Abstract: A field effect transistor-type moisture sensor comprising a field effect transistor device incorporated with a moisture sensitive means, the electrostatic capacity or the electrical conductivity of which varies with the absorption and the desorption of water vapor or moisture, wherein said moisture sensitive means is disposed on a gate insulating film of said field effect transistor device to form an electrode structure, said moisture sensitive means being a film prepared by cross-linking cellulose acetate butyrate with at least one selected from the group consisting of compounds containing two or more isocyanate groups; compounds containing two or more epoxy groups; compounds containing two or more carboxylic acid groups; and acid anhydrides of carboxylic acids.

Abstract: A method of monitoring gases using electronic conductivity changes in ordd organic semiconductor films comprising an insulated substrate fabricated to an interdigital microelectrode and coated with a vapor sensitive semiconductor film. Variations in current flow caused by vapors interacting with the film are indicative of the vapor type.

Abstract: A device comprising a field effect transistor having a floating gate 20 formed on a first surface of a substrate 10 over gate oxide 13a and source and drain regions 11, 12. A responsive layer 15 is provided on the second surface of the substrate and is capacitatively coupled to the floating gate via a thin insulating membrane 13b at a location away from the transistor. The device is applicable in the biomedical domain.

Abstract: Photoresponsive devices, including a photoresponsive electrode, are provided and methods for their use to measure changes in environment at a site at or about the surface of the photoresponsive device. By employing a source of light for irradiating a site on the surface and means for biasing the photoresponsive electrode in relation to a counterelectrode, a variation in electrical signal can be related to a change in a medium in photoresponsive modulation relationship to the photoresponsive electrode surface.

Abstract: In a thickness monitoring system for use in monitoring a thickness of a desired layer to be deposited on a substrate placed on a first electrode member in a hollow space, a quartz crystal is intermittently exposed to a flow of particles sputtered or otherwise traveling from a second electrode member opposite to the first electrode member. For this purpose, a shutter may be placed in front of the quartz crystal and periodically put into operation to shelter the quartz crystal from the second electrode member. When the first electrode member has a rotatable cylinder, the quartz crystal may be placed within an inside hollow space of the cylinder. At least one hole is distributed on the cylinder to allow the material flow to intermittently pass therethrough towards the quartz crystal. When the first electrode member has a rotatable disk, the quartz crystal may be placed backwardly of the disk and is exposed to the second electrode member through at least one aperture formed in the disk.

Abstract: A gas detecting element comprises a substrate, a gas sensitive body provided on the substrate, a pair of electrodes connected to the gas sensitive body and a catalyst layer provided on the surface of the gas sensitive body. The catalyst layer including a carrier material and a catalyst material of copper and tungsten. The gas detecting element in accordance with the present invention has equal sensitivity to a number of different gases.

Abstract: A system for sensing and annunciating the presence at any one of a plurality of locations of accumulations of potentially hazardous gaseous and vapor mixtures prior to their reaching a lower explosive limit thereof. The system has particular applicability to aircraft, and has a number of advantageous features such as adjustable annunciator set points which are settable between relatively wide lower explosive level limits, compensation in the sensor circuitry for temperature variations, built in diagnostic and test features, and a circuit design wherein multiple sensors at multiple locations are operable independently of each other.

Abstract: A method for determining the potential of zero charge of an unpowdered semiconductor material. The semiconductor material is used as the working electrode 12 of a standard three-electrode photoelectrochemical cell 11. The onset potential of the semiconductor material is measured at several different cell temperatures. The slope of the graph of onset potential versus temperature is used to compute the potential of zero charge.

Abstract: An apparatus and a method utilizing a localized electrical field to precisely determine the surface contour of a substantially flat wafer of piezoelectric material having a slight convexity in its opposing faces.

Abstract: A device for measuring a flatness of a plate such as a silicon wafer, a GGG wafer, a printed circuit board, a ceramic substrate, or the like. The measuring device is provided with a disc which is disposed in parallel with the plate on one of the surfaces of the plate and is driven by a rotating drive source and a plurality of detectors for detecting a distance from the detector to the surface of the plate, the detectors being disposed on the surface closer to the disc. With this arrangement, distance data from the plurality of the detectors to the surface of the plate is obtained during the course of the rotation of the disc, and a flatness of the plate is measured.

Abstract: In a method for determining the physical characteristics of a silicon wafer, one side of the wafer (4) is removably fixed to the base (2) of a container (1) so as to close off a hole (3) therein. An electrical connection to this side of the wafer (4) is made thru the hole (3). The wafer (4) forms the working electrolyte of a cell comprising an electrolyte contained in the container (1). An auxiliary electrode (14) is removably placed in the electrolyte. The method and the device implementing it can be used to determine the crystallographic and electrical characteristics of a sample of silicon.

Abstract: A system is adapted to etch an aluminium film on a semiconductor wafer into a predetermined pattern by immersing the film in an etching solution. The system comprises a voltage detecting circuit for detecting a voltage created between a platinum electrode and the aluminium film on the semiconductor wafer which are immersed in the etching solution, a comparator for comparing a reference voltage with the voltage detected by the voltage detecting circuit to produce an output signal, and a timer for starting a time count operation upon receipt of the output signal from the comparator and for producing an etching completion signal when it continuously receives the output signal from the comparator for a predetermined time period.

Abstract: An apparatus and method for determining the doping profile of an epitaxial layer of a semiconductor as a function of conductivity (or resistivity) vs. distance (depth) includes modifying a d.c. generated current by a focused laser beam modulated at high frequencies in the order of 20 MHz, and directed in sequence on a point-by-point basis to the layer surface. Photocurrent variations from point-to-point effected by the laser beam striking the layer at each of the sequence of points are detected to provide a signal related to conductivity, (or, if desired, resistivity) of the layer material.

Abstract: A method utilizing a localized electrical field to precisely determine the surface contour of a substantially flat wafer of piezoelectric material having a slight convexity in its opposing faces.

Abstract: A method, sensor and semiconductor device for determining the concentration of an analyte in a medium. The device features an element constructed of semiconductive organic polymer associated with a binding substance having specific affinity for the analyte.

Abstract: A technique for testing for heavy metal contamination in semiconductor processing furnaces includes use of a chip having a plurality of PN- junctions, at least one of which is completely isolated from the sides of the chip. The chip is manufactured to exhibit a high reverse recovery time and this can be conveniently accomplished by a combination of a gettering layer to getter the heavy metal atoms away from the junction and by never raising the temperature of the chip above 800.degree. C. after the gettering layer is provided.In use, the chip is fed through a furnace either with or, preferably before the wafers being processed, which is operating at the conditions under which semiconductor devices are to be processed. After the chip is removed from the furnace, its reverse recovery time is measured and compared to its initial reverse recovery time to determine if it has decreased.

Abstract: An apparatus and method for measuring the concentration of various components in a fluid sample. The apparatus comprises a chemically sensitive field effect transistor (CHEMFET) having a semiconductor substrate and a pair of diffusion regions formed at the surface of the substrate. An electrical insulating layer is positioned adjacent the substrate and a fluid pervious bridge member is mounted to the insulating layer so as to form a gap between the bridge member and insulating layer. The apparatus also includes means for imposing an electrical charge on the bridge member, means for imposing an electrical potential between the diffusion regions, and means for detecting current flow between the diffusion regions. The fluid sample to be analyzed is introduced through the fluid pervious bridge member and into the gap where various components of the fluid sample are adsorbed by the bridge member, and in another embodiment, also by an adsorptive layer which is applied within the gap.

Abstract: Freon gas detecting element for detecting the presence of freon gas with of a pair of electrodes, a gas detecting body made of a metal oxide semiconductor and covering the pair of electrodes, and a catalytic layer coated on the gas detecting body. The catalyst layer is made of at least one element selected from the group consisting of V, Mo and W supported by one catalyst carrier selected from the group consisting of Al.sub.2 O.sub.3, SiO.sub.2, and SiO.sub. 2 - Al.sub.2 O.sub.3.

Abstract: An improved thick film stannic oxide sensor is disclosed whereby the sensitivity of the sensor to CO is enhanced by the addition of a rare earth oxide to the sensor composition and the catalytic reactivity of the sensor, when contacted by a gas containing a reducing constituent, i.e., H.sub.2 or CO, and oxygen, is enhanced by employing RuCl.sub.3 or PtCl.sub.2 as a catalyst.