Abstract: Disclosed is an indium-containing semiconductor device which includes an ohmic contact formed by application of successive layers of Au-Sn-Cr-Au. The combination of Sn and Cr layers provides an effective barrier to the diffusion of indium to the surface of the contact so that bonding to the contact is not impeded.

Abstract: A method of forming thick film resistor circuits whereby a non-hole metal, such as copper, requiring a reducing atmosphere is included with resistor material requiring an oxidizing atmosphere. A fritless conductor paste with a small percentage of silver is deposited and fired in air at a low temperature. Resistors are then deposited and fired in air. Subsequently, the conductor material is reduced at a sufficiently low temperature so as not to adversely affect the resistors.

Abstract: A high-speed, high pin-out chip carrier package (10) for interconnecting at least one LSI or VLSI chip to a circuit pack is disclosed. The package includes a ground plane (19), a power plane (20), and at least one signal layer (15, 16, 17, 18) containing plural conductors therethrough. Layers (85) of dielectric material separate adjacent conductive layers, (15, 16, 17, 18, 19, 20). By controlling, in design, the width of each signal conductor and its distance to the nearest ground (19) or power plane (20), the package is impedance-matched to the circuit pack. Plural plated-through holes (21) are disposed through the package for electrically interconnecting the signal conductors, the ground plane (19), and the power plane (20) to the circuit pack, and are arranged in a pattern to reduce inductive noise.

Abstract: An optical coupling device for diverting light among different transmission elements. A plurality of transmission elements (11, 12, 13) are coupled to one surface (32) of a focusing element (10). Positioned near the opposite surface (32) are first and second at least partially reflecting elements (15 and 16). The first element (15) may be affixed to the end surface of the focusing element and covers only a portion thereof. The second element is positioned further from the end surface and at an angle to the first element. The area of the first element is chosen to produce a desired splitting ratio, and the angle between elements can be adjusted to maximize coupling efficiency between the transmission elements. The device can be used, for example, as a three port coupler, an asymmetric four port coupler, or a four port power divider.

Abstract: A single heterostructure light emitting device which provides high speed and high efficiency. The device includes adjacent n- and p- regions of a mixed-crystal III-V semiconductor such as GaAlAs. A lightly-doped wide bandgap injection layer is utilized to force recombination in the more heavily-doped adjacent region. The latter region also includes a graded bandgap which allows photon recycling for high efficiency.

Abstract: A method for micromachining precise semiconductor features involving a pre-etch for establishing proper mask alignment. In one embodiment, the pre-etch utilizes a mask opening which has at least two edges oriented at a significant angle with the nominal (110) direction of a silicon wafer. The silicon is anisotropically etched through this opening until the true (110) lines are revealed by the intersection of the (111) planes with the wafer surface. Two parallel lines will therefore be formed to provide alignment of the mask for subsequent feature definition.In a further embodiment, the silicon wafer is completely etched through so that a pit edge on the front surface is offset on the back surface by an amount equal to the wafer thickness. This provides front-to-back alignment in subsequent processing.

Abstract: A polarization independent optical circulator is disclosed. A first birefringent plate (10) is used to separate an incident beam from a first port into two beams having orthogonal polarizations, and a second plate (11) recombines the beams at a second port. Means (12) providing nonreciprocal rotation of the polarizations are disposed between the plates. Placed between the rotating means and the second plate is a third plate (16) to further separate the beams and a reflecting element (17) for deflecting the beams toward the second port. The reflecting element includes a slotted portion (18) so that light from a third port can pass therethrough back toward the first port.

Abstract: A hydraulically driven X-Y stage for use primarily in optical pattern generators, especially those requiring a vacuum. A pair of hydraulic cylinders (10 and 20) provide the motion along the step and slew axes. The cylinders can be constructed so that either the rod (11 and 21) or the outer carriage (12 and 22) moves due to the oil pressure differential. Hydraulic bearings (36) between the rod and carriage prevent sliding friction while providing stiffness to linear motion in undesired directions. The rods have areas designed, in combination with the bearings, to prevent rotational motion. Hollow tubes and chambers (14, 15, 41-44, and 24) are provided for feeding oil to the cylinders, and flexible metal bellows (19, 34, and 35) surround the cylinders and keep the oil contained.

Abstract: A method of fabricating FETs to reduce parasitics. Contact is made to the source and drain regions through a polycrystalline silicon runner which is aligned with the edge of the gate electrode. This is accomplished by providing a layer such as palladium over the gate electrode and depositing the polycrystalline silicon layer over the device. The polycrystalline silicon and palladium form a silicide which is then selectively etched leaving the remaining polycrystalline silicon aligned with the gate.

Abstract: Disclosed is a method of forming a molded, field-installable optical connector. The method uses a support assembly which includes a wire mandrel, (10), a mandrel holder, (11), surrounding a portion of the wire, and a mandrel sleeve, (12), surrounding a portion of the mandrel holder and including an end surface, (15). Positioned at the end surface is a watch bearing jewel, (16), with an aperture, (17), through which the wire is inserted. As backbone insert, (19), is also located around a portion of the mandrel sleeve. The assembly is positioned within a molding apparatus including a precision frusto-conical die, (25), by inserting the wire through a second jewel, (26), mounted in the die. After molding, the connector, which includes the first jewel embedded at one end of the molded part and the backbone insert as a strength member, is removed from the support assembly.

Abstract: A secondary lithium battery system which operates at ambient temperatures. The battery includes an organic solvent for an electrolyte, a conventional cathode, and an intercalation compound for an anode. Such batteries maintain high capacities after numerous discharge-charge cycles.

Abstract: Disclosed is a circuit for biasing FETs which limits unwanted gate current. A first resistor (R.sub.8) is coupled in series with the gate and the output (14) of a differential amplifier (12). Means such as a second resistor (R.sub.9) and a Zener diode (D.sub.2) are coupled to the first resistor and one input of the differential amplifier. Means such as a third resistor (R.sub.3) is also coupled to one input of the amplifier. When excessive gate current appears, the voltage across the first resistor is such as to cause sufficient current flow through the diode and second and third resistors to unbalance the amplifier. This keeps the gate-to-source voltage of the FET at a region of gate current below some maximum value.

Abstract: A method of contouring crystal plates for frequency control. After plate dimensions are established, the plates are kept in a stack separated by a bonding material. The stack is immersed in an etchant which etches the exposed crystal edges in a manner which undercuts the bonding material, thus batch forming bevel contours on at least the outer portions of the major faces of each plate in the stack.

Abstract: Disclosed is a method of improving the coating on electrodes (11 and 12) in spark gap devices which minimizes filament formation, densifies the coating, and ensures a good bond between the coating and underlying electrode. The device is coupled to a circuit (FIG. 2) which includes appropriate components so that a rapid sequence of current pulses having large amplitudes during arc initiation is passed through the device. The coating bonds with a different area of the cathode for each current pulse. The signal may be applied with appropriate reversal of polarities so that essentially the entire surface of both electrodes is thus reacted. Subsequently, the device may be subjected to an additional pulse in order to leave asperities on the surface which will increase field emission and ensure a low surge limiting voltage.

Abstract: Disclosed is a method of coating electrodes in spark gap devices which minimizes filament formation. A coating (21) such as carbon is deposited on the electrode surfaces (11 and 12). A signal is then applied so that the device conducts in the arc mode for several short periods. A small spot of the coating bonds with the negatively biased electrode during each conduction. This operation continues at alternating polarities until essentially the entire surface area of both electrodes is bonded.

Abstract: Disclosed is a method of bonding electronic components (14) to metallized substrates (21) by soldering. The solder is first deposited on an unmetallized substrate (10) in a pattern of discrete pads (11, 12, 13) corresponding to the leads (28, 29, 30) of the components to be bonded. The component leads are then placed on the pads and the solder is reflowed. The solder thereby adheres to the leads so that a controlled amount of solder will remain on each lead when the component is lifted from the substrate. The components can then be soldered to an appropriate metallized substrate.

Abstract: A geometry and method of fabricating thin film resistors which are tolerant of faults in the film and therefore permit attainment of high resistances. The resistor includes a series of connected closed loops (15) each with a member (17) providing a short circuit path. Such members are successively cut and the change in resistance is determined after each cut. This change is compared to certain threshold values to determine the presence or absence of an open circuit fault in each loop. The resistor is then trimmed to its desired value by cutting only the loops where no opens have been discovered.

Abstract: Disclosed is a method for fabricating a circuit including thin film resistors (15) and capacitors (12, 13, 14, 16) on a single substrate whereby stabilization is effected after all such components are completely formed. A high pressure steam atmosphere is utilized for stabilization so that the resistors can be stabilized at lower temperatures and/or times and the capacitors are not degraded.

Abstract: A method of fabricating film circuits whereby thick film crossunders may be included with thin film capacitors (22) on a single substrate (10). At least one dielectric layer (12) is formed on the crossunder electrode (11) and a layer capable of smoothing irregularities (13) is also formed in the area of capacitor formation. Firing of the capacitor underlayer is compatible with the dielectric layer. A layer such as beta tantalum (14) is formed over essentially the entire circuit and etched from the contact areas (21) of the crossunder electrode. The layer is oxidized to form a protective layer (15) for the previously deposited layers as well as an underlay for subsequently formed thin film components.

Abstract: A method of fabricating circuit packages which employ macro-components (10) mounted on supporting substrates (20). In order to maintain sufficient clearance between the component and substrate and achieve high reliability bonds, massive solder preforms (16) are applied to contact pads on either the component or substrate. After contact pads of both carrier and substrate are brought into contact with the spheres, the bond is formed.