Abstract: An ultrasonic sensor utilizing a polarization maintaining optical fibre. The invention includes a polarization maintaining fibre, a light source for launching light beams into the fibre so that the light beams are respectively aligned with each of the principal axes of the fibre, and an output detection system for determining a phase difference induced between the light beams by ultrasonic waves incident upon the fibre. A bias control may be provided to compensate for environmentally induced phase differences. The invention also include a polarization maintaining fibre divided into a sensor portion and a lead portion optically joined together by a 45 degree joint. A light source launches a linear polarized beam into the lead portion in alignment with one of the principal axes and a detection system determines phase difference induced by incident ultrasonic waves between the two components passing through the sensor portion.

Abstract: A differential ECL signal is converted to a first current and a second current that are proportional to the ECL signal. An upper output transistor (16) and a lower output transistor (57) are selectively enabled and disabled by the first current. The second current is used to enable discharging of a storage capacitance of the lower output transistor (57) thereby substantially disabling the lower output transistor (57) before the upper output transistor (16) is enabled. In addition, a capacitor is used to momentarily discharge the storage capacitance as the upper output transistor (16) is enabled. The capacitor is discharged when the upper output transistor (16) is disabled.

Abstract: Electrically-programmable low-impedance anti-fuses are disclosed having capacitor-like structure with very low leakage before programming and a low resistance after programming. The electrically-programmable low-impedance antifuses of the present invention include a first conductive electrode which may be formed as a diffusion region in a semiconductor substrate or may be formed from a semiconductor material, such as polysilicon, located above and insulated from the substrate. A dielectric layer, which, in a preferred embodiment includes a first layer of silicon dioxide, a second layer of silicon nitride and a third layer of silicon dioxide, is disposed over the first electrode. A second electrode is formed over the dielectric layer from a semiconductor material such as polysilicon, or a metal having a barrier metal underneath.

Abstract: A user-programmable interconnect architecture, which may be used for logic arrays for digital and analog system design, is disclosed. In one embodiment, a plurality of logic cells or modules in a matrix are connected by vertical and horizontal wiring channels. The wiring channels may in turn be programmed by the user to interconnect the various logic cells to implement the required logic function. The wiring channels comprise wiring segments connected by normally open programmable elements situated at the intersection of any two segments to be connected.

Abstract: The present invention includes four approaches to reduce the unintended programming of antifuses while programming selected antifuses and to decrease the programming time. The first approach includes circuitry to maintain the voltage placed on unselected antifuses at a constant level by use of a voltage source. According to the second approach, a resistor is included in series with the voltage source. According to the third approach, a diode is included in series with the voltage source. According to the fourth approach, a MOS implementation of a diode is included in series with the voltage source.

Abstract: An already- programmed anti-fuse is DC soaked by passing DC current through the anti-fuse from a DC voltage source applied across the electrodes of the anti-fuse. The anti-fuse resistance is lower when the DC voltage being applied such that the positive end of the voltage source is applied to the electrode having the higher arsenic concentration.An already programmed anti-fuse is AC soaked, by passing alternating current pulses through the anti-fuse from an AC voltage source applied across the anti-fuse electrodes. This AC soak may even be applied following the controlled polarity DC soak disclosed herein. The AC soaked anti-fuse resistance is even lower than DC soaked anti-fuse under the same soak current level.

Abstract: A structure used to protect a dielectric is disclosed wherein a transistor located nearby the dielectric is connected in series with a conductor overlying the fragile dielectric such that the transistor gate will accumulate charge along with the conductive material over the fragile dielectric. After fabrication and during normal circuit operation, this transistor device remians in an off state, isolating the fragile dielectric node from other circuitry. In an alternate embodiment the protection transistor is a floating gate depletion device, which would always be on until the circuit is activated. At the time the circuit is activated, the device is turned off by trapping electrons on the gate by avalanching a junction associated with it. In a preferred embodiment, a buried contact if formed after the conductor overlying the dielectric, usually polysilicon, is formed. This buried contact connects the conductor to the discharging transistor.

Abstract: A quick start initiator for a flourescent light comprises a sealed glass bulb, a long conductor rod centrally located within the bulb, a pair of short conductor rods positioned to either side of the long conductor and electrically connected with a conducting lead protruding from the base of the glass bulb, and a pair of thermally deforming arcuate strips each being electrically connected to one of the short conductor rods. Wherein one arcuate bimetallic strip attached to one short conductor bar is normally separated by a space from the central conductor bar when in the inactive state. The other arcuate bimetallic strip on the other short conductor bar normally contacts the central long conductor when inactive. A mixture of argon and neon gases fills the glass bulb. Each of the leads are electrically connected in series with one respective cathode of a flourescent tube as in a conventional flourescent tube initiator circuit.

Abstract: A misalignment tolerant antifuse includes a lower electrode, bounded by a relatively thick first insulating layer, an upper electrode separated from the lower electrode by a second insulating layer having a thickness less than that of the first insulating layer, a pair of antifuse window regions in the second insulating layer, abutting the first insulating layer on opposite sides of the lower electrode, the insulating material in the window regions being thinner than the remainder of the second insulating layer, and an upper electrode disposed above the second insulating layer and lying over the pair of regions and at least a portion of the first insulating layer.

Abstract: A user-programmable interconnect architecture, which may be used for logic arrays for digital and analog system design, is disclosed. In one embodiment, a plurality of logic cells or modules in a matrix are connected by vertical and horizontal wiring channels. The wiring channels may in turn by programmed by the user to interconnect the various logic cells to implement the required logic function. The wiring channels comprise wiring segments connected by normally open reconfigurable programmable elements situated at the intersection of any two segments to be connected. Sensing circuitry and wiring may be included to allow 100% observability of internal circuit nodes, such as module outputs, from an external pad interface.

Abstract: A structure used to protect a dielectric is disclosed wherein a transistor located nearby the dielectric is connected in series with a conductor overlying the fragile dielectric such that the transistor gate will accumulate charge along with the conductive material over the fragile dielectric. After fabrication and during normal circuit operation, this transistor device remains in an off state, isolating the fragile dielectric node from other circuitry. In an alternate embodiment the protection transistor is a floating gate depletion device, which would always be on until the circuit is activated. At the time the circuit is activated, the device is turned off by trapping electrons on the gate by avalancing a junction associated with it. In a preferred, embodiment, a buried contact is formed after the conductor overlying the dielectric, usually polysilicon, is formed. This buried contact connects the conductor to the discharging transistor.

Abstract: Chlorination of hydroquinone by reacting sulfuryl chloride with hydroquinone in an alkyl ester solvent having 2-8 carbon atoms yields a mixture containing a major proportion of monochlorohydroquinone.

Abstract: Strontium carbonate is prepared by the process of reacting strontium nitrate in an aqueous reaction medium with carbon dioxide to precipitate strontium carbonate product, the nitric acid byproduct that forms being neutralized by the introduction of lime to the reaction medium.

Abstract: Strontium nitrate is prepared by reacting celestite (strontium sulfate) with excess calcium nitrate in limited amounts of water, quickly extracting strontium nitrate from the reaction mixture by vigorous agitation with additional water, and recovering strontium nitrate by evaporation of the extract solution.

Abstract: In the production of SALP tetrahydrate wherein sodium carbonate and aluminum hydroxide are added to aqueous phosphoric acid, the viscous reactive mixture is agitated with water to free the SALP tetrahydrate crystals from the gelatinous matrix. The crystals are recovered by filtration or centrifugation.

Abstract: High strength peroxymonosulfate is prepared by adding concentrated sulfuric acid to a solution of a soluble peroxydisulfate whereby the heat of solvation of the sulfuric acid hydrolyzes the peroxydisulfate to the peroxymonosulfate; the temperature is controlled to provide a range of about 140.degree. to 160.degree. F. After about 15 to 45 minutes, the solution is cooled rapidly to about room temperature.