain includes adjoining two regions. The gate is located between the source and the drain for drawing minority carriers of the substrate to induce a channel, through which the carriers flow between the source and the drain to form a channel carrier current. The carriers flow into the two regions to form two regional carrier currents. The magnitude of a magnetic field where the sensor is placed is measured using the difference in quantity between the two regional carrier currents. The carrier condensing means locally increases carrier density in the channel carrier current in the proximity of an axis that passes between the two regions in order to increase the difference.

Abstract: A semiconductor pressure sensor has a recess formed on a semiconductor substrate. The recess has a sidewall, a bottom wall that serves as a diaphragm for detecting a pressure, and a corner portion provided between the sidewall and the bottom wall and having a radius of curvature R. The radius of curvature R satisfies a formula of: R/S=526·(d/S)2−0.037·(d/S)+a1, where S is an area of the diaphragm, d is a thickness of the diaphragm, and a1 is in a range of 9.6×10−7 to 16×10−7 inclusive.

Abstract: In a revolution detecting device, a tunneling magnetoresistance sensor having an element located in a region is provided. The tunneling magnetoresistance sensor comprises a substrate, a pinned layer composed of ferromagnetism material and located to one side of the substrate, a tunneling layer composed of insulating film and located to one side of the pinned layer and a free layer composed of ferromagnetism film and located to one side of the tunneling layer. The element is configured to detect a change of magnetoresistance of the element according to a magnetic field applied in the region in which the element is located. The change of the magnetoresistance of the element is based on a change of current flowing through the tunneling layer between the pinned layer and the free layer. In the revolution detecting device, a revolution member is disposed in a vicinity of the element in the Y axis from a viewpoint of the element. The revolution member has a surface portion opposite to the element.

Abstract: A pressure detecting apparatus has a single-crystal semiconductor sensor chip disposed on a metallic diaphragm through a low melting point glass. The sensor chip has a planar shape selected from a circular shape, a first polygonal shape having more than five sides and having interior angles all less than 180°, and a second polygonal shape having a ratio of a circumscribed circle diameter relative to an inscribed circle diameter being less than 1.2. Four strain gauge resistors are disposed on X, Y axes passing through a center point O of the sensor chip in parallel with <110> directions. Accordingly, thermal stress is reduced not to adversely affect a detection error and simultaneously high sensitivity is provided.

Abstract: A capacitance type humidity detecting sensor has two electrodes opposing each other with a gap interposed therebetween to form a capacitor on a silicon substrate with a silicon oxide film formed on a surface thereof. A moisture-sensitive film is formed so as to cover the two electrodes with a silicon nitride film interposed therebetween. The silicon nitride film protects the two electrodes from moisture passing through the moisture-sensitive film. The capacitance formed between the two electrodes changes in accordance with ambient humidity. A switched capacitor circuit formed in a circuit element portion processes a signal indicative of a change in the capacitance formed between the two electrodes.

Abstract: In a thin-film infrared sensor, (100)-oriented semiconductor substrate is used for the sensor fabrication. A surface of the substrate is partially masked to provide an unmasked section where a concave is made and a masked section on the back side of an alley between thin-film sensing areas. An anisotropic etching using an etchant such as KOH is applied to the masked substrate to make the concave (the thin-film sensing areas) and to provide an unetched portion of the substrate at the bottom of the concave on the back side of the alley between the sensing areas. The unetched portion of the substrate makes a rim to support the sensing areas. High concentration Boron doping is not necessary. Thus, it is possible to reduce deformation of thin-film sensing areas caused by a stress in the rim and to reinforce the rim.

Abstract: A capacitive humidity sensor includes a pair of opposed electrodes on a substrate. A humidity-sensitive film covers the electrodes. The electrodes are comb-shaped and interdigitated. Humidity is detected based on the capacitance between the pair of electrodes, which changes with changes according to the humidity in the atmosphere. The uniform width of each tooth in the pair of electrodes is L1, and the uniform distance between a tooth of one of the electrodes and a tooth of the other electrode is L2. When L1 is less than 3 micrometers, L2 is 5 micrometers. When L1 is greater than or equal to 3 micrometers, L2 is less than or equal to 5 micrometers.

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: In a sensor having a membrane structure, a sensor chip (silicon substrate) is provided with a through hole that is open on both upper and lower surfaces of the silicon substrate. A sensor element having a membrane structure is formed on the upper surface of the silicon substrate to close the through hole on the upper surface. The lower surface of the silicon substrate is bonded to a stem through adhesive to define a communication passage through which an inside and an outside of the through hole communicate with each other. Accordingly, the sensor can exhibit high reliability.

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: Plural photodetectors for receiving light and generating detection signals. A light amount controlling portion is arranged above the photodetectors for controlling an amount of the light to the photodetectors according to an incident angle. A weighting portion for weighting sensitivities of the photodetectors respectively. The sensitivities are weighted to provide a total output characteristic of the weighted detection signals of which magnitude varies according to the incident angle. Weighting is provided by a signal processing circuit by controlling gains, or a translucent film on the photodetectors for controlling transparencies portions above respective photodetectors, or opaque films on the photodetectors for controlling amounts of the light to respective photodetectors. A first function signal may be obtained from a part of photodetectors for an air conditioner and a second function signal may be obtained from all of photodetectors for head lamp on/off controlling.

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: A humidity sensor has two detection electrodes located on a semiconductor substrate and a humidity sensitive film. The capacitance of the film changes in response to humidity. The sensor includes a reference capacitor and a feedback capacitor. An electrode of each capacitor is located beneath one of the detection electrodes to limit the size of the device.