Abstract: A semiconductor integrated resonant-tunneling device having multiple negative-resistance regions, and having essentially equal current peaks in such regions, is useful as a highly compact element, e.g., in apparatus designed for ternary logic operations, frequency multiplication, waveform scrambling, memory operation, parity-bit generation, and coaxial-line driving. The device can be made by layer deposition on a substrate and includes a resonant-tunneling structure between contacts such that side-by-side first and third contacts are on one side, and a second contact is on the opposite side of the resonant-tunneling structure. Disclosed further are (two-terminal) resonant-tunneling diodes as incorporated in memory devices, e.g., in lieu of 2-transistsor flip-flops; room-temperature device operation; and devices comprising an essentially undoped accelerator region between an emitter contact and a resonant-tunneling structure.

Abstract: Metallization of integrated devices using ruthenium as a metallization material results in well-adhering contacts to source and drain regions as well as to gate oxide. Ruthenium is similarly suited as a diffusion barrier metallization between, e.g., silicon and aluminum and as an interconnection metallization material. And, as a diffusion barrier material, ruthenium dioxide may be used.

Abstract: A resonant-tunneling, heterostructure bipolar transistor having a quantum well between emitter contact and collector region is described. In one embodiment, a compositionally graded portion of the emitter region is adjacent to the base region, and there is a double barrier in the base region. In another embodiment the quantum well is defined by the emitter and a potential barrier in the base region. Further embodiments have a quantum well between emitter and collector regions or else within the emitter region.

Abstract: A method of selective area epitaxial growth using a scanning ion beam is described.

Abstract: A transistor device using an interdigitated gate and electrode surface structure to control thermionic emission over a potential barrier is described. Complementary logic structures comprising such transistors are discussed.

Abstract: To facilitate testing in the manufacture, operation, and maintenance of substrate-supported assemblies such as, e.g., optical transmitters and receivers in subscriber-loop and local-area networks, an assembly is provided with built-in optical test features at selected test points. Preferred test features may include side-by-side couplers or reflector taps as may serve to extract or insert light into a substrate-supported waveguide. Testing may further involve the use of a test set having optical components in alignment with test features of an assembly.

Abstract: A structure of first and second grating sections separated by a phase-shift section serves as a narrow-band resonator filter. Such structure may be optically coupled to a semiconductor laser cavity, and the resulting assembly can serve as a tunable narrow-linewidth laser, e.g., in wavelength-multiplexed and coherent-lightwave communications systems.

Abstract: Epitaxial layers are grown from a body of molten material which includes flux and layer constituent components; included in the flux are lead oxide and a small amount of boron trioxide. As compared with prior-art processing in the absence of boron trioxide, enhanced yield is realized as believed to be due to reduced adhesion of solidifying material entrained upon withdrawal of a substrate after growth. The method is particularly useful in the manufacture of magnetic domain devices designed to operate at extreme temperatures, as well as in the manufacture of magneto-optic devices such as, e.g., switches, modulators, and isolators.

Abstract: Low temperature sintering of grade materials sintered to 99 percent of the theoretical density is described using TiO.sub.2 powder prepared by hydrolyzing titanium isopropoxide and calcining at 850.degree. C.

Abstract: A heterojunction bipolar transistor having means for changing carrier transport properties is described.

Abstract: Complementary structure implemented in Group III-V compound semiconductors is obtained by using an n-channel field effect transistor and a p-channel MODFET.

Abstract: Devices such as, e.g., switches, flowmeters, and proximity sensors, as well as implant devices are made comprising an elongated ferromagnetic element. When the element is exposed to a variable magnetic field an electrical signal is obtained between contact points of the element in response to a change in the magnetic field. Preferred elongated elements have a helically deformed microduplex structure as may be produced by heat treatment and plastic twisting of a body of an alloy such as, e.g., an iron-nickel alloy.

Abstract: A structure of alternating layers of titanium and an insulator or semiconductor material has temperature-sensitive electrical resistivity. In combination with a resistance-measuring circuit, such structure can serve as an accurate temperature sensor. And, since electrical resistivity is inversely related to temperature, disclosed structures can serve as miniature thermistors in integrated circuit devices.

Abstract: A strained layer superlattice comprising Ge.sub.x Si.sub.1-x layers interleaved with Si layers is an excellent photodetector at infrared wavelengths due to the large shift in bandgap caused by the strain in the superlattice.

Abstract: Certain dopant materials, when present in a significant power-carrying portion of a silica-based optical waveguide fiber, are effective as intrinsic loss-reducing agents; the concentration of such dopant materials is at significantly lower levels as compared with levels used for producing a refractive index difference. Suitable in this respect are germania and phosphorus pentoxide as added to essentially pure silica or to silica containing other dopant additives such as, e.g., alumina or fluorine as may be used in a waveguiding core-cladding structure. Intrinsic loss in the vicinity of 0.2 dB/km is readily realized.

Abstract: Low-loss coupling between a local feed connection or node, and a multi-mode optical fiber bus is provided by reflective insertion of a relatively small number of modes into the bus fiber. Essentially all input power available at the node is thus inserted into the bus, while but a small portion of power is extracted from the bus.

Abstract: A distributed-feedback laser includes in its grating a localized phase-slip discontinuity which is placed off-center. Such discontinuity results in a quarter-wave phase slip, and it can be placed, e.g., such as to maximize the difference between threshold gain of the lowest-lasing mode and cavity loss of the next-to-lowest-lasing mode. The invention is applicable especially where laser output intensity differs at two output facets and results in enhanced mode selectivity during laser operation.

Abstract: A modulation-doped field effect photodetector has a fast response time.

Abstract: Semiconductor crystal films on a dielectric substrate are advantageously made by a zone melting method. Single-crystal structure is initiated at a seed surface, and made to extend across a dielectric surface by melting and resolidifying.Melting is effected upon irradiation with optical radiation which is focused onto an elongated zone; the zone is moved so as to locally melt successive portions of a layer of precursor material which may be amorphous or polycrystalline. The use of incoherent radiation is convenient, and focusing is typically by using a reflector.The process is conveniently effected under a controlled atmosphere and the layer being crystallized may be encapsulated so that no free semiconductor surface is exposed to an atmosphere.

Abstract: Electrical interconnection is established by means of an anisotropically conductive, composite layer medium comprising electrically conductive particles in a nonconductive matrix material. Enhanced uniformity of conductivity across the medium, and minimized incidence of lateral shorting are achieved as a result of essentially uniform distribution of electrically conductive particles which are also magnetic, such distribution resulting upon application of a magnetic field essentially perpendicular to a layer before or during hardening of the matrix material.