Abstract: A sound-capturing arrangement uses a set of directional microphones that lie approximately on a sphere having a diameter of 0.9 ms sound travel, which approximates the inter-aural time delay. Advantageously, one directional microphone points upward, one directional microphone points downward, and the odd number of microphones are arranged relatively evenly in the horizontal plane. On one embodiment, the signals from the microphones that point upward and downward are combined with the signals of the horizontal microphones before the signals of the horizontal microphones are transmitted or recorded.

Abstract: A sound-capturing arrangement uses a set of directional microphones that lie approximately on a sphere having a diameter of 0.9 ms sound travel, which approximates the inter-aural time delay. Advantageously, one directional microphone points upward, one directional microphone points downward, and the odd number of microphones are arranged relatively evenly in the horizontal plane. On one embodiment, the signals from the microphones that point upward and downward are combined with the signals of the horizontal microphones before the signals of the horizontal microphones are transmitted or recorded.

Abstract: A sound-capturing arrangement uses a set of directional microphones that lie approximately on a sphere having a diameter of 0.9 ms sound travel, which approximates the inter-aural time delay. Advantageously, one directional microphone points upward, one directional microphone points downward, and the odd number of microphones are arranged relatively evenly in the horizontal plane.

Abstract: A circuit for driving light emitting diodes with a precise amount of current in response to an input pulse is disclosed. The input pulse drives a transistor into saturation, and the collector current of this transistor is increased in value through the use of two cascaded multiplying current mirrors. The second current mirror directly drives the light emitting diodes.

Abstract: X-ray masks are typically made by depositing and patterning a layer of heavy metal on a thin supporting membrane. The metal layer must have a relatively low and uniform stress to prevent stress-induced deformation of the pattern. Tungsten films having excellent stress characteristics are produced by employing a continuously operating capacitance-based measurement technique to allow adjustment of the deposition conditions in rapid response to changes in stress of the film being deposited. The stress gradients in the film are further reduced by transferring heat from the membrane as the metal is deposited thereon.

Abstract: X-ray masks are typically made by depositing and patterning a layer of heavy metal on a thin supporting membrane. The metal layer must have a relatively low stress to prevent stress-induced deformation of the pattern. Tungsten films having excellent stress characteristics are produced by employing a continuously operating capacitance-based measurement technique to allow adjustment of the deposition conditions in rapid response to changes in stress of the film being deposited.

Abstract: A photodetector circuit is disclosed which can extract a carrier frequency signal from an optical beam. A photodiode is back-biased by a voltage supply, and the capacitance of the photodiode is dependent on the value of its back-bias potential. The photodiode is connected in parallel resonance with an inductor, and the parallel resonant combination is connected to the input of an inverting amplifier having a feedback capacitor. This feedback capacitor causes a capacitive component to appear in the input impedance of the amplifier which combines with the photodiode capacitance and the inductor to provide a parallel resonant tank circuit. The amplifier has a change in gain versus change in power supply characteristic. By selecting the value of the feedback capacitor, changes in the capacitive component of the input impedance are equal and opposite to changes in the capacitance of the photodiode, and the resonant frequency of the tank circuit is thereby essentially unaffected by changes in the supply voltage.

Abstract: A computer input device for use as a computer mouse or keyboard comprises a thin, insulating surface covering an array of electrodes. Such electrodes are arranged in a grid pattern and can be connected in columns and rows. Each column and row is connected to circuitry for measuring the capacitance seen by each column and row. The position of an object, such as a finger or handheld stylus, with respect to the array is determined from the centroid of such capacitance values, which is calculated in a microcontroller. For applications in which the input device is used as a mouse, the microcontroller forwards position change information to the computer. For applications in which the input device is used as a keyboard, the microcomputer identifies a key from the position of the touching object and forwards such key identity to the computer.

Abstract: X-ray masks are typically made by depositing and patterning a layer of heavy metal on a thin supporting membrane. The metal layer must have a relatively low stress to prevent stress-induced deformation of the pattern. Tungsten films having excellent stress characteristics are produced by employing a continuously operating capacitance-based measurement technique to allow adjustment of the deposition conditions in rapid response to changes in stress of the film being deposited.

Abstract: Slurry in a slurry polisher is ultrasonically agitated during polishing to dislodge embedded debris and grit from the polishing pad and thereby improve the uniformity of material removal, lengthen the life of the pad and avoid scratches and defects on the surface being polished. The method is particularly useful for applications in which slurry polishing is used for planarizing deposited layers on semiconductor wafers where non-uniformities caused by such embedded material can affect process yields. Apparatus is disclosed for applying ultrasonic energy to the slurry so that such energy is focussed on the pad.

Abstract: A force balancing method and apparatus detects small changes in force or pressure. An LC tuned circuit having a capacitor with at least one movable plate senses force or pressure changes. Deviations in the phase of the response of the tuned circuit are compared to the phase of a driving reference oscillator to generate an error signal. The error signal is used to control the oscillator to increase or decrease its output amplitude for driving the tuned circuit. As a result the electrostatic force across the capacitor plates tends to change in such a way as to precisely balance the effect of external force or pressure changes. The system therefore operates in a force-balance mode and in such a way as to provide a high sensitivity together with a precisely controlled stiffness. This system is particularly applicable to high sensitivity microphones, micro-topography, and atomic force microscopy.

Abstract: This invention provides an in situ monitoring technique and apparatus for chemical/mechanical planarization end point detection in the process of fabricating semiconductor or optical devices. Fabrication of semiconductor or optical devices often requires smooth planar surfaces, either on the surface of a wafer being processed or at some intermediate stage e.g. a surface of an interleaved layer. The detection in the present invention is accomplished by means of capacitively measuring the thickness of a dielectric layer on a conductive substrate. The measurement involves the dielectric layer, a flat electrode structure and a liquid interfacing the article and the electrode structure. Polishing slurry acts as the interfacing liquid. The electrode structure includes a measuring electrode, an insulator surrounding the measuring electrode, a guard electrode and another insulator surrounding the guard electrode.

Abstract: Position indicating apparatus that allows position detection with windings provided on only one of two members and an output signal in which the position of one of the members relative to the other member is directly encoded in the phase of the output signal. A first member has a plurality of spaced ferromagnetic protuberances. A second member, movable with respect to the first member, contains at least first, second and third poles located in proximity to the protuberances and spans 360 spatial degrees. Each pole contains a winding with one terminal of each winding connected to a common point. The windings are driven at a fundamental carrier frequency with individual signals of equal amplitude but different temporal phases that span 360 temporal degrees. Circuit means detect the phase of the resulting carrier signal at the common point, which phase is linearly representative of position.

Abstract: A reinforced, filled hydrocarbon polymer composition, having increased strength and ductility, contains synergistic mixtures of at least two copolymerizable interfacial agents including an adsorbable agent and a soluble agent.